Citystar 3

CityStar 3
Workshop Manual
English Version
Version No.[ JAC-2013050101N3301]
2013
HFC1041 SERIES
Contents
WORKSHOP MANUAL
Group
Name Page
Foreword Code
This workshop manual was prepared 01 General
as reference to properly carry out
servicing and maintenance on JAC 02 Engine
vehicles.
The contents, pictures and technical 03 Clutch system
parameters this manual supplied are the
04 Transmission shaft
latest data. Because of the continuously
development and renewal of technique 05 Rear axle
and products, there may be some
difference between the explanations and 06 Front axle
the vehicles.
07 Drive shaft
The workshop manual for the engine will
be compiled separately. 08 Suspension
This manual was prepared for HFC1041
series light duty trucks. Configurations as 09 Power Steering
follows：
10 Parking brake
HFC4DA1-2C engine, LC5T28
transmission 5.571 gear ratio rear axle, 10 Brake
Please inform Customer Service
Department of JAC International if there is 11 Parking brake
any mistake, and you will be highly
12 Electric system
appreciated.
Tel：0086-0551-2296644 13 Cab
Fax：0086-0551-2296633
14 Circuit diagram
Emai：jac.workshopmanual@jac.com.cn
15 ABS
GENARAL
GENERAL
SPECIFICATIONS
VEHICLE MODEL
VIN
THE MECHANIC PERFORMANCE TABLE OF BOLTS IN CHINA
1
GENARAL
SPECIFICATIONS
Main parameters of 1041 series trucks

1041
Configurations
Configurations： HFC4DA1-2C engine, 2771cc displacement, rated power (Kw/rpm) 85/3600 , torque (N.m/rpm) 250/1800-2800 ;
LC5T28 transmission, 5.571 rear axle， hydraulic brake.
Wheel Cargo Curb Gross
Vehicle Configuration Overall dimension dimension Weight Power Remar
Base weight Tire First 8 digits of VIN
model code (mm) steering k
(mm) （mm）（kg） Kg
HFC1041P73 4230X1790X40 6.50R16/7.0
LD083 3360 5995×1900×2330 2560 4490 Standard LJ11KBBC
K1C3 0 0R16
HFC1041P73 3900X1790X40 6.50R16/7.0
LD084 3360 5995×1900×2330 2560 4490 Standard LJ11KBBC
K1C3 0 0R16
2
GENARAL
Vehicle Model
Company Vehicle Type Main Code from

Code Name Code Specifications Product
Serial No. company
Code
Company Code Name：HFC------represents JAC motor

Vehicle Type Code：1---Cargo truck 2---Off-road vehicle 3---Dumper
4---Tractor 5---Special purpose vehicle 6---Passenger car
7---Sedan 9---Semitrailer
Main Specifications Code：25---represents the maximum gross weight is 25 tons.
Product serial No.： 1---Product development serial No.（1st change，2nd development）
Code from company：K---Diesel R1---King cabin
For example：HFC1061KR1 represents JAC vehicle with king cab, 6 tons maximum gross weight, the
first change.
3
GENARAL
VIN----Vehicle Identification Number
VIN comprises of 17 digits. They separately represent:
黑色

2- O 3
36.5
VI N L J 1 1 K D F A 4 4 0 0 0 2 5 2 1
: R2
73
kW
kg kg

119
125
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
L J 1 1 K D B C X 8 X X X X X X X
Sequence Number
Vehicle Description
Symbol
Assembly Plant
World Manufacturer Identification

Year
Check Code
4
GENARAL
The mechanic performance table of bolts in China
Quality Grade( mark) 6.8 8.8 9.8 10.9 12.9
Tensile strength limit σ b max (MPa) 600 800 900 1040 1220
Yield limit σ s max (MPa) 480 640 720 940 1100
Corresponding to Hyundai standards 4T 6T 7T 8T 10T

The number before the radix point represents one percent of the nominal tensile strength;
The number behind the radix point represents ten times of the ratio between the nominal yield limit
and nominal tensile strength.
5
STANDARD TORQUE TABLE (JAC - All Models)
cod
group
e
item picture Standard（N·m）
1020：54-69
1 steering wheel tightening nut

M20×1.5：60-79
1020：54-69
J1、E0、Z1、Z2：196-250
Connection of pitman arm and steering
2 A1、M1、Z15、E22CH：250-320
gear box
M15、T0、T4：500-600
M45×1.5:550-605
M10×1：65-95
M12×1.25：108-161
connection of steering gear box,support M14×1.5：146-205
3
and chassis M16×1.5: 240-335
Steering M18×1.5: 397-507
system
M20×1.5: 475-598
M10：37-75
connection of steering column steering
4
gear box
M14×1.5: 50-55
Perforation bolt： according to the

brake pipe system connection
M14：53.9-73.5
M16：88.3-118
5 power steering pipe connection
M18：100-130
M20：100-130
M22：130-160
M24：160-200
Φ4.76 pipe：16-20
Φ6 pipe：23-27
Φ8 pipe：27-33
Φ10 pipe：45-53
Φ12 pipe：60-80
Φ15 pipe：70-90
6 Brake pipe connection
Φ6 nylonpipe：22-25
Brake
system
7 brake draw bench equipment

by eyes, to make the spring mat flat
D series tyre nut（M18X1.5） 287-346
3103104N\3103204N（M25X1.5）
N series tire nut(inner)（M16X1.5） 343-441
N series tire nut(outer)（M25X1.5）
3103226J1\3103227J1（M20X1.5）
E4 series tire nut(inner)（M20X1.5） 485-593
E4 series tire nut(outer)（M30X1.5）
3103203M1\3103204M1（M24X1.5）
M1 series tire nut(inner)（M20X1.5） 485-593
M1 series tire nut(outer)（M30X1.5）
3103056A1\3103057A1（M20X1.5）
Tyre nut A2 series tire nut(inner)（M20X1.5） 485-593
equipme 8
nt A2 series tire nut(outer)（M30X1.5）
3103104N\3103204N（M25X1.5）
Z15AA series tire nut(inner)
（M18X1.5） 485-593
Z15AA series tire nut(outer)
（M27X1.5）
T206 series tire nut（M24X1.5）
T206 series tire nut(inner)（M20X1.5） 518-598
T206 series tire nut(outer)（M30X1.5）
T4 series tire nut 540-670

Heavy Truck series tire nut M22x1.5: 590-680
M14：126-154
M16:157-216
M18:287-346
9 Front U-bolt M20:396-480
M22:441-539
M24:618-843
heavy truck M20×1.5：440-550
suspensi
on M14：126-154
M16:157-216
M18:287-346
10 Rear U-bolt M20:396-480
M22:441-539
M24:618-843
M27、M27×3:850-950
E、C、B、K、Q、D、M：157-196
(for mexico E8510 belongs to E
cateory for wide cabin truck)
11 front leaf spring pin N、T、Z：190-260

heavy truck(M14×1.5):85-110 (for
mexico E8510 belongs to E cateory
for wide cabin truck)
E、C、B、K、Q、D、M：157-196
12 Rear leaf spring pin N、T、Z：190-260
heavy truck(M14×1.5):85-110
M12:73-89
13 front spring pin locking bolt
M14:126-154
i
suspensi
on
14 M12:73-89
Rear spring pin locking bolt
M14:126-154
M10:46-56
M12×1.25:78-96
15 Front shock absorber M14：126-154
M18:219-257
M20×1.5:324-396
M10:46-56
M12×1.25:78-96
16 Rear shock absorber M14：126-154
M18:219-257
M20×1.5:324-396
transmission and engine clutch shell
connection：
6782： 155.4-194.6
1045： 80-110
1061： 127.2-156.9
Gearbox clutch shell with engine
flywheel shell connection：
37-75(aluminium alloy:36-44)
engine 17 Engine and transmission connection
Clutch platen bolt((10.9 class ）：
M10×1.5:74×(1±5%)；
M12×1.5: 142×(1±5%)；
M14×1.5:210×(1±5%)
M10×1：46-62
Drive M12×1.25：78-110
18 Drive axle
axle
M14×1.5: 130-180
M16×1.5: 175-260
clutch 19 Clutch pipeline According to the pipe drawing
20 Cabin titling mechanism M10:41-51 M12:75-96 M16:182-222

M8:17-28
M10:37-75
21 Cabin locking mechanism
M12:75-96
M16:182-222
22 Door locks 9-11
cabin 23 Safety belt M12：75-96
M16:182-222
24 engine titling torsion arm
M12：75-96
25 cabin support rod up M8:17-28 down M10:37-75
26 cabin front support bolt M14×1.5: 99-115
connection bolt of Cabin titling

27 mechanism torsion bearing bush and M14×1.5: 99-115
the cabin front support
28 electric plugs 6-8(wide cabin)
Electric
device 29 electric wire hraness Make spring mat flat
Maintenance manual for hfc4da1-2c china-IV diesel engines
Contents
Chapter I Technical Characteristics of Engine .......................................................................................................... 11

Section I Technical Requirements for Fuel, Oils, and Auxiliary Materials ..................................................... 11
Section II Main Technical Specification of Engine ............................................................................................ 14
Section III Performance Curve of Engine .......................................................................................................... 15
Section IV Main Checking and Adjustment Parameters .................................................................................. 16
Section V Tightening Torque for Critical Bolts of Engine ................................................................................. 17
Section VI Main Fitting Clearances and Allowable Wear Limits of Engine ................................................... 21
Section VII Specification of Main Attachments and Accessories...................................................................... 24
Chapter II Maintenance for Main Structures of Engine ........................................................................................... 25
Section I Disassembly of Engine Assembly ......................................................................................................... 25
Section II Assembly of Engine ............................................................................................................................. 43
Section III Crankshaft and Flywheel System ..................................................................................................... 68
Section IV Piston and Connecting Rod Group ................................................................................................... 69
Section V Valve Distribution Mechanism ........................................................................................................... 70
Section VI Lubrication System ............................................................................................................................ 71
Section VII Cooling System ................................................................................................................................. 72
Section VIII Turbocharger and Inter-Cooler System ........................................................................................ 73
Section IX EGR System........................................................................................................................................ 75
Section X Exhaust System .................................................................................................................................... 76
Chapter III Working Principle of Engine Control and Actuator Units ................................................................... 77
Section I Overview of Diesel Common Rail System .......................................................................................... 77
Section II Working Principle of Low Pressure Fuel Line System .................................................................... 79
Section III Working Theory of High Pressure Fuel Line .................................................................................. 82
Section IV Electronic Control Unit of High Pressure Common Rail System .................................................. 84
Chapter IV Engine Diagnosis .................................................................................................................................... 109
Section I. Precautions ......................................................................................................................................... 109
Section II. Maintenance Procedures ................................................................................................................. 111
Section III. Fault Diagnosis ................................................................................................................................ 113
Section IV. DTC List ........................................................................................................................................... 115
Section V. Fault Diagnosis for Electronic-Controlled Common Rail Diesel Engines .................................... 133
1
Chapter I Technical Characteristics of Engine

Section I Technical Requirements for Fuel, Oils, and Auxiliary Materials
I. Diesel
HFC4DA1-2C diesel engine adopts electronically controlled, high pressure common rail, fuel injection system and
conforms to Euro-IV emission regulation and thus extends higher requirements over the fuel. To guarantee the
reliability of the fuel supply system, make sure to use the qualified clean diesel produced by national well-established
fuel company, in order to prevent the blockage or early wear of fuel injector due to poor fuel.
Add the fuel only at the well-established gas station. The use of poor diesel or other diesel intended for
other than vehicle engine application is strictly prohibited.
Make sure to use the fuel conforming to national standard GB 19147. The grade number of the diesel chosen is related
to the temperature of working environment. When the environment temperature is reduced, the paraffins within the
diesel will precipitate to block the fuel pipeline, leading to difficult fuel supply and start failure of the engine.
Therefore, choose different grade number of diesel depending on the environment temperature in different seasons
and regions, in accordance with the table shown below.
Environment temperature Above 5℃ Above -5℃ Above -10℃ Above -25℃

Recommended grade
0# light diesel -10# light diesel -20# light diesel -35# light diesel
number of diesel
Notice!
The cam of the high pressure fuel pump is being lubricated by the fuel. Never cause engine flameout due to depletion
of fuel in the fuel tank, or it will lead to serious wear of the high pressure fuel pump. After adding new fuel, make sure
to firstly use manual fuel pump to bleed the air from the fuel pipe and high pressure fuel pump and thoroughly fill the
fuel pipe and high pressure fuel pump with fuel before starting the engine, in order to prevent the wear of high
pressure fuel pump due to fuel shortage.
Procedure for air bleeding and refueling:
1. Loosen the air bleeding screw;
2. Push down the manual fuel pump with hand and then release. Repeat above operation, till there is no air bleeding
out from the air bleeding screw;
3. Tighten the air bleeding screw and pump the fuel with manual fuel pump, till the fuel injection pump is thoroughly
filled with fuel.
The diesel filter embodies the fuel-water separation function:

The water content in the diesel will bring about great harm to the fuel system. Upon the detection that the diesel filter
water level warning lamp on the instrument panel lights up, it indicates the presence of waste water in the diesel filter.
The waste water shall be drained timely, or it will lead to the rusting and wear of high pressure fuel pump, high
pressure fuel rail, and fuel injector and bring about unnecessary losses.
Procedure for water drainage:
1. Unplug the water level sensor connector;
2. Loosen the water level sensor to drain the waste water, till the diesel flows out.
3
Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
3. Tighten the water level sensor and plug the water level sensor connector.
II. Engine Oil

HFC4DA1-2C diesel engine shall use the diesel engine oil with the quality grade at API CH-4 or above, of which the
viscosity is related to the environment temperature. When the environment temperature is reduced, the viscosity of the
engine oil is increased to increase the start resistance so that the diesel engine can’t reach the start speed and cause
difficult start. Therefore, in different seasons and regions, choose the correct engine oil with different viscosity grade
under different environment temperature, in accordance with the table below.
Environment -30℃~25℃
-15℃~40℃ -20℃~30℃ Extreme cold region
temperature
Engine oil
10W-40/50 or 15W-40 10W-30/40/50 5W-40/50 0W-40/50
trademark
Check engine oil level:
z Stop the engine and wait for several minutes;
z Pull out the engine oil dipstick;
z Wipe the oil dipstick with clean cloth and re-insert the oil dipstick to the end;
z Pull out the oil dipstick again and observe the engine oil level. Check whether the oil level is between the upper
and lower limits of the oil dipstick. If insufficient, add the engine oil.
Upper limit
Lower limit
Notice: Make sure to horizontally park the vehicle while

measuring the engine oil level. Stop the engine and wait
for several minutes, till the engine oil can return to the oil
sump.
Notice!
z Make sure to periodically check the engine oil level.
z The apparatus used for refueling shall be clean.
z In event of sudden rise or drop of engine oil level, check for cause immediately.
4
z Never mix different trademarks of engine oils.
z Periodically replace the engine oil as per the maintenance regulations.
III. Coolant
Make sure to use clean automotive antifreeze coolant featuring antifreeze in winter, anti-boiling in summer, and
anti-corrosion, anti-rusting, and anti-scaling.
Take cautions during the operation:
a. Always use coolant throughout the year and pay attention to the use continuity of the coolant.
b. Depending on the temperature of the region in which the vehicle is used, choose the coolant with different freezing
point. The freezing point of the coolant shall be at least 10ºC below the lowest temperature of the region, in order to
maintain the antifreeze function.
c. Purchase the qualified coolant product, in order to prevent damaging the engine and causing unnecessary economic
losses due to use of disqualified product.
d. Never mix different trademarks of coolants nor use such mixed coolant, in order to prevent the chemical reaction
from impairing the respective comprehensive anti-corrosion performance.
e. Never add the hard water such as well water or running water. Upon the detection of suspended material, sediment,
or smelliness phenomenon in the coolant, it indicates that the coolant is deteriorated and becomes ineffective due to
chemical reaction. In such case, timely clean the cooling system and thoroughly replace the coolant.
f. The glycol coolant is one toxic substance and is harmful to the liver. Never swallow the coolant. In event of skin
exposure to the coolant, thoroughly clean with water immediately. In addition, the nitrite anti-corrosion additive in the
coolant is one carcinogenic substance. Do not dispose the used coolant randomly, in order to prevent contaminating
the environment.
Notice!
z Upon the detection of sudden drop in coolant level, check for cause immediately.
z The cooling system is under pressurized state! Never open the cap of the coolant compensation tank or radiator
while the engine is still hot, or it will lead to scalding danger!
5
Section II Main Technical Specification of Engine

Model HFC4DA1-2C
Inline 4-cylinder, longitudinal layout, water-cooled, 4-stroke, turbocharged
Type
inter-cooler, high pressure common rail, and direct injection engine
Nominal power/speed 85/3600（kw/rpm）
Top torque/speed 250/1800～2800(Nm/rpm)
Minimum fuel consumption
≤ 218g/kw·h Top idling speed 4000rpm
of external characteristic
Exhaust temperature (before
≤ 700℃ Idling speed 800±50 rpm
turbine)
Number of cylinders × bore Total piston
4×93 mm×102 mm 2.771 L
× stroke: displacement
Compression ratio 17 ：1 Fuel grade -10#
Fuel supply advance
Working sequence 1-3-4-2 Electronically controlled
angle
Flameout mode Fuel cut-off Engine mass 270kg
China-IV emission standard
Emission limit (test value) Noise limit ≤ 95dB(A)
compliant
Engine oil trademark Above grade CH-4 Engine oil capacity 7.2L
Engine oil/fuel consumption ratio (24h at full speed) ≤ 0.10%
Temperature of engine oil in oil sump (under nominal working
≤130℃
condition)
Engine oil pressure Idling: ≥98 kPa
Coolant capacity 30L Applicable altitude ≤3500m
Maximum outlet temperature of
Thermostat type Wax type ≤ 110℃
coolant
Thermostat opening
82℃ Thermostat full open temperature 95℃
temperature
Applicable temperature
With heated cold starter and with heater plug in engine
of diesel engine
Length of cylinder
Overall dimensions (L×W×H) 728.9mm×715.6mm×753.3mm 479mm
block
6
Section III Performance Curve of Engine
300 90
扭矩
Torque
Power
80
250 功率
70
200 60
扭矩（N m ）
w）
50
功率（k
150
Power
Torque
40
100 30
20
50
10
0 0
1000
1200
1400
1600
1800
2000
2200
2400
2600
2800
3000
3200
3400
3600
转速（r p m ）
Speed
280 25
油耗率
Fuel consumption
270 油耗量
Fuel consumption
20
260
w . h）
/k(g/kw.h)
/h）
consumption (kg/h)
250
15
Fuel油耗量（kg
consumption
240
油耗率（g
10
230
Fuel
220
5
210
200 0
1000
1200
1400
1600
1800
2000
2200
2400
2600
2800
3000
3200
3400
3600
转速（r pm ）
Speed
7
Section IV Main Checking and Adjustment Parameters

1、At rated power:
(1) Exhaust temperature (master pipe) (ºC) ≤700
(2) Thermostat opening temperature (ºC) 82
(3) Thermostat full open temperature (ºC) 95
(4) Temperature of engine oil in main oil way (ºC) ≤130
(5) Engine oil pressure (kPa) 400～600
2. Engine oil pressure at minimum stable speed (kPa) ≥98
3. Timing phase (in rotation angle of crankshaft)
(1) Open of intake valve (before top dead center) 24.5°
(2) Close of intake valve (after bottom dead center) 55.5°
(3) Open of exhaust valve (before bottom dead center) 54°
(4) Close of exhaust valve (after top dead center) 26°
4. Valve clearance (mm) 0.3～0.4
8
Section V Tightening Torque for Critical Bolts of Engine
☆ Comparison Table of Tightening Torque for Critical Bolts

No. Description N．m
1 Fixing bolt of rockshaft 55
2 Heater plug 25
3 Nut and washer for fuel injector body 40
4 Fuel injector 34
5 Fixing bolt of thermostat housing assembly 25
6 Installation torque of rocker arm assembly 55
7 Camshaft thrust plate bolt 25
8 Camshaft timing gear bolt 110
9 Fixing bolt of rockshaft 50
10 Fixing bolt of engine oil pump filter screen assembly 20
11 Engine oil pump fixing bolt 20
12 Oil sump bolt 23.5
13 Flywheel baffle bolt 85
14 Flywheel bolt 25 for first step
70 for second step
120 for third step
15 Crankshaft bearing cap bolt 20 for first step
110 for second step
170 for third step
16 Tightening bolt of engine oil pump 25
17 Socket nut of engine oil pump 30
18 Torque for cylinder head bolt: 65 for first step
85 for second step
105 for third step
19 Rockshaft support bolt 55
20 Main bearing cap bolt 170
21 Torque for drive shaft nut 66
22 Transmission bracket nut 69
23 Clutch cover – flywheel housing bolt M10：46
M12：91
24 Engine rear bracket nut and bolt M10：40
M12：69
25 Front exhaust pipe bolt 37
26 Clutch working cylinder bolt 19
9

27 Belt pulley bolt 210
28 Fan pulley 12.5
29 Crankshaft bearing cap bolt 170
30 Connecting rod bearing cap bolt 25 for first step
85 for second step
31 Camshaft timing gear 110
32 Fuel injection pump nut 30
33 Idler gear bolt 20
34 Engine oil pipe perforated bolt 20
35 Crankshaft belt pulley bolt 210
36 Fan silicone oil clutch 12.5
37 Connecting rod bearing cap 20 for first step
85 for second step
38 Piston cooling oil pipe bolt M8×1.25 25
M6×1.00 7.5
39 Oil pressure regulation valve M6×1.5 30
40 Socket nut of engine oil pump 30
41 Engine oil pump assembly bolt 25
42 Oil sump bolt 23.5
43 Cylinder head bolt 65 for first step
85 for second step
105±5 for third step
44 Rockshaft support bolt 55
45 Tightening bolt of water outlet pipe 19
46 Protrusion size of water pump impeller 24.6mm
47 Fan center distance 79.2～79.8 m
48 Open temperature of thermostat valve 82 ℃
49 Full open temperature of thermostat valve 95℃
50 Open pressure of vacuum valve at center of radiator 88．2～117．6 kPa
cap valve seat
51 Water pump fixing bolt 25 N.m
52 Alternator fixing bolt 40 N.m
53 Alternator adjustment plate fixing bolt 25 N.m
54 Lock nut, A/C compressor idler gear 27 N.m
55 Nut of engine oil cooler water pipe 25
56 Oil drainage plug 80
57 Fixing bolt of oil pump assembly 20
10

58 Tightening socket nut 30
59 Bolt and nut of starter motor 81
60 Fixing nut of starter cable 9
61 Exhaust branch pipe bolt 30
62 Bolt of heat shield 25
63 Support bolt 40
64 Front exhaust pipe nut 40
65 Crankshaft belt pulley bolt 210
66 Exhaust pipe nut 67
67 Torque of engine bracket bolt M10：40
M12：69
68 Cylinder head cover nut 13
69 Connecting nut between turbocharger and exhaust 25
manifold
70 Connecting bolt between exhaust manifold and 30
cylinder head
71 Bolt of exhaust pipe heat shield 25
72 Connecting bolt of turbocharger air bleeding pipe 25
73 Perforated bolt of lubricating oil pipe M12：41
M14：55
☆ Comparison Table for Standard Bolt Specification and Tightening Torque

Bolt Identification
Less than grade 8.8 Grade 8.8 (High Grade 10.9 (Alloy
Torque (N.m)
(low carbon steel) carbon steel) steel)
Specification
M6×1.0 4~8 5~10 .......
M8×1.25 8~18 12~23 17~31
M10×1.25 21~35 28~47 38~64
M10×1.5 20~34 28~46 37~61
M12×1.25 50~75 62~93 77~116
M12×1.75 46~70 58~86 73~109
M14×1.5 78~117 95~142 116~174
M12×2.0 73~109 90~134 109~163
M16×1.5 106~160 138~208 163~245
M16×2.0 102~152 132~198 156~234
M18×1.5 154~230 199~299 234~352
M20×1.5 210~316 275~413 323~485
11
M22×1.5 256~422 370~555 433~649

M24×2.0 360~550 439~725 565~847
12
Section VI Main Fitting Clearances and Allowable Wear Limits of Engine

Assembly
Fitting Clearance for Wear Limit
No. Name Standard Size (mm)
nature New Engine (mm)
(mm)
Contact width between
valve and seat ring
1 Intake valve 1.7 2.2
Exhaust valve 2 2.5
Valve sinkage
2 Intake valve 0.73 1.28
Exhaust valve 0.71 1.2
3 Backlash 0.05-0.13 0.3
Axial run-out clearance of
4 0.07 0.2
idler gear A
Outside diameter of tappet Φ13 −−00..010

028
5 Clearance 0.01～0.046 0.10
+0.018
Tappet bore Φ13 0
6 Radial run-out of push rod 0.3
7 Deflection of rockshaft 0.3
Outside diameter of 0
rockshaft Φ19 −0.02
8 Clearance 0.01～0.05 0.20
+0.03
Rocker arm bore Φ19 + 0.01
Rod diameter of intake −0.039
valve Φ8 −0.054
9 Clearance 0.039～0.071 0.20
+0.017
Valve guide bore Φ8 0
Rod diameter of exhaust −0.064
valve Φ8 −0.079
10 Clearance 0.064～0.096 0.25
+0.017
Valve guide bore Φ8 0
Free height of valve spring 48
11 Perpendicularity of valve
Φ1.4
spring
Outside diameter of idler
gear A shaft Φ55 −−00..025
055
12 Clearance 0.025～0.080 0.2
Inside diameter of idler gear +0.03
A bearing Φ55 0
+0.065
13 Cylinder sleeve bore Φ93 + 0.020
13
Assembly
(mm)
Assembly
Name Standard Size (mm)
(mm)
Protrusion height of
13 0～０.08
cylinder sleeve
Axial run-out clearance of
0.20
14 camshaft Clearance 0.05～0.13
Cam height of camshaft 42.02±0.05 0.38
Inside diameter of camshaft
bush Φ50 0+0.025
15 Clearance 0.025～0.080 0.12
Diameter of camshaft
journal Φ50 −−00..025
055
16 Deflection of cam bush 0.02 0.1
Outside diameter of piston
pin Φ34 0−0.005
17 Clearance 0.002～0.015 0.03
Piston pin bore Φ34 ++00..010
002
Thickness of connecting
rod large end Φ330− 0.07
18 Clearance 0.175～0.320 0.35
Opening of crankshaft
connecting rod journal Φ33++00..250
175
Clearance of intake and
19 Clearance 0.3～0.4
exhaust valves (cold state)
Main journal Φ 70 −−00..068
086
20 Clearance 0.031～0.066 0.11
Main bush bore (after
assembly) Φ 70 −−00..003
033
Outside diameter of piston
pin Φ340− 0.036 0.05
21 Clearance 0.008～0.026
Inside diameter of +0.020
connecting rod bush Φ34 + 0.038
Crankshaft connecting rod −0.070
journal Φ53 − 0.085
22 Clearance 0.029～0.069 0.1
Connecting rod bush bore −0.016
(after assembly) Φ53 − 0.041
Grouping of piston outside
diameter
Group A 92.957～92.968 Grouping
23 0.053～0.075
Group B 92.968～92.979 clearance
Group C 92.979～92.990
Group D 92.990～93.001
14
Assembly
(mm)
Grouping of cylinder sleeve
inside diameter (after
pressed-in)
Group A 93.021～93.032
Group B 93.032～93.043
Group C 93.043～93.054
Group D 93.054～93.065
Opening of piston ring
1st compression ring 0.2～0.4 1.5
24
2nd compression ring 0.65～0.85 1.5
Oil control ring 0.25～0.50 1.5
End clearance of piston ring
1st compression ring 0.078～0.139 0.15
25 nd
2 compression ring 0.045～0.09 0.15
Oil control ring 0.03～0.07 0.15
15
Section VII Specification of Main Attachments and Accessories

Engine oil pump type Externally engaged gear pump
Flow rate of engine oil pump ≥ 23L/m (at 1,000r/m and 0.4MPa)
Lubrication ≥ 23L/m (at 1,800r/m and 0.44MPa)
system Open pressure of engine oil pump 0.7±0.08MPa
relief valve
Engine oil filter type Filter element type
Water pump type Centrifugal type
Flow rate and head of water pump Head ≥6.5m (at 3,000r/m) at 100L/min flow rate;
Cooling (water temperature at 80±5ºC) Head ≥12m (at 4,000r/m) at 120L/min flow rate;
system Thermostat type Pellet thermostat
Temperature of thermostat Initial open: 82ºC; full open: 95ºC
Fan type Independent electric fan
Preheating plug type Ceramic type
Voltage of preheating plug 12V
Electric
Starter specification 12V，2.8kW
system
Alternator specification 14V，90A
Battery voltage 12V
Radial flow variable section turbocharger
Intake system Turbocharger The top speed of turbocharger is ≤220,000r/m, with
turbocharger ratio at ≤2.2.
Type of EGR valve Position feedback type
EGR Voltage of EGR valve position 5V
sensor
Fuel filter type Spin-on type, with fuel-water separator, manual fuel
delivery pump, and diesel heater
High pressure fuel pump BOSCH CP1H, radial three-plunger pump, with fuel
delivery fuel pump and solenoid valve control
Fuel injector BOSCH CRI2.2, solenoid valve control
Electronically High pressure common rail Maximum rail pressure: 160MPa
controlled Electronic control unit (ECU) BOSCH EDC17, with working voltage at 12V
common rail Crankshaft speed sensor Working clearance: 0.5～1.2mm
fuel system Camshaft position sensor Working clearance: 0.5～1.5
Air flowmeter HFM6, with working voltage at 12V and flow measurement
range at 40~840kg/h.
Water temperature sensor NTC type
Rail pressure sensor Voltage output: 0.5~4.5V
Accelerator pedal position sensor Voltage: 5V
16
Chapter II Maintenance for Main Structures of Engine
Section I Disassembly of Engine Assembly

I. Special Notices:
a) Before overhauling the engine, make sure to firstly disconnect the negative cable of the battery, or it will damage
the harness and other electric units;
b) Unless otherwise specified, rotate the ignition switch to LOCK position;
c) Whenever the air cleaner is disassembled, make sure to plug the intake port, in order to prevent the ingress of
foreign material, which may enter into cylinder and cause serious damage.
II. Disassembly Procedure

z Turn the ignition switch to LOCK position and disconnect the negative cable of the battery.
z Open the oil drainage bolt of the oil sump and fully drain and collect the oil.
z Fully drain the coolant.
z Disassemble the water inlet and outlet hoses of the engine.
z Disassemble the electronic control harness for engine ECU, engine, and complete vehicle.
z Disassemble the power supply wires for alternator, starter, and oil pressure and water temperature sensors.
z Remove the connecting hose between intake connecting pipe and air cleaner.
z Loosen the connecting pipe of inter-cooler.
z Shut off the fuel pipeline and unplug the fuel pipe and return pipe.
z Disconnect the power supply of the radiator fan and when necessary loosen the radiator bracket and take out the
whole radiator.
z Loosen the clutch connecting pipe.
z Disassemble relevant connecting pipes of air conditioner and power steering pump.
z Disconnect the exhaust manifold and exhaust muffler pipe.
z Loosen the connecting mechanism between transmission and the complete vehicle.
z Loosen the fixing bolts between engine and transmission suspension bracket.
z Steadily lower the engine with elevator.
z Loosen the connecting bolts between engine and transmission and separate the transmission from the engine.
17
III. Illustration for Disassembly of Engine
1. Disassemble the flywheel.
a. Block the flywheel with flywheel clamp, loosen the
fixing bolts between damping pulley and flywheel, and
disassemble the flywheel assembly.
2. Disassemble the belt, air conditioner

compressor, and alternator and water
pump pulleys.
a. Use an open-end wrench to remove the fixing nuts of

engine fan and remove the cooling fan of the engine.
b. Loosen the alternator adjustment bolts and fixing bolts,
remove the fan clutch pulley and alternator belt, and
check the side face and toothed face of the belt for
normal state.
c. Remove the oil and vacuum pump oil return pipe
connectors.
d. Loosen the alternator fixing bolts and adjustment bolts
and disassemble the alternator belt. Check the
alternator belt for presence of aging, cracking, and
abnormal wear. If yes, replace the belt. Arrange the
parts disassembled orderly on the part shelf, remove
the alternator, use hand to rotate the alternator pulley,
and check the inside for presence of noise, stagnation,
and unbalance. Check the alternator for presence of
ablation and check the shaft for presence of abnormal
wear noise.
e. Disassemble the water pump pulley.
18
3. Disassemble the exhaust system.
a. Disassemble the fixing bolts of turbocharger lubricating

oil pipe and disassemble the fixing clamp of return
hose.
b. Remove the exhaust pipe shield.
c. Remove the EGR cooler.
d. Remove the exhaust pipe and turbocharger assembly.

e. Remove the fixing bolts and nuts of exhaust pipe,
remove the exhaust manifold and turbocharger
subassembly, and remove the exhaust manifold gasket.
f. Check:
A) Whether the rotor of turbocharger rotates flexibly.
B) Whether the air compressor wheel is damaged,
observed from the inlet of air compressor.
C) Whether the air compressor interferences with the
housing, observed from the inlet of air compressor.
4. Disassemble the relevant accessories
of fuel system.
19
a. Loosen the conical nut at fuel injector end and the

conical nut on fuel injection pump side (one is to
reversely tighten the fuel inlet of fuel injector and one is
to loosen the nut of high pressure fuel pipe); Loosen the
conical nut on fuel injection pump side (Two wrenches
are used mainly for disassembly, of which one is to
reversely tighten the fuel outlet of fuel injection pump
and one is to loosen the nut of high pressure fuel pipe,
in order to prevent the fuel outlet of the fuel injection
pump from follow-up rotation). Remove the high
pressure fuel pipe and install the high pressure fuel pipe
protective sleeve;
b. Remove the fuel injector return hose.
c. Remove the fixing bolts of fuel injector pressure plate,

remove the fuel injector body along with its support,
and install the fuel injector protective sleeve.
4. Disassemble the fuel-gas separator

subassembly
a. Remove the crankshaft breathe hose and fuel-gas

separator return hose.
b. Disassemble the fixing bolts of fuel-gas separator.
c. Remove the fuel-gas separator.
20
d. Remove the fixing bolts of fuel-gas separator housing

and take out the fuel-gas separator filter element. Clean
the fuel-gas separator housing, check the state of filter
element, and when necessary replace the filter element.
e. Disassemble the fixing bolts of fuel-gas separator

bracket and remove the fuel-gas separator bracket.
4. Disassemble the intake manifold and

other peripheral accessories.
21
a. Disassemble the fixing bolts of power steering pump

and remove the power steering pump.
b. Check the power steering pump for presence of oil
leakage and check the belt pulley of power steering
pump for presence of wear;
c. Remove the EGR valve.
d. Remove the fixing bolts of air intake pipe bracket.
e. Remove the air intake pipe bracket and fuel-gas

separator bracket.
22
f. Remove the fuel rail and rail pressure sensor assembly

and the rail bracket and install the fuel pressure rail
protective sleeve;
g. Disassemble
h. Disassemble the fixing bolts of oil dipstick fixing

sleeve and disassemble the oil dipstick conduit.
i. Disassemble the fixing bolts and nuts of intake

manifold. Remove the intake manifold;
23
j. Remove the fixing bolts of compressor bracket and

remove the compressor bracket;
k. Remove the bypass rubber pipe, remove the thermostat

housing and water outlet assembly; Disassemble the
fixing bolts of thermostat housing and remove the
thermostat housing.
l. Remove the fixing bolts of cylinder head shield and

remove the cylinder head shield;
m. Remove the bolts and nuts of rocker arm support as per

specified sequence and remove the rocker arm
assembly. Sequence: 4-1-3-2
n. Notice: The failure to loosen the bolts of rocker arm
support as per the specified sequence will damage the
rockshaft*.
o. Take out the push rod;
24
p. Remove the cylinder head bolts by several times as per

the specified sequence (front circle drawing method).
q. The failure to disassemble by several times as per
specified sequence will damage the cylinder head and
impair the deflection of lower surface of cylinder
head*.
r. Remove the damping pulley.

Remove the fixing bolts of water pump, remove the
water pump, and check the water pump blades for
presence of cracking and corrosion and check the
blade shaft for presence of wear.
s. Disassemble the fixing bolts of timing gear chamber

cover and remove the timing gear chamber cover and
cover gasket.
t. Remove the engine left bracket.

u. Loosen the bypass rubber hose clamp, loosen the
fixing bolts of water inlet pipe weldment, and remove
the water inlet pipe weldment.
25
v. Disassemble the fixing bolts of engine oil filter and

remove the engine oil filter.
w. Use an open-end wrench to disassemble the engine oil

pressure connector and remove the connector and
lubricating oil pipe.
x. Loosen the fixing nuts of fuel injection pump gear,

remove the hexagon socket fixing bolts of fuel
injection pump and the fixing nuts of fuel injection
pump gear, knock lightly the fuel injection pump gear
shaft with rubber hammer, remove the fuel injection
pump and fuel injection pump gear, and install the fuel
injection pump protective sleeve. The fuel injection
pump shall be insulated from the air and dust.
26
y. Remove the fixing bolts of idler gear pressure plate

and remove the idler gear pressure plate, idler gear, and
idler gear shaft.
z. Remove the fixing bolts and fixing nuts of oil sump by

one time as per the specified sequence and remove the
oil sump.
aa. Remove the fixing bolts of engine oil pump and pull
out the engine oil pump.
bb. Remove the fixing bolts of camshaft.
27
cc. Pull out the camshaft.
dd. Remove the nuts of connecting rod large end as per

specified sequence and use piston installation tool to
push out the piston. Position the piston orderly.
Visually observe each piston for presence of
cracking, scratch, and other excessive wear.
ee. Disassemble the fixing bolts of timing gear chamber

and the fixing bolts of idler gear lining plate and
remove the idler gear lining plate.
ff. Use a rubber hammer to knock lightly the timing

gear chamber from both sides to remove the timing
gear chamber.
28
gg. Take out the crankshaft timing gear.
hh. Rotate the bolts of master bearing cap as per

specified sequence to pull out the bolts of master
bearing cap and remove the main shaft bushes
(Position the main shaft bushes orderly).
ii. Overturn the crankshaft to take out the crankshaft
thrust plate and remove the crankshaft and the
crankshaft lower bushes.
jj. Check the wear state of the crankshaft thrust plates.
kk. Disassemble the piston cooling fuel injection pipe

subassembly.
5. Check the parts.
a. Check the lower surface of the cylinder head. Strict

planeness tolerance is required for the fitting surface of
the intake and exhaust branch pipes.
b. These surfaces can be repaired by grinding. If the
surface planeness is out of the specified tolerance,
grind the surface to meet the technical requirements. If
the planeness is excessively out of the technical
requirements, replace the cylinder head.
Deflection of cylinder head lower surface 0.05 or
less Limit 0.20
Cylinder head height Standard value 92 Limit
91.55
c. Use ruler and feeler gauge to measure the deflection of
fitting surface between exhaust branch pipe and
29
cylinder head.
If the measurement is between limit and standard
value, re-grind the fitting surface between exhaust
branch pipe and cylinder head.
If the measurement is out of the specified limit, make
sure to replace the branch pipe.
d. Use a multimeter to measure the outside diameter of

piston at the position 73.9mm reach from the piston
crown.
Standard value:
A: 92.971~92.980mm
B: 92.981~92.990mm
C: 92.991~93.000mm
D: 93.001~93.010mm
e. Use an inside micrometer to measure:

Standard value for inside diameter of cylinder bore
fitted with cylinder sleeve:
A:93.021~93.030mm
B:93.031~93.040mm
C:93.041~93.050mm
D:93.051~93.060mm
f. Subtract the inside diameter of cylinder bore from the

outside diameter of piston to obtain the piston
clearance. The clearance range of piston:
0.041~0.059mm.
If the piston clearance is out of the specified range,
check and replace the cylinder sleeve or piston,
depending on the cylinder bore grouping and the
outside diameter of piston.
(The second line of the stamped code at the rear end
of lower surface of new cylinder block indicates the
inside diameter group of the cylinder bore).
30
g. Measure the cam height of the camshaft. The standard

value is 42.02±0.05mm and the limit is 41.65mm. If
the measurement is out of the limit, make sure to
replace the camshaft.
h. Use a multimeter to measure the outside diameter of
each camshaft journal. If any measurement is out of
the limit, replace the camshaft. The standard value for
outside diameter of journal is 49.945-49.975mm and
the limit is 49.60mm. If any measurement is out of the
limit, replace the camshaft.
i. Use a feeler gauge to measure the axial run-out

clearance of the camshaft. The axial run-out clearance
of camshaft is 0.05~0.114mm.
j. Use a multimeter to measure the outside diameter of

valve stem. If the measurement is less than the
specified limit, make sure to replace the valve and
valve guide in pair.
(Intake valve: 7.946-7.961mm; limit: 7.880mm)
(Exhaust valve: 7.921-7.936mm; limit: 7.850mm)
k. Use a multimeter to measure the inside diameter of

valve guide and subtract the outside diameter of valve
stem from the measurement to obtain the valve guide
clearance. If the clearance obtained is out of specified
limit, make sure to replace the valve and valve guide in
pair.
(Limit of intake valve guide clearance: 0.200mm)
(Limit of exhaust valve guide clearance: 0.250mm)
31
l. Measure the free height of valve spring. If the

measurement is out of specified limit, make sure to
replace the spring.
The standard value is 0.05mm or less and the limit is
0.20mm.
m. Use a feeler gauge to measure the clearance between

piston ring groove and piston ring.
If the clearance between piston ring groove and piston
ring is out of specified limit, make sure to replace the
piston.
n. Use a feeler gauge to measure the opening gap of

piston ring.
If the opening gap of the piston ring is out of specified
limit, make sure to replace the piston.
o. Install the steel-strip oil ring.
32
p. Install the oil ring bush ring.
q. Use a piston ring expander to install the 2nd

compression ring and the 1st compression ring. While
installing the compression rings, face upward the
marking N (The lip of 2nd compression ring shall face
downward).
Illustration of opening directions for
piston rings The overlap position of oil control ring cushion spring
Forward marking and the opening of oil control ring steel strip shall be
Compression
180º away from each other and shall be 90º away from
Opening of oil control
ring
ring steel strip the 2nd compression ring.
Auxiliary
thrust face Main thrust face
Overlap of oil Compressi

control ring on ring
cushion spring
Piston pin direction
r. Measure the outside diameter of main journal and the

inside diameter of main shaft bore.
33
s. Measure the outside diameter of connecting rod journal

and the inside diameter of bush bore of connecting rod
fitted with bush.
Calculate the clearance between main journal of crankshaft
and the main bush bore of crankshaft: The difference
between the diameter of main journal and the inside
diameter of crankshaft main bush bore measured above is
the fitting clearance. The wear limit shall not exceed
0.11mm.
Notice: While measuring the inside diameter of
crankshaft main bush bore, install the bearing cap and
bush onto the bearing block and tighten the bolts to
specified torque. Use an inside multimeter to measure
the inside diameter.
Calculate the clearance between crankshaft connecting rod
journal and connecting rod bush bore: The difference
between the diameter of connecting rod journal and the
inside diameter of connecting rod bush bore measured
above is the fitting clearance. The wear limit shall not
exceed 0.10mm.
34
Section II Assembly of Engine

I. Basic Technical Requirements for Assembly
The assembly of the engine is one important step for service of the engine. The service performance of the engine is
closely related to the assembly accuracy, assembly technical requirements, and the assembly quality. Make sure to pay
attention to following items:
Before the assembly, make sure to thoroughly clean and thoroughly blow dry all parts and components. All friction
surfaces of the parts with relative movement are applied with lubricating oil (grade CE diesel engine oil or above).
Carefully remove all oil dirt and carbon deposit, till the base metal is exposed. Never use electric wire brush to clean
the sealing surfaces of any sealing gasket. Remove the residues from all used sealing gaskets. It’s absolutely
prohibited to use wire brush to clean the piston.
a. Remove the carbon deposit, oil dirt, and water scale and clean all lubricating oil pipes and pipelines.
b. Check the wear state of valve, push rod, and rocker arm contact surfaces and when necessary repair or replace.
c. Check the wear state of piston rings, cylinder sleeves, connecting rod small end bushes, and connecting rod bushes
and when necessary replace.
d. Check the wear state of main bushes and thrust plates.
e. Check the wear state of engagement surfaces of transmission mechanism and drive gear and measure the
engagement clearance and when necessary repair or replace.
f．Check the wear state of intake and exhaust valves and intake and exhaust valve seats and repair, grind, and test the
leakage and when necessary replace.
g．Check the mist injection state of the fuel injector and when necessary grind or replace the fuel injector coupler.
While installing the used fuel injector, clean the carbon deposit with ultrasonic and do not wipe with silk or scrape
with knife, in order to prevent damaging the injector nozzle and blocking the injector orifice.
h. Check the engine oil pump and disassemble for checking or measure the wearing parts and adjust accordingly.
i. Check the cylinder gasket and intake and exhaust pipe gaskets and replace any damaged or failed gasket.
j. Check the alternator and starter, clean all parts and bearings, blow dry and apply new lubricating grease, and check
the wear state of starter gear and check the transmission mechanism for flexible functioning.
k. Check and clean the turbocharger.
35
II. Illustration for Assembly of Engine

1. Install the piston cooling fuel injector
subassembly.
a. Install the piston cooling fuel injector subassembly:
Install the piston cooling fuel injector subassembly
onto the engine block;
b. Tighten the hexagon socket screws to 12.5±2.5N.m;
2. Install the crankshaft, thrust plates,

and main bearing caps.
a. Install the upper and lower main bushes: Align the
stop opening of upper main bush with the slip groove
of the main bearing block bore of engine block and
push 5 upper main bushes to place;
Notice: While installing the main bushes, make
sure to differentiate the upper and lower bushes,
of which the upper bush has oil grooves and the
lower bush has not. Do not install the bushes
reversely.
a. Apply an appropriate amount of clean engine oil onto

the upper bearing bush;
b. Lift up and place the crankshaft onto the engine
block.
36
c. Install the crankshaft thrust plates to the 3rd main

journal portion (The surface with oil groove faces to
crankshaft thrust surface and the oil groove shall be
sprayed with lubricating oil).
d. Spray oil to the main journal portion and install the

1~4 main bearing caps of crankshaft as per the
marked sequence. The arrow markings on the bearing
caps shall face to the front of the engine.
e. Apply the liquid sealant onto the fitting surface
between 5th bearing cap and cylinder block and install
the 5th bearing cap * text: Notice: 1) Before applying
the sealant, the fitting surface of main bearing cap
shall be thoroughly free of any engine oil; 2) Never
block the cylinder threaded holes and bearings by the
sealant.
37
f. Apply engine oil onto the threads of main bearing cap

bolts, install into the main bearing caps, and tighten
the bolts to 170 N.m torque as per the specified
sequence. Tighten to 20 N·m for the 1st step, to 120
N·m for the 2nd step, and 170 N·m for the 3rd step.
Tightening sequence: (From center to two sides)
8415 9
7326 10
g. Adhere the magnetic dial gauge onto the cylinder

block, position the pointer of the dial gauge to the
rear end face of crankshaft, and use a straight
screwdriver to pry lightly the crankshaft to check the
axial clearance of crankshaft (or push the crankshaft
left and right and measure with feeler gauge). If the
thrust clearance is out of the limit, replace the thrust
bearings in pair. Standard value: 0.040mm-0.201mm;
Limit: 0.30mm
h. Rotate the crankshaft and check for flexible rotation

and presence of noise. Alternatively, use a digital
wrench to measure the net torque of crankshaft, listen
for presence of noise, and check whether the torque is
≤6N.m.
a Insert the lubricated tappets in turn into the tappet

holes.
38
b. Install the tappet anti-drop tool.
3. Install the piston connecting rod

assembly.
a. Spray one film of oil onto the cylinder bore.

b. Spray oil onto the piston skirt, install the piston into
the piston taper sleeve, insert into the cylinder bore,
and use nylon bar and guide jig to install the piston.
Notice: (The connecting rod and bolts shall not
come into contact with the cylinder bore and the
large end bore of connecting rod shall be
orthometric with the crankshaft journal.)
c. After installing the large end cap of the connecting

rod, tighten the large end nut of connecting rod to
20N· m and 85N· m by two times.
d. Use a feeler gauge to check the side play of large end
of connecting rod. The side play range for large end
of connecting rod: 0.175-0.29mm.
e. After the installation of pistons for 1st and 4th
cylinders, rotate the crankshaft for 180º and install
the pistons for 2nd and 3rd cylinders.
39
4. Install the timing gear and related

accessories.
a. Insert the lubricated tappets in turn into the tappet
holes.
b. Install the water manifold (The water manifold is

paralleling with the cylinder block)
40
c. Spray oil to the crankshaft gear and then install.
d. Install the gasket of timing gear chamber.
e. Install the timing gear chamber and idler gear lining

plate and pre-tighten the fixing bolts.
41
f. Spray lubricating oil onto the camshaft bush, add

lubricating oil to the head of tappet, and spray
lubricating oil onto the camshaft subassembly.
g. Install the camshaft (with the bottom facing upward

and the left facing forward).
h. Tighten the fixing bolt subassembly of camshaft

thrust plate to 25±5N.m.
i. Install the engine oil pump outlet pipe subassembly

and engine oil pump assembly with strainer.
42
j. Install the idler gear shafts A and C onto the idler

gear lining plate and use nylon bar for idler gear shaft
to lightly knock into the idler gear lining plate.
k. Apply oil onto the surface of idler gear C bush and

lightly rotate into the idler gear shaft C. Then, apply
oil onto the surface of idler gear A bush and use
nylon bar to lightly knock into the idler gear shaft A.
Take caution to apply the force lightly and uniformly,
in order to prevent the abnormal wear of bush.
l. While installing the idler gear A, take caution to
adjust the installation position of idler gear A and "2
2” position of camshaft gear as per the “1 1” marking
of crankshaft gear. (Timing photo)
43
m. Apply oil onto the surface of idler gear B bush and

lightly rotate into the idler gear shaft B. In event of
difficult installation, slightly rotate the crankshaft to
help installation.
n. Use the hexagon flange bolts to install the idler gear

pressure plates A, B, and C onto the idler gear shaft
and tighten the fixing bolts of pressure plate and
fixing bolts of idler gear lining plate to 25±5N. m
torque.
5. Install the oil sump.

a. Use a scraper to remove the excessive portion of the
gear chamber.
b. Install and pre-tighten the stud * 12 of oil sump.
44
c. Apply sealant to the lower end face of timing gear

chamber and the lower rear end of engine block.
d. Install the oil sump gasket.

e. Apply the sealant for the second time to both sides of
oil sump gasket.
f. Install the oil sump assembly with oil drainage screw

plug and use nylon bar to lightly knock the oil sump
to ensure the steady installation of oil sump.
45
g. As per the specified sequence, tighten the fixing bolts

*10 of oil sump and the fixing nuts * 12 of oil sump
to 23.5±3.5N.m torque.
h. Use a cotton cloth to wipe away excessive sealant.
5. Install the timing gear chamber.
i. Pre-install the flange O-ring of fuel injection pump

onto the fuel injection pump.
j. Place the fuel injection pump into installation
position, install and pre-tighten the hexagon socket
fixing bolts of fuel injection pump, and install the
fuel injection pump gear and fixing nuts of fuel
injection pump.
k. Tighten large fixing nuts of fuel injection pump to

70±5 N·m and tighten hexagon socket fixing bolts of
fuel injection pump to 30±5 N·m.
l. Install the water pump O-ring onto the water pump

and use hand to rotate the impeller for two turns to
ensure that the water pump rotates flexibly.
m. Install the water pump assembly to the gear chamber.
46
n. Install and tighten the bolts and nuts of water pump in

diagonal manner to 25±5N.m.
o. Install the timing gear chamber cover subassembly

and attach and tighten the fixing bolts of gear
chamber cover to 20±5 N.m.
p. Torque for hexagon socket fixing bolt: 60±10 N.m.
q. Install the damping pulley and attach and tighten the

fixing bolts of damping pulley to 210±15 N·m.
6. Install the cylinder head and related

accessories.
a. Check whether the upper surface of cylinder block is
normal and the cylinder gasket is normal and install
the cylinder gasket.
47
b. Install the cylinder head onto the cylinder block.
c. Immerse the thread portion of cylinder head bolts into

oil and then install into the cylinder head and
pre-tighten.
d. Tighten the cylinder head bolts by steps from the

center to two sides as per the specified sequence:
65N.m→85N.m→105N.m
e. Install the thermostat housing and water outlet

assembly and tighten the fixing bolts and hexagon
socket fixing bolts.
48
7. Install the intake manifold and

related accessories.
a. Use hexagon flange bolts to fix the fuel rail bracket
onto the cylinder block and tighten to 37.5±9.5N.m.
b. Use hexagon flange bolts to install the fuel rail

assembly with rail pressure sensor onto the fuel rail
bracket and tighten to 25±5N.m.
c. Install the intake manifold gasket.
d. Insert the oil dipstick into the cylinder block and

tighten the fixing bolts and nuts of intake manifold as
per the specified sequence.
49
e. Install the intake manifold and install and tighten the

fixing bolts, plain washers, and fixing nuts.
f. Install the intake manifold harness bracket and intake

pressure and temperature sensor.
8. Install the push rod rocker arm

subassembly and adjust the valve
clearance.
a. Dip the tip of push rod with oil and install into the
cylinder head. Install the rocker arm and pre-tighten
the rocker arm support bolts.
b. Tighten the support bolts by steps. Sequence: 2-3-4-1;

Torque: 55±5N.m
50
c. Rotate the crankshaft, till the top dead center (TDC)

line of crankshaft damping pulley is aligned with the
timing pointer. In such case, either 1st cylinder piston or
4th cylinder piston is at top dead center (TDC) of
compression stroke.
d. Check the clearance of push rod for the intake valve

and exhaust valve of 1st cylinder. If there is a
clearance between 1st cylinder intake valve and valve
push rod, the 1st cylinder piston is at top dead center
of compression stroke (1236). If the 1st cylinder
intake valve is pressed tightly by exhaust valve push
rod, the 4th cylinder piston is at top dead center of
compression stroke (4578).
e. Valve clearance (under cold state): 0.3-0.4 mm

f. Loosen the clearance adjustment screws for the
valves, as shown in the figure.
g. Insert the feeler gauge with appropriate thickness
between rocker arm and valve rod end.
h. Rotate the valve clearance adjustment screw, till a

light resistance is felt on the feeler gauge.
i. Securely tighten the lock nut.
j. Rotate the crankshaft for 360º.

k. Align the TDC marking of crankshaft damping pulley
with the timing pointer.
l. Adjust the clearance for other valves, as shown in the
figure.
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9. Install other peripheral accessories.
a. In turn install the fuel injection assembly with sealing

gasket onto the cylinder head.
b. Install the fuel injector fixing pressure plate and
install and tighten the fuel injector pressure plate
bolts to 8±2N.m+40～45°.
c. Install the 1st cylinder high pressure fuel pipe

assembly, 2nd cylinder high pressure fuel pipe
assembly, fuel injection pump high pressure fuel
pipe, 3rd cylinder high pressure fuel pipe assembly,
and 4th cylinder high pressure fuel pipe assembly and
tighten the corresponding nuts. Notice: 1. Notice the
installation direction of high pressure fuel pipes; 2.
The tightening torque for nuts at fuel injector end is
27±5N.m; 3. The tightening torque is 20±5N.m for
nuts at high pressure fuel rail end, 27±2N.m for high
pressure fuel pipe nuts at fuel pump end, and
20±2N.m for high pressure nuts at fuel rail end.
d. Use accelerator cable bracket bolts to install the fuel

return three-way valve onto the gear chamber and
tighten to 7.5±2.5N.m.
52
e. Install the engine oil filter and O-ring subassembly

and tighten the fixing bolts of engine oil filter bracket
to 25±5 N.m.
f. Install the engine right bracket and shock absorber

subassembly and install and pre-tighten the fixing
bolts.
g. Install the water inlet pipe gasket and water pump

inlet pipe weldment subassembly, pre-tighten the
bolt, spring, and plain washer subassembly (of water
pump inlet pipe), and install and tighten the bracket
fixing bolts at the lower end of water pump inlet pipe
weldment.
h. Install the engine left bracket and shock absorber

assembly and tighten the fixing bolts.
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i. Check the cylinder head shield O-ring.
j. Install the cylinder head shield and install and tighten

the cylinder head shield bolts to 13±5N.m.
k. Install the exhaust manifold gasket and install the

exhaust manifold and turbocharger subassembly.
l. Install the spring washers and hexagon nuts and

tighten the fixing nuts and fixing bolts as per
specified sequence.
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Tighten bolts as per sequence shown in figure.
m. Install the EGR cooling steel pipe and tighten the

fixing bolts.
n. Install the EGR valve and tighten the fixing bolts.
o. Apply sealant onto the thread of vacuum pump oil

inlet pipe connecting bolts, install the connecting
bolts onto the cylinder block oil outlet, and tighten to
18±2 N.m.
p. Install the alternator belt and water pump pulley.

q. Install the fan and clutch assembly and install and
pre-tighten the clutch fixing nuts.
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r. Adjust the tension of alternator belt and tighten the

alternator adjustment bolts and clutch fixing nuts.
s. Tighten the alternator fixing nuts.
t. Install the vacuum pump oil inlet pipe fixing bolts I

(M8×20) and tighten the fixing bolts to 18±2N.m and
25±5N.m respectively.
u. Install the exhaust pipe heat shield and install and

tighten the fixing bolts.
v. Install the power steering pump and tighten the fixing

bolts of power steering pump.
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w. Install the compressor bracket and tighten the bracket

fixing bolts.
x. Use perforated bolts II and copper washers II to install

the turbocharger oil inlet pipe assembly onto the
turbocharger oil inlet and use perforated bolts I and
copper washers I to install another end onto the
cylinder block oil hole and tighten the perforated
bolts I and II. 1. Tightening torque for perforated
bolts I is 55±10N.m; 2. Tightening torque for
perforated bolts II is 41±6N.m.
y. Install the fuel-gas separator bracket and intake

manifold bracket.
z. Install the fuel-gas separator assembly.
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aa. Install the VNT electromagnetic valve and connect

various vacuum hoses.
10. Install the flywheel and related

accessories.
a. Apply oil to the outer ring and lip of the crankshaft
rear oil seal and use installation jig I to push the rear
oil seal into the oil seal groove. Then install the
installation jig II and knock with steel hammer lightly
and uniformly to install the crankshaft rear oil seal to
place.
b. Install the flywheel baffle and fixing bolts and tighten

the fixing bolts of flywheel baffle to 85±10 N.m.
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c. Install the flywheel.

d. Install the flywheel fixing gasket and install and
pre-tighten the fixing bolts of flywheel.
e. As per the specified sequence, tighten the fixing bolts

of flywheel to 25N.m→70N.m →140N.m by steps,
in order to prevent the occurrence of false tightening
torque. This tightening torque is really high and will
easily lead to thread failure of the bolts.
f. Install the lubricated guide ball bearings into the

installation jig and knock with steel hammer
uniformly into the rear end of crankshaft.
g. Insert the clutch guide into the driven disc and install
to the rear end of flywheel. Install the clutch cover
and install and tighten the fixing bolts of clutch
cover.
59
Section III Crankshaft and Flywheel System

z It works along with the connecting rod to convert the gas pressure applied onto the piston into rotating power and
transmit to the transmission mechanism of the chassis. At the same time, it drives the valve distribution
mechanism and other accessories, such as fan, water pump, and alternator.
z The crankshaft is made of medium carbon steel alloy forging. To improve the wear resistance and fatigue
resistance, the journal surface is treated with high-frequency hardening or nitriding treatment and high-precision
grounded to meet the higher surface hardness and surface roughness requirements.
z With fully supported structure and 8 balance weights, the crankshaft is cast to an integral structure with balance
weights to improve the rigidity and bending strength of the crankshaft.
z The crankshaft is made of high strength steel alloy forging, with fillet rolled journals.
z Its front end adopts rubber-embedded crankshaft torsional shock absorber to reduce the crankshaft torsional shock
generated during the running of the engine. The signal wheel of crankshaft position sensor is installed at the last
crank.
z There are two pieces of crankshaft thrust plates installed on two sides of the 3rd main bearing block, with the face
with oil groove facing to the thrust surface of the crankshaft.
z The grouping numbers for crankshaft main journal and connecting rod journal are stamped on the first crank of
the crankshaft.
z The flywheel assembly is installed at the rear end of crankshaft and the flywheel is located by locating pin and
connected by flywheel bolts.
z The crankshaft, flywheel, and clutch assembly qualified the dynamic balance test before the factory leave.
Signal gear of flywheel

crankshaft position sensor
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Section IV Piston and Connecting Rod Group

z The piston crown is of ω type combustion chamber;
Depending on the performance and reliability requirements, the piston
profile designed can guarantee the normal working of engine under high
speed, high temperature, and high pressure conditions. The good skirt sizes
can reduce the frictional power consumption of piston and improve the
economic performance of the engine.
z The HFC4DA1-2C piston rings include two compression rings and one
oil control ring:
The first ring adopts the trapezoid tubbish ring, which can effective reduce
the consumption of engine oil.
The second compression ring adopts the torsional trapezoid ring to increase
the flexibility of piston ring and improve the capability of piston ring for
adapting to deformation of cylinder sleeve.
The oil control ring is of coil spring expander type and adopts the combined oil ring composed of two side guide rings
(upper and lower) and the middle expander, featuring the advantages of low mass and outstanding oil scraping effect.
It can reduce the consumption of engine oil and the grain emission while meeting the Euro-IV emission standard.
40~50% of the frictional power consumption of the engine is attributed to the pistons and piston rings. The piston
rings of 4DA1 engine can effectively arrange the engine oil, reduce the friction power of piston subassembly, and
improve the fuel economy.
z The piston is stamped with mark, which shall
face upward during assembly. During assembly, take
caution to position the spring connector 180º away
from the opening of oil control ring. Notice the
opening direction of the ring while installing the
cylinder sleeve. The openings of the piston rings shall
separate 120º from each other and the ring opening
shall not face towards the piston pin. Apply an
appropriate amount of lubricating oil during the
assembly. The piston rings shall rotate flexibly after
being installed in the ring grooves.
a. The arrow on the piston crown shall point to the
front of the engine.
b. It adopts variable section connecting rod to effectively reduce the force applied onto the connecting rod.
c. The piston pin is of full-floating structure and adopts retainer ring for limiting. The piston pin can be directly
assembled during installation.
d. The body of connecting rod adopts H-shaped cross section, featuring good bending strength and light weight.
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Section V Valve Distribution Mechanism

z It’s a device that opens and closes at fixed times the intake and exhaust valves of all cylinder to enable the
ingress of fresh air into cylinders and the exhaust of exhaust gas from the cylinders.
z The front valve distribution timing adopts gear drive, featuring stability and reliability.
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Section VI Lubrication System

While the engine is working, all motion parts apply one specific force onto another part and generate relatively high
speed motion. With the relative motion, the friction is necessarily generated on the part surfaces, which will accelerate
the wear. Therefore, to relieve the wear, reduce the friction resistance, and prolong the service life, the engine must be
fitted with lubrication system.
z The engine oil filter is functioned to filter out the metallic wear dust, mechanical impurity, and engine oil oxide
from the engine oil. The ingress of these impurities into the lubrication system along with the engine oil will
speed up the wear of engine parts and may block the oil pipe or oil passage.
z The engine oil pump is of externally engaged gear pump and is driven by the crankshaft.
z The cooling nozzle of piston is arranged on the main oil passage to realize the stable oil spray for cooling. The
spray of engine oil into the cold oil passage within the piston can effectively reduce the thermal load of the
piston.
Valve
mechanism Splash Rocker arm bearing
cylinder block
Oil way of
Various cam Splash Various camshaft bearings

tappets
cylinder block
Oil way of
Piston group Splash Various crankshaft Timing gear Turbocharger

main bearings
cylinder block
Turbocharger
oil inlet pipe
Turbocharger oil
Oil way of
return pipe
Cooling nozzle
Main oil way
Engine oil filter

Relief valve
Bypass
Engine oil cooler

Oil outlet
pipe
Engine oil pump

Relief valve
Strainer
Oil sump
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Section VII Cooling System

z The cooling system is functioned to maintain the engine within an appropriate temperature range under all
working conditions.
z The cooling system can prevent the engine against overheating and prevent the engine from being too cold in
winter.
z After the cold start of the engine, the cooling system can guarantee the rapid temperature rise of the engine to
reach normal working temperature as soon as possible.
z Composition: Water pump, cooling fan, silicone oil fan clutch, thermostat, engine cylinder block, water jacket in
cylinder head, and other accessories.
z The cooling system is of enclosed forced recirculation water cooling type. Its structure is mainly composed of
radiator (water tank), water pump, fan, thermostat, cooling water jacket, and pipeline.
z The cooling recirculation of the heater system and engine oil cooler is always under working state and is not
subject to the restraints of large or small recirculation.
Dual thermostat control: When the water temperature is less than 82ºC, the thermostat is under natural state (namely
the cooling water from the water tank is closed and the cooling water from the cooling module is opened). In such
case, the cooling circuit works in the small recirculation circuit and the cooling water from the cooling module enters
into the engine block and cylinder head for recirculation through the water pump so that the temperatures of the water
and oil in the engine block and the cylinder head will rise. When the water temperature reaches 82ºC, the thermostat
starts to open. When the thermostat is opened, the small valve closes the small recirculation circuit. As the thermostat
is not fully opened, the cooling water from water tank enters into the cylinder block for large recirculation through
water pump. If the water temperature continues to rise to 95ºC, the thermostat valve is fully opened.
Water tank
Thermostat
Cylinder head
Radiator
Heater
Cylinder block
Water pump
Oil cooler
Inlet of
water
64
Section VIII Turbocharger and Inter-Cooler System

The turbocharger technology utilizes the motion energy of engine exhaust gas to drive the rotation of turbine. At the
same time, the coaxial air compressor compresses the air and provides more air to the cylinder so that more fuel can
combust to generate higher power, promote the engine torque, and reduce the fuel consumption.
The common turbocharger is of bypass valve turbocharger, which can’t provide sufficient pressure while the engine is
running at low speed and thus restrains the torque output at low speed and influences the engine performance. To
change this situation, the 1.9CTI engine adopts variable nozzle turbocharger (VNT) control system to promote the
turbocharger pressure at low speed of engine and at the same time adopts inter-cooler system to exert higher torque at
low speed of engine and promote the engine performance.
Theory of inter-cooler: The temperature of the air compressed at high speed may reach 100~120ºC. The high
temperature air will impair the intake efficiency of the engine and lead to power drop of the engine. Therefore, it’s
necessary to cool down the air to approximate 60ºC. The inter-cooler is located in front of the radiator or at windward
position easily arranged, in order to reduce the temperature of air entering into the cylinder, further improve the
combustion of diesel engine, and promote the performance and emission of the diesel engine.
Inter-cooler Compressed air
Engine
Turbocharger
Intake
Exhaust
Exhaust gas of engine
Variable nozzle turbocharger (VNT): The VNT is functioned similar to one turbine housing in which the size is
varying steplessly. The VNT actuator can accurately control the nozzle area within the entire working condition range
so that the engine can not only maintain the turbine efficiency at high speed, but also increase the turbine efficiency at
low speed, promote the torques at low speed, maximum torque output, and nominal working condition, improve the
cold start performance and low speed performance of turbocharged diesel engine, realize high specific power and low
speed torque of the engine simultaneously, and greatly reduce the smoke intensity and improve the economy.
Meanwhile, the VNT can reduce the turbine lag, improve the engine response, and enhance the braking capability and
safety.
Adjustment theory for variable nozzle turbocharger (VNT): There are two passages, one is in constant section and one
is in variable section. If the pressure is same for two passages, the speed of airflow passing through the variable
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section passage is greatly higher than that passing through the constant section passage.
Small passage High speed

Idling of section Large passage running of engine
engine section Rotation direction of adjustment ring
66
Section IX EGR System

The exhaust gas recirculation (EGR) introduces one small portion of exhaust gas from the exhaust pipe into the intake
pipe that is mixed with the fresh intake air to artificially increase the exhaust amount in the fresh intake air and thus
reduce the combustion temperature of engine and reduce the formation of NOx.
z The NOx is increased following the increasing of engine load and the EGR ratio shall increase accordingly.
z The EGR is not be performed when the engine coolant temperature is low;
z The EGR is not performed under idling or low load, as the NOx emission is not high in such case.
z The EGR is not performed under full load or acceleration;
z The water-cooled EGR further reduces the temperature of exhaust gas entering into the cylinder and further
reduces the emission of NOx.
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Section X Exhaust System

The exhaust pipe is composed of four exhaust manifolds leading to the exhaust master pipe and one manifold leading
to the exhaust gas chamber of EGR valve. During the operation, the exhaust gas from the combustion chamber is
introduced into the EGR valve by the manifold leading to the exhaust gas chamber of EGR valve through the EGR
passage in the cylinder head. Under the control of the EGR valve, the exhaust gas is mixed with fresh air and enters
into the combustion chamber to realize exhaust gas recirculation and reduce the emission.
4DA1-2C diesel engine real-time monitors the pressure drop of the exhaust gas post-treatment unit to determine
whether the post-treatment system is working normally. Via two pressure ports on the sensor, the pressure on two
sides of the exhaust gas post-treatment unit is introduced. The sensor converts the measurement into voltage value and
feeds back to the control unit, which can guarantee the sufficient oxidization of grains and prevent the blockage of
catalytic converter.
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Chapter III Working Principle of Engine Control and Actuator Units
Section I Overview of Diesel Common Rail System

Diesel common rail injection system
Fuel pressure sensor

Cut-off valve
High pressure (optional) Distribution
pump pipe
Pressure
regulation valve
Fuel temperature Fuel delivery pump

Other sensors
sensor
Accelerator
pedal
Fuel-water Fuel injector
t Crankshaft
position
sensor
Camshaft position
Fuel tank High pressure
sensor
Low pressure
The electronically controlled high pressure common rail system means one fuel supply mode in which the generation
of injection pressure and fuel injection are completely separated in the closed-loop system composed of high pressure
fuel pump, pressure sensor, and ECU. The high pressure fuel pump generates high pressure fuel and conveys to the
common rail pipe to realize precise control of fuel pressure within the common rail pipe. This fuel injection system
can ensure that the fuel injection pressure will not vary following the variation of the engine speed and thus relieve the
defect of traditional diesel engines. Instead of the common pulse theory, this system adopts the pressure-time
measuring theory and combines the high pressure common rail with the control of fuel injection solenoid valves of all
cylinders, in which the last pulse of the control unit introduces the injection signal into the solenoid valve to trigger
one injection cycle and the injection amount is controlled by the accumulated pressure and the open duration of the
injector. The injection pressure of EDC17 control system adopted by this engine is up to 1,600bar.
The electronically controlled common rail fuel injection technology of diesel engine integrates the computer control
technology, modern sensing and measuring technology, and advanced fuel injection mechanism. The main
characteristic of this technology is as below: The main parameters (including speed, torque, power, oil temperature, oil
pressure, water temperature, and turbocharger pressure of the diesel engine) under actual working conditions of the
diesel engine are measured by modern sensing and measuring technology and transmitted to the ECU and the ECU
compares these measurements with the pre-inputted optimized running MAPs of the diesel engine and processes and
calculates out the best values to control the pressure of common rail pipe and the open moment, duration, and
injection frequency of the high speed solenoid valves of the fuel injectors, in order to realize the best working state of
the diesel engine. The electric pulses generated by the ECU trigger the solenoid valves of the fuel injector as per
specified sequence to determine the open and close moments of each fuel injection cycle of the engine and flexibly
control the fuel injection speed and frequency. The common rail fuel injection mechanism forms directly or indirectly
constant high pressure fuel and distributes to each fuel injector. The electronically controlled common rail fuel
injection technology of the diesel engine can guarantee that the diesel engine achieves the best air-combustion ratio
and excellent atomization.
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The high pressure common rail system is composed of fuel tank, diesel filter, high pressure fuel pump, common rail
pipe, electronically controlled fuel injector, high pressure fuel pipe, and low pressure fuel return pipeline.
z It adopts direct injection combustion chamber system and common rail fuel supply system to realize high
performance, clean emission, low noise, and low vibration;
z Single camshaft and four-valve technology brings about higher air charging efficiency and improves the
combustion;
z High power per liter design and compact design;
z Variable nozzle turbocharger (VNT) control;
z Exhaust Gas Recirculation (EGR);
z Electronic throttle control.
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Section II Working Principle of Low Pressure Fuel Line System

I. Composition of low pressure fuel line:
The low pressure fuel line is functioned to supply sufficient fuel to the
high pressure fuel line and is composed of:
z Fuel tank (including filter screen)
z Fuel filter (including manual fuel delivery pump)
z Low pressure fuel delivery pump
z Other low pressure fuel hoses
II. Fuel tank

The fuel tank shall be fabricated from anti-corrosion material and shall maintain 0.3bar pressure under all working
conditions and be free of fuel leakage under the application of the doubled working pressure. The fuel tank shall also
set up appropriate opening or safety valve or adopt appropriate measures to relieve the excessive pressure whenever
it's needed. When the motor vehicle is subject to slight vibration, makes turns or travels or parks on a slope, the fuel in
the fuel tank shall not leak from the fuel tank cap or the pressure balancing device.
III. Fuel filter (including manual fuel delivery pump)

Sunray long-wheelbase model adopts two-stage diesel filter, including
one primary filter and one fine filter. Compared with traditional diesel
engines, it requires cleaner fuel supply. The impurities contained in
the fuel will damage the fuel system including the high pressure pump,
high pressure common rail, and fuel injector. The fuel filter purifies
the fuel inputting into the high pressure fuel pump, in order to help the
normal functioning of the high pressure pump. The contaminant,
impurity, and particle in the fuel will lead to the damage of pump units,
fuel supply valve, and fuel injector. Therefore, the use of fuel filter
capable of meeting the fuel injector requirements becomes the
premise for normal working of the engine and guarantee of service life.
The water content in the diesel may exist in non-free radical form
(emulsified fuel) or radical form (such as water condensate generated
due to variation of temperature). If entering into the fuel injection
system, this water content will lead to damage of parts due to corrosion.
Similar to other fuel injection systems, common rail system requires
the fuel filter with water collection chamber as well as the automatic
water content alarm. When the alarm lamp lights up, make sure to
drain the water from the water collection chamber.
The fuel filter is composed of fuel temperature sensor, fuel heater,
manual fuel pump, fuel-water separator, and water level sensor.
The fuel leakage during traveling or the air ingress into fuel pipeline
after replacement of fuel filter may lead to start failure or poor
functioning of the engine. Therefore, make sure to bleed the air from
the low pressure fuel pipeline after the installation of manual fuel
delivery pump. Installed on the fuel filter, the manual fuel delivery
pump is the device for supplying fuel to the fuel filter and the device
required to guarantee the first start of the engine. In event of the
following conditions, press the manual fuel delivery pump, till the
manual fuel delivery pump can’t be further pressed, before starting the
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engine.
z After the fuel is used up.
z After the water drainage from the fuel-water separator.
z After the replacement of fuel filter
Replacement of fuel filter
1. Replacement interval of fuel filter: Once every 7,000km;

2. Water separation interval: Once every 5,000Km;
3. It’s prohibited to use any used fuel filter.
IV. Low pressure fuel delivery pump

The low pressure fuel delivery pump is one gear pump and is stalled
at the rear end within the high pressure pump housing. The low
pressure fuel delivery pump continually supplies the required fuel
amount to the high pressure pump from the fuel tank.
The fuel delivery pump is functioned to supply sufficient fuel
supply to the high pressure pump under following conditions:
(1) Under any working condition;
(2) Under necessary pressure;
(3) Throughout the entire service life.
The low pressure fuel delivery pump is one mechanical gear pump and is installed at the rear end of high pressure
pump and driven by the high pressure pump shaft. Its main parts are two gears rotating in opposite direction. While
rotating, two gears engages to vacuumize the fuel into the chamber formed between gears and pump walls and then
conveys to the outlet (pressure end). The closing line of the rotating gears realizes the sealing between vacuumization
end and pressure end of the pump and prevents the fuel backflow.
The fuel supply amount of the gear pump is approximately in proportion to the engine speed. This is why the fuel
supply amount of the gear pump can be reduced by means of the throttle valve at the inlet end or can be restrained by
means of the relief valve at the outlet end.
No maintenance is required for the gear pump. Charge the fuel from the fuel system before the first start. When the
fuel in the fuel tank is used up, operate the manual fuel delivery pump to charge fully the low pressure fuel line.
V. Fuel pipeline
Besides the steel pipe, the low pressure fuel line can also adopt flame-retardant braided and armored fuel hose. The
fuel pipes shall be arranged in such manner to prevent the mechanical damage and that the fuel dripped or evaporated
will not concentrate nor burn.
In event of vehicle distortion, engine displacement, or similar conditions, the functions of the fuel pipeline shall not be
impaired. All fuel delivery pipelines shall have the radiation shield measures.
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VI. Common malfunctions and troubleshooting for low pressure fuel line
No. Malfunction Troubleshooting Remarks
1 Weak pumping of Retighten the connectors (temperature The tightening torque for connectors is
fuel sensor, plug, and pile connector), in 30-35N.m. Higher torque will lead to
order to prevent the pumping failure thread failure.
due to ingress of air. If ineffective,
replace the manual pump.
2 Fuel leakage of air Check the screw hole of manual pump The tightening torque is 7~9N.m. Higher
bleeding screw for presence of thread failure. If yes, torque will lead to thread failure. While
replace the transitional thread insert assembling the transitional thread insert,
and air bleeding screw and washer. add an appropriate amount of thread sealant
onto the thread. Prevent the ingress of
sealant into the manual pump.
3 Fuel leakage of Replace the manual pump The knocking or improper use will lead to
manual pump fuel leakage of manual pump
4 Slow acceleration The filter is blocked. Replace the filter. The blockage of fuel filter will increase the
and difficult start If the malfunction still occurs after pressure difference.
due to difficult replacement of fuel filter, check other
fuel supply engine parts.
5 Failure for timely Make sure to drain the water when the If the water is not drained, the water
water drainage water level sensor indicator lamp lights content in fuel will increase to impair the
up. engine performance.
6 Light-up failure of 1. Water level sensor is damaged.

water level sensor 2. Indicator lamp is damaged.
indicator lamp at
3. Circuit malfunction
engine start
7 Working failure of 1. The heater is damaged.
heater 2. Circuit malfunction
3. Low battery current
4. The heater is punctured due to high
current
8 Working failure of Damage o temperature sensor
temperature Circuit malfunction
sensor
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Section III Working Theory of High Pressure Fuel Line

I. High pressure fuel line parts
The high pressure fuel line generates and accumulates
1. Drive shaft
sufficient fuel pressure required for the fuel injectors. 2. Eccentric cam
The parts include: High pressure pump, fuel rail, high 3. Plunger pump
pressure fuel pipe, and fuel injector. 4. Fuel suction valve
5. Fuel outlet valve
II. High pressure pump 6. Fuel inlet
The high pressure pump compresses the fuel to a system

pressure of up to 1,450bar and then the fuel is
transmitted to the tubular high pressure fuel accumulator
(rail) via the high pressure pipe.
The high pressure pump is the interface between low pressure stage and high pressure stage. Under all working
conditions, it can reliably supply sufficient high pressure fuel throughout the entire service life of the vehicle,
including supplying addition fuel required for rapid start and the
rapid establishment of pressure in the common rail. The high
pressure pump continually generates the system pressure required
for the high pressure accumulator (rail). Therefore, it means that,
compared with traditional system, it’s unnecessary to compress the
fuel for each individual injection cycle.
The fuel is compressed by three plunger pumps arranged radially at
spacing of 120º from each other. As each rotation turn can generate
three compression strokes and only generate low peak drive torque,
the drive unit of the pump maintains uniform force application. As
far as 16Nm torque is concerned, this torque is only 1/9 of the
torque required for driving similar distribution pump. This means
that, compared with traditional fuel injection systems, the common rail generates lower load onto the drive unit of the
pump. The raising power of the drive pump is in proportion to the preset pressure of common rail and the speed of the
fuel pump (fuel delivery amount).
Working mode:
Through one water separator, the fuel delivery pump pumps out the fuel from the fuel tank and the fuel enters into the
lubricating and cooling lines of high pressure pump via the fuel inlet. The drive shaft with eccentric wheel drives three
pump plungers for upward and downward movements along with the profile of the cam. The pump plungers move
downward under the application of the fuel delivery pressure (fuel suction stroke). When the plungers overpass the
bottom dead center, the fuel inlet valve is closed so that the fuel in the pump chamber will not leak out. In such case,
the fuel is compressed so that the fuel pressure exceeds the fuel delivery pressure of the fuel delivery pump. In such
case, once the pressure established exceeds the pressure in the common rail, the fuel outlet valve opens so that the fuel
enters into the high pressure line. The pump plungers will continue the fuel supply, till the top dead center is reached
(fuel delivery stroke). Then the pressure drops and the fuel outlet valve closes. The residual fuel is pressure relieved:
The pump plungers move downward. When the pressure in the pump chamber is less than the fuel delivery pressure,
the fuel inlet valve re-opens and the pumping process is started again.
III. Fuel rail (Common rail)

The high pressure accumulator (rail) stores the high pressure fuel and at the same time restrains the pressure variation
generated during the fuel supply and fuel injection of the high pressure pump. The high pressure accumulator is
shared by all cylinders and therefore is referred to as “common rail”. Even when a great amount of fuel is drained, the
common rail can maintain its internal pressure basically unchanged. Therefore it maintains the constant fuel injection
pressure of the fuel injector.
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The space of the common rail is always filled with high
pressure fuel. It utilizes the fuel compressed due to high
pressure to achieve the accumulator effect. When the fuel is
departed from the common rail for injection, the pressure in the
high pressure accumulator is basically constant. At the same
time, the pressure variation generated by the pulsed fuel supply
of high pressure pump is balanced and the pressure information
is provided to the ECU.
IV. High pressure fuel pipe

The high pressure fuel pipe is used to convey the high pressure
fuel and is made of steel to endure the intermittent high
frequency pressure variation under the maximum system pressure of the engine. The fuel pipe is generally 6mm in
outside diameter and 2.4mm in inside diameter. All high pressure fuel pipes between fuel rail and fuel injectors are
same in length, which means that the distances between the fuel rail and all fuel injectors are the same and the bending
points compensate the corresponding length differences.
IV. Fuel injector

The fuel injectors are the core parts of the high pressure common rail and are installed on the high pressure common
rail. In accordance with the directive of the ECU, the fuel
injectors spray high pressure well-atomized fuel into the
combustion chamber at specified moment and specified
pressure for a specified duration.
The fuel injector is mainly composed of fuel injector
nozzle, hydraulic servo unit, and solenoid valve. When
the coil control valve acquires control signal through the
ECU, the control valve will depart from its seat ring so
that the fuel pressure in the needle valve control chamber
drops rapidly. As the pressure at the injector nozzle holder
is maintained at similar pressure with common rail, the
needle valve opens and the injection starts. When the
current of the solenoid control valve drops to zero, as the
control valve returns to the seat cushion under the
application of coil spring, the pressure of the needle
control chamber will increase to lightly higher than he
pressure at the injector holder so that the needle valve
closes the injector and the injection stops. The sealing
copper washer beneath the fuel injector must be replaced
once the fuel injector is disassembled or loosened. During
the disassembly, use the special tools recommended or
designated by JAC Multifunctional Commercial Vehicle
Company. Note: Never disassemble the fuel injector by
self in any case. All maintenances and services of the fuel
injector body shall be fulfilled by Bosch relevant service
stations or JAC designated service stations.
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Section IV Electronic Control Unit of High Pressure Common Rail System

The EDC17 system of HFC4DA1-2C engine belongs to electronically controlled diesel injection system and
incorporates the dynamic fuel injection timing system and air and fuel management system. It adopts the BOSCH
diesel high pressure common rail system, with the rail pressure up to 1,600bar, and applies new technologies
including VNT, electronically controlled EGR, and POC pressure difference control to meet the Euro-IV emission
standard, with potential compliance for Euro-V emission standard.
The characteristics of this system is one single ECU, one set of fuel injection control system, and one set of sensor
system. It’s functioned to inject the fuel into the engine cylinder, with accurate injection timing and fuel amount, so
that the fuel is mixed with air in the cylinder to achieve best combustion efficiency.
The electronic control unit of the diesel common rail system is mainly composed of three parts: sensor, ECU, and
actuator.
① Sensor part: The sensors and rated value transmitters collecting the running state and rated values of the engine
and complete vehicle, which convert various types of physical parameters into electric signals.
② ECU: It’s functioned to process the information as per definite mathematic calculation method and issue the
electric signals of the directives.
③ Actuator: It’s functioned to convert the electric signals of the directives issued by the ECU into mechanical
parameters.
I. Sensor part
1. Crankshaft position sensor
1) Overview
z The crankshaft position sensor is one electromagnetic sensor.
z The position of piston in the combustion chamber determines
the start moment of fuel injection. As the engine piston is
connected with crankshaft through connecting rod, the
crankshaft position sensor can provide all data information for
the piston position and the engine speed determines the
revolution per minute of the crankshaft.
z Generation of signal: The crankshaft is connected with one
60-tooth ferromagnetic actuation gear. The actuation gear Crankshaft speed sensor
actually in use has two teeth missing. This large gap 1. Permanent magnet 2. Sensor housing
3. Engine outer cap 4. Soft iron core
corresponds to one specified crankshaft position of 1st cylinder. 5. Coil 6. Sensing gear
The crankshaft position sensor records the tooth sequence of
the actuation gear. It’s composed of one permanent magnet and
soft iron core with copper coil. The magnetic flux in the sensor
varies along with the gear and gap passing through and
generates one sine AC voltage, of which the amplitude rapidly
increases following the speed of the engine (crankshaft). It can
achieve sufficient amplitude even when the speed is at 50r/min.
z The crankshaft position sensor is situated on the rear clutch
housing of the engine;
z Wiring terminals: 1. Signal terminal of crankshaft position
sensor; 2. Grounding terminal of crankshaft position sensor;
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z Resistance: 860 Ohm;
z Clearance between sensor and top of signal gear: 0.5~1.2mm.
2) Working Principle
The electromagnetic sensor simulates the AC signal generator, namely such sensor generates AC signal, and is
generally composed of a magnet wound by coil and two wiring terminals. These two coil terminals are the output
terminals of the sensor. When the steel annular gear (sometimes referred to as magnetic resistance gear or target gear
or signal gear) rotates to pass through this sensor, the magnetic flux of the magnet passing through the coil varies at
certain level and the induction voltage is generated in the coil.
The same tooth profiles of the signal gear will generate continual pulses in same form. The pulses have consistent
form amplitudes (peak-peak voltages) and are in proportion to the speed of crankshaft signal gear. The frequency of
the output signal is based on the rotation speed of the magnetic resistance gear and the air gap between sensor
magnetic pole and the magnetic resistance gear is of great influence over the amplitude of the sensor signal (Attention
shall be paid to the backlash during the installation). During the production, removing the synchronous pulse
generated by one tooth or two really close teeth from the sensor can determine the signal of top dead center, which
will lead to the frequency variation of output signal. When the number of teeth is reduced, the voltage output
amplitude will vary greatly. This pulse signal is transmitted to the ECU, based on which the ECU controls the fuel
injection of the engine.
As the electromagnetic crankshaft position sensor is weak in signal and sensitive and is vulnerable to the
electromagnetic interference by the electric devices such as car telephone, fan, and starter, it will lead to malfunction
of traveling performance or generate trouble code. To prevent the occurrence of such phenomenon, two signal wires of
the crankshaft position sensor adopt the twisted-pair structure in the manufacturing of engine harness, which can
effectively guard the signal of crankshaft position sensor against the external signals and reduce the production cost.
3) Measurement analysis:
Signal
Speed sensor
Grounding
Shielding wire
1 – Signal -; 2 – Signal +; Use a multimeter to measure the resistances for two signal terminals of the crankshaft
position sensor. The resistance measurement shall be 860 Ohm.
4) Malfunction Mode:
z Short-circuit or open-circuit of sensor;
z Distorted, error, and suspicious signal;
z Unstable sensor signal;
z Sensor signal is out of range.
The crankshaft position and speed sensor is the main sensor of the engine electronic control system. In event of the
malfunction of crankshaft position and speed sensor, the engine can’t start. If the malfunction occurs after the start of
the engine, the engine will stop immediately.
5) Troubleshooting
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Use diagnosis instrument to check the trouble code and determine the
malfunction position. Mainly check whether the sensor is installed in place and
whether the clearance is normal, check the sensor circuit whether there is
short-circuit or open-circuit to grounding wire, check whether there is
short-circuit or open-circuit to the power supply, and check whether the circuit
is consistent with the given pin definition.
Notice: Take caution to install the sensor and make sure not to add any washer,
or it may lead to signal distortion of sensor.
2. Camshaft position sensor
1) Overview
z The camshaft position sensor is one Hall sensor.
z The camshaft position sensor utilizes the Hall effect to determine the camshaft position. One steel actuation gear
rotates along with the camshaft, the Hall effect integrated circuit is installed between actuation gear and
permanent magnet, and the permanent magnet generates a magnetic field perpendicular to the Hall unit. If one
tooth of actuation gear passes through the current-carrying linear sensor unit (semiconductor chip), it changes the
strength of magnetic field perpendicular to the Hall unit. In such case, the electron driven by the voltage in major
axis direction is offset in the direction perpendicular to the current direction to generate one temporary signal
voltage (Hall voltage) so that the calculation circuit integrated with the sensor Hall integrated circuit will process
the signal and output as square wave signal.
z The camshaft position sensor is installed on the cylinder head shield.
z Wiring terminals: 1. +5V power supply, 2. Signal output, 3. Grounding;
z The clearance between sensing end of sensor and the signal gear of camshaft: 0.5~1.5mm. Required torque:
8±0.5Nm
The camshaft controls the intake and exhaust valves of the engine, of which the speed is only half of the crankshaft
speed. When the piston moves towards the top dead center, the camshaft position determines whether the piston is at
compression stroke or the exhaust stroke and then judges the fuel injection or not. If the engine is under start stage,
such data information can’t be acquired from the crankshaft position. On the other hand, during the normal working
of the engine, the data information generated by the crankshaft sensor is enough to determine the engine state. In
other words, while the vehicle is traveling, even the camshaft sensor is failed, the ECU can still receive the data
information of engine working state from the crankshaft sensor.
The camshaft sensor utilizes Hall effect to determine the camshaft position. One steel toothed part is fixed on the
camshaft and rotates along with the camshaft. When this toothed part passes through the semiconductor chip of the
camshaft sensor, its magnetic field will offset the electron of the semiconductor chip towards the current direction.
Therefore, one temporary voltage signal (Hall voltage) is generated to remind ECU that the 1st cylinder enters into the
compression stroke.
3) Measurement analysis
Wiring terminals: 1 - +5V, 2 – Signal +, 3 – Grounding
Power supply terminal

Camshaft
position Signal terminal
sensor
Grounding terminal
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4) Malfunction Mode
z Distorted, error, and suspicious signal;
5) Troubleshooting
Use diagnosis instrument to check the trouble code and determine the malfunction position. Mainly check whether the
sensor is installed in place and whether the clearance is normal, check the sensor circuit whether there is short-circuit
or open-circuit to grounding wire, check whether there is short-circuit or open-circuit to the power supply, and check
whether the circuit is consistent with the given pin definition.
3. Pressure difference sensor
1) Overview
z The pressure difference sensor is functioned to real-time monitor the pressure drop of the POC and determine
whether the after-treatment system is working normally. The pressure at two ends of the POC is introduced via
two pressure ports of the sensor and then the sensor converts the measurement into voltage value and feeds back
to control unit. This can not only guarantee the sufficient oxidization of grains, but also prevent the blockage of
catalytic converter.
z The pressure difference sensor and the POC are connected via stainless steel pipe and high temperature rubber
hose. The pressure is introduced via stainless steel pipe, which is at least 250mm in length, from two sides of
POC and then is led to the pressure difference sensor via high temperature rubber hose, which is capable of
enduring more than 150ºC.
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3) Test analysis
Wiring terminals: 1 - +5V, 2 – Signal +, 3 – Grounding
5V power supply
Pressure Pressure difference signal
difference Earthing
sensor
3. Turbocharger pressure sensor
1) Overview
The turbocharger pressure sensor is connected to the
intake pipe and is functioned to measure the absolute
pressure of the intake pipe. This sensor is composed of
one pressure unit with two sensing units and one
evaluation circuit chamber. The sensing units and
evaluation circuit are mounted on common ceramic
substrate. Each sensing unit incorporates one horn-shaped
diaphragm embodying the benchmark capacity for
determination of internal pressure. The diaphragm moves
towards large or small open extent as a function of
charging pressure. The pressure sensitive resistor is
mounted on the diaphragm surface, of which the resistance
varies under the application of pressure. These resistors are
connected to form a resistor bridge. Therefore, any
movement of the diaphragm will change the balance of
resistor bridge, namely the voltage of the resistor bridge is
one measurement of turbocharger pressure. The evaluation
circuit is functioned to amplify the bridge voltage and
compensate the linear variation of temperature influence
and pressure characteristic. The output signal of evaluation
circuit is transmitted to ECU and then the turbocharger
pressure is obtained by means of the programming
characteristic curve.
z The temperature sensor incorporates one negative
temperature coefficient (NTC) thermistor that is
connected in the voltage division circuit of 5V power
supply.
z The voltage drop on the resistor is inputted to the ECU via one analog and one digital converters (ADC), which
is one measurement for evaluating the temperature. The ECU micro-processor embodies one characteristic curve,
which defines the temperature as a function of given voltage.
z It’s installed on the pressure stabilizing chamber of intake manifold and take the priority to measure the pressure.
z Wiring terminals: 1 – Grounding, 2 – Temperature signal, 3 – +5V, 4 – Pressure signal.
The turbocharger pressure sensor is connected in the intake pipe and is capable of measuring the absolute pressure of
intake pipe at 0.5~3bar. This sensor is composed of one pressure unit with two sensing units and one evaluation circuit
chamber. The sensing units and evaluation circuit are mounted on common ceramic substrate. Each sensing unit
incorporates one horn-shaped diaphragm embodying the benchmark capacity for determination of internal pressure.
The diaphragm moves towards large or small open extent as a function of charging pressure. The pressure sensitive
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resistor is mounted on the diaphragm surface, of which the resistance varies under the application of pressure. These
resistors are connected to form a resistor bridge. Therefore, any movement of the diaphragm will change the balance
of resistor bridge, namely the voltage of the resistor bridge is one measurement of turbocharger pressure. The
evaluation circuit is functioned to amplify the bridge voltage and compensate the linear variation of temperature
influence and pressure characteristic. The output signal of evaluation circuit is transmitted to ECU and then the
turbocharger pressure is obtained by means of the programming characteristic curve.
The voltage drop on the resistor is inputted to the ECU via one analog and one digital converters (ADC), which is one
measurement for evaluating the temperature. The ECU micro-processor embodies one characteristic curve, which
defines the temperature as a function of given voltage.
Wiring terminals: 1 – Grounding, 2 – Temperature signal, 3 – +5V, 4 – Pressure signal.
5V power supply
Turbocharger pressure
Intake pressure signal
and temperature
Grounding
sensor
Intake temperature signal
4) Malfunction Mode
The light-up of the engine malfunction indicator lamp indicates the presence of malfunction in the engine system and
it’s necessary to diagnose with diagnosis instrument. Use Sunray special diagnosis instrument to communicate with
ECU of electronic injection system and read out the malfunction data in the ECU.
5) Troubleshooting
Use Sunray special diagnosis instrument to check the trouble code and determine whether there is short-circuit or
open-circuit between circuit of malfunction position and the grounding wire, whether there is short-circuit or
open-circuit to power supply, and whether the circuit is consistent with the given pin definition.
4. Thermal diaphragm air flowmeter

1) Overview
z The thermal diaphragm airflow sensor is one air mass sensor fitted with
logic output. To obtain the air flow, the sensor diaphragm on the sensor is
heated by the heating resistor installed in the middle and the temperature
distribution on the diaphragm is measured by the temperature resistors
installed paralleling with the heating resistor. The air flow passing through
the sensor changes the temperature distribution on the diaphragm to cause
resistance difference between two temperature resistors. The resistance
difference depends on the direction and flow rate of the airflow so that the
airflow sensor has high requirements over the flow rate and direction of the
airflow. The sensor manufactured by micro-machinery features small size,
low thermal capacity, and <15ms response time.
z The sensor is internally fitted with intake temperature sensor to measure the
intake temperature.
z The air flowmeter is installed at the port of the air cleaner.
z Wiring terminals: 1. +12V power supply; 2. Grounding; 3. Air temperature signal; 4. Airflow rate signal.
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This sensor is composed of two sensors, namely airflow sensor and intake temperature sensor, and is installed on the
intake hose after the air cleaner. This type of sensor requires that there shall be free of air leakage from the sensor to
the engine combustion chamber, or it will lead to unstable idling of engine or even engine flameout.
The airflow sensor integrates some micro-electronic units on a ceramic substrate. When the engine is working, the
diaphragm will be heated. The intake airflow passing through the diaphragm will take away the heat and the
Wheatstone bridge integrated on the diaphragm will increase the current to supplement the heat loss, which leads to
the variation of electric signal. This signal is transmitted to the engine control unit ECU, based on which the ECU can
obtain the load variation of the engine and thus control the fuel injection pulse width.
The intake temperature sensing unit is one negative temperature coefficient (NTC) thermistor. The sensor installs two
same sensing units on two sides of the thermal diaphragm. When the intake airflow flows through the diaphragm, the
temperature of the temperature sensing unit on the front of diaphragm is slightly lower than that of temperature
sensing unit on the rear. Based on this characteristic, the ECU can judge the direction of airflow.
Voltage output V
Common rail
pressure
Wiring terminals: 1. +12V power supply; 2. Grounding; 3. Air temperature signal; 4. Airflow rate signal.
Air flowmeter
4) Malfunction Mode
The subsequent electronic device of the air flowmeter in the ECU can judge the malfunctions such as open-circuit or
short-circuit of internal circuit and connecting circuit of air flowmeter and the damage of sensor. Upon the detection
that the output signal of the sensor is out of its output characteristic curve, the ECU will judge as malfunction of
sensor.
5) Troubleshooting
When the airflow sensor is failed, the engine cooling fan will run at high speed for one period after the ignition key is
turned to Off. For instance: When the airflow rate is higher than the upper limit of airflow or less than the lower limit
of airflow, the ECU will judge as malfunction of sensor (Though the intake airflow rate is less than lower limit
(closing to zero) at the start of the vehicle, the ECU can judge the start condition) and at the same time light up the
engine malfunction lamp and work under malfunction mode.
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5. Rail pressure sensor

1) Overview
The resistance of the metal film installed on the diaphragm will change accordingly following the change of shape.
This change of shape generated by the established system pressure (approximate 1mm under 1,500bar pressure) will
change the resistance and lead to the change of voltage between two sides of 5V bridge composed of resistor units.
This voltage change range is 0~70mv (depending on the applied pressure) and is amplified to 0.5~4.5V by the
evaluation circuit.
The accurate measurement of rail pressure is of great importance to the effective working of the system. This is one of
the causes for very strict tolerance over the rail pressure sensor during the pressure measurement. Under the scope of
main working conditions, the measurement accuracy is approximately ±2% of the full scale reading.
Wiring terminals: 1. Grounding; 2. Rail pressure sensor signal; 3. +5V power supply.
It transmits one voltage signal to the ECU, depending on the fuel pressure. The rail pressure sensor must measure the
instant pressure in the fuel rail and embody sufficient accuracy and rapid response capability. The rail pressure sensor
is composed of following parts:
cIntegrated sensing unit welded onto the pressure device
d Printed circuit board (PCB) with electric evaluation circuit
sensor housing with electric connector. The fuel flows into the rail pressure sensor via one hole on the common rail
and the end of this hole is sealed by one sensor diaphragm. The fuel under high pressure reaches the sensor diaphragm
via one blind hole. One sensing unit (semiconductor unit) is arranged on this diaphragm and converts the pressure into
electric signal. This signal generated is transmitted via wire to evaluation circuit, which will amplify this signal and
transmit to the ECU.
3) Test analysis
Wiring terminals: 1 - Grounding; 2 - Rail pressure sensor signal; 3 - +5V power supply.
5V power supply
Rail
pressure Rail sensor signal
sensor
Grounding
4) Malfunction Mode
The malfunction indicator lamp lights up if the voltage is higher or less than this limit. If the voltage is out of the
normal working voltage range, but is not out of the limit, the malfunction indicator lamp will not light up.
5) Troubleshooting
The light-up of the engine malfunction indicator lamp indicates the presence of malfunction in the engine system and
it’s necessary to diagnose with diagnosis instrument. Use JAC special diagnosis instrument to communicate with ECU
of electronic injection system and read out the malfunction data in the ECU.
6. Engine coolant temperature sensor
1) Overview
z The sensor is installed on the cylinder head, closing to the water outlet. The body is made of brass to protect the
resistor unit fabricated from negative temperature coefficient (NTC) resistor;
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z The temperature resistor of the temperature sensor is one part of the 5V Characteristic curve of temperature sensor
voltage division circuit. Two terminals of the temperature sensor is
connected with the voltage charged circuit. When the temperature
resistor of the temperature sensor changes along with the temperature,
the voltage of the voltage charged circuit changes accordingly, which
will be inputted to the analog/digital conversion circuit of ECU
interface circuit. The relationship characteristic curve between voltage
Resistance
and temperature is stored in the ECU of engine management system;
z Sunray is equipped with 3-wire water temperature sensor to save the
cost and guarantee the system unity.
Temperature
The coolant temperature sensor is used to measure the working temperature of the engine. The ECU will provide the
engine with best control scheme, depending on different temperatures.
This sensor is one negative temperature coefficient (NTC) thermistor, of which the resistance reduces following the
increasing of coolant temperature in a non-linear mode. The negative temperature coefficient thermistor is installed
within one copper heat conducting sleeve. By means of one voltage division circuit, the ECU converts the resistance
change of thermistor to one varying voltage and provides to the ECU and thus monitors the change of water
temperature (internal structure of ECU).
Signal terminal
Water Grounding
temperature
sensor To water temperature gauge
Wiring terminals: 1 – Temperature signal; 2 – Grounding
Reference values: -10℃ 8.642---10.152 kΩ
20℃2.351---2.649 kΩ
80℃0.313---0.332 kΩ
4) Malfunction Mode
Upon the detection that the water temperature signal is higher or less than the limit range, the ECU will light up the
malfunction indicator lamp.
5) Troubleshooting
Sunray is fitted with one independent coolant temperature sensor to transmit the water temperature signal to the
instrument for display of instrument water temperature alarm. If the water temperature alarm indicator lamp lights up,
stop for cooling immediately. If the water temperature alarm indicator lamp lights up frequently, drive to the
authorized service station of JAC Multifunctional Commercial Vehicle Company for service.
7. Water level sensor
1) Overview
z The fuel-water separator position sensor is functioned to measure the water content in the fuel filter;
z When the water content reaches a predefined level, the ECU will control the working of the engine. This sensor
is installed on the bottom of the fuel filter;
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z The fuel-water separator position sensor is installed on the bottom of the fuel filter;
z Wiring terminals: 1. Water level sensor; 2. Water level signal; 3. +12V power supply.
The grain substances are high-accuracy filtered by means of the interception and absorption of the filter medium and
the water concentrated on the filter medium is Signal terminal of
separated by gravity force. The water separated fuel-water separator
is deposited in the water chamber at the lower position sensor
portion of filter housing.
The water level sensor is installed at the lower
portion of water chamber. When the water level Water level sensor of
reaches the sensing point of the sensor, the fuel-water separator
internal circuit of sensor is actuated to output
signal to the ECU. At the same time, the signal is
transmitted to the instrument to light up the
water level alarm lamp.
Wiring terminals: 1 - Water level sensor; 2 - Water level signal; 3 - +12V power supply.
4) Malfunction Mode
1) Troubleshooting
Use Sunray special diagnosis instrument to check the trouble code and determine the malfunction position. Mainly
check the circuit of sensor and determine whether there is short-circuit or open-circuit between circuit and the
grounding wire, whether there is short-circuit or open-circuit to power supply, and whether the circuit is consistent
with the given pin definition.
8. Accelerator pedal position sensor
1) Overview
The accelerator pedal position sensor is mounted on
Output voltage
the accelerator pedal.

The accelerator pedal position sensor and the
accelerator pedal form one integral part. The
accelerator pedal position sensor internally
incorporates two same potentiometer sensors to
provide the driver’s driving demand signal to the ECU.
This process is completely same with the presently
mechanical pedal in terms of operation, in order to Full close Full open
adapt to the years of driving habit of the driver. Two Open angle of accelerator pedal
same sensors provide the accelerator signal to the
ECU respectively, which guarantees more safety and reliability of the system.
Wiring terminals: 1. +5V; 2. +5V; 3. Grounding of accelerator pedal 1; 4. Signal of accelerator pedal 1; 5. Grounding
of accelerator pedal 2; 6. Signal of accelerator pedal 2.
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2）Working Principle
The accelerator pedal position sensor internally adopts the damping structure and internally incorporates two same
potentiometer sensors. The signal pointers of the sensors are coaxial with the pedal. When the accelerator pedal is
stepped down, the potentiometer pointer will rotate coaxially with the pedal and, following the sliding of the
potentiometer pointer, the signal terminals output different voltage or resistance signal. Two movable potentiometer
sensors with different resistances within the position sensor output different resistances. However, there is a defined
relationship between the resistances outputted by two sensors. The ECU adopts the voltage signals, instead of the
resistance signals of the sensor, in order to prevent the signal distortion caused by the voltage fluctuation of the
alternator. A comparison circuit is adopted to compare the signal voltage outputted by the sensor with the standard
voltage and the ECU adopts the comparison result to judge the movement amplitude of the pedal. The ECU compares
the signals inputted by the sensor 1 and sensor 2 and considers other sensors (engine speed, load, etc.) to jointly judge
the trueness of the signals outputted by the sensors. If the signal distortion is judged in any of two sensors, the ECU
controls the engine to actuate malfunction mode and adopt restrained driving measures.
The accelerator pedal position sensor provides one signal voltage varying along with the accelerator pedal position.
The engine control unit (ECU) will provide independent 5V reference voltage and low level reference voltage to each
accelerator pedal position sensor. When the accelerator pedal is stepped down, the signal voltage of the accelerator
pedal position sensor 1 is increased, namely from approximate 0.7V at the free position to above 4V at the fully
stepped down position. When the accelerator pedal is stepped down, the signal voltage of the accelerator pedal
position sensor 2 is increased, namely from approximate 0.3V at the free position to above 2V at the fully stepped
down position. Two data monitor mutually via control system.
Wiring terminals: 1 - +5V; 2 - +5V; 3 - Grounding of accelerator pedal 1; 4 - Signal of accelerator pedal 1; 5 -
Grounding of accelerator pedal 2; 6 - Signal of
accelerator pedal 2.
Power supply of sensor 1
Working voltage of sensor: 5V
Signal 1
Malfunction Mode
Accelerator Grounding of sensor 1
Short-circuit or open-circuit of sensor 1; pedal
module Power supply of sensor 2
Short-circuit or open-circuit of sensor 2;
Signal 2
Unstable sensor signal;
Grounding of sensor 2
Sensor signal is out of range.
4) Troubleshooting
Characteristic of sensor internal structure: Two potentiometer sensors within the sensor adopt independent power
supply and independent grounding wire, which can guarantee the system safety. When one sensor is damaged, another
sensor can still work. However, the engine system has already actuated the malfunction mode in such case and the
electronic control system will adopt the restrained driving measures.
9. Vehicle speed sensor
1) Overview
The vehicle speed sensor is located at the rear portion of the transmission and is mainly functioned to provide speed
signal to the engine control unit and instruments.
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2）Working Principle
The signal of vehicle speed sensor provides vehicle speed signal to the ECU, based on which the ECU calculates the
vehicle speed. It’s internally composed of one Hall speed sensor. Please refer to the camshaft position sensor for the
working principle.
3）Measurement analysis
Input signal
of vehicle
speed sensor
10. Clutch switch

1) Overview
The clutch switch is located on the upper portion of the clutch pedal and is mainly functioned for cruise control and
engine torque smoothness control.
The clutch switch is installed at the clutch pedal and transmits the operation signal of clutch pedal to the engine ECU.
Its inside is one two-pin contact switch. When the clutch pedal is stepped down, the lower central position of the
clutch switch springs out. In such case, two pins of the clutch switch are connected. When the clutch pedal is released,
two pins of the clutch switch are disconnected. Therefore, the engine can learn the operation state of the driver by
measuring the electric level (high or low) of the clutch switch signal wire.
4) Malfunction Mode
Short-circuit or open-circuit of sensor;
Unstable sensor signal;
Sensor signal is out of range.
5) Troubleshooting
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11.Dual brake switch
1) Overview
The dual brake switch is located on the upper portion of the brake pedal and internally incorporates two independent
switches.
The brake switch monitors the action of the brake pedal and transmits the signal measured to the engine ECU. The
brake switch is equipped with two switching mechanisms, which are the main and secondary units of the brake switch.
When the signals from both units are inputted, the engine ECU will judge as normal braking signal. These switching
signals are related to the accelerator pedal and are used to control the fuel amount during the braking. This means that
the operation of accelerator pedal will not lead to malfunction when the brake pedal is stepped down, but the operation
of accelerator pedal will reduce the fuel amount when the brake pedal is stepped down.
12. A/C switch
1) Overview
The A/C switch is located on the A/C control panel and is mainly functioned to transmit actuation directive of A/C
compressor to the engine control unit.
2). Working Principle

A/C request is the input signal that the driver requests the working of A/C and controls the working of A/C relay as
well as the speed promotion of the engine.
Low pressure A/C switch

High pressure
z Short-circuit or open-circuit of signal circuit;
z Unstable signal;
z The signal is out of range.
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5) Troubleshooting
Use Sunray special diagnosis instrument to check the
trouble code and determine the malfunction position.
Mainly check the circuit of sensor and determine whether
there is short-circuit or open-circuit between circuit and the
grounding wire, whether there is short-circuit or
open-circuit to power supply, and whether the circuit is
consistent with the given pin definition.
II. Engine control unit (ECU)

1) Overview
The engine control unit is located on the firewall on the
back of the bottom of the glove box.
The ECU has one metal housing and the sensors, actuators, and power supply are connected to the ECU via multi-pole
plug. The power supply parts for direct control of actuators are integrated in the ECU so that their heat can be
effectively expanded to the ECU housing.
Requirements for ECU are as below:
- Surrounding (ambient) temperature: -40ºC~+85ºC
- Resistance to fuel, lubricating oil, etc.
- Resistance to moisture.
- The mechanical load has high requirements of the exposure to electromagnetic compatible (EMC) signal.
The ECU is used to calculate the signal received from the external sensors and control at the allowable voltage level.
Based on these input data and stored characteristic graph, the microprocessor can calculate out the duration and
accurate moment for fuel injection and convert into time-signal curve. The specific accuracy requirement and high
dynamic response of engine require high level calculation capability.
The driver stage is actuated by means of the output signal and supplies proper power to the actuators to control the
common rail pressure and the high pressure pump units. In addition, the actuators can control the engine functions
(such as relays for exhaust gas recirculation actuator, turbocharger pressure actuator, and electronically controlled fuel
pump) and other auxiliary functions (such as fan relay, auxiliary heater relay, and electric heating plug relay, and air
conditioner). The driver stage has the short-circuit protection and the protection against damage due to current
overload. These types of malfunctions and the open-circuit will be reported to the microprocessor. The diagnosis
function of the fuel injector driver stage can identify the error signal curve occurred. In addition, one series of output
signal can be transmitted to other vehicle systems via different interfaces. Within the specific safety concept
framework, the ECU can monitor the entire injection system.
The actuation of fuel injector advances special requirements over the driver stage. Within the fuel injector, the current
from the driver stage generates one magnetic field force in the magnetic coil that applies onto the hydraulic high
pressure system. To ensure the accurate tolerance and high repeatability of the fuel injection amount, this coil must be
actuated in front of a steep current wave. This requires ECU to form high voltage.
The actuation time (fuel injection duration) can be classified by the current control circuit into start current stage and
holding stage. It must work accurately to ensure that the fuel injectors can guarantee the repeatability of fuel injection
under all working conditions. In addition, it must reduce the energy loss in the ECU and the fuel injectors.
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Outlet
Interface A
Outlet
Interface K
Definition for ECU pins of EDC17 control system:
Terminal Terminal
Description Description
No. No.
Interface A
A01 High fuel injector of 3rd cylinder A31 Low fuel injector of 2nd cylinder
A02 High fuel injector of 2nd cylinder A32
A03 A33 Low fuel injector of 4th cylinder
A04 Power supply of EGR actuator A34
A05 A35 Earthing of camshaft position sensor
A06 5V power supply of rail pressure sensor A36
A07 5V power supply of absolute pressure sensor A37 High coolant temperature signal
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Terminal Terminal
No. No.
A08 5V power supply of camshaft position sensor A38
A09 A39
A10 A40 Earthing of rail pressure sensor
A11 A41
A12 A42
A13 Signal of crankshaft position sensor A43
A14 Earthing of crankshaft position sensor A44
A15 A45
A16 High fuel injector of 1st cylinder A46 Low fuel injector of 3rd cylinder
A17 High fuel injector of 4th cylinder A47 Low fuel injector of 1st cylinder
A18 A48
A19 Earthing of EGR actuator A49
A20 A50 Low coolant temperature signal
A21 A51
A22 Air conditioner relay control A52 Rail pressure sensor signal
Temperature signal of absolute pressure
A23 A53
sensor
Pressure signal of absolute pressure
A24 A54
sensor
A25 A55
Shielding wire of crankshaft position
A26 A56
sensor
A27 A57 Signal of camshaft position sensor
A28 Earthing of absolute pressure sensor A58
A29 A59
A30 A60 Control of fuel metering unit
Interface K
K01 Positive pole of battery K48 Vehicle speed sensor output
K02 Negative pole of battery K49
K03 Positive pole of battery K50
K04 Negative pole of battery K51 Cruise control lamp
K05 Positive pole of battery K52 Cruise control mode
K06 Negative pole of battery K53 Cruise control mode
K07 K54 Anti-theft cable
K08 K55 Clutch switch control
K09 K56
K10 K57 Preheating feedback signal
K11 K58 Grounding of accelerator pedal sensor 2
K12 Intake temperature signal of air flowmeter K59 Pressure difference sensor signal
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Terminal Terminal
No. No.
K13 K60 Accelerator pedal sensor signal 2
K14 K61
K15 K62
K16 K63 Earthing signal of air flowmeter
K17 K64
K18 K65
K19 Vehicle speed signal input K66 CAN communication
K20 Intake flow signal of air flowmeter K67 Grounding of accelerator pedal sensor 1
K21 Exhaust brake switch control K68
K22 Power supply 2 of accelerator pedal sensor K69 Control signal of turbocharger actuator
K23 5V power supply of EGR K70 Malfunction indicator lamp
K24 K71 OBD indicator lamp
K25 K72
K26 K73
K27 5V power supply of pressure difference sensor K74 Cruise control mode
K28 Power supply 1 of accelerator pedal sensor K75
K29 Exhaust brake relay control K76
K30 Anti-theft cable K77 Water level signal
K31 Position signal of EGR K78 Auxiliary brake switch
K32 K79
K33 K80 Earthing of pressure difference sensor
K34 K81 Accelerator pedal sensor signal 1
K35 K82
K36 K83
K37 Air conditioner switch signal K84
K38 Main brake switch K85
K39 Earthing of EGR position sensor K86
K40 Cruise control mode K87 CAN communication
K41 K88
K42 K89
K43 Engine speed signal output K90 Preheating control signal
K44 Line K diagnosis K91 Preheating indicator lamp
K45 K92
K46 Ignition switch power switch control K93
K47 Main relay control K94
4) Malfunction Mode
Unstable idling, poor acceleration, start failure, high idling, out-of-tolerance of emission, difficult start, failure of air
conditioner, control failure of fuel injector, engine flameout, etc.
Failure arising from the burnout of ECU internal parts due to electric overload of external devices; rusting of circuit
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board due to water ingress of ECU.
5) Troubleshooting
Connect the plug and use engine data diagnosis cable to read the engine malfunction records; disconnect the plug and
check whether the ECU connecting wire is intact. Mainly check whether ECU power supply and grounding circuit are
normal, whether the external sensors are working normally, whether the output signal are reliable, and whether the
circuit is intact.
Check whether the actuators are working normally and whether their circuits are intact. Finally replace the ECU for
test.
III. Actuators
1. Fuel injector
1) Overview
The fuel injectors are located on the engine cylinder head and are mainly functioned to provide accurate fuel injection
for the engine at the correct moment.
To realize effective fuel injection start point and accurate injection amount, the common rail system adopts the special
fuel injector with hydraulic servo system and electronic control unit (solenoid valve). At the start of fuel injection
process, the fuel injector needs to adopt a relatively high current to rapidly open the solenoid valve. Till the needle
valve of the fuel injector nozzle reaches the maximum travel and the fuel injector nozzle is fully opened, the control
current is reduced to a relatively low constant current. In Fuel injector
such case, the fuel injection amount depends on the open a. Close of fuel injector (Still state) b. Open of fuel injector (Fuel
injection)
moment and the pressure in the common rail. When the 1. Fuel return pipe 2. Electric connector 3. Control unit
solenoid valve is no longer working and is closed, the fuel (electromagnetic field) 4. Rail fuel inlet (high pressure) 5. Ball
supply process is completed. valve 6. Fuel drainage hole 7. Fuel inlet hole 8. Valve control
chamber 9. Valve control plunger 10. Fuel inlet groove to
The fuel injection start moment and the fuel injection injector nozzle 11. Injector nozzle needle valve
amount are regulated by the electronically controlled fuel
injector. These fuel injectors substitute the fuel injector
assembly (injector nozzle and fuel injector body). Similar to
the fuel injector assembly of modern direct injection diesel
engine, the holders are used to install the fuel injector on the
cylinder head. In other words, it’s unnecessary to make any
large modification to the cylinder head to install the
common rail fuel injectors onto the modern direct injection
diesel engine.
Design structure
The fuel injector (figure) can be divided into several
functional blocks:
- Injector nozzle
- Hydraulic servo system
- Solenoid valve
As shown in the figure, the fuel enters into nozzle through
high pressure connecting pipe (4) and fuel inlet groove (10)
and enters into the valve control chamber (8) through fuel
inlet (7). The control chamber is connected with fuel return
pipe (1) via fuel drainage hole (6) and the fuel drainage hole
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is opened by solenoid valve. After the fuel drainage hole is closed, the hydraulic force applied onto the valve
controlled plunger (9) exceeds the pressure on the pressure shoulder of injector nozzle needle valve (11). Therefore,
the needle valve is pushed into the needle valve seat to block the high pressure passage to the combustion chamber.
When the solenoid valve of the fuel injector is actuated, the fuel drainage hole opens. In such case, the pressure in the
control chamber drops and thus the force applied onto the plunger reduces. Once the hydraulic pressure is less than the
force applied onto the pressure shoulder of the needle valve, the injector nozzle needle valve opens and the fuel injects
into the combustion chamber via the injection hole. The cause to indirectly control the injector nozzle needle valve by
hydraulic gain system is that the solenoid valve can’t directly generate the force required to rapidly open the needle
valve. The control amount required to open the injector nozzle needle valve is not included from the actual fuel
injection amount and is conveyed to the fuel return pipe through the fuel drainage hole of the control chamber.
Besides the control amount, the loss control fuel and the leak fuel at the injector nozzle needle valve and the valve
plunger chamber are conveyed to the fuel tank via the fuel return pipe and the fuel collection pipe connecting the
relief valve.
Depending on the working condition of the engine and the pressure generated by the high pressure fuel pump, the fuel
injector can be classified to 4 working conditions:
- Close of fuel injector (due to application of high pressure)
- Open of fuel injector (start of fuel injection)
- Full open of fuel injector
- Close of fuel injector (complete of fuel injection)
These working conditions are generated by means of the pressure distribution applied onto the fuel injector parts.
When the engine is stopped and there is no pressure in the common rail, the injector nozzle spring will close the fuel
injector.
Close of fuel injector (still state):
The solenoid valve is not actuated under still state and thus the fuel injector is closed (a). When the fuel drainage hole
is closed, the valve spring will press the ball vale of armature onto the fuel return orifice. The high pressure of
common rail is formed in the valve control chamber. Afterwards, a similar pressure is formed within the injector
nozzle chamber. The pressure applied onto the end face of control plunger by the rail pressure and the injector nozzle
spring force work together against the open force applied onto the conical pressure bearing face of needle valve by
fuel to maintain the needle valve at close state.
Open of fuel injector (start of fuel injection):
While the injector nozzle is at still state, the solenoid valve is actuated by the start current to ensure rapid open (b).
The force generated by the actuated solenoid valve overcomes the spring force so that the armature opens the fuel
drainage hole. Almost at the same time, the high start current drops to the low holding current required by the electric
magnet. This is possible as the air cap of the magnetic circuit becomes really small. When the ball valve of the fuel
drainage hole opens, the fuel flows from the valve control chamber to the empty chamber above and then returns to
the fuel tank via the fuel return pipe. The fuel drainage hole makes the pressure not completely balanced so that the
pressure in the valve control chamber drops. Therefore, the pressure in the valve control chamber is less than the
pressure of the fuel rail, which is still maintained in the fuel injector chamber, and the pressure drop in the valve
control chamber reduces the force applied onto the control plunger so that the injector nozzle needle valve opens and
the fuel injection starts.
The open speed of the injector nozzle needle valve depends on the flow difference between the fuel drainage hole and
the fuel inlet hole. The control plunger reaches its top dead center and then is held by one film of fuel, which is
formed by the fuel flow between the fuel drainage hole and the fuel inlet hole. In such case, the injector nozzle
completely opens and the fuel is injected into the combustion chamber at a pressure almost equaling to the fuel
pressure in the common rail. The pressure distribution in the injector nozzle is similar to that at the open stage.
Close of fuel injector (complete of fuel injection):
When the solenoid valve is no longer actuated, the valve spring pushes down the armature so that the ball of the valve
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closes the fuel drainage hole. The armature is of two-part design. Though the armature block is guided by the pressure
shoulder during the downward movement, it can bounce back following the return spring and thus will not apply
downward force onto the armature and the ball valve.
The close of fuel drainage hole enables the entry of fuel via fuel inlet hole into the control chamber for pressure
establishment. This pressure is equivalent to the rail pressure and applies additional force onto the end face of the
control plunger. The resultant force from this force and spring force overcomes the pressure in the injector nozzle
chamber to close the injector nozzle needle valve.
The close speed of the injector nozzle needle valve depends on the flow passing through the fuel inlet hole. Once the
injector nozzle needle valve hits its lower seat again, the fuel injection stops.
Fuel injector 1 “high”
Fuel injector 1 "Low” Cylinder 1

Fuel injector 4 "Low”
Cylinder 4

Fuel injector 3 "Low”
Cylinder 3
Fuel injector 2 "Low” Cylinder 2
4) Matching of fuel injector

The matching of fuel injector must be performed in event of any
of the following conditions:
z Replacement of fuel injector.
z Replacement of ECU
z Confusion of installation serial number before and after the
maintenance.
While performing the matching, input the matching code on the
fuel injector (as shown in the figure) in order into the diagnosis
instrument for matching.
2. EGR valve control system
EGR valve
1) Overview
z The electronically controlled EGR valve controls the
open extent of the valve by means of the positive and
reverse rotation of the DC motor and performs the
close-loop control as per the feedback signal of the
position sensor.
z To guarantee the NOx emission of the engine, the ECU
measures and calculates the EGR percentage as per the
input parameters of the engine (such as speed and intake
pressure) and the calibrated MAPs), issues control Intake manifold
assembly
signal to the EGR valve, and performs the close-loop
control via the position sensor.
z The EGR valve is installed on the intake manifold. The constant temperature of the EGR valve inlet emission
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can't exceed 260ºC, with the peak temperature no more than 300ºC.
EGR power supply
EGR position signal

EGR passage section
EGR signal grounding
EGR control signal terminal

EGR control grounding
terminal
EGR actuator
3. Variable nozzle turbocharger (VNT) control

1) Overview
z HFC4DA1-2C adopts variable section turbocharger technology so that the turbocharger and the engine are well
matched under all working conditions to realize best engine performance.
z The blades of the VNT are connected to the control tie rod and the displacement of the control tie rod is
controlled by the vacuum pressure of the vacuum chamber on the VNT. Changing the vacuum pressure of the
vacuum chamber can change the position of VNT blades and control the flow area of the turbine. The vacuum
pressure of the vacuum chamber is controlled by VNT solenoid valve, of which one port is connected to the
vacuum chamber on the VNT, one port is connected to the vacuum pump, and another port is connected to the air.
This connector in the engine is additionally fitted with filter to prevent the ingress of contaminant (such as dust)
into the valve. The open extent of the VNT solenoid valve is regulated by the PWM wave issued by ECU and the
solenoid valve is installed on the crossbeam of the body water tank.
Turbocharger actuator
Turbocharger control signal
4. Fuel metering unit

1) Overview
The fuel metering unit is located on the high pressure fuel pump and is functioned to control the fuel amount from the
low pressure pump to the high pressure pump.
The fuel metering valve is installed at the high pressure fuel inlet of high pressure fuel pump and is functioned to
regulate the fuel supply amount and fuel pressure, of which the regulation requirement is subject to the control of
ECU. The control coil of the metering valve is closed when not electrified, which cuts off the fuel supply to the
plunger of high pressure fuel pump. The ECU changes the fuel inlet section area of metering unit by means of pulse
signal to increase or reduce the fuel supply amount.
Wiring terminals: 1 – Signal terminal; 2 – 12V voltage.
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Fuel metering unit signal
Fuel metering unit
4) Malfunction Mode
Short-circuit or open-circuit of metering valve; damage of metering valve; contamination of metering valve.
5) Troubleshooting
check the circuit of metering valve and determine whether there is short-circuit or open-circuit between circuit and the
CP1H and CP4.x metering unit
Fuel supply to high
Fuel amount pressure pump
Full load fuel amount

Fuel amount characteristic
Idling fuel amount
Ampere
5. Preheating control unit

1) Overview
The preheating control unit is located in the engine compartment and is mainly functioned for the rapid start of engine
under cold state.
The preheating control unit is functioned to ensure effective cold start and shorten the warm-up time, which is closely
related to the exhaust emission. The preheating time is a function of coolant temperature. At the start of the engine or
during the actual running, the turn-on duration of the electric heating plug depends on one series of parameters,
including the fuel injection amount and engine speed. The control of the electric heating plug is realized by one power
relay (GCU).
The main part of the electric heating plug is the tubular heating unit. The heating unit is firmly and air-tightly installed
within the electric heating plug housing to guard against corrosion and thermal gas impact. The heating unit is one
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helical metal wire embedded within the magnesium oxide powder (Figure). This helical metal wire is composed of
two resistors in series connection and one heating oil and one control coil are installed on the tip of the heating tube.
The heating coil maintains one resistance almost irrelevant to the temperature and the control coil is made of positive
temperature coefficient (PTC) material. In the new generation heating plug (GSK2), the rise amplitude in the
resistance of control coil is larger than common electric heating plug. With capability of rapidly reaching the
temperature required for ignition (up to 850ºC within 4s) and relatively low constant temperature, new electric heating
plug GSK features outstanding performance. Therefore, the temperature of the electric heating plug is restrained at
one critical value. Therefore, after the start of the engine, the GSKZ electric heating plug can continue to maintain
electrified for 3min. This after-combustion performance improves the noise and exhaust emission of start and
warm-up stages.
The control instrument of the electric heating plug adopts one power relay and the electric switch set to control the
electric heating plug, which control the heating time of electric heating plug and feature the protection and monitoring
functions. Thanks to its diagnosis function, higher grade of electric heating plug control instrument can identify the
malfunction of single electric heating plug and display to the driver. The control input terminal of the electric heating
plug control instrument is connected to the electronic control unit (ECU) via multi-pole plug. To prevent the voltage
drop, the series connection circuit connected to the electric heating plug adopts the threaded pin or connector.
The controlled preheating process and the start process are controlled by the electric heating plug starter switch. The
preheating process is started when the key is turned to “ON” position. When the heating control lamp goes out, the
electric heating plug reaches sufficient temperature and the start process can be conducted. In the subsequent start
process, the fuel drips injected will be atomized and get combusted in the compressed hot air so that the heat released
starts the combustion process.
The after-heating after the successful start can help the warm-up process to form one speed promotion and idle run
with no interruption and little smoke. This can reduce the combustion noise at the cold start. In event of
non-successful start, the protection circuit of the electric heating plug is turned off to prevent the excessive discharge
of the battery.
Fuse 5
To preheating
plug Power supply
Preheating relay
Preheating time feedback
Preheating control unit
Short-circuit or open-circuit of preheating control unit;
Damage of preheating control unit;
5) Troubleshooting:
Use special diagnosis instrument to check the trouble code and determine the malfunction position. Mainly check the
circuit of preheating control unit and determine whether there is short-circuit or open-circuit between circuit and the
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6. Malfunction indicator lamp
1) Overview
The malfunction indicator lamp is located on the instrument. In event of malfunction of engine control system units,
the engine malfunction indicator lamp will light up to
remind the driver for checking and service by the service
station as soon as possible.
The malfunction indicator lamp (MIL) is located on the
instrument panel and is directly powered by the voltage of
battery. The engine control unit (ECU) lights up the
malfunction indicator lamp by grounding the control circuit
of malfunction indicator lamp. When the ignition switch is
turned on but the engine is not started, the malfunction
indicator lamp (MIL) shall light up for 5s and then go out.
Functions of malfunction indicator lamp:
z The malfunction indicator lamp reminds the driver of the occurrence of malfunction. The vehicle shall be
serviced as soon as possible.
z The malfunction indicator lamp lights up during the test of the malfunction indicator lamp.
z If the diagnosis procedure requests to light up the malfunction indicator lamp, one diagnosis trouble code will be
stored.
Light-up of malfunction indicator lamp
z When the ignition switch is turned on but the engine is not started, the malfunction indicator lamp will light up
for 5s and then go out.
z The malfunction indicator lamp goes out after the engine is started.
z If any malfunction is detected by the self-diagnosis system, the malfunction indicator lamp will keep lighted up.
z If no malfunction is detected, the malfunction indicator lamp will go out.
Malfunction indicator lamp
OBD indicator lamp
4) Malfunction Mode
Short-circuit or open-circuit between engine control
unit to instrument circuit.
5) Troubleshooting:
Use Sunray special diagnosis instrument to check the
trouble code and determine the malfunction position.
Mainly check the circuit from engine control unit to
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instrument circuit and determine whether there is short-circuit or open-circuit between circuit and the grounding wire,
whether there is short-circuit or open-circuit to power supply, and whether the circuit is consistent with the given pin
definition.
7. Diagnosis interface
1) Overview
The diagnosis interface is located in the electric box beneath the driver’s side instrument panel and is used to connect
the special diagnosis instrument.
This is one data transmission interface for communication with ECU and is one standard OBD interface.
4) Malfunction Mode
Short-circuit or open-circuit between engine control unit and diagnosis interface.
Working failure of engine control unit.
5) Troubleshooting:
check the circuit from engine control unit to diagnosis interface circuit and determine whether there is short-circuit or
open-circuit between circuit and the grounding wire, whether there is short-circuit or open-circuit to power supply,
and whether the circuit is consistent with the given pin definition.
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Chapter IV Engine Diagnosis
Section I. Precautions
1. Removal/Installation Requirements for Electronic Control Unit (ECU):
z Remove the controller before welding or baking finish;
z When removing the controller, turn off the ignition switch and disconnect the battery from the system at the same
time, in order to avoid damaging the ECU.
z It is not allowed to remove power cord from the battery when the engine or the electrical system is working.
z Large-current equipment such as charger is not allowed to be directly connected to the starting motor.
z Note: The ambient temperature of ECU should not be greater than 75 degree.
2. Cleaning Requirements:
Please observe the following rules before the operation of fuel supply system and fuel injection system:
z The removed components should be placed at clean field and properly covered by the cloth other than fiber type
(cotton cloth or gauze cloth)
3. All types of harness connectors and the connector for diagnostic instrument should be
connected and disconnected only when the ignition switch is turned off:
z When measuring the power voltage or ground wire of the ECU, please ensure the wiring sequence and method is
correct.
z Disconnecting the power cord or the ground wire of the battery from the system or removing ECU harness
connector will result in the loss of diagnosis and self-learning information stored in ECU. (If the vehicle model is
different, the time of retaining Pleas of the ECU is also different after the loss of power.)
4. Please pay attention to the following points when maintaining the fuel supply system (fuel
supply pipe, fuel pump and fuel injection system):
z Please be very careful during installation/removal of fuel pump on the fuel tank with fuel.
z Prepare proper materials around the fuel tank opening to absorb a lot of fuel leaked from it timely..
z Avoid the fuel contacting your body.
z Thoroughly clean the part and its surrounding before loosening a connector.
z Please prevent any fuel from splashing from the loose part and place a rug around the connector.
z If the disassembled parts could not be timely repaired or properly treated, store the parts properly.
z Take the spare parts out of the package only when they are needed to be installed. Do not use unpacked spare
parts and the spare parts in severe damaged package
z Do not damage the O-ring of return pipe when assembling fuel injector return pipe. Coat a little diesel oil on the
O-ring for assembling convenience.
z Do not use the compressed air and do not move the vehicle after the fuel supply system is disassembled.
5. Safety Measures
To prevent the maintenance technicians from being injured and the fuel and ECU being damaged, please pay attention
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to the following points:
z If the engine is working or at the starting speed, it is not allowed to check for any single cylinder failure by the
way of disconnecting the fuel injector harness.
z If the engine needs to be dragged but not started by the starter, such as when you check the engine cylinder
pressure, the harness plug should be disconnected from the crankshaft position (engine speed) sensor and
camshaft position (phase) sensor. After inspection, all sensors should be well connected and system DTCs should
be cleared by using the special diagnostic instrument for JAC commercial vehicles.
z It is not allowed to touch the engine gear train and rotating parts when the engine is at high speed;
z When the engine reaches normal operating temperature, the coolant temperature and pressure of cooling system
is very high; therefore, stop the engine and let the cooling system fully cool down if it is needed to repair the
engine cooling system.
z If the engine compartment relevant maintenance is necessary to be conducted in repairing engine fuel system,
please do it after the engine compartment is fully cooled down.
z Don’t touch the engine cooling fan at any time when the system is normally electrified, for the cooling fan is
likely to be started suddenly.
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Section II. Maintenance Procedures

Fuel system of common rail engine consists of low-pressure delivery pipes and high-pressure oil pipes and maximum
pressure of it is over 1800bar. Some components of fuel injector and HP pump are machined with accuracy of 0.1mm.
Pressure regulation and fuel injection are controlled by engine ECU. In the case of stuck internal needle valve, fuel
injector will maintain open and HP pump keeps operating to supply high-pressure fuel oil. Therefore, excessive fuel
will be sprayed into combustion chamber and this will lead to rapid increase of combustion chamber internal pressure
(over 250bar) and even serious engine damage.
Core component of fuel system possesses very high accuracy and will be easily influenced by dust or tiny foreign
matters. Therefore, the following preparations and procedures should be carried out or there will be a lot of system
failures.
Operation Procedures:
1. It is necessary to keep maintenance site clean (it should be free of dust especially);
2. It is necessary to keep maintenance tools clean (they should be free of oil and foreign matters);
3. Wear ethylene pinafore to prevent hairs, dust and foreign matters from entering engine fuel system. Wash your
hands instead of wear gloves;
4. Prior to fuel system maintenance, carry out the following procedures:
Carefully listen to customer’s description about

symptoms and faults
Check appearance and connection of wire harness

and connectors in engine compartment
Carry out test procedures with special diagnostic

apparatus (carry out road test when necessary)
Confirm the fault. If the fault is in fuel system,

please carry out Step1~3 above.
5. If the fault is in HP pump, fuel delivery line or fuel injector, prepare clean special tools and sealing covers and carry
out relevant procedures for engine fuel system. Prior to maintenance, clean relevant areas to engine compartment
completely;
6. Find out faulted parts according to the above operation procedures and replace these parts with parts from OEM;
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Remove battery negative cable.
For safety reasons: Confirm whether system

pressure is low prior to high-pressure system
disassembly.
Apply special tools and torque wrenches in

calibration.
In disassembly or replacement of fuel injector, it is necessary to apply new copper washers and tighten fixing bolts for
fuel injector according to fixed torque at the same time. Otherwise, injection position of fuel injector will deviate from
correct position and this will make engine operation out of control.
7. Apply clean and intact sealing covers on disassembled components and keep them well;
8. After fuel injector replacement, carry out fuel injector matching with special diagnostic apparatus;
9. Keep pressing manual oil delivery pump on oil-water separator to provide low-pressure line with fuel oil until the
pump can not be pressed any longer.
Attention: Do not start the engine before the pump is filled up.
10. Recheck installed components, connect battery cable and start the engine for engine operation condition
inspection;
11. Apply special diagnostic apparatus to check current faults for existence and eliminate historical faults.
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Section III. Fault Diagnosis

1. Fault Information Record
Electronic control unit continually monitors sensors, actuators, relevant circuits, MILs, battery voltage and even its
self and carries out reliability tests to sensor output signals, actuator drive signals and internal signals. Once there are
faults in certain link or certain signal is unreliable, electronic control unit sets fault information record in RAM fault
memory immediately. Fault information record is stored in the form of diagnostic trouble code (DTC) and shown in
the sequence of fault occurrence.
Faults can be divided into “steady fault” and “random fault” (such as faults caused by temporary open circuit of
harness or poor contact of connectors) according to fault occurrence frequency.
2. Fault Condition
If duration of an identified fault exceeds set stabilization time for the first time, ECU identifies it as a steady fault and
stores it as a “steady fault”. If the fault disappears, ECU identifies it as a “random fault” and “nonexistent”. If the fault
is identified once again, it is still a “random fault”. However, “existent” historical faults will not influence normal
application of engine.
3. Fault Type
Short to power supply positive pole
Short or open to ground (In the case of pull-up or pull-down resistor for input stage, ECU will identify open circuit
failure of input port as the fault of input port short to power supply positive pole or short to ground)
Unreliable signal
4. Fault Frequency Counter

For every identified fault, there is an individual frequency counter value (HZ). Frequency counter value (Hz)
determines storage time of corresponding fault information record in the memory after fault disappearance (fault
elimination).
For the first time fault identification, it (Hz) is set to be its initial value as 40. If fault condition does not change, this
value will maintain the same forever.
Once identified fault has disappeared and then the condition has been maintained for certain period of time, the value
(Hz) is reduced by 1 after every successful engine start (engine speed exceeds that of engine start completion). At this
moment, ECU recognizes the fault has disappeared but fault information record still exists.
If the fault (such as fault caused by poor contact) appears and disappears frequently, the value (Hz) is increased by 1
but the value will not exceed set upper limit of 100.
When the value (Hz) becomes zero, all fault information records in the fault memory are cleared completely.
5. Fault Alarm
In the case of electronic control system, when there are faults in some important components such as ECU, coolant
temperature sensor, phase sensor, boost pressure sensor, revolution speed sensor, air flow meter, fuel injector, fan relay
and etc, ECU will give alarms via MIL flashing until faults are eliminated.
6. Fault Reading
Fault information records can be brought out from electronic control unit via fault diagnostic apparatus. However,
some faults can be detected only when vehicle reaches corresponding operation condition.
105
7. Elimination of Fault Information Record
Fault information records in memory should be cleared after fault elimination. DTC can be cleared with ways as
follows:
When value of ECU frequency counter (Hz) becomes 0, fault information records in fault memory are all cleared
automatically.
In the case of “Fault memory zero clearing” command, fault information records can be cleared with the application
of fault diagnostic apparatus.
8. Fault Detection
After obtaining fault information records with means above, only suspicious positions for fault occurrence are known.
However, this does not mean faults have been detected. Therefore, cause for one fault may be damaged electrical
component (like sensor or actuator or ECU, etc), wire in open circuit, wire short to ground or battery positive pole and
even mechanical failure.
Faults are internal with their external expressions as various symptoms. When symptoms are detected, check fault
information record for existence with fault diagnostic apparatus or flash code first of all and then eliminate
corresponding faults. Finally, detect faults according to engine symptoms.
106
Section IV. DTC List

S/N DTC Meaning
1 P0030 The linear oxygen sensor heater circuit is open.
2 P0031 The linear oxygen sensor heater circuit is short to ground.
3 P0032 The linear oxygen sensor heater circuit is short to battery.
4 P0045 EGR valve circuit is open.
5 P0046 Overtemperature of EGR valve bridge-H chip
6 P0047 EGR valve circuit is short to ground.
7 P0048 EGR valve circuit is short to power supply.
8 P0068 Short-term drifting error in the process of throttle offset self-adaption
The absolute difference between intercooler downstream air pressure and ambient
9 P0069
pressure is unreliable.
10 P0070 Reliability check function for ambient temperature
11 P0072 Too low ambient temperature
12 P0073 Too high ambient temperature
13 P0087 The minimum rail pressure is below the lower limit.
14 P0088 The maximum rail pressure is above the upper limit.
15 P0097 The signal level of intercooler downstream temperature is too low.
16 P0098 The signal level of intercooler downstream temperature is too high.
17 P00BE The original value of fuel rail pressure is incoherent.
18 P0100 The supply voltage of air flow sensor exceeds the limit.
19 P0101 Timeout error of air flow sensor hardware signal
20 P0102 The sensitivity deviation of air flow sensor is below the lower limit.
21 P0103 The sensitivity deviation of air flow sensor is above the upper limit.
22 P010C The signal level measured by air flow sensor is too low.
23 P010D The signal level measured by air flow sensor is too high.
24 P0112 The voltage is below the lower limit of intake air temperature sensor.
25 P0113 The voltage is above the upper limit of intake air temperature sensor.
26 P0116 Error reported in dynamic reliability test of coolant temperature sensor
27 P0117 Coolant temperature signal level is too low (downstream).
28 P0118 Coolant temperature signal level is too high (downstream).
29 P0119 Error reported in static reliability test of coolant temperature sensor
30 P0122 The signal level of accelerator pedal position sensor 1 is relatively low.
31 P0123 The signal level of accelerator pedal position sensor 1 is relatively high.
32 P0127 The signal level of air temperature sensor is relatively high.
107
S/N DTC Meaning

33 P0128 Closed-loop control is actuated due to too low coolant temperature.
34 P0131 Oxygen sensor IAIPUNVG point is short to ground.
35 P0132 Oxygen sensor IAIPUNVG point is short to battery.
36 P0168 The signal level of fuel temperature sensor is relatively high.
37 P0182 The signal level of fuel temperature sensor is below the lower limit.
38 P0183 The signal level of fuel temperature sensor is above the upper limit.
39 P0191 The uncorrected rail pressure value is above the upper limit of drift.
40 P0192 The voltage of fuel rail pressure sensor is below the lower limit.
41 P0193 The voltage of fuel rail pressure sensor is above the upper limit.
42 P0194 The uncorrected rail pressure value is below the lower limit of drift.
43 P0195 Engine oil temperature signal fault on CAN
44 P0196 The oil temperature signal is unreliable.
45 P0197 The oil temperature signal level is too low.
46 P0198 The oil temperature signal level is too high.
47 P0201 The 1st cylinder fuel injector circuit is open.
48 P0202 The 2nd cylinder fuel injector circuit is open.
49 P0203 The 3rd cylinder fuel injector circuit is open.
50 P0204 The 4th cylinder fuel injector circuit is open.
An error is reported when the time for electrifying the 1st cylinder reaches to the
53 P020A
maximum.
An error is reported when the time for electrifying the 2nd cylinder reaches to the
54 P020B
maximum.
An error is reported when the time for electrifying the 3rd cylinder reaches to the
55 P020C
maximum.
An error is reported when the time for electrifying the 4th cylinder reaches to the
56 P020D
maximum.
57 P020E
maximum.
58 P020F
maximum.
59 P0215 Avoid resonance of double mass flywheel when stopping.
60 P0219 Overspeed protection for engine parts
61 P0222 The signal level of accelerator pedal position sensor 2 is relatively low.
62 P0223 The signal level of accelerator pedal position sensor 2 is relatively high.
108
S/N DTC Meaning

63 P022A EGR valve circuit is open.
64 P022B EGR valve circuit is short to ground.
65 P022C EGR valve circuit is short to power supply.
The signal level at the output position of EGR cooling bypass valve position sensor
66 P022E
is below the lower limit.
The signal level at the output position of EGR cooling bypass valve position sensor
67 P022F
is above the upper limit.
68 P0234 The actual air intake flow is greater than the target set by system.
The original voltage of intercooler downstream air pressure sensor is below the
69 P0237
lower limit.
The original voltage of intercooler downstream air pressure sensor is above the
70 P0238
upper limit.
71 P023D The long-term jitter of EGR valve exceeds the limit.
72 P023E The short-term jitter of EGR valve exceeds the limit.
An error is reported when the temperature of EGR cooler bypass valve in
73 P024A
electrifying phase is too high.
The signal level measured by EGR cooler bypass valve position sensor is below the
74 P024E
limit.
The signal level measured by EGR cooler bypass valve position sensor is above the
75 P024F
limit.
76 P0251 The fuel metering unit circuit is open.
77 P0252 The temperature of fuel metering unit driver module is too high.
78 P0253 The fuel metering unit circuit is short to ground.
79 P0254 The fuel metering unit circuit is short to power supply.
80 P0255 Poor contact between ECU and fuel metering unit
81 P025C The voltage of fuel metering unit is below the lower limit.
82 P025D The voltage of fuel metering unit is above the upper limit.
83 P0263 An error is reported when the electrifying time reaches to the maximum.
89 P0299. The positive deviation of pressure controller is above the upper limit.
90 P0335 No signal from crankshaft
91 P0336 Crankshaft speed signal is irrational.
92 P0339 Camshaft speed signal is irrational.
109
S/N DTC Meaning

93 P0340 No signal from camshaft
94 P0341 The offset angle of camshaft is too large.
95 P0380 The preheating indicator light output circuit is high.
96 P0382 The preheating indicator light output circuit is low.
99 P0401 The actual air intake flow is greater than the target set by system.
100 P0402 The actual air intake flow is less than the target set by system.
102 P0404 The short-term jitter of EGR valve exceeds the limit.
103 P0405 The original voltage of EGR valve sensor signal is below the lower limit.
104 P0406 The original voltage of EGR valve sensor signal is above the upper limit.
106 P040C The signal level of EGR cooler downstream temperature sensor is relatively low.
107 P040D The signal level of EGR cooler downstream temperature sensor is relatively high.
108 P0426 Upstream temperature fault of oxidation catalytic converter
The signal level of upstream temperature of oxidation catalytic converter is
109 P0427
relatively low.
The signal level of upstream temperature of oxidation catalytic converter is
110 P0428
relatively high.
115 P0487 CJ945 Power level no-load fault
116 P0488 CJ945 Overheating fault
119 P0500 Wheel fault
120 P0501 Unreliable vehicle speed
121 P0503 Signal of speed sensor exceeds the upper limit.
122 P0504 Unreliable brake signal
123 P0520 Engine oil pressure signal fault on CAN
124 P0521 The maximum oil pressure signal is unreliable.
125 P0522 The signal level of oil pressure sensor is relatively low.
110
S/N DTC Meaning

126 P0523 The signal level of oil pressure sensor is relatively high.
127 P0524 The minimum oil pressure signal is unreliable.
128 P0532 The signal level measured by A/C coolant pressure sensor is too low.
129 P0533 The signal level measured by A/C coolant pressure sensor is too high.
130 P0537 The signal level of A/C evaporator’s temperature is relatively low.
131 P0538 The signal level of A/C evaporator’s temperature is relatively high.
132 P0562 The signal level of battery voltage sensor is too low.
133 P0563 The signal level of battery voltage sensor is too high.
134 P0571 False brake signal
135 P0575 The analog cruise control signal is unreliable.
136 P0576 The analog cruise control signal level is too low.
137 P0577 The analog cruise control signal level is too high.
138 P0578 The analog cruise control button is stuck.
139 P0607 Cy320 Hardware error reported
140 P060A Error reported in monitoring too high voltage
141 P060D The accelerator pedal voltage signal is unreliable.
142 P0611 The injection frequency is limited by system.
143 P061B Error reported in torque comparison
The deviation difference between the engine speed signals obtained from the 1st level
144 P061C
and the 2nd level is too large.
145 P061D The set value of air system is limited by the torque limit of the function control unit.
146 P061F Error reported in the process of throttle offset self-adaption
147 P0627 The control line of priming fuel pump is open.
148 P0628 The control line of priming fuel pump is short to ground.
149 P0629 The control line of priming fuel pump is short to power supply.
150 P062A Overheating of priming pump
The set value of fuel injection amount is limited by the torque limit of the function
151 P062B
control unit.
152 P062F Error reported in EEP read-write
153 P0643 The sensor power supply monitoring fault 1
154 P0645 The compressor circuit is open.
155 P0646 The compressor circuit is short to ground in electrifying phase.
156 P0647 The compressor circuit is short to power supply in electrifying phase.
111
S/N DTC Meaning

159 P0660 The positive deviation of throttle controller exceeds the upper limit for a long time.
160 P0661 The Port 1 of EGR valve bridge-H chip is short to ground.
161 P0662 The Port 1 of EGR valve bridge-H chip is short to power supply.
162 P0663 Short circuit / overload of EGR valve bridge-H
165 P0668 The voltage of ECU temperature sensor is below the lower limit.
166 P0669 The voltage of ECU temperature sensor is above the upper limit.
168 P0686 The main relay opens too early.
169 P0687 The main relay opens too late.
175 P0704 Clutch signal error
176 P0737 Then engine speed output signal circuit is open.
177 P0738 Then engine speed output signal circuit is short to ground.
178 P0739 Then engine speed output signal circuit is short to power supply.
179 P0A32 Parking counter error
180 P1000 The long-term jitter of EGR valve exceeds the limit.
181 P1001 The relief valve reaches to the maximum permissible opening position.
182 P1002 The relief valve reaches to the maximum permissible opening time.
183 P1003 The average fuel rail pressure regulated by relief valve is out of the range.
184 P1004 Check the flow equilibrium if the relief valve is opened normally.
185 P1005 The relief valve opens.
186 P1006 The relief valve is forced open to implement the pressure shock.
The torque in MAP for torque and fuel conversion does not increase along the fuel
187 P1007
direction strictly and monotonically.
188 P1008 PhyMod_trq2qBas_MAP contains non-strict and non-monotonic Q curve.
189 P1011 The positive deviation of rail pressure is above the upper limit.
190 P1012 The negative deviation of rail pressure is below the lower limit.
191 P1013 The maximum negative deviation of rail pressure is below the lower limit.
112
S/N DTC Meaning

192 P1020 The heating drive circuit of fuel filter is open.
193 P1021 The heating drive circuit of fuel filter is short to power supply.
194 P1022 The heating drive circuit of fuel filter is short to ground.
195 P102A The signal level of ambient pressure sensor is relatively high.
196 P102B The signal level of ambient pressure sensor is relatively low.
197 P102C The signal level of ambient temperature sensor is relatively high.
198 P102D The signal level of ambient temperature sensor is relatively low.
200 P1031 Short circuit / overload of EGR valve bridge-H
201 P1032 Overcurrent of EGR valve bridge-H based on temperature
202 P1033 Under-voltage of EGR valve bridge-H
203 P1034 The EGR valve in closed status is stuck.
204 P1035 The EGR valve in open status is stuck.
205 P1036 The long-term jitter of EGR valve exceeds the limit.
206 P1037 An error is reported when the EGR valve is stuck in closing or opening.
207 P1038 The physical value of EGR valve position sensor is too high.
208 P1039 The physical value of EGR valve position sensor is too low.
209 P103A The signal level of intercooler downstream temperature is relatively high.
210 P103B The signal level of intercooler downstream temperature is relatively low.
211 P103C EGR valve offset is unreliable.
212 P103D The positive deviation of regeneration controller is above the limit.
213 P103E The positive deviation of regeneration controller is below the limit.
214 P1040 Overheating of throttle bridge-H
215 P1041 Short circuit / overload of throttle bridge-H
216 P1042 Overtemperature caused by overcurrent of throttle bridge-H
217 P1043 Long-term deviation in the process of throttle self-adaption
218 P1044 Output circuit 2 of throttle bridge-H is short to ground.
219 P1045 Under-voltage of throttle bridge-H
220 P1046 Output circuit 2 of throttle bridge-H is short to power supply.
221 P1047 The physical value of throttle position is below the lower limit.
222 P1048 The throttle circuit is short to ground.
223 P1049 The physical value of throttle position is above the upper limit.
224 P104A The throttle circuit is short to power supply.
225 P1060 OBD General fault 1
113
S/N DTC Meaning

235 P106A OBD General fault 4
236 P106B OBD General fault 5
237 P106C OBD General fault 6
238 P106D OBD General fault 7
239 P106E OBD General fault 8
240 P106F OBD General fault 9
241 P1070 Blockage of particulate filter
242 P1100 The regulated idling value of air flow sensor is above the upper limit.
The duty cycle of air temperature sensor on the air flow meter is above the upper
243 P1102
limit.
The duty cycle of air temperature sensor on the air flow meter is below the lower
244 P1103
limit.
The time interval measured by the air temperature sensor on the air flow meter is
245 P1106
above the upper limit.
The time interval measured by the air temperature sensor on the air flow meter is
246 P1107
below the lower limit.
247 P110A System degradation 0
248 P110B Level-1 degradation
249 P110C Level-2 degradation
250 P110D Level-3 degradation
251 P110E Vehicle performance limit function is activated.
252 P1110 The detected signal within physical range is relatively high.
253 P1111 The engine coolant temperature signal level is relatively low.
254 P1120 The correction of air flow sensor load exceeds the maximum deviation limit.
255 P1121 The physical value of air flow meter is above the upper limit.
256 P1122 The physical value of air flow meter is below the lower limit.
114
S/N DTC Meaning

The signal level of intake air temperature sensor (integrated inside the air flow
257 P1123
sensor) is relatively low.
258 P1130 The signal level of fuel temperature sensor is relatively low.
259 P1131 The signal of fuel temperature is unreliable.
260 P113A The signal of too high oil temperature is unreliable.
261 P113B The signal level of oil temperature sensor is relatively high.
262 P113C The signal level of oil temperature sensor is relatively low.
263 P1200 Short circuit between the high end and low end of the 1st cylinder fuel injector
264 P1201 Short circuit between the high end and low end of the 2nd cylinder fuel injector
265 P1202 Short circuit between the high end and low end of the 3rd cylinder fuel injector
266 P1203 Short circuit between the high end and low end of the 4th cylinder fuel injector
269 P1207 1st cylinder special error
270 P1208 2nd cylinder special error
271 P1209 3rd cylinder special error
272 P120A 4th cylinder special error
273 P120B 5th cylinder special error
274 P120C 6th cylinder special error
An error is reported when the time for electrifying the 1st cylinder reaches to the
275 P1210
minimum.
An error is reported when the time for electrifying the 2nd cylinder reaches to the
276 P1211
minimum.
An error is reported when the time for electrifying the 3rd cylinder reaches to the
277 P1212
minimum.
278 P1213
minimum.
279 P1214
minimum.
280 P1215
minimum.
281 P1216 Maximum deviation error in the inner control circuit of electronic throttle
282 P1217 Minimum deviation error in the inner control circuit of electronic throttle
283 P1218 Maximum deviation error in the outer control circuit of electronic throttle
284 P1219 Minimum deviation error in the outer control circuit of electronic throttle
285 P121A 1st cylinder IQA error
286 P121B 2nd cylinder IQA error
115
S/N DTC Meaning

rd
287 P121C 3 cylinder IQA error
288 P121D 4th cylinder IQA error
289 P121E 5th cylinder IQA error
290 P121F 6th cylinder IQA error
291 P1220 The signal level of intercooler downstream temperature sensor is relatively high.
292 P1221 The signal level of intercooler downstream temperature sensor is relatively low.
293 P122A The positive deviation of throttle controller exceeds the upper limit for a long time.
294 P122B The negative deviation of throttle controller is below the lower limit for a long time.
295 P1230 Error reported in monitoring the OBDII maximum threshold correction
296 P1231 Error reported in monitoring the OBDII minimum threshold correction
297 P1245 System degradation information
An error is triggered when the ET time of the 1st cylinder reaches the maximum limit
298 P1250
(when the ZEL comes into effect).
An error is triggered when the ET time of the 2nd cylinder reaches the maximum
299 P1251
limit (when the ZEL comes into effect).
An error is triggered when the ET time of the 3rd cylinder reaches the maximum limit
300 P1252
An error is triggered when the ET time of the 4th cylinder reaches the maximum limit
301 P1253
An error is triggered when the ET time of the 1st cylinder reaches the minimum limit
302 P1254
An error is triggered when the ET time of the 2nd cylinder reaches the minimum limit
303 P1255
An error is triggered when the ET time of the 3rd cylinder reaches the minimum limit
304 P1256
An error is triggered when the ET time of the 4th cylinder reaches the minimum limit
305 P1257
310 P140A The signal level of the EGR cooler downstream temperature is relatively high.
311 P140B The signal level of the EGR cooler downstream temperature is relatively low.
312 P1410 The positive deviation of throttle controller exceeds the upper limit for a long time.
313 P1411 The negative deviation of throttle controller is below the lower limit for a long time.
314 P1415 The time for transforming from RGN to NRM mode is too long.
315 P1418 The indicator actuator circuit for EGR bypass regulating valve is open.
116
S/N DTC Meaning

316 P1419 Overheating of indicator actuator for EGR bypass regulating valve
317 P141A The indicator actuator circuit for EGR bypass regulating valve is short to battery.
318 P141B The indicator actuator circuit for EGR bypass regulating valve is short to ground.
319 P141C The relay actuator circuit for EGR bypass regulating valve is open.
320 P141D Overheating of relay actuator for EGR bypass regulating valve
321 P141E The relay actuator circuit for EGR bypass regulating valve is short to battery.
322 P141F The relay actuator circuit for EGR bypass regulating valve is short to ground.
323 P1420 The maximum exhaust temperature signal of the 1st cylinder is too strong.
324 P1421 The maximum exhaust temperature signal of the 2nd cylinder is too strong.
325 P1422 The maximum exhaust temperature signal of the 3rd cylinder is too strong.
326 P1423 The maximum exhaust temperature signal of the 4th cylinder is too strong.
329 P1426 The minimum exhaust temperature signal of the 1st cylinder is too strong.
330 P1427 The minimum exhaust temperature signal of the 2nd cylinder is too strong.
331 P1428 The minimum exhaust temperature signal of the 3rd cylinder is too strong.
332 P1429 The minimum exhaust temperature signal of the 4th cylinder is too strong.
333 P142A The minimum exhaust temperature signal of the 5th cylinder is too strong.
334 P142B The minimum exhaust temperature signal of the 6th cylinder is too strong.
335 P1430 The exhaust temperature T0 in cold start is unreliable.
341 P1436 The exhaust temperature signal is unreliable.
342 P1437 Unreliable monitoring of the 1st cylinder exhaust temperature
343 P1438 Unreliable monitoring of the 2nd cylinder exhaust temperature
344 P1439 Unreliable monitoring of the 3rd cylinder exhaust temperature
345 P143A Unreliable monitoring of the 4th cylinder exhaust temperature
346 P143B Unreliable monitoring of the 5th cylinder exhaust temperature
347 P143C Unreliable monitoring of the 6th cylinder exhaust temperature
348 P1440 Negative deviation error of oxygen sensor regulator
349 P1441 Positive deviation error of oxygen sensor regulator
117
S/N DTC Meaning

350 P1442 Conversion failure of oxygen sensor regulator
351 P1450 The particulate filter upstream temperature is unreliable.
352 P1451 The signal level of particulate filter upstream temperature is relatively high.
353 P1452 The signal level of particulate filter upstream temperature is relatively low.
354 P1453 The signal level of particulate filter upstream temperature sensor is relatively high.
355 P1454 The signal level of particulate filter upstream temperature sensor is relatively low.
356 P1455 Connection failure of particulate filter differential pressure sensor hose
357 P1456 The particulate filter differential pressure sensor is unreliable.
358 P1457 Maximum characteristic differential pressure of particulate filter
359 P1458 Minimum characteristic differential pressure of particulate filter
360 P1459 Minimum deviation of particulate filter
361 P145A The signal level of particulate filter flow impedance is high.
362 P145B Maximum deviation of particulate filter smoke mass
363 P145C Minimum deviation of particulate filter smoke mass
364 P145D Maximum value of particulate filter smoke mass
365 P145E The signal level of particulate filter flow impedance is relatively high.
366 P145F The signal level of particulate filter flow impedance is relatively low.
367 P1460 The maximum differential pressure signal of particulate filter is enhanced.
368 P1461 The minimum differential pressure signal of particulate filter is enhanced.
369 P1462 The dynamic differential pressure of particulate filter is unreliable.
370 P1463 The differential pressure self-adaption of particulate filter hose is unreliable.
371 P1464 Particulate filter differential pressure error
The physical value of differential pressure sensor for particulate oxidation catalyst
372 P146A
exceeds the upper limit.
The physical value of differential pressure sensor for particulate oxidation catalyst
373 P146B
falls below the lower limit.
374 P146C CAN Signal error
375 P146D CAN Signal error
376 P1470 Nernst signal error of oxygen sensor
377 P1471 The oxygen sensor is virtually grounded.
378 P1472 The dynamic signal level of oxygen sensor is relatively low.
379 P1473 Oxygen sensor heater coupling signal fault
380 P1474 The oxygen sensor heater signal is unreliable.
381 P1475 The oxygen sensor battery voltage is relatively low.
382 P1476 The calibration signal level of oxygen sensor is relatively high.
118
S/N DTC Meaning

383 P1477 The calibration signal level of oxygen sensor is relatively low.
384 P1478 The oxygen concentration of oxygen sensor exceeds the maximum threshold.
385 P1479 The oxygen concentration of oxygen sensor exceeds the minimum threshold.
386 P147A Relatively high oxygen concentration is unreliable.
387 P147B Relatively high oxygen concentration is unreliable.
388 P147C Relatively high oxygen concentration is unreliable.
389 P147D Relatively low oxygen concentration is unreliable.
390 P147E Relatively low oxygen concentration is unreliable.
391 P147F Relatively low oxygen concentration is unreliable.
392 P1480 The calibration value of oxygen sensor internal impedance is too high.
393 P1481 The calibration value of oxygen sensor internal impedance is too low.
394 P1482 The SPI battery voltage of oxygen sensor is too low.
395 P1483 The SPI signal of oxygen sensor is unreliable.
396 P1484 The oxygen sensor temperature is above the upper limit.
397 P1485 The oxygen sensor temperature is below the lower limit.
398 P1486 The oxygen sensor voltage in shunting exceeds the threshold.
399 P148A The signal level of turbocharger upstream temperature sensor is relatively high.
400 P148B The signal level of turbocharger upstream temperature sensor is relatively low.
401 P1500 The voltage signal level of vehicle speed sensor is relatively high.
402 P1501 The voltage signal level of vehicle speed sensor is relatively low.
Power supply diagnosis is disabled in electrifying phase due to overvoltage of
403 P150A
battery.
Power supply diagnosis is disabled in electrifying phase due to under-voltage of
404 P150B
battery.
Overtemperature of compressor torque reduction command circuit in electrifying
409 P1514
phase
410 P1515 A/C switch CAN input signal is unreliable.
The compressor torque reduction command circuit in electrifying phase is short to
411 P1516
ground.
The compressor torque reduction command circuit in electrifying phase is short to
412 P1517
power.
413 P1520 Short circuit of turbocharger bridge-H
119
S/N DTC Meaning

414 P1521 Under-voltage of turbocharger bridge-H
415 P1522 Overcurrent of turbocharger bridge-H
416 P1523 Overtemperature of turbocharger bridge-H
417 P1524 Overcurrent of turbocharger bridge-H temperature sensor
418 P1525 The valve is stuck in deviation learning process.
419 P1526 Output circuit 1 of turbocharger bridge-H is short to ground.
420 P1527 Output circuit 1 of turbocharger bridge-H is short to ground.
421 P1528 Output circuit 1 of turbocharger bridge-H is short to battery.
422 P1529 Output circuit 2 of turbocharger bridge-H is short to battery.
424 P1602 Too high downstream temperature of coolant temperature sensor is unreliable.
429 P160A EGR valve circuit is open.
430 P160B Overtemperature of EGR valve bridge-H chip
431 P160C Overcurrent of turbocharger bridge-H temperature sensor
432 P1610 Execute closing fuel injection under standard ICO mode.
433 P1613 The electrifying time detected by galloping prevention monitor is too long.
434 P1614 Several faults occur during SPI communication.
435 P1615 Time-out when trying to set up or cancel alarm task
436 P1617 Error reported in monitoring under-voltage
437 P1618 WDA works abnormally.
439 P161A EGR valve circuit is short to ground.
440 P161B EGR valve circuit is open.
441 P161C EGR valve circuit is open.
442 P161D Failure in software reset visibility
443 P161E Failure in software reset visibility
444 P161F Failure in software reset visibility
445 P1620 TTLAMP drive circuit is open.
446 P1621 The drive circuit for fuel consumption display is short to power supply.
447 P1622 The drive circuit for fuel consumption display is short to ground.
120
S/N DTC Meaning

448 P1623 The drive circuit for fuel consumption display is open.
449 P1624 Overtemperature of the drive circuit for fuel consumption display
450 P1625 TTLAMP drive circuit is short to power supply.
451 P1626 TTLAMP drive circuit is short to ground.
452 P1627 Overheating of TTLAMP drive circuit
453 P1633 The signal level of ECU temperature sensor is relatively high.
454 P1634 The signal level of ECU temperature sensor is relatively high.
455 P1635 The signal level of ECU temperature sensor is relatively low.
456 P1636 The signal level of ECU temperature sensor is relatively low.
457 P1637 The power supply voltage is too high.
458 P1638 The power supply voltage is too low.
459 P1639 The physical value of ECU temperature sensor exceeds the upper limit.
460 P163A The physical value of ECU temperature sensor falls below the lower limit.
461 P163B ECU temperature sensor SPI fault (LM71)
462 P1640 Compressor overtemperature in electrifying phase
463 P1643 Signal safety checkout error
464 P1645 The injection frequency is limited by the boosting electric quantity charging balance.
The injection frequency is limited by the high pressure fuel pump fuel quantity
465 P1646
balance.
466 P1647 The injection frequency is limited by the runtime.
467 P164C EGR valve circuit is open.
468 P164D EGR valve circuit is short to power supply.
469 P164E EGR valve circuit is short to ground.
470 P1650 EEP Clear Error
471 P1651 EEP Clear Error
472 P1652 An error is reported when the module’s data-writing is disabled for three times.
473 P165A Null dataset identifier
474 P165B Dataset switchover fault
475 P165C EEPROM data-reading error
476 P1660 ADC open circuit pulse test fault
477 P1662 The voltage being transformed by ADC module exceeds the set range of test voltage.
478 P1663 The radiometry correction exceeds the set range.
479 P1664 Monitoring control communication fault
480 P1665 SPI Monitoring control communication fault
121
S/N DTC Meaning

481 P1666 Several faults occur when testing the whole ROM zone.
The number of responsive bytes obtained from CPU in monitoring mode is too small
482 P1667
/ Error of the set response time of monitoring mode
483 P1668 Error of the set response time of monitoring mode
484 P166A OFF-route test time-out
485 P166B The electrifying time for injection is unreliable.
486 P166C The initial electrifying angle (SO E) is unreliable.
487 P166D ZFC is unreliable.
488 P166E Fuel injection monitoring mode 1
489 P166F Fuel injection monitoring mode 2
490 P1670 Error reported in fuel injection correction
491 P1671 Unreliable rail pressure
The torque limit is set once any error is detected before the MoCSOP's error is
492 P1672
generated.
493 P1673 Monitoring OFF-route forward test fault
494 P1674 Monitoring fault mode 3
495 P1675 The negative deviation of throttle controller is below the lower limit for a long time.
496 P1676 Open circuit of EGR valve bridge-H
497 P1677 Overload of EGR valve bridge-H
499 P167B CY33X fault
The set value of rail pressure is limited by the torque limit of the function control
500 P167C
unit.
501 P1680 The cruise indicator drive circuit is open.
502 P1681 Overtemperature of cruise indicator drive circuit
503 P1682 The cruise indicator drive circuit is short to power supply or high level.
504 P1683 The cruise indicator drive circuit is short to ground.
505 P1684 The grill heater is always ON.
506 P1685 DFC mechanical fault when turning on ignition switch
507 P1686 Fuel filter heating power level temperature fault
508 P1687 CJ945 Power level no load fault
509 P1688 CJ945 Power level no load fault
510 P1689 Overheating of intake air heater drive circuit
511 P168A CJ945 Overheating fault
512 P168B CJ945 Power level is short to battery.
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S/N DTC Meaning

513 P168C CJ945 Power level is short to battery.
514 P168D CJ945 Power level is short to ground.
515 P168E CJ945 Power level is short to ground.
516 P1700 Unreliable clutch signal / Clutch signal error
517 P1710 Overheating of engine speed sensor
518 P1720 Transmission neutral position signal
519 P2002 The particulate oxidation catalyst device is removed.
520 P2004 Overcurrent of EGR valve bridge-H based on temperature
524 P2014 Under-voltage of EGR valve bridge-H
525 P2015 The turbocharger control valve is stuck.
526 P2072 The throttle valve is frozen.
527 P2076 An error is reported when the EGR valve is stuck in closing or opening.
528 P2077 The signal level of swirl valve position sensor is relatively low.
The signal level measured by the variable swirl valve position sensor is above the
529 P2078
limit.
530 P207A Overtemperature of EGR valve bridge-H chip
531 P207B The short-term jitter of EGR valve exceeds the limit.
532 P2100 Open circuit of throttle bridge-H
533 P2101 Overcurrent of throttle bridge-H
534 P2102 Output circuit 1 of throttle bridge-H is short to ground.
535 P2103 Output circuit 1 of throttle bridge-H is short to battery.
536 P2135 Signals of accelerator pedal position sensor 1 and 2 are unreliable.
537 P213A Open circuit of EGR valve bridge-H
538 P213B Overload of EGR valve bridge-H
539 P213C The Port 2 of EGR valve bridge-H chip is short to ground.
540 P213D The Port 2 of EGR valve bridge-H chip is short to ground.
543 P2146 Short circuit
544 P2149 Short circuit
545 P2157 Unreliable vehicle speed signal
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S/N DTC Meaning

546 P2173 False positive deviation of throttle regulator
547 P2175 False negative deviation of throttle regulator
548 P2226 Fault of signal obtained from CAN by air pressure sensor
549 P2228 The signal value of ambient pressure is below the lower limit.
550 P2229 The signal value of ambient pressure is above the upper limit.
552 P2265 An error is reported when the moisture content in fuel is detected.
556 P2269 The sensor self-checking signal level is above the upper limit.
557 P2290 The rail pressure is below the minimum set value.
558 P242F The particulate filter smoke load exceeds the maximum.
559 P2454 The signal level of particulate filter differential pressure sensor is relatively low.
560 P2455 The signal level of particulate filter differential pressure sensor is relatively high.
561 P2458 Particulate filter regeneration permanent fault
562 P245A EGR cooler bypass valve fault
563 P245B Too low EGR cooling efficiency
564 P245D The signal level of EGR cooler sensor is relatively high.
565 P250F Danger is caused by too low fuel level and air ingress into hydraulic system.
566 P2519 A/C switch CAN input signal error
567 P2522 The compressor torque reduction command circuit in electrifying phase is open.
568 P2562 The turbocharger bridge-H chip circuit is open.
569 P2563 The turbocharger control valve is stuck.
570 P2564 The original voltage of EGR valve sensor signal is below the lower limit.
571 P2565 The original voltage of EGR valve sensor signal is above the upper limit.
572 P2621 The throttle signal level is relatively low.
573 P2622 The throttle signal level is relatively high.
574 P2626 The oxygen sensor pump current terminal IP is in open circuit.
575 B0020 Airbag collision status
576 U0121 ABS ECU main data loss
577 U0400 CAN received frame BCM1 message length error
578 U0415 CAN received frame ABS1 message length error
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Section V. Fault Diagnosis for Electronic-Controlled Common Rail Diesel Engines

z Prior to disconnecting or reconnecting the power cord of engine control module (ECM), be sure to turn off the
ignition switch, in order not to damage the ECM.
z All types of engine DTCs are stored in the ECM memory.
z The engine DTCs should be cleared after the maintenance.
Common DTCs and Troubleshooting Methods for Electronic Control Systems of Diesel Engines
1.
DTC P0475 The exhaust brake valve control line is open.

P0476 The ECU internal driver module of exhaust brake valve control line is
overheating.
P0477 The exhaust brake valve control line is short to ground.
P0478 The exhaust brake valve control line is short to high level.
Exhaust brake actuator
Fault Description: The engine control unit (ECU) shall actuate the exhaust braking after processing the signal
received from the exhaust brake switch and also check if the exhaust brake feedback signal matches with the ECU
control command. If not, DTC shall be reported.
Diagnosis Hint: The intermittent failure may be caused by poor contact of wire, abrasion of the insulation or damage
of the wire inside insulation.
Check for the following conditions:
z Poor contact of ECU or exhaust brake valve – Check the harness connector
– Loose terminal
– Poor matching and connection
– Breakage of keeper
– Distortion or damage of terminal
– Poor contact between terminal and wire
z Damage of harness – Check the harness for any damage
Terminal ECU
K29 Exhaust brake actuator
125
Fault Tree:
Check the检查制动阀连接
connection of brake valve.
Connector
插接件问题 fault Y Repair or replace it.
检修或更换
Check the appearance of brake valve.

对制动阀外观检测
Fault of brake valve

制动阀问题 Y Replace the brake valve.
更换制动阀
Check the ECU connector.

检查ECU插接件 Y Repair or replace it.
检修或更换
Replace
更换ECUthe ECU.
Get the Technical Support.

联系技术支持
126
2.
DTC P0069 The boost pressure sensor drift

The boost pressure sensor output voltage is below the lower limit (the wiring
P0237
is short to ground).
The boost pressure sensor output voltage is above the upper limit (the wiring
P0238
is open or short to high level).
The voltage of intake air temperature sensor is too low (the wiring is short to
P0097
ground).
The voltage of intake air temperature sensor is too high (the wiring is open
P0098
or short to high level).
5V power supply
Boost pressure /
Pressure signal
intake air
temperature sensor Ground
Temperature signal
Fault Description: The boost pressure sensor shall make response to the pressure change of intake manifold. The
pressure changes with the engine load. The ECU shall supply 5V voltage to the 5V reference voltage circuit of boost
pressure sensor and also supply grounding for the low reference voltage circuit. The boost pressure sensor shall
provide a signal that is related to the pressure change of intake manifold to ECU via the boost pressure sensor signal
circuit. When the intake manifold pressure is relatively low (for example: during idling period), the low level signal
voltage shall be detected by the ECU. When it is relatively high (for example: with the accelerator pedal fully open
(WOT)), the high level signal voltage shall be detected. The boost pressure sensor is also for determining the
barometric pressure (BARO). When the ignition switch is turned on without starting the engine, the following
condition shall occur. As long as the accelerator pedal position sensor signal is more than 28%, the barometric
pressure reading shall be updated. The boost pressure sensor includes the following circuits:
z A 5V reference voltage circuit
z A low reference voltage circuit
z A MAP sensor signal circuit
If the boost pressure sensor signal detected by ECU is beyond the set range, relevant DTC shall be generated.
The intake air temperature (IAT) sensor is a kind of variable resistor that can measure the temperature of air into the
engine. The ECU shall supply 5V voltage to the signal circuit of IAT sensor and also supply grounding for the
reference voltage circuit of IAT sensor. When the IAT sensor is in cold state, the sensor resistance is relatively high.
When the air temperature increases, the sensor resistance shall decrease. When the sensor resistance is relatively high,
the voltage of IAT sensor signal circuit detected by ECU shall be relatively high. With the decrease of sensor
resistance, the voltage of IAT sensor signal circuit detected by ECU shall decrease also. If the signal voltage of IAT
sensor detected by ECU is too low (indicating the temperature is too high), or too high (indicating the temperature is
too low), relevant DTC shall be generated.
127
Diagnosis Hint:
The normal boost pressure sensor shall make quick response to the change of accelerator pedal position, so its slow
action should not appear or it should not act slower than the change of accelerator pedal position.
For poor contact inspection between ECU and IAT sensor, please check the ECU harness connector for the following
conditions:
− Loose terminal
− Poor matching and connection
− Breakage of keeper
− Distortion or damage of terminal
− Poor contact between terminal and wire
Terminal ECU
A07 Power supply terminal of sensor
A53 Temperature signal terminal
A54 Pressure signal terminal
A28 Ground terminal of sensor
128
Fault Tree:
Check the component connector.
Connector fault Repair or replace it.
Detect the sensor.
Sensor fault Replace the sensor.
Fault of ECU connector Repair or replace it.
Check continuity and insulating

property.
Electrical fault Repair the harness.
Replace the component.
Does the problem still exist? Get the Technical Support.
129
3.
DTC P0087 The fuel pressure is below the lower limit.

P0088 The fuel pressure is above the upper limit.
P0191 The forward drift of common rail pressure sensor is too large.
The common rail pressure sensor output voltage is below the lower limit (the wiring
P0192
is short to ground).
The common rail pressure sensor output voltage is above the upper limit (the
P0193
wiring is open or short to high level).
P0194 The reverse drift of common rail pressure sensor is too large.
P1011 The positive deviation of rail pressure control is above the upper limit.
P1012 The positive deviation of rail pressure control exceeds the upper limit greatly.
P1013 The negative deviation of rail pressure control is below the lower limit.
5V power supply
Common rail Rail pressure signal
pressure sensor
Ground
Fault Description: The common rail pressure sensor shall make response to the change of fuel pressure in common
rail pipe. The pressure changes with the engine load. The ECU shall supply 5V voltage to the 5V reference voltage
circuit of common rail pressure sensor and also supply grounding for the low reference voltage circuit. The common
rail pressure sensor shall provide a signal that is related to the change of fuel pressure in common rail pipe to ECU via
the common rail pressure sensor signal circuit. When the fuel pressure in common rail pipe is relatively low (for
example: during idling period), the low level signal voltage shall be detected by the ECU. When it is relatively high
(for example: with the accelerator pedal fully open (WOT)), the high level signal voltage shall be detected. The
common rail pressure sensor provides an important parameter for determining engine operation. When its signal is
lost, the engine shall stop operation. The common rail pressure sensor includes the following circuits:
z A common rail pressure sensor signal circuit
If the common rail pressure sensor signal detected by ECU is beyond the set range, relevant DTC shall be generated.
Diagnosis Hint: When the ignition switch is turned on with engine off, the pressure in common rail pipe is zero and
the signal voltage level is low. By comparing the readings with those of the same sensor that is known good, the
accuracy of the suspicious sensor can be checked. Their difference should be no more than 0.4V. Perform overall
inspection for common rail pressure sensor to see if it is damaged.
During engine starting, any pressure change in the common rail pipe should be detected by the common rail pressure
sensor, through which, we can determine if the sensor is stuck at a certain value.
The normal common rail pressure sensor shall make quick response to the change of accelerator pedal position, so its
slow action should not appear or it should not act slower than the change of accelerator pedal position.
130
Terminal ECU
A06 Power supply terminal of common rail pressure sensor
A52 Signal terminal of common rail pressure sensor
A40 Ground terminal of common rail pressure sensor
131
Fault Tree:
Read DTC.
Fault of fuel metering unit Repair accordingly.
Check the common rail pressure

sensor.
Fault of common rail pressure

sensor Repair accordingly.
Check the low pressure oil circuit

by referring to fault tree of “Low
Pressure Oil Circuit”.
Fault of the low pressure oil

circuit Repair accordingly.
Fault of the high pressure oil

Repair the harness.
circuit
132
Inspection for Low Pressure/High Pressure Oil Circuit:
Low pressure oil circuit
Check fuel tank supply. Only checking the fuel tank

level indicator is not enough, for its indication may
be invalid.
Is there no fuel in the fuel tank? Add fuel.
Check the status and function of manual pump.
Fault of manual pump Repair accordingly.
Visually inspect the low pressure pipeline (leakage,

coordination, connection)
Fault of low pressure pipeline Repair accordingly.
Ensure there is no air bubble in the low pressure oil

circuit.
Find out where the air comes from
Is there air in the oil circuit? and repair the system, and then clean
the fuel pipe.
Ensure the diesel filter model and the connection of

fuel inlet and outlet are correct.
Replace the current filter with the

Incorrect signal or connection original one or connect the inlet and
outlet pipes of filter correctly.
High pressure oil circuit
Make diagnosis for the high pressure oil circuit in

strict accordance with the diagnostic procedures for
high pressure oil circuit.
Is there any problem? Repair accordingly.
The high pressure oil circuit is intact.
133
4.
DTC P0116 The dynamic characteristics of coolant temperature sensor are unreliable.
The coolant temperature sensor output voltage is below the lower limit (the
P0117
wiring is short to ground).
The coolant temperature sensor output voltage is above the upper limit (the
P0118
wiring is open or short to high level).
P0119 The static characteristics of coolant temperature sensor are unreliable.
Coolant temperature
Coolant temperature signal (High)
sensor Coolant temperature
signal (Low)
Fault Description: The engine coolant temperature (ECT) sensor is a kind of negative temperature coefficient
variable resistor, which can measure the engine coolant temperature. Its resistance shall decrease with the increase of
temperature, so the signal value input into ECU in the form of voltage shall decrease accordingly. The voltage signal
range is 0-5V. The ECU searches the characteristic curve of the sensor and converts it into engine coolant temperature.
The diagnostic module of engine coolant temperature sensor shall make fault judgment based on this temperature
value. The ECU shall supply 5V voltage to the signal circuit of engine coolant temperature sensor and also supply
grounding for the low reference voltage circuit. If the signal voltage of engine coolant temperature sensor detected by
ECU is too low (indicating the temperature is too high), or too high (indicating the temperature is too low), relevant
DTC shall be generated.
The following table illustrates the difference among temperature, resistance and voltage.
Resistance of coolant temperature Signal voltage of coolant temperature

Engine coolant temperature
sensor sensor
Low High High
High Low Low
Diagnosis Hint:
Overheating may result in generation of this DTC. After the engine is started, the temperature of engine coolant
temperature sensor should increase steadily and become stable after the thermostat is disconnected. Test the engine
coolant temperature sensor under different temperature to check for any error of sensor. If any, the error may result in
failure of control performance. After the engine is laid up for a night, the indication difference between IAT sensor and
engine coolant temperature sensor should be within 3°C (5°F). Refer to “Temperature and Resistance”.
Poor contact between ECU and engine coolant temperature sensor – Check the harness connector for:
− Loose terminal
134
Check the harness for any damage. If the harness appears normal, observe the ECT indication on the diagnostic tool
while moving relevant connector and harness of ECT sensor. If the ECT indication changes, there must be failure in
that part. If the DTC won’t appear again, the fault record data can be used for determining the self-diagnostic code and
the running mileage after the previous setting can be used for determining the occurrence frequency of that condition,
which can facilitate the troubleshooting for overheating.
After the engine is started, the engine coolant temperature shall increase steadily to about 90°C (194°F) and then
become stable after the thermostat is disconnected.
Terminal ECU
A37 Signal terminal of ECT sensor
A50 Ground terminal of ECT sensor
135
Fault Tree:
Check the sensor connection.
Connector fault Repair accordingly.
Detect the sensor resistance. (Is it consistent with

the vehicle condition?)
Fault of sensor resistance Replace the sensor.
Fault of ECU connector Repair accordingly.
Check continuity and insulating property.
136
5.
DTC P0122 The output voltage of accelerator pedal potentiometer 1 is below the lower limit.
P0123 The output voltage of accelerator pedal potentiometer 1 is above the upper limit.
P0222 The output voltage of accelerator pedal potentiometer 2 is below the lower limit.
P0223 The output voltage of accelerator pedal potentiometer 2 is above the upper limit.
Power supply of sensor

1
Signal 1
Ground of sensor 1
Electronic
accelerator pedal Power supply of sensor
2
Signal 2
Ground of sensor 2
Fault Description: The accelerator pedal assembly consists of two accelerator pedal position (APP) sensor. The APP
sensors are installed on the pedal assembly and are not repairable. The APP sensor shall supply a signal voltage that
changes with the accelerator pedal position. The ECU shall supply an individual 5V reference voltage circuit and a
low level reference voltage circuit to each APP sensor. With the pedal depressed, the signal voltage of APP sensor 1
shall increase, viz. increasing from about 0.7V (at the released position) to above 4V (at the fully depressed position).
With the pedal depressed, the signal voltage of APP sensor 2 shall increase, viz. increasing from about 0.3V (at the
released position) to above 2V (at the fully depressed position).
APP sensor 1 and 2 are installed in the accelerator pedal assembly. Each one consists of the following circuits:
z A signal circuit
With those circuits, the APP sensors can provide the signal voltage that is proportional to the displacement of
accelerator pedal to the ECU. Two processors, located in the ECU, are adopted to monitor the data of throttle actuator
control system. Each signal circuit shall provide the signal voltage that is proportional to the displacement of
accelerator pedal to two processors. Those two processors shall monitor each other to verify whether the indicated
value of pedal position is correct or not. The test method of ECU is: making the signal of APP sensor 2 lower
instantaneously to see if the signal of APP 1 is also made lower.
Diagnosis Hint: During testing, if it is necessary to detect the ECU harness connector or component harness
connector, a diagnostic connector should be adopted to test the adapter component.
If several DTCs appear simultaneously, please check if the signal circuits for APP sensor 1 and 2 are short to each
other.
137
Terminal ECU
K28 Power supply terminal of APP sensor 1
K81 Signal terminal of APP sensor 1
K67 Ground terminal of APP sensor 1
K22 Power supply terminal of APP sensor 2
K60 Signal terminal of APP sensor 2
K58 Ground terminal of APP sensor 2
138
Fault Tree:
Visually check the component.
Component fault Replace the component.
ECU connector fault Repair accordingly.
139
6.
DTC P0201 The 1st cylinder fuel injector circuit is open.

P0263 Other errors of the 1st cylinder fuel injector
P1200 The forward error correction of the 1st fuel injector is too large.
P1201 The reverse error correction of the 1st fuel injector is too large.
P120C The dynamic forward error correction of the 1st fuel injector is too large.
P120D The dynamic reverse error correction of the 1st fuel injector is too large.
P1613 The electrifying time detected by galloping prevention monitor is too long.
1st cylinder fuel injector “High”
1st cylinder fuel injector “Low” 1st cylinder
Fault Description: The ECU controls the switching-on circuit of fuel injector directly. The ECU controls the time for
switching on each fuel injector via adopting a device named “Driver” to supply PWM current to each fuel injector
control circuit. The driver owns a feedback circuit, which is monitored by ECU to verify if the control circuit is open
or short. If any failure in the fuel injector control circuit is detected by ECU, the fuel injector control circuit DTC shall
be generated.
Diagnosis Hint: For the failure in wire connector shall trigger the setting of DTC, be sure to check the connectors
relevant to this diagnostic procedure for short circuit of terminal or poor contact of wire, prior to replacement of any
component. Observe the state parameter of relevant fuel injector on the diagnostic tool while shaking the wire and
connector relevant to the test. If any intermittent failure is existed in the tested wire or connector, the relevant failure
shall be displayed on the diagnostic tool.
Performing compression test is helpful for locating the intermittent failure.
Terminal ECU
A16 1st fuel injector “High”
A47 1st fuel injector “Low”
140
Fault Tree:
Turn off the ignition switch and check the fuel
injector connector.
Disconnect the fuel injector and turn on the ignition

switch.
Refer to “Inspection of Fuel Injector

Does the problem still exist? Wiring” listed below.
Clear the DTC, turn off the ignition switch, reconnect

the fuel injector and turn on the ignition switch.
Replace relevant fuel injector and

update the ECU data.
Does the problem reoccur?
Repeat the above procedures for other fuel injectors.
Check the wiring of fuel injector.
141
7.
DTC P0202 The 2nd cylinder fuel injector circuit is open.

P0264 The low end of the 2nd fuel injector is short to the high end.
P0265 The low end of the 2nd fuel injector is short to the high level.
P0266 Other errors of the 2nd cylinder fuel injector
P1202 The forward error correction of the 2nd fuel injector is too large.
P1203 The reverse error correction of the 2nd fuel injector is too large.
P120E The dynamic forward error correction of the 2nd fuel injector is too large.
P120F The dynamic reverse error correction of the 2nd fuel injector is too large.
2nd cylinder fuel injector “High”
2nd cylinder fuel injector “Low” 2nd cylinder
be generated.
Diagnosis Hint:
For the failure in wire connector shall trigger the setting of DTC, be sure to check the connectors relevant to this
diagnostic procedure for short circuit of terminal or poor contact of wire, prior to replacement of any component.
Observe the state parameter of relevant fuel injector on the diagnostic tool while shaking the wire and connector
relevant to the test. If any intermittent failure is existed in the tested wire or connector, the relevant failure shall be
displayed on the diagnostic tool.
Terminal ECU
A02 2nd fuel injector “High”
A31 2nd fuel injector “Low”
142
Fault Tree:
injector connector.

switch.
Does the problem still exist? Refer to “Inspection of Fuel Injector

Wiring” listed below.


Does the problem reoccur? update the ECU data.
143
8.
DTC P0203 The 3rd cylinder fuel injector circuit is open.

P0267 The low end of the 3rd fuel injector is short to the high end.
P0268 The low end of the 3rd fuel injector is short to the high level.
P0269 Other errors of the 3rd cylinder fuel injector
P1204 The forward error correction of the 3rd fuel injector is too large.
P1205 The reverse error correction of the 3rd fuel injector is too large.
P1210 The dynamic forward error correction of the 3rd fuel injector is too large.
P1211 The dynamic reverse error correction of the 3rd fuel injector is too large.
P1239 Other errors of the 3rd cylinder fuel injector
P123A Other errors of the 3rd cylinder fuel injector
P123B Other errors of the 3rd cylinder fuel injector
1st fuel injector “High”

3rd cylinder
1st fuel injector “Low”
be generated.
Terminal ECU
A01 1st fuel injector “High”
A46 1st fuel injector “Low”
144
Fault Tree:
injector connector.

switch.

Does the problem still exist?
Wiring” listed below.
Clear the DTC, turn off the ignition switch,

reconnect the fuel injector and turn on the ignition
switch.

145
9.
DTC P0204 The 4th cylinder fuel injector circuit is open.

P0270 The low end of the 4th fuel injector is short to the high end.
P0271 The low end of the 4th fuel injector is short to the high level.
P0272 Other errors of the 4th cylinder fuel injector
P1206 The forward error correction of the 4th fuel injector is too large.
P1207 The reverse error correction of the 4th fuel injector is too large.
P1212 The dynamic forward error correction of the 4th fuel injector is too large.
P1213 The dynamic reverse error correction of the 4th fuel injector is too large.
P123C Other errors of the 4th cylinder fuel injector
P123D Other errors of the 4th cylinder fuel injector
P123E Other errors of the 4th cylinder fuel injector
2nd fuel injector “High”

4th cylinder
2nd fuel injector “Low”
be generated.
Terminal ECU
A17 2nd fuel injector “High”
A33 2nd fuel injector “Low”
146
Fault Tree:
injector connector.

switch.

Does the problem still exist? Wiring” listed below.


147
10.
DTC P0251 The control line of fuel level control unit is open.
P0252 The ECU internal driver module of fuel level control unit is overheating.
P0253 The control line of fuel level control unit is short to ground.
P0254 The control line of fuel level control unit is short to high level.
Control of fuel metering unit Fuel metering unit
Fault Description: The fuel metering unit is for adjusting the fuel supply and the fuel pressure. When the control coil
of metering unit is off, the inlet fuel metering proportional valve of the unit shall be closed, cutting off the fuel
supplied to the high pressure fuel pump plunger component. When the control coil of metering unit is electrified, the
ECU shall change the fuel inlet sectional area of metering component via pulse signal according to the actual demand,
through which, the fuel supplied to the high pressure fuel pump plunger component shall be changed. If the fuel
metering control signal voltage detected by ECU is abnormal, the DTC shall be generated.
Diagnosis Hint: The metering component is mounted at the fuel inlet of high pressure pump. The engine’s fuel
supply shall be affected directly by the opening sectional area of the fuel metering unit control valve. Provided that the
fuel metering unit control line is normally connected, monitor the engine fuel supply amount and pressure while
moving relevant connector and wire to check if any fault is triggered. If any, the indication of fault diagnostic unit
shall change. This is help for locating the intermittent failure.
The intermittent failure may be caused by poor contact of control part. As for poor contact between ECU and fuel
metering unit, please check the ECU harness connector for the following conditions:
− Loose terminal
Check the harness for any damage. If the harness appears normal, observe the fuel pressure indicated on the diagnostic
tool while moving relevant connector and harness of fuel metering unit. If the pressure indication changes, there must
be failure in that part.
Terminal ECU
A19 Power supply terminal of fuel metering unit
A49 Signal terminal of fuel metering unit
148
Fault Tree:
Check the connector of fuel metering unit.
Measure the resistance of fuel metering unit

(it is about 5.3 Ohms at 20℃)
Resistance fault Repair the fuel metering unit.
149
11.
DTC P0335 No signal from crankshaft sensor

P0336 False signal from crankshaft sensor
Signal
Wheel speed sensor Ground
Shielded wire
Diagnosis Hint: The signal of crankshaft position (CKP) sensor is used for indicating the rotary speed and position of
crankshaft. The CKP sensor shall generate an AC voltage of different amplitude and frequency. The frequency relies
on the rotary speed of crankshaft and the output AC voltage relies on the crankshaft position. The CKP sensor shall
coordinate with a 58X variable reluctance rotor fixed on the crankshaft. The ECU can synchronize the timing control
for fuel injectors according to the input signals of CKP sensor and camshaft position sensor. The CKP sensor can also
be applied for testing misfire and tachometer indication. The signal circuit and the low reference voltage circuit of
CKP sensor are directly connected to ECU. The shielded and grounded circuit should be grounded. In addition, when
the 1st and the 4th cylinders are at TDC, the CKP sensor shall also send a signal to ECU. The ECU shall monitor the
signals of CKP sensor and camshaft position sensor to determine whether the 1st cylinder is in compression stroke or
not. The circuits between CKP sensor and ECU include:
Signal circuit of CKP sensor
Low reference voltage circuit of CKP sensor
Shielded and grounded circuit
If the number of crankshaft position pulses sent out by the CKP sensor detected by the ECU is incorrect, the DTC
shall be generated.
Diagnosis Hint: There is failure in camshaft position sensor circuit.
CKP sensor variable reluctance rotor is dislocated or incorrectly installed.
Large crankshaft end play leads to dislocation of variable reluctance rotor.
There is blockage between CKP sensor and variable reluctance rotor.
Check connectors of CKP sensor and ECU for any corrosion.
Prior to maintenance, all fragments should be removed from the connector surfaces. Prior to diagnosis or replacement,
please check the connector gaskets to ensure they are properly installed to avoid ingress of any pollutant.
z Poor terminal connection – Check the harness connector for any loose terminal, mismatching, damaged keeper,
improper form or damage, poor contact between terminal and wire. Check if the matched terminal is adopted.
Check if the test tension is appropriate.
z Harness damage – Check the harness for any damage. If the harness appears normal, observe the indication on
the diagnostic tool while moving relevant connector and harness of the sensor. If the indication changes, there
must be failure in that part.
150
z Check if the ground and connection of ECU and engine is reliable and clean. If the DTC is determined to be
intermittent failure, please refer to the fault records to find out when the previous DTC is set.
Terminal ECU
A13 Signal terminal of CKP sensor
A14 Negative signal terminal of CKP sensor
A56 Shielded terminal of CKP sensor
151
Fault Tree:
The new sensor is connected.
Does the problem still exist? Replace the target wheel.
The new target wheel is installed.
152
12.
DTC P0340 No signal from phase sensor

P0341 False signal from phase sensor
5V power supply
Camshaft position
sensor CMP signal
Ground
Fault Description: The camshaft position (CMP) sensor is a Hall Effect switch. The ECU shall supply 5V voltage to
the 5V reference voltage circuit and also supply grounding for the low reference voltage circuit. The CMP sensor shall
provide a signal voltage to ECU by coordinating with 1X variable reluctance rotor. The ECU shall make use of this
signal voltage to determine the camshaft position. The CMP sensor links the crankshaft with the camshaft position to
facilitate ECU to determine which cylinder the fuel should be injected to. During the rotation of camshaft, the variable
reluctance rotor changes the magnetic field generated by the magnet in sensor and send a signal to ECU via the signal
circuit. The CMP sensor circuit is directly connected to ECU. The CMP sensor can also be adopted to tell which
cylinder has misfire. The circuits between CMP sensor and ECU include:
High reference voltage circuit of CMP sensor
Ground circuit
Camshaft position signal circuit
When no occurrence of minimum camshaft position synchronization is detected by ECU or there is failure in CMP
sensor signal circuit, DTCs shall be generated.
Diagnosis Hint: Prior to maintenance, all fragments should be removed from the connector surfaces. Prior to
diagnosis or replacement, please check the connector gaskets to ensure they are properly installed to avoid ingress of
any pollutant.
Poor terminal connection – Check the harness connector for any loose terminal, mismatching, damaged keeper,
improper form or damage, poor contact between terminal and wire. Check if the matched terminal is adopted. Check
if the test tension is appropriate.
Harness damage – Check the harness for any damage. If the harness appears normal, observe the indication on the
diagnostic tool while moving relevant connector and harness of the sensor. If the indication changes, there must be
failure in that part.
Check if the ground and connection of ECU and engine is reliable and clean. If the DTC is determined to be
intermittent failure, please refer to the fault records to find out when the previous DTC is set.
Terminal ECU
A08 Signal terminal of phase sensor
A57 Negative signal terminal of phase sensor
A35 Shielded terminal of phase sensor
153
Fault Tree:
Visually check the sensor.
Sensor fault Replace the sensor.
Check the signals of camshaft and crankshaft

sensor with oscilloscope if possible.
Signal fault Repair accordingly.
Check the target wheel of camshaft.
Fault of target wheel Replace the target wheel.
Check the positioning of camshaft target wheel.
False positioning of camshaft target wheel Correct the positioning of target wheel.
154
13.
DTC P0380 The glow plug works without the command from ECU.
P0382 The glow plug doesn’t work with the command from ECU.
P0383 ECU control line for glow plug is short to ground.
P0384 ECU control line for glow plug is short to high level.
P0670 ECU control line for glow plug is open or its driver module is overheating.
Glow plug
Power supply
Preheating control signal

Preheating relay Main relay
Preheating feedback signal
Fault Description: The main part of glow plug is tubular heating element, which is securely and tightly installed
inside the glow plug shell, making it resistant to corrosion and thermal shock. The heating element is composed of
two resistance elements connected in series; they are installed in the top of heat pipe forming respectively a heating
coil and a control coil. The glow plug controller controls over the glow plug via a power relay and electrical switch
group. It can control the heating time of glow plug and also serve as a protection and monitoring device. The higher
level glow plug controller has diagnosis function, so it can distinguish an individual fault of glow plug and indicate it
to the driver. A multilevel socket is equipped on the control input terminal of glow plug controller for connecting with
ECU. To avoid voltage drop, screw pins or plugs should be equipped in the series circuit that is connected with the
glow plug. The post-heating upon a success start can facilitate the uninterrupted speed increase and idling with little
smoke in the process of heating, which can reduce the combustion noise in cold starting. If it fails, the glow plug
protection circuit shall open to avoid overdischarging of battery. If no preheating control signal is detected by ECU or
the detected control signal is inconsistent with the actual, relevant DTCs shall be generated.
Diagnosis Hint: The failure may be caused by poor contact of wire or loose connector. As for poor contact of ECU or
preheating control unit, check the harness connector for the following conditions:
Loose terminal
Poor matching and connection
Distortion or damage of terminal
Poor contact between terminal and wire
Damage of harness – Check the harness for any damage
Terminal ECU
K90 Control signal of preheating relay
K57 Preheating time feedback signal
155
Fault Tree:
Check检查预热塞接插件
the connector of glow plug.
接插件问题
Connector fault Y Repair
做必要的修理accordingly.
N
检查ECU接插件
接插件问题
Connector fault Y 做必要的修理
Repair accordingly.
Check continuity
检查连续性和绝缘性 and insulating property.
Electrical
电气问题 fault Y Repair
修理线束the harness.
Replace
更换预热塞the glow plug.
Does 问题仍否存在
the problem still exist? Y Get the Technical Support.
联系技术支持
156
14.
DTC P0500 Error of vehicle speed sensor acquisition hardware

P0501 The vehicle speed sensor signal is unreliable.
Fault Description: Vehicle speed sensor (VSS) provides vehicle speed signals to ECU. It is a kind of Hall Effect
sensor. When the rotor gear tooth of transmission output shaft passes through the magnetic field of sensor, the VSS
shall generate a signal voltage, whose frequency shall increase with the vehicle speed. The ECU shall convert the
signal voltage into vehicle speed and make use of the vehicle speed signal to determine the working status of vehicle.
If this signal is lost or abnormal, relevant DTCs shall be generated.
Diagnosis Hint: Check the harness for any damage. If the harness appears normal, observe the indication on the
digital multimeter while moving relevant connector and harness of the actuator. If the indication changes in testing,
there must be failure in that part. The intermittent failure may be caused by poor contact, abrasion of wire insulation
or breakage of the wire inside insulation. Make sure the vehicle speed sensor is correctly fixed onto the transmission
housing.
Terminal ECU
K75 VVS input signal
157
Fault Tree:
Check the VVS.
VVS fault Replace the VVS.
158
15.
DTC P0504 Unreliable comparison between main and auxiliary brake pedal signals
Main brake switch

Auxiliary brake switch
Fault Description: The brake switch detects the brake pedal action and sends the signal to ECU. The brake switch is
equipped with two switches, viz. main and auxiliary brake switches. When these two signals are input, these signals
are determined by ECU to be normal brake signals. The switch signals are relevant to the accelerator pedal, for
controlling the fuel amount during braking. There should be no failure when you operate the accelerator pedal at the
point of depressing the brake pedal, but the fuel amount shall be reduced when you operate the accelerator pedal with
the brake pedal depressed. If the voltage signal of brake switch is inconsistent with the actual, the DTC shall be
generated.
Diagnosis Hint: Check the wiring connector for poor contact, distorted or damaged terminal.
Terminal ECU
K17 Main brake switch signal
K80 Auxiliary brake switch signal
159
Fault Tree:
Visually check the component.
Component fault Replace the component.
ECU connector fault Repair accordingly.

property.
160
16.
DTC P0562 Too low battery voltage

P0563 Too high battery voltage
P1617 The engine cannot be shut down with too high internal supply voltage.
P1618 The engine cannot be shut down with too low internal supply voltage.
P1637 Too high voltage in ECU internal power supply module
P1638 Too low voltage in ECU internal power supply module
Ignition
switch
Power supply of main relay Main relay
Control of main relay
Power supply of ignition switch
Fault Description: The ECU monitors the system voltage via the ignition voltage circuit. When the voltage exceeds
the set range, the parts may be damaged and the input reading may be incorrect. When the system voltage detected by
ECU is too low (below 11V) or too high (above 16V), relevant DTCs shall be generated.
Diagnosis Hint: Check if the diagnostic system is normal.
Check if the charging system is normal.
Perform relevant test for intermittent failure or poor contact.
Terminal ECU
K01 Positive battery terminal +Ra
K03 Positive battery terminal +Rb
K05 Positive battery terminal +Rc
K47 Main relay control
K46 Ignition switch power supply
161
Fault Tree:
Check the battery voltage at
igniting.
Battery fault Charge the battery.
Check the battery connection.
Fault of battery connectors Repair accordingly.
Check the resistance between chassis

and ECU ground.
Is the resistance too high? Adjust the ECU ground.
Check the charging circuit of battery.
Fault of charging circuit Repair accordingly.
162
17.
DTC P060A Communication failure of ECU internal chip CJ940
Fault Description: It is mainly used for monitoring the internal microprocessor integrity failure in ECU to determine
whether the ECU program is executed. With engine OFF and ignition switch ON, the ECU shall perform
self-diagnosis. If the self-diagnosis process is not finished, the control module shall record the corresponding
operating condition and store this information into “Fault Records” to set DTC.
Diagnosis Hint: If the self-diagnosis process is finished smoothly, the current DTC shall be cleared.
If this diagnostic instrument and other diagnosis irrelevant to exhaust pass the test in 40 continuous preheating
processes, the history DTC shall be cleared.
Fault Tree:
Read DTC.
Replace the ECU with a good one for debugging.
163
18.
DTC P0642 Sensor supply voltage 1 is too low.

P0643 Sensor supply voltage 1 is too high.
P0652 Sensor supply voltage 2 is too low.
P0653 Sensor supply voltage 2 is too high.
Fault Description: Due to the nature of sensor, some sensors require a voltage to finish the required function and
operation. The supply voltage of sensor is supplied by ECU. The ECU shall calculate the required voltage of sensor
according to its characteristic and supply the voltage to the sensor via control circuit. In the process of voltage
signaling, DTCs may occur due to virtual connection or poor connection of control circuit, etc.
Sensor supply voltage 1: The power supply for accelerator pedal 1 and CMP sensor
Sensor supply voltage 2: The power supply for accelerator pedal 2, absolute pressure sensor and common rail
pressure sensor.
Diagnosis Hint: Check the ECU power voltage for any fault. The power voltage detected by multimeter should
generally be 5V. Check the voltage signal supplied to relevant sensor. The fault may be caused by virtual connection,
poor contact of wire, abrasion of insulation or damage of the wire in insulation. Check the circuit for the following
conditions:
– Loose terminal
– Poor matching and connection
– Breakage of keeper
– Distortion or damage of terminal
– Poor contact between terminal and wire
– Damage of harness – Check the harness for any damage
164
Fault Tree:
Read DTC.
Provided that the signal lost is caused

by a certain sensor, disconnect each
sensor one by one until the fault
Read DTCs of all sensors corresponding disappears and the failed sensor is
to the power connector located. If all sensors are normal, check
for short circuit and the insulating
property of wires.
Match the connector correctly.
The problem is solved.
165
19.
DTC P0686 The main relay opens too early.

P0687 The main relay opens too late.
Ignition
switch
Power supply of main relay Main relay
Control of main relay
Power supply of ignition switch
Fault Description: With the ignition switch OFF, the input circuit of main relay through K47 is actuated by V3 and
ECU Pin K46 and the electromagnet picks up the contact of output circuit, so the output circuit of main relay is in
continuity. Then, the power supply into the internal control module via ECU Pin K01, K03 and K05. If the ECU
signal for relay control is distorted, DTC shall be generated.
Diagnosis Hint: The intermittent failure may be caused by poor contact, abrasion of wire insulation or breakage of
the wire inside insulation. The ignition 1 relay fault shall lead to the failed starting of engine, for there is no voltage in
the ignition coil or fuel injectors in electronic ignition system and they cannot work without being electrified.
Terminal ECU
K47 Main relay control signal
166
Fault Tree:
Check the relay connector.
Replace the relay (running ISO

circulation.)
Fault of ISO circulation Get the Technical Support.
167
20.
DTC P0704 Clutch signals are unreliable.
Clutch switch
Fault Description: Transmission control unit (TCU) is integrated with engine control unit (ECU) and calculates
optimal time and speed for clutch engagement according to feedback information from sensors of accelerator pedal,
transmission gear position, transmission input/output shaft speed, engine speed, throttle opening and etc. Automatic
transmission (AT) actuating mechanism consists of electric oil pump, solenoid valve and clutch cylinder. When ECU
gives command to drive electric oil pump, high-pressure fluid generated in the pump goes through solenoid valve and
gets into clutch cylinder. ECU controls magnitude of current of solenoid valve for the control of fluid flow and fluid
passage change. Thus piston movement of clutch cylinder is realized in order to complete clutch operation during
vehicle starting and shift. In the case of inconformity between clutch signal and actual condition, DTC occurs.
Diagnosis Hint: clutch switch fault
Check switch wire harness (Check Terminal 58 of ECU for open circuit, short circuit and poor contact.)
Check switch power supply voltage and operation condition.
Determine ECU replacement according to actual condition.
Terminals ECU
K55 Clutch switch signal
168
Fault Tree:
Check clutch switch.
Clutch switch fault Replace the clutch switch.
Check clutch switch harness.
Harness fault Repair the harness.
Check clutch switch power supply voltage.
Power supply signals are distorted. Repair accordingly.
Replace ECU and check
169
21.
There are faults (short circuit or open circuit) in ECU OBD malfunction
DTC P0650
indicator lamp (MIL) output connecting wire.
Connection of ECU system MIL output connecting wire is short to high
P1619
level.
P161A Connection of ECU system MIL output connecting wire is short to ground.
P161B ECU system MIL output connecting wire is open.
P161C ECU system MIL drive module is overheated.
Malfunction indicator lamp (MIL)
OBD indicator lamp
Fault Description: Malfunction indicator lamps (MIL) are located on instrument panel cluster (IPC). MILs inform
driver about fault generation and necessary maintenance for engine control system. Control module monitors MIL
control circuit for inconformity of commands for MILs. For example, when MIL is disconnected by command, control
module monitors low voltage or when MIL is connected by command, control module monitors high voltage. This is
indicated that there are faults. When control module discovers incorrect voltage or overhigh temperature of MIL
control circuit, DTC occurs. In the case of 20 samplings for output status of MIL drive, open circuit or overhigh
temperature faults are detected in 15 samplings at least. There are 100msec for each sampling. ECU detects incorrect
output status or overlarge current of MIL drive and such status lasts for more than 2sec; for every 10 samplings of
MIL drive output status, there are short circuit faults in 5 samplings at least with time consumption for each sampling
process as 12.5msec and ECU detects short circuit for more than 1sec under MIL drive output status. In the case of
conditions above, DTCs occur.
Diagnosis Hint: When short circuit fault is detected, control module should stop starting MIL drive within remained
travel. Control module records operation condition when diagnosis is failed. For the first diagnosis failure, control
module will keep this information in fault record. If diagnosis failure occurs during the second continuous ignition
cycle, control module records operation condition under diagnosis failure and writes the operation condition in frozen
fault condition and updates fault record.
Terminal ECU
K70 System MIL output signal
K71 OBD indicator lamp
170
Fault Tree:
Check connection between instrument panel and ECU.

检查仪表板与ECU的连接

接插件问题 Y 做必要的修理
Check continuity and insulating property..

检查连续性和绝缘性

电气问题 Y 修理线束
Replace corresponding components.

更换相应的器件

问题仍存在 Y 联系技术支持
171
22.
Mass air flow (MAF) signals measured by air flow meter without correction
DTC P0100
are too strong or too weak (Connection is in open circuit or short circuit).
Mass air flow (MAF) signals measured by air flow meter with correction are
P0101
too strong or too weak (Connection is in open circuit or short circuit).
P0102 Mass air flow sensor negative drift
P0103 Mass air flow sensor positive drift
P0104 Mass air flow sensor zero drift
P1100 Air mass flowmeter software correction is excessive.
Intake air temperature signal Power supply
Intake air flow signal

Air flow meter
Ground signal
Fault Description: Mass air flow (MAF) sensor is an air flow meter which is used in measurement of air inflow of
engine. ECU correctly supplies fuel supply with the use of signals from mass air flow sensor for all engine speeds and
loads. In the case of small air inflow of engine, it is indicated there is vehicle deceleration or engine idling. In the case
of large air inflow of engine, it is indicated there is vehicle acceleration or high engine load. Mass air flow (MAF)
sensor possesses circuits as follows:
One ignition 1 voltage circuit
One ground circuit
One signal circuit
ECU applies a voltage to sensor via signal circuit. The sensor uses the voltage to generate a corresponding frequency
for air inflow which gets through the sensor. During idle running, the frequency changes in the range around 2000Hz.
ECU calculates predicted air flow value with input signals from sensors as follows:
Atmosphere pressure in the case of ignition key connection
Intake manifold absolute pressure sensor
Intake air temperature sensor
Engine coolant temperature sensor
Engine speed
ECU compares mass air flow sensor frequency signal with predicted air flow valve and verify signal lag (lack of
change), too low or too high signal level under given operation condition with the comparison. When D-value
between actual mass air flow sensor frequency signal which is detected by ECU and air flow meter calculated value is
not in preconcerted range, DTC occurs.
Diagnosis Hint: Check mass air flow sensor harness and verify whether harness arrangement is too close to
components as follows:
172
— Additional accessories after sale
— Secondary ignition wires or coils
— Solenoid valve
— Relay
— Motor
In the case of idle running or deceleration, air flow goes through sensor may reach its minimum and this may lead to
DTC occurrence. Check down stream of mass air flow sensor for vacuum leaks. Check mass air flow sensing elements
for affixed dirt or scraps. Check intake system for water penetration. Once there is water in mass air flow sensor, it
will lead to sensor deviation and DTC occurrence.
Wide open throttle during vehicle acceleration for starting may lead to rapid parameter increase of mass air flow
sensor on fault diagnostic apparatus. In other words, 3-10g/sec during idle running will increase to 150g/sec for shift
from the 1st gear to the 2nd. If parameters do not increase, check intake system and exhaust system for clogging.
Check engine coolant temperature sensor for deviation or lag.
In the case of too high resistance in ignition 1 voltage circuit (i.e. equals to or more than 15Ω), DTC occurs.
Terminal ECU
K12 Intake air temperature signal
K20 Intake air flow signal
K63 Ground signal
173
Fault Tree:
Check air flow meter connectors.

检查空气流量计接插件
Repair accordingly.
Connector
接插件问题 fault Y 做必要的修理
检查ECU接插件
Check ECU connectors.
Connector
接插件问题 fault Y Repair accordingly.
做必要的修理
Check for continuity and insulating property.

Repair the harness.

电气问题
Electrical fault Y 修理线束
Replace air flow meter.

更换空气流量计

问题仍否存在 Y 联系技术支持
174
23.
Connection for additional air temperature sensor of air mass flowmeter is

DTC P0110
short or open.
Temperature for additional air temperature sensor of air mass flowmeter is
P0112
too low.
Temperature for additional air temperature sensor of air mass flowmeter is
P0113
too high.
Analog output voltage for additional air temperature sensor of air mass
P1101
flowmeter is too high or too low.
Output duty ratio signal level of additional air temperature sensor of air
P1102
mass flowmeter is too high or too low.
Output duty ratio signal cycle of additional air temperature sensor of air
P1106
mass flowmeter is too long.
Output duty ratio signal cycle of additional air temperature sensor of air
P1107
mass flowmeter is too short.
Fault Description: Intake air temperature (IAT) sensor is a variable resistance for measurement of engine intake air
temperature. Air temperature sensor possesses a signal circuit and a low reference voltage circuit. ECU provides air
temperature sensor signal circuit with 5V voltage and provides air temperature sensor reference voltage circuit with
grounding. When air temperature sensor is under cold status, sensor resistance value is high. When air temperature
increases, sensor resistance value decreases. In the case of high sensor resistance, voltage of air temperature sensor
signal circuit detected by ECU is high. With decrease of sensor resistance, voltage of air temperature sensor signal
circuit detected by ECU reduces. In the case of too low detected air temperature signal voltage by ECU (it is indicated
that temperature is too high) or too high signal voltage (it is indicated that temperature is too low), DTC for this
occurs.
Differences among temperature, resistance and voltage are shown as the table below:
Temperature Temperature Sensor Resistance Temperature Sensor Signal Voltage

Low High High
High Low Low
Diagnosis Hint: Test air temperature sensor under different temperatures for evaluation of sensor errors. In the case of
sensor error, there will be control performance fault. Lay the engine up for one night, D-value between air temperature
sensor and engine coolant temperature sensor displayed values should be within 3°C (5°F). Please refer to
“Temperature and Resistance”. In the case of too high resistance of temperature sensor signal circuit or low reference
voltage circuit, DTC may not occur.
Check ECU harness connector for poor contact between ECU and temperature sensor
− Terminal looseness
− Poor fit of matching parts
− Locking plate fracture
− Terminal deformation or damage
175
Check harness damage. If the harness seems to be normal, move relevant connector and harness for intake air
temperature (IAT) sensor and check display about IAT on diagnostic tool. If display of IAT changes, it is indicated that
there is fault in the part.
Fault Tree:
检查传感器连接
Check sensor connection.
接插件问题
Connector fault Y 做必要的修理
Repair accordingly.
检查传感器电阻（检查其是否与车辆
Check sensor resistance (for conformity with vehicle
状态一致
status).
Replace the sensor.

器件问题
Component fault Y 更换传感器
检查是否为ECU插接件问题
Check ECU for connector faults. Y 做必要的修理
Repair accordingly.
Electrical fault
电气问题 Y Repair
Get联系技术支持
the Technical Support.
176
24.
DTC P0300 Multi-cylinder misfire

P0301 The 1st cylinder misfire
P0302 The 2nd cylinder misfire
P0303 The 3rd cylinder misfire
P0304 The 4th cylinder misfire
Fault Description: ECU determines when engine misfire occurs with the help of information from ignition control
(IC) module and camshaft position (CMP) sensors. ECU can detect single misfire via crankshaft speed change for
each cylinder. In the case of some vehicle running condition, too high misfire rate will lead to three way catalytic
converter (TWC) overheating. In the case of three way catalytic converter overheating, MIL will flash. If misfire rate
detected by ECU is enough to make emission level to exceed mandatory standard, DTC occurs. If diagnosis operation
fails in two continuous ignition cycle, control module lightens MIL. Control module records operation condition when
diagnosis is failed. For the first diagnosis failure, control module will keep this information in fault record. If
diagnosis failure occurs during the successive ignition cycle, control module records operation condition under
diagnosis failure and writes the operation condition in frozen fault condition and updates fault record.
Diagnosis Hint: Influence factors for misfire diagnosis—In the case of misfire diagnosis, it is required that all
vehicle parts are under mass production or equivalent. All changes which may influence engine crankshaft speed will
interfere with correct diagnosis for misfire.
In the case of faults in components as follows, misfire diagnosis will pause to avoid incorrect diagnostic
results—intake pressure/throttle position rationality fault; low voltage or open circuit of intake pressure sensor circuit;
high voltage of intake pressure sensor circuit; low voltage or open circuit of coolant temperature sensor circuit; high
voltage of coolant temperature sensor circuit; high voltage of throttle position sensor; low voltage of throttle position
sensor; signal interference of crankshaft position sensor circuit; no signals in crankshaft position sensor circuit; no
signals in camshaft position sensor circuit; camshaft position sensor rationality fault; high voltage or open circuit of
intake air temperature sensor circuit; low voltage of intake air temperature sensor circuit; no signals in vehicle speed
sensor.
Severe vibration which is not caused by engine may lead to setting fault (vibration source may lead to wears or
damages to brake discs with different thicknesses and additional drive belts).
177
Fault Tree:
Turn off ignition switch and check fuel injector connectors.
关闭点火开关并检查喷油器接插件
Connector
接插件问题 fault Y Repair
Check crankshaft position sensor clearance.

检查曲轴位置传感器间隙
Adjust clearance of crankshaft position sensor

调整曲轴位置传感器间隙
曲轴位置传感器间隙问题？
Are faults in crankshaft position sensor clearance? Y
（0.6~0.7mm）
(0.6mm~0.7mm)
检查减震皮带轮与传感器
Check damping belt pulley and sensor.
Readjust installation of crankshaft damping belt

重新调整曲轴减震皮带轮安装，
Check belt pulley and sensor for interference. pulley. If faults occur again, replace damping
皮带轮与传感器是否干涉 Y 还不行，更换减震皮带轮并进行
belt pulley and carry
齿讯学习out gear message learning
Check crankshaft position sensor.

检查曲轴位置传感器
Faults are in crankshaft position sensor. Replace crankshaft position sensor.

曲轴位置传感器问题 Y 更换曲轴位置传感器
Get the 联系技术支持

Technical Support.
178
25.
DTC P0401 Actual fresh air inflow is larger than target air inflow set by EGR system.
P0402 Actual fresh air inflow is smaller than target air inflow set by EGR system.
ECU internal drive module of EGR valve actuator control wire is
P0403
overheated.
P0404 EGR valve actuator control wire is open.
Voltage of EGR valve position sensor is below the lower limit (Connection is
P0405
short to ground).
Voltage of EGR valve position sensor is above the upper limit (Connection is
P0406
open short to high level).
P0489 EGR valve actuator control wire is open.
P0490 EGR valve actuator control wire is short to high level.
EGR5V Power supply
EGR position signal EGR position sensor
EGR ground signal
EGR actuator power supply
EGR actuator ground EGR actuator
Fault Description: Exhaust gas recirculation system is applied in reduction of Nitrogen oxides emission due to high
temperature combustion. Main component of the system is electronic control exhaust gas recirculation valve. Exhaust
gas recirculation valve delivers a small amount of exhaust gas into intake manifold to reduce combustion temperature.
Recirculation gas flow is controlled by ECU according to changes in engine load. In the case of deceleration, gas flow
test for exhaust gas recirculation (EGR) system is carried out by ECU. Therefore, ECU gives a transient command to
open exhaust gas recirculation valve and simultaneously monitors signals of intake manifold air pressure (MAP)
sensor and exhaust gas recirculation position sensor. In the case of inconformity of intake manifold absolute pressure
signals with exhaust gas recirculation valve spool shaft position, ECU records measured D-value of intake manifold
absolute pressure and adjust calibrated failure counter to failure technical threshold value. For error quantities of
detected exhaust gas recirculation flow are different, required test times for exhaust gas recirculation flow concerned
excessive failure technical threshold value of may be different, too. When ECU detects incorrect control signals, DTC
occurs.
Diagnosis Hint: Carry out inspection to engine control system; check engine for historical faults; check exhaust gas
recirculation system for faults as follows—vacuum leaks between exhaust gas recirculation valve and intake manifold.
In the case of carbon deposition or exhaust gas noise around component faying surface, it is indicated there is external
leakage. Check passage and exhaust gas recirculation valve for clogging; check exhaust system for relevant faults
(such as leakage due to exhaust component damage, clogging due to excessive back pressure and too low engine
vacuum and etc.); finally, carry out inspection to mechanical system.
179
Terminal ECU
K23 EGR position sensor 5V power supply
K31 EGR position sensor position signal
K39 EGR position sensor ground
A04 EGR actuator power supply
A19 EGR actuator ground
180
Fault Tree:
Check actuator connectors.
Check actuator resistance.
Actuator resistance faults Replace the actuator.
Check ECU for connector faults. Repair accordingly.
Replace components.
181
26.
DTC P0480 ECU Fan I control wire is open

P0481 ECU Fan II control wire is open.
P0483 ECU Fan I control wire internal drive module is overheated.
P0484 ECU Fan II control wire internal drive module is overheated.
P0691 ECU Fan I control wire is short to ground.
P0692 ECU Fan I control wire is short to high level.
P0693 ECU Fan II control wire is short to ground.
P0694 ECU Fan II control wire is short to high level.
Fault Description: ECU provides low-speed relay with grounding via so-called “drive” internal solid component in
order to control cooling fan low speed operation. For cooling fan high speed operation, ECU adopts the method of
high speed and S/P replay control circuit grounding with simultaneous low-speed control circuit grounding. Battery
positive voltage is provided to low-speed, high-speed and S/P fan relays. When ECU commands fan relay to be
connected, control circuit voltage is low level which is close to 0V. When ECU commands fan relay to be
disconnected, control circuit voltage should be high level which is close to battery voltage. ECU monitors relay
control circuit for conditions as follows:
It is short to ground.
It is short to voltage.
It is open.
When ECU detects incorrect voltage in low-speed or high-speed drive circuit, DTC occurs and corresponding drive
will stop operating.
Cooling Fan Relay I control circuit controls low-speed cooling fan relay.
Cooling Fan Relay II control circuit controls high-speed cooling fan relay.
Diagnosis Hint: Check harness for intermittency and good contact.
Prior to maintenance, remove all fragments from connector surface. Check connector pads for correct installation to
prevent contamination from entering prior to diagnosis and component replacement.
z Poor terminal connection—Check harness connectors for looseness, mismatching, retainer damage, improper
shape or damage and connection failure with wires. Apply corresponding matching terminals for test of proper
tension.
z Harness damage—Check wire harness for damage. In the case of no harness faults, move relevant connectors and
wire harness and observe display of fault diagnostic apparatus. Fault diagnostic apparatus displays changes to
indicate fault positions.
z Check ECU and engine ground connection for reliability and cleanness. If it is determined that DTC is an
intermittent fault, please refer to Fault Record to check the time of last DTC occurrence.
182
Fault Tree:
Check relay connectors.
Replace the relay (carry out ISO cycle).
ISO cycle faults Get the Technical Support.
183
27.
DTC P0487 Throttle valve actuator control wire is open.

P0488 ECU internal drive module of throttle valve actuator is overheated.
P2141 Throttle valve actuator control wire is short to ground.
P2142 Throttle valve actuator control wire is short to high level.
Fault Description: ECU is the control center for throttle valve actuator control system. ECU can judge driver’s
intention and then calculate corresponding throttle valve response. ECU realizes throttle valve positioning via
providing throttle valve actuator control motor with pulse width modulation (PWM) voltage. Throttle valve actuator
control system adopts circuits as follows:
Motor control 1
Motor control 2
Besides, two processors are applied in throttle valve actuator control system data monitoring. These two processors
are located in ECU, testing data of each other to prove correctness of throttle valve position.
Diagnosis Hint: Check for connection and disconnection faults or seizures due to temperature. Under extremely hot
or cold condition, existed contaminations or freeze may lead to unsmooth component movement.
If it is an intermittent fault, the possible causes may be poor contact, worn wire insulating layer or damaged wire in
insulating layer.
z Poor contact of ECU or exhaust brake valve—Check harness connectors.
– Terminal looseness
– Poor fit of matching parts
–Locking plate fracture
–Terminal deformation or damage
–Poor contact between terminal and wire
z Harness damage—Check harness for damage.
184
Fault Tree:
Check throttle valve actuator
connection.
Connector fault Repair or replace.
Check throttle valve appearance.
Throttle valve faults Replace the throttle valve.
Check ECU connectors. Repair or replace.
Replace the ECU.
185
28.
DTC P0615 ECU starting motor control wire is open or drive module is overheated.
P0616 ECU starting motor control wire is short to ground.
P0617 ECU starting motor control wire is short to high level.
Fault Description: ECU provides starting motor with grounding via so-called “drive” internal solid component in
order to control starting motor operation. Under starting motor control circuit command, when fault diagnostic
apparatus is connected, it is indicated that starting motor circuit is grounded via control module in order to provide
starting motor with voltage; when fault diagnostic apparatus is disconnected, it is indicated that starting motor circuit
is not connected via control module command currently. ECU monitors starting motor circuit for conditions as
follows:
It is open.
When ECU detects incorrect voltage signals, DTC occurs and corresponding drive will stop operating.
Prior to component maintenance, remove all fragments from connector surface. Check connector pads for correct
installation to prevent contamination from entering prior to diagnosis and component replacement.
tension.
186
Fault Tree:
Check starting motor connectors.
Check for continuity and insulating property
Replace starting motor relay.
Are faults still in existence? Get the Technical Support.
187
29.
ECU instrument panel engine speed output connecting wire is short to high
DTC P1605
level.
ECU instrument panel engine speed output connecting wire is short to
P1606
ground.
P1607 ECU instrument panel engine speed output connecting wire is open.
Fault Description: Vehicle speed sensor (VSS) provides ECU with vehicle speed information. When rotor teeth on
transmission output shaft go through sensor magnetic field, vehicle speed sensor generates signal voltage. Frequency
of this signal voltage increases with vehicle speed increase. ECU transforms the signal voltage into vehicle speed and
displays the speed on instrument panel via control circuit. ECU determines vehicle operation condition with vehicle
speed signals in order to guide driver operation. ECU monitors the circuit between ECU and instrument panel for
conditions as follows:
It is open.
When ECU detects incorrect voltage signals, DTC occurs
tension.
188
Fault Tree:
Check connection between instrument panel
检查仪表板与ECU的连接
and ECU.
Connector
接插件问题 fault Y 做必要的修理
Repair accordingly.
N
Check continuity
检查连续性和绝缘性 and insulating property
Electrical
电气问题 fault Y 修理线束
Repair the harness.
更换相应的器件
问题仍存在
Does the problem still exist? Y Get the Technical Support.
联系技术支持
189
30.
ECU instrument panel preheating indicator lamp output connecting wire is

DTC P1608
short to high level.
P1609
short to ground.
P160A
open.
ECU instrument panel preheating indicator lamp output wire drive module
P160B
is overheated.
Fault Description: During glow plug operation, preheater relay will send a signal to ECU. Then, ECU sends
command to preheating indicator lamp on instrument panel via control circuit. Driver carries out the next operation
via observing preheating indicator lamp status. ECU monitors the circuit between ECU and instrument panel for
conditions as follows:
It is open.
When ECU detects incorrect voltage signals, DTC occurs.
tension.
Terminal ECU
K92 Preheating time indicator lamp
190
Fault Tree:
Check connection between instrument
panel and ECU.
Check for continuity and insulating

property.
191
31.
DTC P2228 Atmosphere pressure sensor output voltage is too low.

P2229 Atmosphere pressure sensor output voltage is too high.
Fault Description: Atmosphere pressure indicates connection of ignition switch. When engine stops operation,
control module calculates atmosphere pressure with signals sent by intake manifold absolute pressure sensor. Intake
manifold absolute pressure sensor responses to internal pressure changes of intake manifold and the pressure changes
according to different engine loads. Intake manifold absolute pressure sensor possesses circuits as follows:
5V reference voltage circuit
Low reference voltage circuit
Intake manifold absolute pressure sensor signal circuit
ECU provides intake manifold absolute pressure sensor with 5V voltage via 5V reference voltage circuit. ECU
supplies grounding via low reference voltage circuit and intake manifold absolute pressure sensor provides ECU with
a signal via signal circuit. This signal is related to intake manifold internal pressure changes. When ignition switch is
connected and engine is shut down, intake manifold absolute pressure sensor displays signals of atmosphere pressure.
In the case of engine running with wide open throttle, reading of atmosphere pressure will be renewed. ECU
determines whether voltage exceeds normal range via detecting intake manifold absolute pressure sensor signals.
When intake manifold absolute pressure sensor displays atmosphere pressure, if sensor signal voltage is not in
specified range, DTC occurs.
Diagnosis Hint: When ignition switch is connected and engine is shut down, intake manifold pressure equals to
atmosphere pressure and signal voltage is low level. ECU takes this information as vehicle elevation indication.
Moreover, to make comparison between this reading with that of an intact vehicle which possesses the same sensor is
a good method for sensor accuracy inspection. D-value of two readings should not exceed 0.4V. It is necessary to
carry out comprehensive inspection to pressure source of supercharger pressure sensor in order to check intake system
for clogging.
In the case of engine start, intake manifold absolute pressure sensor can detect any change of manifold pressure. This
test is carried out to determine sensor lag at a certain value.
In the case of normal intake manifold absolute pressure sensor, it will make rapid response to changes of acceleration
pedal positions and it should not be “lagged” or slower than changes of acceleration pedal position.
192
Fault Tree:
Check sensor connection.
Check sensor resistance (for conformity with

vehicle status).
Sensor resistance faults Replace the sensor.
Check ECU for connector faults. Repair accordingly.
Check continuity and insulating property
Replace components.
193
32.
DTC P2264 There are faults in water level sensor of diesel filter oil-water separator.
P2267 Water in diesel filter oil-water separator is overflowed.
Water level signal
Drain switch
Fault Description: Main function of oil-water separator is to separate moisture from oil in fuel to ensure combustion
quality of fuel. When fuel oil goes through oil-water separator, oil content and moisture content in the fuel are
separated. For water density is larger than that of oil, separated water is stored in “water tank” under filter element.
Fuel filter lower water level sensor is applied in water level detection in “water tank”. When accumulated water
reaches certain level, warning lamp on instrument panel will be lightened to remind driver to carry out draining. In the
case of delayed water drainage, DTC occurs.
Diagnosis Hint: In the case of DTC existence, it is necessary to check water level first of all. Normally, carry out
water drainage for every 8000-10000km engine running. For oil quality problems, water drainage should be carried
out ahead of time for fuel which contains much moisture. Besides, test relevant connectors for this diagnostic
procedure for short circuit of terminals or poor contact of wire, avoiding water level sensor signal distortions caused
by short circuit or poor contact.
194
Fault Tree:
Drain filter.
Is there still water? Eliminate the fault.
Check water level sensor for electrical faults.
Are there still electrical faults? Repair accordingly.
Check water level sensor connectors.
Are there still connector faults? Repair accordingly.
Check water level sensor resistance.
Replace water level sensor.

Is there still resistance fault?
Are there still connector faults? Repair accordingly.
195
33.
DTC P2299 Depress accelerator pedal and brake pedal at the same time.
Fault Description: Accelerator pedal assembly consists of two accelerator pedal position (APP) sensors. Accelerator
pedal position sensors are installed on pedal assembly and they are not maintainable. When driver depresses
accelerator pedal, air inflow of cylinder is increased and ECU increases fuel injector pulse width in order to supply
additional fuel during acceleration process for engine demand. Brake switch is a normally open one. When brake
pedal is depressed, this switch is closed in order to provide TCU with voltage for brake application. In the case of
misoperation of driver during driving, brake system will be locked after depressing brake pedal and brake pedal can
not return to its original position. Under such condition, depressing accelerator pedal will lead to DTC occurrence due
to conflict between acceleration and brake signals in the case of engine braking status. In addition, improper
maintenance or ECU control circuit failures will lead to such faults.
Diagnosis Hint: Check brake system and acceleration system for stuck pedal position without pedal returns. Check
the circuit between ECU and components for good contact of connection and good harness insulating property. For
connection test for ECU and components, diagnostic connectors should be applied.
196
Fault Tree:
Check brake system and acceleration system
mechanical parts.
Mechanical part failures Replace it accordingly.
Check accelerator switch adjusting position.
Adjust accelerator switch position

Check switch position for improper (accelerator pedal electric
adjustment. potential standard value: 750±
85mv)
Check ECU for connector faults.

Replace it accordingly.
Check connecting circuit

between ECU and the system.
Connecting circuit failures Replace the harness.
Replace the ECU and carry out debugging.
197
34.
In the case of the maximum fault reading, there are EEPROM errors/ICM
DTC U0167
time-out communication failures.
Fault Description: They are mainly taken as integrity failures for ECU internal microprocessor, being applied in
determination of ECU programming procedure implementation. In the case of engine shutdown and ignition switch
connection, ECU carries out self-diagnosis. In the case of diagnosis failure, control module records operation
condition under diagnosis failure and stores this information in “Fault Record”, DTC occurs. During engine operation,
when there is deviation between ECU detected signals and standard signals, the fault will be stored and expressed as
DTC via internal communication module of ECU. In the case of external signal intrusion, this will lead to system
disorder and DTC occurs. When various faults occur at the same time under the same operation condition, there will
be multiple DTCs. For there is a process for ECU response to each fault, ECU response time will be longer in the case
of multiple simultaneous faults in existence. During response process, DTC may occur due to ECU internal
communication errors or hardware faults.
Diagnosis Hint: In the case of fault occurrence, relevant test can be carried out after ECU replacement for possible
fault cause may be too long ECU internal response time. Check ECU circuit to verify whether it is circuit failure that
leads to fault occurrence.
198
Fault Tree:
Check continuity and insulating property
Control circuit failures Repair the harness.
Check ECU.
Replace the ECU or refresh ECU

ECU faults data.
199
35.
DTC P0045 Supercharger actuator control wire is open.

ECU internal drive module of supercharger actuator control wire is
P0046
overheated.
P0047 Supercharger actuator control wire is short to ground.
P0048 Supercharger actuator control wire is short to high level.
Control signal Booster actuator
ECU is the control center fro supercharger actuator control system. ECU calculates corresponding supercharger
actuator response according to engine operation condition. ECU realizes actuator positioning via providing
supercharger actuator control motor with pulse width modulation voltage.
Diagnosis Hint: Check for connection and disconnection faults or seizures due to temperature. Under extremely hot
or cold condition, existed contaminations or freeze may lead to unsmooth component movement.
If it is an intermittent fault, the possible causes may be poor contact, worn wire insulating layer or damaged wire in
insulating layer.
z Poor contact of ECU or exhaust brake valve —Check harness connectors.
– Terminal looseness
– Poor fit of matching parts
–Locking plate fracture
–Terminal deformation or damage
–Poor contact between terminal and wire
z Harness damage—Check harness for damage.
200
Fault Tree:

检查ECU的接插件
Connector
接插件问题 fault Y Repair
Check for 检查连续性和绝缘性

continuity and insulating property.
Control
控制线路问题circuit failures Y Repair
Check
检查ECUECU.
ECU faults
ECU问题 Y Replace the ECU or refresh ECU
更换ECU或者刷新ECU数据
data.

联系技术支持
201
36.
DTC P1070 Catalytic converter is clogged.

P2002 Catalytic converter is removed.
P2454 Catalytic converter front and rear differential pressure is too low.
P2455 Catalytic converter front and rear differential pressure is too high.
5V power supply
Differential
pressure Differential pressure signal
sensor
Ground
Differential pressure sensor is a Hall Effect switch. ECU provides differential pressure sensor with 5V voltage via 5V
reference voltage circuit and provides the sensor with grounding via low reference voltage circuit. Differential
pressure sensor provides ECU with signal voltage according to front and rear differential pressure changes of catalytic
converter. ECU determines catalytic converter differential pressure with this signal voltage. Differential pressure
sensor circuit is connected to ECU directly. Moreover, differential pressure sensor can be applied in determination of
catalytic converter damages. Circuits between differential pressure sensor and ECU include the followings:
Differential pressure sensor high reference voltage circuit
Ground circuit
Differential pressure signal circuit
When ECU detects incorrect sensor signals or no signals, DTC occurs.
Diagnosis Hint: Poor terminal connection—Check harness connectors for looseness, mismatching, retainer damage,
improper shape or damage and connection failure with wires. Apply corresponding matching terminals for test of
proper tension.
Harness damage—Check wire harness for damage. In the case of no harness faults, move relevant connectors and
wire harness and observe display of fault diagnostic apparatus. Fault diagnostic apparatus displays changes to indicate
fault positions.
Check ECU and engine ground connection for reliability and cleanness. If it is determined that DTC is an intermittent
fault, please refer to Fault Record to check the time of last DTC occurrence.
Terminal ECU
K27 Differential pressure sensor power supply
K59 Differential pressure sensor signal terminal
K80 Ground
202
Fault Tree:
Connector fault Repair or replace.
Check the sensor.
Sensor faults Replace the sensor.
Check ECU connectors. Repair or replace.

property
Replace components.
203
Brief Introduction
As one of the most important part of BOSCH EDC system, DSM provides the after-market service with relative
diagnosis information, which could help to solve problem more quickly and exactly.
DSM includes following two content:
Error information storage and management: when a error occurs, DSM will storage the error information into FCM
orderly based on error class definition, and activate the malfunction indication lamp accordingly. The error information
includes diagnosis trouble code, related environmental condition signal, freeze frame signal and so on. It could be read
out via diagnosis connector for after-market service using.
System reaction: besides storagement and management of error information, DSM system would also activate some
substitute function and limitation to deal with the fault condition, so that engine and vehicle could running safely with
error.
Via diagnosis connector, diagnosis tester could read out the error code information from ECU, so that it could be
known which part has problem. And here if it is on hand of the error detection logic and possible reasons, then it could
be more efficiently to check related items to find out the solution.
Therefore, it is prepared of the BOSCH Common Rail System Error Description. This document is summarized based
on SW document description and series of error simulation result, which contents include error name, diagnosis trouble
code, error detection logic, possible system reaction, possible reason and check items for service.
E.g. P0201 means injector of cylinder 1 open load, this error will cause vehicle vibration while running, for service, it is
suggested to check the wiring harness status at first, if no problem then could check whether the injector resistance
exceeds the normal range or not, if exceed, that means the injector has problem, change the injector could solve the
problem.
We hope this document could be useful in after-market service.

RBCD/EAP1-OBD Team
2011.07.08
© Robert Bosch reserves all rights even in the event of industrial property rights.
We reserve all rights of disposal such as copying or passing to third parties. -2-
编写说明
DSM是博世电控ECU的重要组成部分，可为售后维修服务提供相关的故障诊断信息，从而快速地准确地
解决问题。
DSM包括两方面内容：
故障信息存储管理：当故障发生时，DSM能够根据故障的类别有序地将故障信息存入故障内存，并相应
地激活故障灯警示。相关的故障信息包括故障码，故障发生时的环境变量信号，冻结帧信号等。存入故
障内存的故障信息可以通过诊断接口读取，以供维修使用。
故障发生后的系统响应：对故障进行存储管理的同时，诊断系统会针对故障情况触发相应的替代功能，
限制功能，以保证发动机及车辆能够在故障状态下安全运行。
通过诊断接口，诊断仪可以从ECU的故障内存中读取故障码信息，从而获知该车辆哪个部件出了什么问
题。此时，如果清楚知道该故障的判断逻辑及可能原因，就能够迅速排查，找到真正原因解决问题。
为此，我们根据软件逻辑以及一系列的故障模拟试验总结归纳了博世共轨系统的故障诊断说明书，内容
包括故障码对应的故障名，该故障的判断逻辑，可能的系统响应，引起该故障的可能原因，以及相应的
排查项目。例如，系统测到P0201第一缸喷油器开路故障，则故障发生时车辆可能会有震荡现象，维修
时应先检查该回路线束连接情况，如果没有问题则测量喷油器的电阻值，若阻值超出正常范围则说明喷
油器有问题，需要更换喷油器。
希望该手册可以在售后服务中起到一定的作用。
RBCD/EAP1-OBD Team
2011.07.08
© Robert Bosch reserves all rights even in the event of industrial property rights.
We reserve all rights of disposal such as copying or passing to third parties. -3-
CLUTCH
CLUTCH
General
Main data and specifications
Clutch assembly
Clutch control equipment
Clutch main cylinder
Clutch cylinder
CLUTCH
General
Clutch assembly
CLUTCH
Clutch driven plate assembly

CLUTCH

Type of clutch： Single-sheet dry type film-sheet spring clutch
Exterior diameter of driven plate Ф275mm
Cylinder diameter of clutch main pump Ф19.05mm
Diameter of clutch cylinder Ф24mm
Travel of clutch panel 160mm
Free travel of clutch panel 3—5mm

CLUTCH
Clutch assembly
Disassembly
Disassembly sequence
⑴ Transmission assembly
⑵ Clutch pressure plate
⑶ Clutch drive plate
⑷ Release sleeve
⑸ Release fork
CLUTCH
Disassembly steps:
Support vehicle and hold it safely.
Note: do not let brake liquid flow on painted
surface in disassembly process.
If having, wipe off immediately.
1． Dismantle gearbox (referring to the operation
about gearbox in this manual).
2． Pressure plate assembly
3． Driven plate assembly
Prevent driven plate assembly from sliding with a
guiding shaft.
Make marks on flywheel and pressure plate, and
head these marks in re-assembly.
4． Dismantle clutch separator fork.
5． Separate sleeve assembly
Dismantle separator sleeve together with return
spring.
Inspection and repair

If excessive abrasion and damage have been
found in checking process, it is necessary to
adjust, repair or change parts.
Check abrasion and heat crack of pressure plate
with eyes, if there is any excessive abrasion or
too-deep heat crack, it is necessary to change
pressure plate.
Distortion of pressure plate
Measure plane degree of friction surface of
pressure plate, if it exceeds limit, change
pressure plate assembly. Using limit: 0.3mm
Clutch cover
Check the abrasion, crack and other damages
on whole clutch cover with eyes, if there is any
excessive abrasion, crack or other damages,
change the cover.
CLUTCH
Assembly pressure of clutch

1） Reverse clutch pressure plate.
2） Put a metal block with depth of 8.3mm on
pressure plate.
3） Press down pressure plate until distance “B”
has reached 0 mm.
4） Record pressure reading on meter.
480 kg
Standard pressure：480
Height of film-sheet spring separator

finger
1) Put a metal block with depth of 8.3mm under
pressure plate.
2) 2) Press down pressure plate until distance
“B” has reached 0 mm.. Two methods could
be used:
a． Press down it from the top of pressure plate.
b． Screw assembly bolts of pressure plate.
3) Measure the height from base surface to
separator finger end. Standard height
41.0-43.0mm
Driven plate assembly

Check whether torsion spring has been loosened,
softened or ruptured with eyes.
If there is any situation above, it is necessary to
change driven plate assembly.
Check whether there is any crack, grease or
excessive scorch on friction surface with eyes.
If there is any situation above, it is necessary to
clean or change driven plate assembly. Check
whether driven plate assembly could slide on
spline of one shaft of gearbox.
CLUTCH
Distortion of driven plate

Insert guiding shaft in spline hub.
Guiding shaft should be level and straight.
Install a scale meter on exterior circle of driven
plate.
Turn driven plate assembly slowing, and read the
scale on meter.
If measured value exceeds limit, it is necessary
to change driven plate assembly.
Limit 1.0mm
Abrasion of driven plate spline hub

Clean inner part of spline hub.
Install driven plate on spline of one shaft of
gearbox.
Install a surface measuring meter on exterior
circle of driven plate.
Turn driven plate slowly, and measure the
change of exterior circle.
Abrasion limit of driven plate slpine hub
1.0mm
Depth of rivet head of driven plate

Measure the distance from rivet head to friction
surface with a depth gauge.
Measure two sides.
Depth limit of rivet head of driven plate 0.2mm
CLUTCH
Release fork and supporting

Check the surface contacting with release sleeve
and supporting on release fork with eyes.
If there is any excessive abrasion or surface
roughness, it is necessary to change parts.
Release sleeve assembly

Check the abrasion and roughness of release
sleeve assembly before separating sleeve
assembly.
a. There is any surface roughness of release
bearing or noise caused by rotation under
light press.
b. There is surface roughness or damage.
(With contacting surface of release fork and
front cover surface of release bearing)
Warning: for release bearing has been installed
with lubricant, do not put it in solvent to wash,
this could dissolve lubricant. Note if there is any
problem, do not disassemble the sleeve. Check
whether return spring has been ruptured or
softened. If there is any situation above, it is
necessary to change parts.
CLUTCH
Re-assembly
Re-assembly sequence
1． Clutch release fork 2；
2． Release sleeve assembly 3；
3． Driven plate assembly 4；
4． Pressure plate assembly 5；
5． Gearbox 6.
CLUTCH
Re-assembly step
1． Release fork
Apply multi-purpose lubricating grease
(molybdenum disulfide) on the surface which
contacts with release sleeve assembly and
supporting on release fork.
2． Release sleeve assembly

Install release sleeve together with return spring.
3． Driven plate assembly
4． Pressure plate assembly
Apply multi-purpose lubricating grease
(molybdenum disulfide) in spline hub of driven
plate.
Install driven plate assembly with guiding shaft.
Screw assembly bolts of pressure plate tightly by

numeric sequence.
Tightening torque of assembly bolts of pressure
plate 1.8kgf.m.
Warning: after screwing assembly bolts of
pressure plate, take off steel wires used for
protecting diaphragm spring.
CLUTCH
Clutch control equipment
Disassembly
1. Clutch pipe and soft pipe 2. Oil-intake soft pipe of main pump 3. Clutch panel and bracket
assembly 4. Clutch switch or limit bolt 5. Shaft 6. Pin 7. Return spring 8. Clutch panel 9.
Clutch main pump assembly 10. Soft pipe 11. Clutch cylinder
Preparation
Dismantle instrument shell and instrument.
Disassembly step of clutch control equipment
Drain out brake liquid in hydraulic pressure pipeline of clutch.
Warning: do not let brake liquid remain on the surface with paint, if having, wipe off immediately.
If there is any excessive abrasion or damage about parts in checking process, it is necessary to
adjust, repair or change those parts.
CLUTCH
Re-assembly
1. Clutch cylinder 2. Soft pipe 3. Clutch main pump assembly 4. Clutch panel 5.
Return spring 6. Pin 7. Shaft 8. Clutch switch or limit bolt 9. Clutch panel and
bracket assembly 10. Oil-intake soft pipe of main pump 11. Clutch pipe and soft pipe
Re-assembly step
1. Clutch cylinder
Tightening torque of assembly bolts of clutch
cylinder 1.6 kgf·m
Adjust handspike of clutch cylinder rightly before
installing return spring of clutch cylinder.
Unscrew locking nuts of clutch handspike.
Turn handspike until supporting separator fork.
Turn back handspike for 1.5 circles. (Free travel
of separator fork is about 2 mm)
Screw locking nuts.
Tightening torque of locking nut 1.9 kgf.m
CLUTCH
1. Clutch soft pipe

2. Clutch main cylinder
Install clutch main cylinder on clutch panel
and bracket. Tightening torque of assembly
nut 1.3 kgf.m.
3. Clutch panel
4. Return spring
5. Pin and shaft
6. Clutch switch or limit bolt
7. Clutch panel and bracket assembly
Tightening torque of clutch panel and bracket
assembly bolt 3.8 kgf.m
After those assemblies above, it is necessary to
adjust clutch control equipment
Height and travel of clutch panel
1) Unscrew locking nuts of clutch main pump
handspike
2) Turn handspike to adjust panel.
Height of clutch panel A: 160-170mm
Travel of clutch panel B: 159-169mm
3) Tightening torque of locking nuts of clutch
main pump handspike 1.3 kgfm
4) Re-install instrument to adjust free travel of
clutch panel, unscrew clutch switch or panel limit
bolt, Adjust clutch switch or panel limit bolt to
make free travel of clutch panel is 3—5mm.
Deflation of clutch pipeline should be made by

following steps:
1. Strain park arrester.
2. Put brake liquid in oil storage pot until
reaching maximal liquid level. It is necessary
to note whether there is any brake liquid in oil
storage pot.
3. Dismantle bleed screw rubber cap on clutch
cylinder, link plastic pipe on bleed screw, and
insert the other end of plastic pipe into
translucent vessel with brake liquid.
4. After stepping down clutch panel for several
times continually, step on clutch panel.
5. When keeping on stepping on penal,
unscrew bleed screw to discharge air, then
screw bleed screw.
6. Repeat those operations above, until the air
in pipeline has been drained out completely.
After deflation operation, intake brake liquid
until ＂MAX＂ mark in oil storage pot.
CLUTCH
Disassembly
1. Pipe tie-in 2. Handspike fork 3. Locking nut 4. Dustproof cover 5. Clamp ring
6. Limit block 7. Handspike 8. Piston assembly 9. Return spring 10.Pump body

Measure the inner diameter of main pump body.
Inner diameter of main pump body ：
19.050---19.102mm
Clearance between clutch main pump piston and
inner diameter of main pump body:
0.12mm(limit)
CLUTCH
Re-assembly
1.Pump body 2. Return spring 3. Piston assembly 4. Handspike 5. Limit block
6. Clamp ring 7. Dustproof cover 8. Locking nut 9. Handspike fork 10. Pipe tie-in
Re-assembly notes:
1. Dip the pump body and piston with clean brake liquid before re-assembly.
2. Spread a sheet of thin lubricating grease on skin bowl.
3. It is necessary to note to prevent the lip of skin bowl from being damaged in assembly process.
CLUTCH
Clutch cylinder
Disassembly
1. Handspike 2. Dustproof cover 3. Piston assembly 4. Deflation screw 5. Cylinder body
If there is any excessive abrasion or damage about parts in checking process, it is
necessary to adjust, repair or change those parts.
Clutch cylinder assembly

Wash clutch cylinder body with brake liquid.
Measure the inner diameter of cylinder body.
Inner diameter of cylinder body ：
23.99---24.042mm
Clearance between clutch cylinder piston and
inner diameter of cylinder body: 0.12mm(limit)
Warning: for disassembled clutch cylinder, it is
necessary to change repair bag.
CLUTCH
Re-assembly
1. Cylinder body 2. Deflation screw 3. Piston assembly 4. Dustproof cover 5. Handspike
Re-assembly notes:
1．Dip the pump body and piston with clean brake liquid before re-assembly.
2．Spread a sheet of thin lubricating grease on skin bowl.
3．It is necessary to note prevent the lip of skin bowl from being damaged in assembly process.
目录（ Catalogue）
目录（ Catalogue ）-------------------------------------------------- 1

主要技术参数和速比 ( Main Specification and Gear Ratio )-------------- 2
使用说明（ Operation Structure Manual ）----------------------------- 3
检查与维修 ( Check and Maintenance)----------------------------------- 5
故障诊断 ( Fault Diagnosis )------------------------------------------ 7
1．变速器噪音（ T/M Noise ）----------------------------------- 7
2．齿轮脱档 ( Gear Dislocation )-------------------------------- 8
3．齿轮不能平滑变速（ Shift Unskillfully ）--------------------- 9
零部件图 ( Parts Picture )-------------------------------------------- 10
易损件目录( Parts Wear Catalogue )------------------------------------- 22
1
主要技术参数（ Main Specification ）：
形式 (Type) 五档超速型(Overspeed with 5th gear position)
额定输入扭矩 (Input Torque) 300N·m
中心距(Center Distance) 88mm
总成质量(Assembly quality) 约 70Kg(about 70Kg)

85W/90 GL-4
润滑油型号(Lubricating Oil Type)
（85W/90 GL-4 Gear Oil)
润滑油量(Lubricating Oil Capacity) 约 2.7L(about 2.7L)
速比 (Gear Ratio)
一档 (1st) 4.717 四档(4th) 1.000
二档(2nd) 2.513 五档(5th) 0.784
三档(3rd) 1.679 倒档(Rev.) 4.497
2
使用说明（Operation Structure Manual）
1．LC5T28(A2Q02),江淮代号：1701001E8Q28 变速器的各前进档均带有锁环式同步器，为了减轻齿轮和同步器
的磨损，使同步器和齿轮顺利脱开，
防止打碎齿轮，换档动作要和缓。汽车只有在停稳后才能由前进档换入倒档或由倒档换入前进档。
2. 应特别注意：变速器的五档为超速档，为避免超速齿轮损坏，在整车不超载，路面状况较好，车速达
到 50 公里/小时以上才能使用五档。在使用五档时，如遇某种情况致使整车速度降到 50 公里/小时以
下，此时应换入低档，如继续使用五档，极易使五档齿轮打碎。
3．变速器可使用 85W/90 GL-4 齿轮油，汽车通常行驶 6000 公里时换一次油。放完脏油后，变速器挂倒档，
将后桥顶起，注入煤油，使变速器齿轮旋转 2～3 分钟，放出脏油，再加入纯净的齿轮油.
4．汽车在下坡滑行时，不允许将发动机熄火，更不允许发动机在熄火状态下，利用下坡滑行的惯性启动
发动机，以免损坏齿轮。
Ⅰ. Since each forward gear position in LC5T28 T/M is with lock-ring synchronizer,in order to lessen
the wear between gear and synchronizer,disengage the synchronizer from the gear,the gear-
shifting should be gentle to avoid breaking the gear.Only after the truck parks completely，
can be the forward gear position change into the reverse position or the reverse
3
into the forward.
Ⅱ. Warn:Since the fifth gear position is overspeed,it should be engaged only under the con-
dition of good road, being not overload and speeding more than 50km/h.Otherwise the gear
will be broken.If the speed is less than 50km/h,the lower position should be engaged and
the fifth position should not be used any more.
Ⅲ. 85W/90 GL-4 Gear Oil should be adopted.Change the oil at the completionof driving 6000km.
After discharging the dirty oil,engage the reverse position,raise therear axle ,add
kerosene,rotate the gear 2～3 minutes,discharge the dirty oil,and refill with purified gear
oil.
Ⅳ. Do not stop the engine during descending from a steep hill.Do not start the engine in
use of the inertia of descending from a hill under the resting state of the engine.so
as not to break the gear.
4
检查与维修 ( Check and Maintenance )
通过检查如发现零件磨损、损坏或其它故障时，应进行必要的修理或更换。肉眼检查：检查所有拆
下零件的磨损、损坏或其它故障情况，具体要求如下：
Check the wear,break of the parts.Repair or change if necessary. The requirements are as
following:
1.换档拨叉厚度（thickness of the shift fork）mm 2.倒档限位弹簧自由长度（the free length of reverse set spring）mm
标准（standard）极限(limit) 标准（standard）极限(limit)
10.0 9.0 39.8 38.5
3.同步器齿环和结合齿间的间隙 mm 4. 同步器齿环和滑块间的间隙 mm
（clearance between gear ring and engaging gear） (clearance between gear ring and slide)
标准极限
档位（gear position）档位（gear position）标准（standard）
（standard） (limit)
二、三、四、五档
三、四档（3rd 4th） 1.0 4.34～4.66
( 2nd 3rd 4th 5th )
0.5
一、二、五档（1st 2nd
1.5 一档、倒档 ( 1st Rev ) 4.84～5.16
5th）
5
5.同步器齿毂与滑块间的间隙 mm 6.变速器二轴径向跳动 mm 7.齿轮内孔与二轴间的间隙 mm
(clearance between hub and slide) (radial jig of mainshaft) (clearance between inner hole and mainshaft)
标准（standard） 0.09～0.31 极限(limit) 0.1 档位（gear position）标准（standard）极限(limit)
三档 (3rd) 0.05～0.08
0.2
五档（5th） 0.05～0.09
8.衬套与倒档轴间的间隙 mm 9.球轴承径向跳动 mm
（clearance between sleeve and reverse gear shaft）（radial jig of ball bearing）
标准（standard）极限(limit) 极限(limit) 0.2
0.04～0.08 0.2
6
故障诊断 ( Fault Diagnosis )
一．变速器噪音（T/M Noise）
在怠速转动时，如果从变速器周围发出噪音，首先应检查离合器。若踩下离合器踏板后，噪音停止，则说明噪音发自变速器。
（If there is noise from the surroundings of the T/M during idle rotation,first check the clutch。 If the noise disappears
when the pedal is engaged, the trouble derives from the T/M.）
检查齿轮油面 ( Check oil level )
检查齿轮油质量…类型、污染、杂质含量、粘度
加注推荐的齿轮油太低正常 (Check oil quality…type, contamination,
(Refill with oil) （Too low） ( Normal ) impunity content,velocity)
加注推荐的齿轮油
足够（Enough）不足（Not enough）
(Refill with oil)
大修变速器（ Overhaul the T/M ）
齿轮磨损或损坏轴承/花键磨损或损坏轴向间隙过大

(Gear wear or break) （Bearing/key wear or break） (Too muck radial clearance)
更换 (change) 更换 (change) 更换 (change)
7
二．齿轮脱档( Gear Dislocation )
间隙过大、松动或失调检查控制零件的间隙、松动或失调
（Too much clearance ,looseness , maladjustment）（Check and control the clearance looseness maladjustment）
调节或更换 (Adjust or change) 检查各个连接件是否松动 (Check if couplings loosen) 正常 (Normal)
松动（Loose）松动（Loose）
大修变速机构 (Overhaul) 拧紧 (Tighten)
连接件松动变速臂磨损或弯曲变速杆槽磨损卡簧弹力减弱正常

（Couplings loosen) (Shift arm worn or curved) (Shift lever groove worn) （Snap spring elasticity lessen）（Normal）
更换 (Change) 更换(Change) 更换 (Change) 更换 (Change) 大修变速器 (Overhaul)
齿套和接合齿磨损过大
轴承磨损过大齿轮磨损过大花键在旋转方向间隙过大
(Too muck worn sleeve and
（Bearing worn too much）（Gear worn too much）（Too much spiral clearance of key）
engaging gear)
更换 (change) 更换 (change) 更换 (change) 更换 (change)
8
三．齿轮不能平滑的变速（变速时发出噪音）Shift not freely (shift with noise)
检查离合器踏板自由间隙 (Check free clearance of clutch pedal)
检查齿轮油位 (Check oil level) 正常 (Normal) 不正确 (Abnormal) 调整到规定值 ( Adjust)
检查控制杆移动和长度加注推荐的齿轮油
正常 (Normal) 太低 (Too low)
(Check the sliding of control lever) ( Refill )
正常 (Normal) 大修变速机构 (Overhaul) 不正常 (Abnormal) 调整到规定值 (Adjust)
检查拨叉轴和变速臂是否弯曲
弯曲过大 (Too much curved) 更换 (Change)
（Check if shift shaft and shaft arm curved）
不弯 (Not curved) 大修变速器 (Overhaul) 检查零件轴向间隙 (Check radial clearance)
同步器的零件磨损或损坏
正常 (Normal) 间隙过大 (Too much clearance)
(Parts of synchronizer worn or broken)
更换 (Change) 更换 (Change)
9
图一 LC5T28(A2Q02)
LC5T28(A2Q02)变速器盖及换档机构
LC5T28(A2Q02) TRANSMISSION COVER AND GEAR---SHIFT MECHANISM
10
图一 LC5T28(A2Q02)
LC5T28(A2Q02)变速器盖及换档机构
LC5T28(A2Q02) TRANSMISSION COVER AND GEAR---SHIFT MECHANISM
序号图号或代号数量序号图号或代号数量
产品名称 (Name) 产品名称 (Name)
(No.) （Code） (Number) (No) （Code） (Number)
1 N-1702111-24-01 变速器盖（Transmission Cover） 1 18 N-1702241-21 1/2 档拨块（Shift Block,1/2） 1
2 N-1702111-23-01 变速器盖衬垫（Gasket-Transmission Cover） 1 19 N-1702232-20 1/2 档拨叉（Shift Fork,1/2） 1
3 N-1702190-00Z 内选档摇臂（Gear-select Rocker Arm） 1 20 N-1702212-20-01 3/4 档拨叉轴（3/4 Shaft Shift） 1
4 N-1702193-00 平垫圈（Plain Washer） 1 21 N-1702241-20 3/4 档拨块（Shift Block,3/4） 1
5 N-1702174-00-15 外选档摇臂合件（Outer Select Rocker Arm Assy） 1 22 N-1702230-20 3/4 档拨叉（Shift Fork,3/4） 1
6 N-1702112-00 变速器盖油封（Oil Seal） 2 23 N-1702243-20-01 R/5 档拨叉轴（R/5 Shaft Shift） 1
7 Q5280525 弹性圆柱销 (Column Pin) 7 24 N-1702241-01 R/5 档拨块（Shift Block,R/5） 1
8 N-1702174-00-15 外换档摇臂合件 (Shift Rocker Arm Assy) 1 25 N-1702242-30-01 R/5 档拨叉（Shift Fork,R/5） 1
9 J-1702180-00-00 内换档摇臂（Gear-shift Rocker Arm） 1 26 JK611CB 倒车灯开关（Reverse Lamp Switch,Assy） 1
10 N-1702176-00Z 平垫圈（Plain Washer） 1 27 N-1701011-20-01 加油螺塞总成（Oil Filler Plug） 1
11 N-1702173-00 平垫圈 (Plain Washer) 1 28 Q5240440 滚花圆柱销（Column Pin） 1
12 J-1702254-00-00 锁球弹簧（Ball---Set Spring） 3 29 Q150B0612 六角螺栓（Bolt） 1
13 N-1702255-01 互锁顶销 (Pin) 1 30 N-1702211-04 垫圈（Plain Washer） 1
14 8.731-GB308-84 钢球（Steel Ball） 7
15 Q5280325 弹性圆柱销 (Column Pin) 6
16 N-1702174-20 倒/5 档阻力弹簧（Spring） 1
17 N-1702233-20-01 1/2 档拨叉轴（1/2 Shaft Shift） 1
11
图二 LC5T28(A2Q02)
LC5T28(A2Q02)变速器一轴及离合器壳
LC5T28(A2Q02) TRANSMISSION PRIMARY SHAFT AND CLUTCH HOUSING
序号数量序号数量
图号或代号（Code）产品名称 (Name) 图号或代号（Code）产品名称 (Name)
(No.) (Number) (No.) (Number)
1 N-1601311-04 离合器壳 (Clutch Housing) 1 14 90/96.5 GB/T305 止动环（Bearing Thrust Ring） 1
3 N-1601320-00 离合器壳油封 (Oil Seal) 1 15 N-1701132-00 一轴垫片(Washer) 1
4 N-1601310-21 一轴前盖(Bearing Cover) 1 16 N-1701133-00 卡环(Snap Ring) 1
5 Q218B0612 内六角圆柱头螺钉(Bolt) 6 18、19、分离抽成套筒总成（Bearing Cover of
1602050Z1 1
20 Separate ）
6 Q1501240F3 螺栓（Bolt） 5 分离叉总成 (Yoke-Release
21 1602040Z1 1
7 N-1601311-00 挡尘片(cleaning slice) 1 Clutch,Assy)
分离叉护套（ Dust-proof
8 N-1601321-00 球头支架(stand for fork head ) 1 22 1602049E4 1
Piece,Housing）
9 Q2580820 螺栓（Bolt） 1
11 Q1501260F3 螺栓（Bolt） 1
12 J-1701110-00-02 一轴与接合齿环合件（Primary Shaft,Assy） 1
13 TM6308YA1-RS1 N/P63 一轴前轴承(Bearing) 1
12
图三 LC5T28(A2Q02)
LC5T28(A2Q02)变速器第二轴及其附件
LC5T28(A2Q02) TRANSMISSION MAINSHAFT AND ITS ACCESSORIES
13
图三 LC5T28(A2Q02)
LC5T28(A2Q02)变速器第二轴及其附件
LC5T28(A2Q02) TRANSMISSION MAINSHAFT AND ITS ACCESSORIES
序号图号或代号数量序号图号或代号数量
产品名称 ( Name ) 产品名称 (Name)
(No) （Code） (Number) (No) （Code） (Number)
1 J-1701210-00-00 滚针轴承---二轴前、一轴内 ( Needle Bearing ) 1 19 J-1701280-00-00 二轴一档齿总成（1st Gear Assy） 1
2 N-1701222-01Z 卡环 ( Snap Ring ) 1 20 N-1701201-00-12 二轴（Main Shaft） 1
3 N-1701226-00 3/4、5 档同步器齿环 ( Gear Ring,3/4,5 ) 3 二轴倒档齿轮总成 ( Reverse Gear

21 J-1701290-00-00 1
Assy )
4 J-1701225-00-00 3/4、R/5 档同步器弹簧（Spring, 4/5,R/5） 4 22 N-1701332-20 R/5 档齿套（Sleeve,R/5） 1
5 N-1701221-20 3/4 档同步器齿毂 ( Hub,3/4 ) 1 23 N-1701331-20 R/5 档齿毂（Hub,R/5） 1
6 N-1701223-01 3/4 档同步器齿套 ( Sleeve,3/4 ) 1 24 N-1701333-01 R/5 档同步器滑块（Slide,R/5） 3
7 N-1701224-00 同步器滑块---1/2 档、3/4 档 ( Slide,1/2,3/4 ) 3 25 J-1701230-00-00 二轴五档齿轮总成（5th Gear Assy） 1
8 N-1701244-20 滚针轴承-主三齿（Needle Bearing） 1 二轴五档齿轮止推垫圈( Thrust Washer,5th
26 N-1701321-01 1
Gear )
9 J-1701240-00-00 二轴三档齿轮总成 ( 3rd gear ,Assy ) 1
27 63/32NY1C3Z2 轴承（Radial Ball Bearing） 1
10 N-1701235-00Z 卡环（Snap Ring） 2
28 75/81.6GB305 止动环(Bearing Thrust Ring) 1
11 N-1701236-00 二轴二档齿止推垫圈 ( Thrust Washer,2nd Gear ) 1 里程表齿轮前隔套 ( Distance Tube，
29 N-1701361-00-12 1
12 N-1701260-01 滚针轴承-二轴二档、倒档（Needle Bearing） 2 Odometer Gear )
里程表主动齿轮 (Drive Gear ，
13 J-1701250-00-00 二轴二档齿轮总成 ( 2nd gear ,Assy ) 1 30 N-1701362-21 1
Odometer )
14 N-1701276-01 1/2 档同步器齿环 ( Gear Ring,1/2 ) 2 31 N-1701371-30-08 二轴法兰盘 ( Flange ) 1
15 N-1701274-00 1/2 档同步器弹簧 ( Spring, 1/2 ) 2 32 N-1701372-01 O 型密封圈 ( O Seal ) 1
16 N-1701271-01A 1/2 档同步器齿毂 ( Hub,1/2 ) 1 33 N-1701375-01 碟型垫圈 ( Washer ) 1
17 N-1701272-30-01 1/2 档同步器齿套 ( Sleeve,1/2) 1 34 N-1701374-01-01 二轴螺母 ( Nut，Mainshaft ) 1

里程表齿轮后隔套 ( Distance Tube，
18 N-1701260-02A 滚针轴承-主一齿（Needle Bearing） 1 35 N-1701362-00-12 1
Odometer Gear )
14
图四 LC5T28(A2Q02)
LC5T28(A2Q02)变速器中间轴及倒档轴
LC5T28(A2Q02) TRANSMISSION COUNTERSHAFT AND REVERSE GEAR SHAFT
序号 (No.) 图号或代号（Code）产品名称 (Name) 数量 (Number)

1 GB894.1-86-35 挡圈-中间轴前（Snap Ring） 1
2 6207NC3Z2 单列向心球轴承---中间轴前轴承( Bearing ) 1
3 J-1701413-00-00 中间轴（Countershaft） 1
4 N-1701133-00 卡环（Snap Ring） 1
5 J-1701411-00-00 中间轴五档齿轮 ( 5th Gear ) 1
6 63/32NC3Z2 轴承（Bearing） 1
7 75 81.6GB305 止动环(Bearing Thrust Ring) 1
8 N-1701133-03 卡环（Snap Ring） 1
9 J-1701480-00-00 倒档齿轮总成（Reverse Gear Assy） 1
10 N-1701483-00 倒档轴（Reverse Gear Shaft） 1
11 N-1701502-00 倒档轴销（Pin） 1
15
图五 LC5T28(A2Q02)
LC5T28(A2Q02)变速器壳体、第二轴轴承盖
LC5T28(A2Q02) TRANSMISSION HOUSING MAINSHAFT BEARING CAP
数量
序号
图号或代号（Code）产品名称 (Name) (Number
(No)
)
1 N-1701001-22 变速器壳体 ( Housing ) 1
2 Q9001 通气塞总成( Breathing Plug,Assy ) 1
3 N-1701362-21 里程表主动齿( Driven Gear,Odometer ) 1
4 N-1701521-N1-02 后盖 ( Rear Cover ) 1
5 N-1701522-02 后盖油封（Oil Seal,Rear Cover） 1
6 J-1701295-00-00 二轴法兰盘 ( Flange ) 1
7 N-1701372-01 O 型密封圈 ( O Seal ) 1
8 N-1701375-01 碟型垫圈 ( Washer ) 1
9 N-1701374-01 二轴螺母 ( Nut，Mainshaft ) 1
10 22022082Z8 法兰盘螺母 4
11 N-1701512-01 侧盖衬垫 (Gasket, Side Cover ) 1
12 N-1701511-01 侧盖 ( Side Cover ) 1
里被齿主动齿轮前隔套（Distance 1
13 N-1701361-00-12
Tube,Odometer Gear）
14 N-1701513-01 六角螺栓（Bolt） 17
15 N-1701007-20-01 放油螺塞总成（Bleeding Plug） 1
16 N-1701513-04 六角螺栓 ( Bolt ) 6
17 N-1700011-03 里被齿轮 ( Driven Gear,Odometer ) 1
18 GB1235-76 24X2.4 O 型密封圈 ( O Seal ) 1
19 N-1700021-00 轴套油封 (Oil Seal,Cable Sleeve ) 1
20 N-1700023-03 里程表轴套 (Cable Sleeve,Odometer ) 1
16
易损件目录( Parts Wear Catalogue )
序号
图号或代号（Code）产品名称 (Name) 数量 (Number) 备注 (Memo)
(No.)
1 N-1701512-01 侧盖衬垫（Gasket,Side Cover） 1
2 N-1702111-23-01 变速器盖衬垫（Gasket,Upper Cover） 1
3 N-1701522-02 后盖油封 (Oil Seal,Rear Cover） 1
4 N-1601320-00 离合器壳油封 (Oil Seal） 1
17
REAR AXLE
REAR AXLE
REAR AXLE
General
Main data and specifications of rear axle
Item
Half-shaft bearing type Full-float type

Driving and driven gear type Hyperboloid gear
Driving and driven gear clearance （mm） 0.18－0.25
Driving gear bearing preload
（without oil seal）（kg） 1.3－2.2
Differential bearing preload （kg） 1.5－2.6
Lubricating grease number of single wheel hub （gram） 280
Dosage of lubricating oil （litre） 3
REAR AXLE
Tightening torque (kgf.m)
Rear wheel hub
33—43
9.5—11.6
REAR AXLE
Main retarder and differential
16---20 15---17
14.5---17.5
7---9
9--11
30---35
REAR AXLE
Disassembly
1. Wheel assembly 2. Half shaft 3. Exterior oil seal 4. Locking washer
5. Bearing nut 6. Wheel hub and brake drum assembly 7. Exterior bearing
8. Inner oil seal 9. Inner bearing 10. Wheel hub, brake drum
REAR AXLE
Important works
I. Dismantle rear axle half shaft
1. Dismantle bolts and nuts of half shaft
2. Knock half shaft flange end surface lightly with

copper hammer until half shaft has been
loosened.
3. Screw bolts to thread hole of flange plate until

flange plate has left its position, then take out
half shaft.
II. Dismantle wheel hub and brake drum

assembly
1. Dismantle locking washer
2. Dismantle locking nuts of wheel hub bearing
Note:
Dismantle adjusting nuts with wheel hub bearing
nut-adjusting wrench.
3. Dismantle wheel hub and brake drum

assembly.
Note
Note：
Use wheel hub puller to dismantle
REAR AXLE
III
III.. Dismantle and install the bolts and nuts of
wheel
Thread turning direction of tyre bolts and nuts on
right wheels is right.
Thread turning direction of tyre bolts and nuts on
left wheels is left.
Note: distinguish the direction in disassembly
and re-assembly process to avoid any mistake.
IV. Dismantle and install the nuts in bolts of

wheel hub and brake drum assembly
Tightening torque of the nuts in bolts of wheel
hub and brake drum assembly 30--36 kgf. m
Make three mark pegs on each nut after
re-assembly screw to avoid any loose.

If there is any abrasion, damage or any other
abnormal situation in checking process, it is
necessary to repair or change parts according to
requirement.
Visual inspection
Wheel bearing, oil seal, wheel Check whether there is any abrasion, damage or
hub, brake drum, any other abnormal situation about parts on left
side.
axle shell ventilation plug
assembly
Concentric degree limit of half shaft 1．0mm

REAR AXLE
RE-assembly
1. Wheel hub, brake drum 2. Inner bearing 3. Inner oil seal 4. Exterior bearing
5. Wheel hub and brake drum assembly 6. Bearing nut 7.Locking washer 8. Exterior oil seal
9. Half shaft 10. Wheel assembly
REAR AXLE
Important works
1. Dosage of lubricating grease on each side
wheel hub is 280 gram, after spreading inner and
exterior bearing, complete surplus lubricating
grease should be spread on middle part of wheel
hub evenly.
2. Adjustment of wheel hub bearing preload

Screw bearing nut until wheel hub is immovable
or heavy, then unscrew bearing nut back for
1/6—1/8 rings, measured preload tangential pull
on tyre bolts is 3—5. 5 kg.
3. Fix locking washer

If convex pin of locking washer could not head
thread stop slot of positive half shaft sleeve,
reverse locking washer; if it could not head after
reversal all the time, it is necessary to turn
bearing nut by requirement.
4．Wheel
Tightening torque of wheel nut 33—43kg．m
5. Dosage of changed rear axle gear oil
（reference）3 litres
REAR AXLE
REAR AXLE
Main retarder
Disassembly and assembly
Disassembly sequence 1．Transmission shaft 2．Half shaft 3．Main retarder assembly

Assembly sequence 1．Main retarder assembly 2．Half shaft 3．Transmission shaft
Important works
Dismantle main retarder assembly
1. Dismantle the nuts on main retarder shell
2. Screw the bolts into thread hole of main
retarder shell, and turn the bolts to loosen main
retarder assembly.
3. Use transmission jack to move main retarder

assembly.
Assembly
Tightening torque of fixed nuts of main retarder
shell 6－8 kgf.m
Tightening torque of transmission shaft assembly
7--9kgf.m
REAR AXLE
Main retarder
Disassembly
sequence：
1. Main retarder shell assembly 2. Locking sheet 3. Bearing cap
4. Adjusting nut 5. Exterior loop of differential bearing 6. Differential assembly
7. Driving gear assembly 8. Adjusting washer of driving gear bearing saddle
9. Retainer plate of guiding bearing 10. Exterior ring of guiding bearing

REAR AXLE
Important works
1. Before disassembly, make assembly marks on
Adjust mark
bearing cap and main retarder shell to avoid any
mistake.
Adjust mark
2. Before adjusting the nuts, make assembly
marks on adjusting nut and bearing cap.
3. Before dismantling the adjusting nut, it is
necessary to unscrew fixed bolts of bearing cap
at first.
Left
4. Left and right mark of bearing cap, adjusting
nut and inner and exterior bearing ring should be
placed independently to avoid mixed assembly.
5. Get through differential assembly with a

proper stick, and lift differential assembly with
hand or crane.
REAR AXLE
Disassembly of differential assembly
sequence：
1. Differential right shell 2. Half shaft gear 3. Thrust washer of half shaft gear
4. Thrust washer of planetary gear 5. Planetary gear 6.Cross shaft
7. Driven gear, half shaft gear and differential left shell
Important works
To install left and right shell of differential on
Adjust mark
original position in re-assembly process, make
adjusting marks on left and right shell body
before dismantling differential shell.
REAR AXLE
REAR AXLE
Disassembly of driving gear assembly
Disassembly sequence ：
1. Flange nut 2. Flange plate 3. Drive gear bearing saddle 4. Bearing space cover and
adjusting washer 5. Drive gear, inner bearing and guiding bearing 6. Oil seal of main gear 7.
Inner loop of exterior bearing
Important works
1. Flange nut
Fix driving gear assembly on table vice, and
dismantle flange nut with lengthened wrench.
Change driven gear

1．Place driving gear together with driven gear all
the time.
2.Tightening torque16--20kg ． m 。 When
installing driven gear, add loose-proof glue on
the thread of bolts and the thread hole of driven
gear, then screw the bolts to regulated torque.
REAR AXLE
Clearance between cross shaft and planetary

gear
Limit 0．2mm
Clearance between half shaft gear and

differential shell
Limit 0．2mm
Clearance between half shaft gear and half shaft

spline
Limit0．5
Clearance between half shaft gear and planetary

gear
Limit 0．2mm
REAR AXLE
Drive gear assembly

Drive
Re-assembly
1. Inner ring of exterior bearing 2. Oil seal of main gear 3 . Driving gear, inner bearing and
guiding bearing 4. Bearing space cover and adjusting washer 5.Driving gear shaft bearing
saddle 6. Flange 7.Flange nut

REAR AXLE
Important works
Clean inner part of dustproof cover, and spread a
sheet of lubricating grease.
Spread a sheet of engine oil on sliding surface of
main gear oil seal.
Lubricating
grease oil
Adjustment of main gear bearing preload

1. Adjust main gear bearing preload by
increasing/decreasing adjusting washers.
2. Without installing main gear oil seal,
measured tangential force on bolt hole of
bearing saddle is 1, 3-2.2 kg.
After adjusting main gear bearing preload,

operate by following steps:
1. Dismantle flange and install oil seal.
folding space
sheet
2 ． Install flange, then after screwing flange nut

with 30—35 kg. m torque, make two mark pegs
on the nut.
REAR AXLE
Differential assembly
Re-assembly
1.Driven gear, half shaft gear and differential left shell 2.Cross shaft 3.Planetary gear
4.Thrust washer of planetary gear 5.Thrust washer of half shaft gear 6. Half shaft gear
7.Differential right shell
Important works
1. Find adjusting marks on the equipment.
2. Abandon original fixed bolts and nuts, and
install new ones.
Make two mark pegs on each nut after screwing.
Torque 14．5－17．5kg .m
REAR AXLE
Main retarder
Re-assembly
sequence：
1. Exterior ring of guiding bearing 2. Retainer plate of guiding bearing
3. Differential assembly 4. Exterior ring of differential bearing
5. Adjusting nut 6. Bearing cap 7. Adjusting washer of driving gear bearing saddle
8.Driving gear assembly 9. Locking sheet
REAR AXLE
Important works
1. Adjustment of differential bearing preload
Screw fixed bolts on bearing cap to torque 5kg．
m，and adjust left and right adjusting nut to adjust
side bearing preload. Measured tangential pull
on fixed bolts is 1.5－2.6 kg.
2．Inspection of driven gear deflection

Deflection limit measured on negative surface of
driven gear is 0.2 mm.
3．Adjustment of clearance between driving and

driven gear side
Measure on four positions placing along round
ring of driven gear, and measuring head of
micrometer should be vertical with the surface of
measured point.
Clearance between driving and driven gear side
is 0．18—0．25 mm.
REAR AXLE
4．Driving gear bearing saddle

Screwing moment of fixed bolts on driving gear
seat: 9－11kg．m
5．Adjustment of mesh mark of driving and driven

gear
Correct mesh mark is shown in left figure, and
the mark locates at small end of high and middle
part of driven gear occupying over 60% of gear
surface. Correct mesh mark is adjusted by
increasing/decreasing adjusting washers of
driving gear bearing saddle and adjusting
Correct gear contact
washers of differential bearing, just liking that in
following table.
To guarantee adjusted differential bearing
preload is unchangeable, screwed ring number
of one end adjusting nut should be equal with
that number on the other end adjusting nut.
Finally, fix locking sheet.
6．Fix bearing saddle

After getting correct gear mesh mark, screw the
bolts of bearing cap, its tightening torque is
17—20kg．m.
REAR AXLE
Contacting mark of
Reason Adjusting step
driven gear
Driving gear is too 1．Adjust driven gear close
close to driven to driving gear.
gear
2．Adjust driving gear apart

from driven gear (increase
adjusting washers)
Driven gear root
Driving gear is too 1．Adjust driven gear apart

apart from driven from driving gear.
gear
2．Adjust driving gear close to
driven gear (decrease
adjusting washers)
Driven gear top
Driven gear is too 1．Adjust driving gear apart

close to driving from driven gear. (increase
gear adjusting washers)
2．Adjust driven gear apart

from driving gear.
Driven gear small end

Driven gear is too 1．Adjust driving gear close to
apart from driving driven gear (decrease
gear adjusting washers).
2．Adjust driven gear close to

driving gear.
Driven gear big end

FRONT AXLE
FRONT AXLE
Maintenance data
Adjusting of front wheel
Front axle
FRONT AXLE
Maintenance data
Tread
Adjusting of front wheel（mm）
Front wheel toe-in 4~6（diagonal tyre） 1~3（Radial ply tyre）
Front wheel camber 1°
King pin caster 1°30′
King pin inclination(KPI) 7.5°
Steering angle:
Outer 35°
inner 42°
Dosage of lubricating grease on one side
of the front wheel hub bearing (g)
Preload of the front wheel hub bearing
New bearing (N) 17~31
Old bearing (N) 14~28
Front suspension standard limit
external diameter of leaf spring pin 25 24.7
clearance between shackle pin and liner 0.1 0.5
FRONT AXLE
Adjusting of front wheel
1. clearance of the front wheel hub bearing Inspection:

2. clearance of the steering link connecting Inspect whether the items listed in the left
ball pin form are normal.
3. tightening of the parts of the front
suspension
4. clearance of the king pin bearing
Measuring of the front wheel toe-in
(1) Stop the front wheel on even ground.
(2)Jack up the front axle.
(3) Make marks on central part of the tire tread
with a chalk.
(4) Place toe-in measuring equipment

on central position of the wheel.
(5) Score tyre central line by turning
wheel.
(6) Let the vehicle fall on ground.
(7) Adjust height of the toe-in measuring
equipment pointing at the mark on tyre.
(8) Measure the distance between tyre
central lines (A).
(9) Jack up the front axle again.

(10) Turn each wheel by 180°.
(11) Make the toe-in measuring
equipment point at the mark on tyre.
(12) Measure the distance between tyre
central lines on rear side of the front
wheel（B）.
The toe-in value equivalents: B－A
Toe-in value:
Diagonal tire 4~6
Radial tire 0~3
FRONT AXLE
Toe-in adjustment:
1. Loose the tie rod connecting lock nut
2. Rotate the tie rod to adjust the toe-in.
3. Tighten the lock nut to specified torque
Tightening torque of the lock nut:：
Tightening torque 113
(1)Put a cushion block of the same

thickness with the steering angle
measurer under each rear wheel.
(2)Jack up the front wheel
(3) Put each front wheel on a steering
angle measurer.
Tire central line should align with the center
of steering angle measurer.
(4) Let the front wheel fall.

(5) Set the scale of the steering angler
measurer to zero.
(6) Remove the front wheel hub cover.
(7) Wipe the steering knuckle ends
and clean up all lubricating grease.
(8) Install upper front wheel--king pin
camber measurer and turn the
steering knuckle left and right
horizontally.
(9) Read camber degree from the dial
directly.
(11) Repeat step (8) and step (9) on
another steering knuckle.
If measured camber degree deviates
the specification: Adjust toe-in
(a) Check whether the steering swivel
pin, bearing and the liner bushing
have been abraded too much.
(b) Check whether the front wheel
hub bearing has loosed.
(c) Check the torsion and
extroversion of the front axle.
Camber degree of the front wheel：

1°
FRONT AXLE
Measurement of the castor of the

steering king pin and K.P.I.
The castor of the steering king pin and
the K.P.I of the king pin can be
measured by the front wheel king pin
camber measurer at the same time.
(1)Adjust the scale of the steering angle

measurer to zero (after finishing the camber
measuring).
(2) Turn the steering wheel right until the front
wheel has turned by 20 ° (measured by the
steering semi diameter measurer).
(3) Adjust the scale of the right king pin castor
and K.P.I of the front wheel to zero.
(4) Turn the steering wheel in opposite direction
until the front wheel has turned left by 20 °
(measured by the steering angle measurer).
(5) Read the degree of the right king pin castor
and K.P.I from the right scale directly.
(6) With the wheel turning left by 20 °, adjust
the scale of the left king pin castor and K.P.I of
the front wheel king pin camber to zero.
(7) Turn steering plate in opposite direction until
front wheel has turned left to 20 ° (measured by
the steering angle measurer).
(8) Read the left king pin castor and K.P.I from
the left scale directly.
Caster angle and Inward inclination angle：

Caster angle 1°30′
Inward inclination angle 7.5°
If the degree of the king pin camber is
measured to deviate the specification：
（a） Check whether the steering
knuckle, the bearing and the liner
bush have been abraded too
much.
（b） Check the abrading situation of the
front steel plate spring.
（c） Check torsion and camber of the
front axle.
FRONT AXLE
Measuring of sideslip
Measuring of sideslip should be made after the measuring
and adjusting of the camber of toe-in and king pin
(1) Roll the wheel across the sideslip measurer as
slowly as possible.
(2) Read out the reading indicating on the sideslip
measurer.
If sideslip value exceeds 5 mm per meter, it is
necessary to adjust the wheel alignment again.
Measurement of the maximal steering angle

1. Stop the vehicle on even place.
2. Jack up the front wheel
(3) Put each front wheel on a steering
angle measurer.
Tire central line should align with the center of
steering angle measurer.
(4) Let the front wheel fall.

(5) Set the scale of the steering angle
measurer to zero.
6. Turn the steering wheel right until it is blocked.
7. Measure the steering angle
a--- Maximal steering angle of exterior wheel
b--- Maximal steering angle of interior wheel
8. Turn steering wheel left until it is blocked.
9. Measure the steering angle
a--- Maximal steering angle of exterior wheel
b--- Maximal steering angle of interior wheel
interior wheel and exterior wheel：

interior wheel 42°
exterior wheel 35°
If the steering angle is measured to deviate the

specification, please adjust it with steering
knuckle stop bolt.
FRONT AXLE
Fixed torque
FRONT AXLE
sequence：
1. brake tube
2. shock absorber
3. drag link
4. steel spring U-bolt U-nut
Assembly sequence
sequence：
Just the opposite of the disassembly
sequence
FRONT AXLE
Disassembly
sequence：
As before mentioned
Removal of the drag link ：

Use special tools
Removal of the U-bolt：

If corrosion of the U bolt is serious, lubricate
the thread with certain quantity of oil, and
then loose the nut in case of thread damage.
Reassembly sequence ：
As mentioned before
Assembly of U nut and U bolt ：

When tighten U bolt or U nut ，lubricate the
thread with certain quantity of oil in case of
Reinstallation thread damage.
Tightening torque of U-bolt：

tightening torque 127Nm
Assembly of drag link ：

Tighten the drag link nut to specified torque, if
the nut opening does not align with the cotter
hole, increase the torque slightly to adjust it.
Tightening torque of the drag link nut：

Tightening torque 167Nm
Assembly of rear shock absorber ：

Install shock absorber nut, gasket and rubber
liner bush according to the diagram.
Tightening torque of absorb nut ：

Upper nut
Lower nut 95Nm
FRONT AXLE
Knuckle and king pin
Disassembly sequence ： Assembly step:

1. Oil retainer 13. I-beam
2. Brake shield plate 10. Knuckle
3. Steering knuckle tie rod and 12. Thrust bearing
tension bar attachment 11. Adjusting shim
4. Knuckle curved arm 9. Swivel pin
5. Knuckle straight arm 7. Locking pin
6. King pin cap 6. King pin cap
7. Locking pin 8. Stops up covers
8. Stops up the lid 5. Knuckle straight arm
9. Swivel pin 4. Knuckle curved arm
10. Knuckle 3. Steering knuckle tie rod and
11. Adjusting shim tension bar attachment
11. Thrust bearing 2. Brake shield plate
12. I-beam 1. Oil retainer
FRONT AXLE
Disassembly ：
Preparation ：
Jack the vehicle up and support it on the chassis
platform
Steps of removal:
Steps of removal are introduced at before.
Removal of steering knuckle tie rod ball:
Remove with the special-purpose tool and the
hammer impact
Removal of the knuckle drop arm and the curved

arm:
Removal of lock pin:

Remove it with the special-purpose tool.
Removal of the swivel pin:

Remove it with the special-purpose tool.
FRONT AXLE
Inspection and repair ：

1. I-beam Inspection and repair:
2. Knuckle When inspect, if find wearing, damage or
3. Changes the drop arm and the any other abnormal situations, Repair or
curved arm replace the parts if necessary.
4. Steering knuckle tie rod and
tension bar attachment
5. Swivel pin, bushing, thrust
bearing and adjusting shim
Visual inspection：
6. Universal joint ball
Check the parts listed in left form for
7. Front wheel hub, bearing and oil
wearing, damage or any other abnormal
seal
situations
8. Brake drum
9. Brake facing
I-beam inspection:
1. Put the steering swivel pin (or
inspection stick) into the steering swivel pin
hole.
2. Tighten a string (or inspection stick)
between the steering swivel pins.
3. The string should be consistent with
the spring holder center bolt hole as you
look down from it.
4 From the side looked the swivel pin (or
examines stick), the swivel pin (or
examines stick) to be supposed to be at
good vertical to the uneven condition
5 Inserts a new swivel pin into the pin
hole and inspect the cooperation situation
of the steering swivel pins in the steering
swivel pin hole. If cooperation of the swivel
pins becomes less compact, the front axle
must replaced; if the upper of lower flange
of the king pin mounting hole is excessively
worn, the front axle must also be replaced.
FRONT AXLE
Inspection of the steering knuckle:

1. Check the knuckle for cracking or other
damages with the magnetic flaw detector
2. Surveys diameter of the bearing and oil

seal assembly surfaces A, B
Model A B
35mm 50mm
Inspection of the universal joint ball:

1. Outer diameter survey
Axle model Standard Limit
39.0mm 38.5mm
1. Spreads light special mixture on the

universal joint ball cone-shape spot (mixture of
red lead and machine oil)
2. Installs the drop arm and the curved arm
on the universal joint ball
3. Inspect whether the universal joint ball
contacts well. The contacted area should not
be shorter than 3/4 of the entire length.
4. If the universal joint ball does not contact
well, it must be repaired or replaced.
FRONT AXLE
Diameter of the steering swivel pin：

（mm）
Model Standard Limit
30.0 29.9
Clearance between swivel pin and bushing：

0.06mm 0.15mm
Notes: When install the bushing, its lubricant

filler is supposed to align with the filler of
the universal joint.
Inspection of cooperation of the steering

swivel pin and king pin bushing:
Put the king pin into the king pin bushing, and
inspect according to following method.
Along the king pin spool thread direction,

bulldozes end of the king pin with fingers, and
inspect whether the fingers can move
smoothly.
If the king pin bushing is excessively tight,

ream the bushing with a reamer to ensure the
concentricity of the upper cotter hole and
lower cotter hole of the steering knuckle.
FRONT AXLE
Assembly Steps of installation:

Steps of installation are introduced at before.
Installation of the thrust bearing:
4. Spreads lubricating grease on the thrust
bearing
5. Keep the dust cover surface upward.
6. Install the thrust bearing
Installation of the adjusting shim:
After installing the adjusting shim, inspect the
clearance between the steering knuckle and
the front axle.
0~0.10mm 0.20mm
：Adjust specification of the shim:（mm）

Thickness 0.50、0.55、0.60、0.65、0.70、
0.80、0.90
Installation of king pin:

1. Apply the lubricating grease on the king
pin and the bushing
2. Align lock dowel slot of the king pin and
lock dowel hole of the front axle
3. Install the steering swivel pin, and
inspect whether the knuckle turns smoothly.
FRONT AXLE
Tightening torque of the lock dowel:：

32Nm
Specification of adjusting shim：

Thickness 0.50、0.55、0.60、0.65、0.70、0.80、
0.90
Installation of blocking cap:

Install the blocking cap upwardly with an
appropriate stick.
Installation of the drop arm and the curved arm:

Tighten the nut to specified tightening torque,
caulk the nut.
Tightening torque of the nut：

441Nm
Tightening torque of the tie rod jointing nut：

186Nm
Tightening torque of the brake shield plate

bolt
69Nm
DRIVE SHAFT
DRIVE SHAFT
General
Specifications
Maintenance
Disassembly sequences
Disassembly
Check and repairs
Re-installation
DRIVE SHAFT
General
Intermediate drive shaft

assembly
Rear drive shaft assembly
Intermediate supporting
assembly
DRIVE SHAFT
Specifications
Intermediate drive shaft assembly Rear drive shaft assembly Intermediate
bearing
OD × Wall Universal joint Universal joint
depth (mm) crossing shaft crossing shaft
OD (mm) OD×ID×W
diameter (mm) diameter
(mm)
69×2.5 18.46 69 18.46 75×32×20
Intermediate drive shaft assembly
OD
Depth
Rear drive shaft assembly
Diameter
Crossing shaft
Diameter of crossing
shaft pin
DRIVE SHAFT
Maintenance
Apply the oil
Drive shaft universal joint and sliding
sleeve (GB49 2 calcium base grease)
Drive shaft intermediate supporting bearing

for lubricating grease
Remove the intermediate bearing, clean it,
and then fill in No. GB49 2 calcium base
grease. In case the vehicles are frequently
used under harsh condition, fill in the
lubricating grease frequently by grease
nipple of the middle support.
DRIVE SHAFT
Before removing the drive shaft, support it with a crane or other metal lines for safety.
Disassembly sequences Assembly sequences

1. Bolt, nut and spring washer, differential end 6. Intermediate drive shaft assembly
2. Bolt, nut and spring washer 4. Nut and spring washer, transmission end
3. Rear drive shaft assembly 7. Intermediate bearing bracket
4. Nut and spring washer, transmission end 5. Bolt, nut and washer
5. Bolt, nut and washer 3. Rear drive shaft assembly
6. Intermediate drive shaft assembly 1. Bolt, nut and spring washer, differential end
7. Intermediate bearing bracket 2. Bolt, nut and spring washer
DRIVE SHAFT
Important – assembly
1. Nut and spring washer, transmission end
Torque (N·m) 46-62
2. Bolt, nut and spring washer, differential

end
Torque (N·m) 46-62
3. Bolt, nut and spring washer
Torque (N·m) 46-62

DRIVE SHAFT
Disassembly torques
（N·m）
DRIVE SHAFT
Disassembly
Disassembly Sequence
1. Universal joint end ring 10. Dust cover
2. Needle bearing 11. Retainer
3. Flange yoke 12. Bearing
4. Crossing shaft 13. Buffer rubber
5. Washer and nut 14. Sleeve spline pipe assembly
6. Intermediate drive shaft flange assembly 15.Rear axle drive shaft bearing assembly
7. Grease nozzle 16. Dust cover
8. Middle supporting assembly 17. Oil seal
9. Intermediate drive shaft assembly 18. Spline tube
DRIVE SHAFT
Important --- disassembly

2. Needle bearing
Knock out the bearing by impacting the
upper end of flange.
5. Washer and nut

Nut code: Q340B10
Wrench: 10mm
Check and repairs

In case of abrasion, damages or any other
unusual conditions, make a necessary
correction or replace parts.
Crossing shaft Visual check

Check the following parts for abrasion,
Needle bearing damages or other unusual conditions.
Buffer rubber
Spline tube assembly
Diameter of crossing shaft pin
Flange yoke
Bearing (mm)
Dimension Limit
18.46 18.43
Diameter of
crossing shaft pin
Check for maladjustment (only for
reference)
Measure an unbalance value between
crossing shaft end.
Rate of unbalance
Dimension Tube
turning value (g·
(mm) (mm)
(rpm) cm)
706
(intermediate 69 3200 40
shaft)
DRIVE SHAFT
Re-installation
1. Spline tube 10. Intermediate drive shaft assembly
2. Oil seal 11. Middle supporting assembly
3. Dust cover 12. Grease nozzle
4. Rear axle drive shaft bearing assembly 13 Intermediate drive shaft flange assembly
5. Sleeve spline pipe assembly 14. Washer and nut
6. Buffer rubber 15. Crossing shaft
7. Bearing 16. Flange yoke
8. Retainer 17. Needle bearing
9. Dust cover 18. Universal joint end ring
DRIVE SHAFT
Important
Right
4. Rear axle drive shaft bearing assembly
13 Intermediate drive shaft flange assembly
16. Flange yoke
Wrong
After applying the lubricating grease on the splilne,
install the flange yoke。
7. Bearing
Supplement the lubricating grease.
After tightening flanges at two sides of drive

shaft, please tighten the intermediate
Supplement bearing bracket.
lubricating grease
5. Washer and nut

Nut code: 2202042N
Wrench: 30mm
Torque (N·m) 343-539

Use a new nut. Do not use the old one.
Make a marking stake on the nut.

DRIVE SHAFT
15. Crossing shaft

Install the lubricating grease nozzle
according to the specified angle.
17. Needle bearing

Insert the crossing shaft into the flange
yoke, and install the needle bearing to the
yoke hole by using a wrench with soft
surface.
1) Always use a new universal joint end ring
2) After installing end ring, check
whether it is correctly placed.
SUSPENSION
SUSPENSION
Front suspension
General
Disassembly
Re-installation
Tightening torque
Rear suspension
General
Disassembly
Check and repair
Re-installation
Tightening torque
Shock absorber assembly

SUSPENSION
FRONT SUSPENSION
General
Specifications
Serial Leaf spring
No. L (mm) W (mm) D (mm)
1 1140 70 8
2 1140 70 8
3 1150 70 8
4 1030 70 7
5 910 70 7
6 790 70 7
7 670 70 7
8 550 70 7
9 440 70 7
10 320 70 7
11 200 70 7
SUSPENSION

Type Hydraulic double telescopic
Max. OD of liquid tank (mm) ￠45
Max. OD of dust cover (mm) ￠53
Main stroke (mm) 220
Compression length (mm) 330
Extended length (mm) 550
SUSPENSION
Disassembly
1. Rubber mat, washer and nut 9. Spring washer and nut
2. Nut, washer and rubber bearing shell 10. Leaf spring cotter
3. Shock absorber assembly 11. Grease nipple
4. Nut 12.Spring washer and nut
5. U-bolt 13. Leaf spring cotter
6. Front buffer block assembly 14. Grease nipple
7. Leaf spring assembly 15.Spring washer and nut
8. Grease nipple 16. Front spring lug and lug cotter
SUSPENSION
Important --- Disassembly

2. Nut, washer and rubber bearing shell
Disassemble the vibration absorber
assembly, nut, washer and bearing shell as
shown.
4. Nut
5. U-bolt
(1) Release (do not remove) U-bolt and
nut
(2) Lift the vehicle and support it on the
chassis bracket.
(3) Remove the U-bolt and nut
Check and repairs

SUSPENSION
Re-installation
Re-installation sequences
1. Front spring lug and lug cotter 9. Grease nipple
2. Spring washer and nut 10. Leaf spring assembly
3. Grease nipple 11. Front buffer block assembly
4. Leaf spring cotter 12. U-bolt
5. Spring washer and nut 13. Nut
6. Grease nipple 14. Nut, washer and rubber bearing shell
7. Leaf spring cotter 15.Vibration absorber assembly
8. Spring washer and nut 16. Rubber mat, washer and nut
SUSPENSION
Important --- assembly

Front
Back
10. Leaf spring assembly
Install the leaf spring assembly by
double wrapping end of left steering
side
12. U-bolt
13. Nut
(1) Place the vehicle at a horizontal plane
and install U-bolt to a corresponding
position of the leaf spring.
(2) Lift the vehicle.
(3) Align with the front axle hole and U-bolt.
(4) Apply the engine oil on the nut before
tightening them to prevent damages of
thread.
(5) Tightening nuts.
14. Nut, washer and rubber bearing shell

15. Front vibration absorber assembly
Disassemble the vibration absorber
assembly, nut, washer and bearing shell as
shown.
Tighten the nut till the washer contacts with
fitting face of bearing end.
SUSPENSION
Tightening torque
(Unit: N•m)
SUSPENSION
REAR SUSPENSION
General
Specifications
Serial Main spring
1 1300 70 10
2 1320 70 10
3 1140 70 8
4 970 70 8
5 800 70 8
6 630 70 8
7 300 70 8
8 300 70 8
Serial Auxiliary spring

1 960 70 7
2 910 70 7
3 710 70 7
4 560 70 7
5 420 70 7
6 270 70 7
7 170 70 7
SUSPENSION
Disassembly
1.U-bolt and nut 6.Leaf spring cotter and grease nipple
2. Rear spring plate 7.Leaf spring
3.Leaf spring cotter, locking bolt and nut 8. Rear leaf spring lug
4.Leaf spring cotter and grease nipple 9. Buffer block
5.Leaf spring cotter and grease nipple
Important
1. U-bolt and nut

After loosening the nut, lift the vehicle, and
support it by chassis platform. Remove
U-bolt and move the front axle assembly.
4. Leaf spring pin

Lift the leaf spring assembly by a jack,
remove the nut and eject the bolt
outwards.
SUSPENSION
Re-installation
1. Buffer block 6.Leaf spring cotter
2. Rear leaf spring lug 7.Leaf spring cotter, locking bolt and nut
3. Rear leaf spring assembly 8. Washer
4. Leaf spring cotter 9. Rear spring plate
5. Leaf spring cotter 10.U-bolt and nut
SUSPENSION
Tightening torque
(Unit: N·m )
Steering gear
General
Maintenance
Steering column and shaft
Check and repairs
Steering gear assembly
Power steering device
Disassembly
Re-installation
General
Steering mechanism
Power steering pipe

Diameter of steering wheel (mm) 410
Free stroke (mm) 10----15
Type of steering shaft Double shaft

Type Recirculating ball
Angle ratio 17：1
Max. working pressure （Mpa） 10
Working flow （l/min） 7
Theoretic max. output torque (N·m) 1200
Direction of turning Left
Output swing angle (°) ±43
Maintenance
Adjustment of free stroke of
steering wheel
In case of too large free stroke of steering

wheel, check whether steering shaft, universal
joint has clearance. If these parts are normal,
then adjust it by an adjusting screw of device.
Rotate the adjusting screw clockwise, the free
stroke will reduce; rotate it anticlockwise, it will
increase.
Oil level check (for power

steering)
Remove a level meter rod from the oil tank

and check the oil level of the meter rod.
Exhaust of power steering pipe

(1) Fill steering oil into the power steering oil
reservoir (use the specified one), separate
the front wheel and the ground by lifting the
front axle, and turn the steering wheel to the
limit position by two sides several times.
Note: During exhaust, check the liquid level
in the power steering oil reservoir frequently,
and fill up in case of insufficiency
(2) Start up the engine, and turn the steering

wheel to the limit position by two sides
several times while it is idle running.
(3) During expelling of air, fill up the steering oil

liquid continuously to the oil reservoir to
ensure it not empty. In case of no air out, it
indicates air in the steering system has been
expelled.
(4) Lower the front wheel and rotate the steering
wheel by double directions while the engine
is running at medium speed. In case of no
unusual noises for steering operation, it
indicates air has been expelled.
(5) In case of unusual noises, continue the

above-mentioned exhaust operations.
(6) After exhaust operations, check whether

steering device and pipes are oil leaking.

1. Horn button 9. Steering column and shaft assembly
2. Nut and spring washer of steering wheel 8. Steering column sleeve cover assembly
3. Steering wheel 7. Bolt: fixing worm shaft and steering yoke
4. Steering shaft cover 6. Steering shaft sleeve cover assembly
5. Combination switch assembly 5. Combination switch assembly
6. Steering shaft sleeve cover assembly 4. Steering shaft cover
7. Bolt: fixing worm shaft and steering yoke 3. Steering wheel
8. Steering column sleeve cover assembly 2. Nut and spring washer of steering wheel
9. Steering column and shaft assembly 1. Horn button
Important – disassembly
1. Horn button
Pull out the horn button by hands
3. Steering wheel
Make a mark by crossing the steering wheel
and steering shaft to ensure the parts could be
at the original position while assembling.
Positioning mark
7. Bolt: fixing worm shaft and steering yoke

(1) Incline the cab upwards and support it by a
supporting rod.
(2) Mark a positioning mark at the steering
Installing bolt
yoke and worm.
(3) Remove the installation bolt by pneumatic

wrench or open-end wrench, and then pull the
flange yoke out of the shaft.
(4) Put down the cab gradually.
Positioning
mark
7. Bolt: fixing worm shaft and steering yoke
While installing, align with the positioning
mark made for the disassembly.
Range of locking torque:

Torque (N·m) 37-75
3. Steering wheel
Make a mark by crossing the steering
wheel and steering shaft to ensure the
parts could be at the original position while
assembling.
锁紧力矩范围： Range of locking torque:
Torque (N·m) 54-68.6
Positioning mark
Check and repairs

Steering gear assembly

1. Locking nut 4. Steering gear
2. Spring washer 3. Steering vertical arm
3. Steering vertical arm 2. Spring washer
4. Steering gear 1. Locking nut
Important – disassembly
Note: Disassemble the input, output oil hoses of power steering pipe parts
before removing the steering gear assembly. Pay special attention to
those areas around the connection and plug, or seal the oil port after
removing the oil pipe to prevent entry of dust or other foreign
substances.
3. Steering vertical arm

Positioning Align with the positioning mark.
mark
(cut groove)
Range of locking torque:
Torque (N·m) 196-250
Disassembly
Sequences
1. Locking nut 5. Sealing ring
2. Bolt 6. Bolt
3. Side cover assembly and steering arm shaft assembly 7. Valve body assembly
4. Dust cover 8. Shell assembly
Important
3. Side cover assembly and steering arm
shaft assembly
Do not damage tooth face, thread and oil
seal while disassembling.
7.Valve body assembly

Disassemble valve body together with
piston assembly.
8.Shell assembly
(1) Check whether the shell has cracks,
whether there are scratches on the
surface in the shell and sliding surface
of the piston.
(2) Check the steering arm shaft. In case of
abrasion, bending, scratches, or partial
abrasion, replace it for a new one.
(3) Check the bearing. In case of abrasion,

scratches of the surface or jamming,
replace it for a new one.
(4) Check the piston and worm shaft. In

case of abrasion or too large clearance,
replace it.
Re-installation
Sequences
1.Shell assembly 5. Dust cover
2.Valve body assembly 6. Side cover assembly and steering arm shaft assembly
3. Bolt 7. Bolt
4. Sealing ring 8. Locking nut
Important
2.Valve body assembly

For parts with valve body assembly,
make the worm gear of the piston face
the fanshaped gear. Apply the liquid on
the contacting surface of the valve body.
Center gear 6. Side cover assembly and steering arm

shaft assembly
Ball nut Align the center gear of the piston with
that of steering arm shaft.
Steering arm
shaft
8. Locking nut
(1) Assemble the steering vertical arm.
(2) Keep the steering vertical arm upward
and vertical.
(3) Tighten the nut after adjusting the
clearance.
BRAKE
BRAKE SYSTEM
General
Main data and specifications of brake
Screwing moment of main bolts and nuts of brake
Disassembly
Re-assembly
Brake main cylinder assembly
Parking brake
BRAKE
General
Brake

Item
Type Front brake: dual self-servo brake
Inner diameter of brake drum (mm)

：front 310
：rear 310
Brake main cylinder
：inner diameter (mm) 28.58
：travel (mm) ≥32
Wheel brake cylinder
inner diameter ：front (mm) 28.58
：rear (mm) 28.58
Vacuum booster
Diameter of film sheet (mm) 230
Free travel (mm) 34
Panel free travel (mm) 5—8
Brake liquid Synthetic brake liquid

Accord with the JG3 requirement in GB10830
“Using technical conditions for vehicle brake
liquid”.
BRAKE
Front brake dual self-servo type

brake（dual type）
Disassembly
1．Return spring of brake 2．
Link lever of brake hoof 3．Pressure spring assemblies
of brake hoof 4．Brake hoof spring 5．Adjusting bolt 6．Brake cylinder assembly
of brake hoof 7 . Brake pipe 8 .Tie-in 9 . Deflation screw 10 .Brake cylinder
11 . Jam of adjusting hole 12 . Bottom plate of brake

BRAKE
Rear brake dual self-servo type

brake（dual type）
Disassembly
1．Return spring of brake 2．Link lever of brake hoof 3．Pressure spring assemblies of brake
hoof 4． Brake hoof spring 5．Adjusting bolt 6． Brake hoof assembly 7 .Exhasut screw
8 .Tie-in 9 . 10. Brake cylinder 11 . Jam of adjusting hole 12 . Bottom plate of brake

similar situation in checking process, it is
Brake friction sheet Brake hoof sheet necessary to repair or change the parts by
Return spring Brake drum requirement.
Brake soft pipe Brake pipe Visual inspection
Brake cylinder Check whether there is any abrasion, damage or
any other abnormal situation about those parts in
left part.
BRAKE
Dismantle old friction liner sheet.
Rivet new friction liner sheet
Brake drum
（mm）
Note: if inner diameter of brake drum has been

increased for the abrasion or milling, it is
necessary to adopt size-added brake friction
sheet.
Inner diameter using limit 311.5
Brake cylinder
Clearance between brake cylinder piston and
cylinder body
Clearance using limit 0.25
Re-assembly of brake
Assembly sequence is opposite with disassembly sequence

BRAKE
Important works
Adjusting screw
1． Spread lubricating grease on adjusting
screw.
2． Brake cylinder assembly
3． Screw adjusting screw to end.
Adjustment of brake panel

Adjust the height of brake panel with adjusting
bolt, then adjust free travel of panel to 5---8mm
by turning vacuum booster handspike. Forbid
dismantling return spring in adjusting process.
Deflation
Air drain valve Notes in deflation
Liquid level in oil storage pot should keep some
quantity in deflation process.
Deflation step
2．After moving brake panel up and down several
times, some resistance will be felt, at this time,
step on panel and unscrew vent screw on brake
to deflate, then screw the vent screw.
3 ． Repeat those operations above until no air
bubble discharge from pipeline.
4 ． Intake brake liquid in oil storage pot to the
mark ”MAX”.
Note: it is necessary to use brake liquid
according with related requirements, and brake
liquids with different types produced by different
factories could not mix.
BRAKE
Brake main cylinder assembly

Disassembly
1.Clamp 2. Oil-intake tie-in 3. Limit screw 4.Clamp loop 5.Rear piston 6. Front piston

similar situation in checking process, it is
necessary to repair or change the parts by
requirement.
Check the diameter of brake main pump with
eyes, if there is any screape, it is necessary to
change.
Use micro-meter and bore gauge to measure the

diameter of piston and inner diameter of cylinder
body independently, and gain the clearance of
piston and cylinder body by calculation.
Clearance using limit 0.22
BRAKE
Re-assembly
Re-assembly sequecne is opposite with disassembly sequence
Important works
Clean cylinder body with compressed air before

assembly, especially note cleaning the small
oil-return hole on cylinder body.
Dip front and rear piston with clean brake liquid

before installation, then install them in cylinder
body.
BRAKE
Parking brake
Parking brake is a kind of in-stretch type brake operated by machine, it is installed in rear part of
gearbox shell body. Parking brake operation draw thread connects with parking brake operation
handle in cab.
BRAKE
Disassembly
Disassembly of parking brake system
1. Parking brake operation handle 2. Parking brake operation draw thread
3. Parking brake drum 4. Flange 5. Parking brake
BRAKE
Disassembly step
Unscrew adjusting nut 1 to dismantle operation
draw thread from handle.
Unscrew nut 2 dismantle handle.
BRAKE
Re-assembly
1. Parking brake 2. Flange 3. Parking brake drum 4. Parking brake operation draw thread
5. Parking brake operation handle
BRAKE
Re-assembly step
1. Parking brake assembly
Tightening torque of the nut on parking arrester
is 8.5 kgf.m
2. Flange
Tightening torque of flange nut is 23 kgf.m
3. Connect parking brake operation draw thread

with handle.
4. Adjustment of parking brake

Adjust ing bolt Stretch direct ion of brake hoof
Adjustment of the clearance of brake drum
Draw back and put down parking brake handle
Brake drum
for 3 to 4 times continually.

Brake hoof
Adjus ting tool
Dial adjusting bolt with adjusting tool
Clearanc e (screwdriver) until brake drum has been locked.
Dial it in opposite direction for 26 gears, at this
time, the clearance of brake drum is about
0.6mm.
5. Adjustment of parking brake operation handle
Draw back and put down parking brake
operation for several times completely.
2. Unscrew locking nut of draw thread.
Adjust the adjusting nut to following requirement:
Draw back the handle with 15 kg strength, and
move the handle for 5—8 gears.
BRAKE
Parking brake
Disassembly
1. Tension rod spring 2. Return spring 3. Adjusting equipment 4. Adjusting spring
5. Second brake hoof and lever assembly 6. Main brake shoe assembly 7. Strut bar
8. Operation draw thread assembly
Measure the thickness of brake liner sheet with

vernier.
It the thickness is less than 1 mm, it is necessary
to change brake liner sheet assembly.
Measure inner diameter of brake drum with

vernier.
If inner diameter exceeds 191 mm, it is
necessary to change brake drum.
BRAKE
Re-assembly
sequence：
1. Operation draw thread assembly 2. Strut bar 3. Main brake hoof assembly 4. Second
brake hoof and lever assembly 5. Adjusting spring 6. Adjusting equipment 7. Return
spring 8. Drag rod spring
Brake
Brake and Control System
General
Technical parameters
Tightening torque
Front brake assembly
Rear brake assembly
Parking brake assembly
Trouble shooting
1
Brake
General
Front brake assembly Rear brake assembly
Parking brake Vacuum booster
2
Brake
Brake master cylinder
Brake pipe drawing

steel pipe connector
hose connector
vacuum hose
flexible hose
vacuum steel pipe
brake oil pipe
rubber hose
A、oil pot；B、vacuum booster, with serial master brake cylinder assembly；C、5-way connector；
D、front wheel cylinder；E、oil pipe tee；F、rear wheel cylinder；G. vacuum pump；H、vacuum
pipe tee；I、venting aux. brake；J. venting aux. brake solenoid valve；K、vacuum barrel；L、vacuum
pipe connecting plate.
3
Brake
Brake Specifications
Front brake
Rated pressure of pipeline: P=10Mpa
Effective radius: Rm=115mm
Piston bore: double-cylinder：Φ=54mm
Brake disc
Brake disc diameter:Φ=296mm
Brake disc thickness: 35mm
Brake disc wear allowance: single side: 2mm
Brake force torque of brake: Mc=2x0.95fFRe=3403.9N.m
Friction block assembly

Friction block assembly thickness: 20mm
Friction material area: 7873.6mm²
Friction material thickness after wear allowance: 2mm
Pipeline pressure (Mpa)

Item
6 8 10 12 14
Brake caliper
assembly
≤2.6 ≤3.0 ≤3.5 ≤4.0 ≤4.5
required liquid
level(ml)
Service brake
Rear
Type Duo duplex shoe
Brake plate/drum ID (mm) 320
Length (mm) 307
Friction plate size Width (mm) 75
Thickness (mm) 8.1
Free length (mm) 208.0
Brake shoe return
Design length (mm) 224.0
spring
Design load (N) 225~275
Clearance between friction plate and brake Below 0.05 at rivet, below 0.2 at side, below 0.3
shoe (mm) at end face
4
Brake
Brake master cylinder
31.75
ID (mm)
Piston stroke（front + rear）(mm) 18+15.5
Wheel cylinder
Front Rear
ID (mm) 30.16 30.16
Parking brake
Brake drum ID (mm) 178
Length (mm) 193
Friction plate size Width (mm) 35
Thickness (mm) 5.0
Spring serial No. First Second
Brake shoe return Free length (mm) 62 49

spring Design length (mm) 70 57
Design load (N) 108～132 90～110
Vacuum booster
Diaphragm diameter (mm) 228+203
Stroke (mm) 35
Pedal
Free stroke (mm) 5～8
5
Brake
(N··m)
Fixed torque (N
Front brake assembly (two leading shoe)
Rear brake assembly (two leading shoe)
5
Brake
Front brake assembly (two leading shoe)
Disassembling
Parts repair: wheel cylinder
Disassembling sequence
1. brake shoe spring rod, hold down spring and spring holder 9.oil cover
2. brake shoe return spring 10.locking claw
3. brake shoe assembly 11.shield
4. brake hose 12.piston
5. brake connecting pipe 13.adjusting screw
6. brake connecting pipe 14.piston cup
7. tee connector assembly 15.venting screw and its cover
8. wheel cylinder assembly 16.wheel cylinder body
6
Brake
Important operation
2 、 Remove the return spring of the

brake shoe.
4、Hose
Loosen the connecting nut ① , and take down

the clip ② and the hose.

brake drum
Repair or replace the parts if they are
brake friction plate
found worn out, damaged or with other problems
wheel cylinder body after inspection.
piston
Visual inspection
piston cup
return spring Check the following parts for any abrasion,
corrosion, scratches or other problems.
Thickness of brake friction plates
Max. thickness: 1.0mm
7
Brake
Return spring
Free length: 208.0mm
Design length: 224.0mm
Design load: 225～275N
Washing wheel cylinder parts

The wheel cylinder parts must be
washed and with clean brake fluid.
Do not use any mineral based cleaning
solution like gasoline, kerosene, and
acetone, paint thinner, CO4, etc.
Piston cup
Check the piston cup for any abrasion,
deformation, damage or other problems.
Clearance between wheel cylinder and
piston
Max: 0.15mm.
Brake drum
mm
Standard Maximum
ID 320 321.5
Out-of-roundness ≤0.13
8
Brake
Reassembling
Parts repair: wheel cylinder
Reassembling sequence
1. wheel cylinder body 9.whell cylinder assembly
2. piston brake shoe 10.tee connector assembly
3. piston cup 11.brake connecting pipe
4. shield 12.brake connecting pipe
5. adjusting screw 13.brake hose
6. venting screw and its cover 14.brake shoe assembly
7. locking claw 15.return spring
8. oil cover 16.brake shoe spring rod, hold down spring and its holder
9
Brake
shield Important operation

piston piston cup
3. Piston cup
When fixing the piston cup, have its

grease butterfly side facing the cylinder. First, apply
clean brake fluid to the piston cup, take care not
to damage the cup lip. Apply rubber grease to
the piston shoulder.
4. Shield
To prevent water entry, apply clean

brake fluid to the shield inner surface.
6. Venting screw
Tightening torque：7～12N·m
9. Wheel cylinder assembly
10. Tee connector assembly
10
Brake
11,12. Tee connector assembly
13. Hose
Fix the hose clip ① on the bracket, and tighten

the connecting nut②.
14. Brake shoe
Apply a thin layer of heat resistance grease to

the brake shoe, wheel cylinder and the inner
surface of the back plate.
When fixing the brake shoes, have

their tip sides facing the wheel
cylinder and the adjuster.
11
Brake
Rear brake assembly (two leading show)
Disassembling
� parts repair, wheel cylinder body
1. brake shoe spring rod, hold down spring and spring holder 8.shield
2. brake shoe return spring 9.piston
3. brake shoe assembly 10.adjusting screw
4. brake connecting pipe 11.piston cup
5. brake connecting pipe 12.venting screw and its cover
6. wheel cylinder assembly 13.wheel cylinder body
7. locking claw
12
Brake
Repair or replace the parts if they are

found worn out, damaged or with other
problems after check.
Visual inspection
brake drum Check the following parts for any abrasion,
brake friction plate corrosion, scratches or other problems.
wheel cylinder body ,
piston
piston cup
return spring
Thickness of brake shoe friction plate
Max. thickness: 1.0mm
Return spring
Free length：208.0mm
Design length：224.0mm
Design load：225～275N
13
Brake
Washing wheel cylinder parts
The wheel cylinder parts must be

washed and with clean brake fluid.
Do not use any mineral based cleaning

solution like gasoline, kerosene, and
acetone, paint thinner, CO4, etc.
Piston cup
Check the piston cup for any abrasion,

deformation, damage or other problems.
Clearance between wheel cylinder and

piston
Max: 0.15mm.
Brake drum
mm
Standard Limits
ID 320 321.5
14
Brake
Reassembling
� parts repair, wheel cylinder body
1. wheel cylinder body 8. wheel cylinder assembly
2. piston 9. piston brake connecting pipe
3. .piston cup 10. brake connecting pipe
4. shield 11 brake shoe assembly
5. adjusting screw brake connecting pipe 12. brake shoe spring rod, hold down
6. venting screw and its cover spring and spring holder
7.locking claw 13. brake shoe return spring
15
Brake
Important operation
piston cup piston shield
3. Piston cup
When fixing the piston cup, have its butterfly

grease
side facing the cylinder. First, apply clean brake
fluid to the piston cup, then insert the cup. Take
care not to damage the cup lip. Apply rubber
grease to the piston shoulder.
4. Shield
To prevent water entry, apply clean

brake fluid to the shield inner surface.
Adjusting screw 5.Adjusting screw
When fixing the wheel cylinder adjuster, have

the shallow slot side face the outside.
6 Venting screw
Tightening torque 7～12N·m
9. Wheel cylinder assembly
16
Brake
9, 10. Brake connecting pipe
11. Brake shoe
Apply a thin layer of heat resistant

Adjuster grease to the back plate A between the brake
Side shoe and wheel cylinder as well as the inner
part B.
Narrow When fixing the brake shoes, have
Slot Side the tips face the wheel cylinder and
adjuster.
17
Brake
Parking brake
Disassembling
4 3
1. Parking brake handle 2. Parking brake control cable 3. Parking brake drum
4. Flange 5. Parking brake
18
Brake
Parking brake
Disassembling
1. pull-rod spring 2. return spring 3. adjuster 4 adjusting spring 5. 2nd brake shoe and lever
assembly 6. 1st brake shoe assembly 7. hold down rod 8. control cable assembly
Disassembling steps
Loosen the adjusting nut①, and remove

the control cable from the handle.
Loosen the nut② before removing the handle.
19
Brake
Repair or replace the parts if they are found

worn out, damaged or with other problems after
check.
● brake drum
● brake friction plate
● return spring
● strut
● control cable
● control handle
Brake drum
mm
Standard Limit
ID 178 179
Thickness of brake friction plates
Measure the thickness of brake lining by

a vernier caliper. If it is less than 1mm
thick, the brake shoe assembly should be
changed.
Return spring
Free length：62.1mm
Design length：66.9mm
Design load：54～66N
free length
20
Brake
Reassembling
1. control cable assembly 2. push rod 3. 1st brake shoe assembly 4.2nd brake shoe and lever
assembly 5. adjusting spring 6. adjuster 7. return spring 8. pull-rod spring
Adjustment of parking brake
Brake friction plate adjustment

Move the adjuster upward with a screw driver,
until the brake drum is locked. And then move the
adjuster back for about 25 notches. The
clearance between the brake drum and friction
plates is about 0.5mm by now.
Adjustment of the parking brake handle travel
Pull up the parking brake handle to the end ，
count the number of the gears in the brake lever. If the parking brake handle is pulled with a force
of 300N, its travel covers 9 to 14 notches. Adjust the parking brake if necessary.
Before adjustment of the parking brake, make sure that the clearance of the rear brake shoe is
already adjusted.
1. Loosen the locknut, rotate the adjuster to adjust the travel distance.
2. Tighten the locknut.
21
Brake
Trouble shooting
Brake not working
Check the margin of brake pedal

NO YES
Check brake fluid Check operation of vacuum booster
NO YES YES NO
Check the hose on the booster

Change brake Check brake drum & friction disc
YES NO
NO YES
Check wheel cylinders Repair & change booster Change damaged

Change
parts,
NO YES
Change necessary parts Adjustment
22
Brake
Brake
Check the free travel &

margin of the brake
NO YES
Necessary Check driving brake friction

disc gap and brake pedal
YES NO
Necessary
All wheels dragging One wheel

dragging
Check for blockage in return

Check driving brake disc
hole of brake master cylinder
NO
Check wheel Adjust the clearance,

cylinders, piston or change the return
Noise from brake
Parts cleaning
Check friction disc
23
Brake
Brake not working
Check free travel of the pedal
NO YES
Check brake
Check brake fluid

NO YES
NO YES
Clean or
Check if the
change the
Add brake fluid and Check for
vent air from the pipes leakage of brake
Change parts
NO YES
Change necessary Check brake drum & friction
NO
Change necessary Adjust brake
24
Brake
Brake
side-slipping
Check side abrasion of tires
NO YES
Change the parts Check wheel positioning
NO YES
Adjust & repair Check for any leakage of brake
pipes
NO YES
Change necessary Check the wheel

parts cylinder operation
NO
YES
Check friction disc of brake drum
NO
YES
Check the brake return spring
NO
Change or repair the parts
25
Electrical System
General
I . Operation table
II. Electric diagram identification
1. Wire code identification:
2 . Electrical component identification:
III .Electrical designations and usages of the complete vehicle
1. Battery
2. Starter
3. Generator
4. Speed sensor
5. Electric preheating
6. Fuel cutoff solenoid valve
7. Wiper
8 .Washer
9. Headlamp
10 .Front small lamp
11. License lamp
12. Direction signal lamp and hazard warning lamp
13. Rear combination lamp
14 .Reversing lamp and switch
15. Interior lamp and switch 150
16. Brake lamp and switch
17. Parking brake lamp and switch
18 Fog lamp and switch
19. Electric horn
20. Vacuum alarm
21 .Various relays
22 .Combined switches
23. Combined instrument
24 .CD player
25. Idle speed boost device
26. Exhaust brake controller
1
27. Electrical device
2
General
I . Operation table
12 V
Battery
Speedometer B
Thermometer B
Instrument Fuel meter B
Two abnormal shape crystal
B
Headlamp headlamps
Fog lamp B
Speedometer B
Thermometer B
Fuel meter B
Illuminator Meter board B
Direction indicator and hazard
B
lamp
Far beam indicator B
Parking brake indicator B
Brake liquid level indicator B
Heating plug indicator B
Oil pressure indicator B
Indicator and caution Exhaust brake indicator B
lamp Water separator indicator B
Brake lamp and reversing lamp B
Interior lamp Three level lamp changes B
Intermittent wiper B
Cigarette lighter B
Horn B
CD player and stereo
B
radio cassette player
Buzzer Vacuum warning buzzer B
Warm air and air conditioner B
Manually-operated door and window B
Motor-driven door and window O
3
Note: B: Standard equipment O: Optional
II. Electric diagram identification
1. Wire code identification:
Specifications and colors of wires on the wiring diagram are distinguished by different
codes. As different countries use different color codes for the wires, JAC product
users and maintenance personnel should identify the wires according to Wire Color
Code in Electric Maintenance Manual of JAC automobile.
E.g.: 1.5GR
1.5----------Section of wire conductor is 1.5 mm2
G-----------Color of insulating layer is green
R-----------Color strip is red
Wire conductor section -Insulating layer ground color Color strip
1.5 G R
Color strip
Ground color
Cross-section area
Color codes of cables
Vinylon insulated wire

Application circuit
Black - white Black- yellow Black- red
Black (B)
Starter motor (BW) (BY) (BR)
White- red White- black White- blue White-
White (W)
Charging circuit (WR) (WB) (WL) Green (WG)
Red- white Red- black Red- yellow Red- green Red- blue
Red (R)
Lamp circuit (RW) (RB) (RY) (RG) (RL)
Green-
Green- white Green- red Green- Green-
Green (G) orange
(GW) (GR) yellow (GY) black (GB)
Signal circuit (GO)
Yellow- red Yellow- black Yellow- Blue -
Yellow (Y)
Metering circuit (YR) (YB) black (YB) yellow (LY)
Blue- white Blue- black Blue-
Blue (L) Blue- red (LR)
Wiper circuit (LW) (LB) orange (LO)
Lamp green Lamp green - Lamp green -
Miscellaneous (Lg) black (LgB) red (LgR)
4
Brown- white Brown- red Brown-
Brown (Br)
(BrW) (BrR) yellow (BrY)
2 . Electrical component identification:

Electrical components in the JAC automobile electrical diagrams are indicated in
common general signs. Refer to Common Automobile Electrical Signs for details.
Battery unit Fuse Relay Flasher Button

switch
Solenoid Electric Illuminator, Speaker Fuel gauge

valve horn indicator
tº
Combination Buzzer General Radio Thermometer

lamp hand cassette
switch sign player
M
U A
Motor Voltage Semiconductor Twin-filament Amperemeter

regulator diode lamp
Fig. 2 Common automobile electrical signs
III .Electrical designations and usages of the complete vehicle

1. Battery
(1) Battery is a kind of reversible low voltage direct current power supply that can
convert chemical energy into electric energy and vice versa. Lead acid battery is
supplied by JAC, which is dry-charged battery.
(2) Electrolyte in the battery is prepared by pure sulfuric acid and pure distilled water
5
in a certain proportion. Electrolyte purity is an important factor affecting the electrical
performance and service life of the battery. As the industrial sulphuric acid and
ordinary water contains foreign materials as copper and iron that accelerate the self
discharge, it cannot be used in battery. The sulfuric acid and distilled water used must
meet specialized standard.
(3) The battery is composed of six separate single cells that are connected in series
with led rod. The voltage of a single cell is 2V, so the nominal voltage of one battery of
six cells of series connection is 12V.
(4) The battery has charging hole that is sealed by plug screw. Charging hole plug
screw has vent hole to release hydrogen and oxygen generated from chemical
reaction. The vent hole must be kept clear in service. The shell may crack or explode
if it is clogged.
(5) Battery inspection: a If the electrolyte level is too low, please add distilled water to
the max. liquid level; b If the measured specific weight is under 1.23 (at 20℃), add or
replace the electrolyte.; c Keep the terminals reliably connect, remove any corrosive
marks and keep the battery terminal, power line and earth wire connection clean.
Battery inspection:
1. Check the terminal post for
looseness and corrosion
Keep the connection reliable. Remove
Max. level Max. level any corrosive mark and keep the
connection clean.
2. Check the electrolyte level of the
battery
If the electrolyte level is too low ，
Min. level please add distilled water to the max.
liquid level
2. Starter
The function of starter is to convert the electric energy of battery into mechanical
energy to drive the engine.
The starter used in this vehicle is 12V DC series excitation motor. It is composed of
three parts: (1) DC series excitation motor: to convert the electric energy of battery
into mechanical energy to generate torque; (2) Drive mechanism, also called
engaging mechanism: To engage the driving gear of the starter into the engine
flywheel toothed ring when the engine is started, so that the torque of starter is
transmitted to the engine crankshaft, and to disengage the driving gear of starter and
the engine flywheel toothed ring after the engine is started; (3) Control device: To
connect and disconnect the starter and battery.
6
Starter structure:
Adjusting shim
Moving core Reset spring Electromagnetic switch
Screw
Shift yoke
Conducting strip
Clutch
Brush
Driving gear Middle support Armature Reverser Magnetic

plate pole
Starter operating circuit:

Main power switch coil Combined switch (key) Earth
Power supply Main power switch contact Ampere meter Combined switch (start) Starting relay coil Earth
Fuse Starting relay contact Electromagnetic switch Starter

Earth
The maintenance personnel should carry out inspection and repair for the lines
indicated by the starter operating circuit diagram.
3. Generator
AC generator is the main power for the automobile. It is actually a self-exciting
three-phase synchronous generator. There are three windings at an interval of 120º
on the stator core of the generator. The ends of the three windings are connected,
which are usually called star connection. The rotor has field winding on it. Magnetic
field is generated when direct current passes the rotor winding. When the rotor is
turned by the engine, relative cutting movement is generated between magnetic line
of the rotor and three-phase winding of the fixed stator. Three phase alternating
electromotive force, i.e., AC power, is generated in the three-phase winding. DC
power is used in automobile circuit. So the AC power generated by the AC generator
must be rectified before using. The rectifying is made mainly by the silicon rectifier in
the generator. The three phase bridge full wave circuit composed of several silicon
diodes commutates alternating current into direct current.
7
Silicon rectifying shunt excitation AC generator is adopted in this vehicle, which is
composed of three phase AC motor and silicon diode rectifier. Minus earth is adopted.
Do not connect otherwise, or the generator may be damaged.
A
winding
Rotor
Winding
用蓄
Rotor
D D 电电
consumers
Electricity
设
池
Battery
备
D
C D D D
Stator
AC generator Rectifier
Fig. 1 AC generator wiring diagram
4. Speed sensor
Speed sensor is fit on the generator end. The signal is taken from generator speed
signal terminal P. The number of pole pairs is 6. The generator and engine
transmitting ratio is 82: 145. The sensor output waveform is regular square wave.
5. Electric preheating
Electric preheating for the engine is adopted in cold season for this vehicle. The
heating wires should not be electrified for more than 30 sec., or they may be
damaged.
If the preheating effect is not good, check if the circuit is switched on first. If the circuit
is OK, use universal meter to check the heating wire and replace the burned-out
electric heater.
6. Fuel cutoff solenoid valve

There is one electronic component on the rear end of the engine injection pump. Its
function and wiring is as follows:
8
The electrical component is fuel cutoff solenoid valve. Its function is the same with that
of electric engine shut down device. The fuel cutoff solenoid valve is powered on
when the engine is started. The electric magnet lifts up the seal iron, so the injection
pump of the engine starts to supply oil and the engine starts normal operation. When
the engine needs to be shut down, turn the key to shutdown position, so the fuel cutoff
solenoid valve is power off and the seal iron cut the fuel path by the spring operation.
Power supply → Fuse→ Ignition lock→ LOCK (shutdown)
7. Wiper
The electric wiper of this vehicle is automatic reset type. For installation, the motor
should be in reset state. Then connect the link rod and wiper blade (wiper blade
position should be in reset state).
The variable speed switch controls the motor circuit to implement variable speed
wiping. The variable speed control circuit is as shown in the figure. The control
process is as follows:
a) Low speed wiping。 When the power switch is ON and the variable speed switch is
in I position, the current flow is as follows: battery positive pole→power switch→fusing
element→brush B3→armature→brush B1→variable speed switch I position
earth→battery negative terminal. As the brush B2 has an offset angle, the wiper blade
swings fast when the motor is running at high speed.
b) When the power switch is ON and the variable speed switch is in II position, the
current flow is as follows: battery positive pole→power switch→fusing
element→brush B3→armature→brush B2→variable speed switch II position
earth→battery negative terminal. As the brush B2 has an offset angle, the wiper blade
swings fast when the motor is running at high speed.
c) Shutdown and reset. The automatic reset mechanism of motor wiper is as shown in
Fig. 1－21 (b). The nylon impeller is embedded with copper ring 7 and 9. The copper
ring has two parts. The larger copper ring 9 is connected to the casing to earth.
Contact piece 3 and 5 is made of phosphorus copper or other elastic material.
Wiper variable speed control wiring diagram
9
1-Power switch; 2-Fusing element; 3、5-Auto reset contactor; 4, 6-Contact;
7, 9-Auto reset slide ring (copper ring); 8-Worm wheel; 10-Armature; 11 - Permanent
magnet
Contact 4 and 6 is riveted on one end. As contact 3 and 5 is elastic, when impeller 8
turns, contact 4 and 6 maintains contact with the end surface of impeller 8 (including
copper ring 7 and 9).
When wiper variable speed switch is in "0" position, if the rubber brush does not stop
at bottom edge of the windshield glass, the impeller turning will make contact 6 and
copper ring 9 connect, so the current keeps flowing into the armature. Here the
current forms a circuit from battery positive pole→power switch→fusing
element→brush B1→variable speed switch→contact piece 5→contact 6→copper ring
9→earth→battery negative terminal. The motor runs at low speed until the impeller
turns to the position shown in Fig. 1－21 (a) and contact 4 and 6 connects with copper
ring 7.
When contact 4 and 6 is connected with copper ring 7, the motor cannot stop
immediately owing to the inertia force of armature turning. Instead, electricity is
generated with engine operation. As the direction of electromotive force generated by
armature winding is opposite to that of external supply voltage, the current flows in the
circuit of brush B3→contact piece 3→contact 4→copper ring 7→contact 6→contact
piece 5→variable speed switch→brush B1. Torque is also generated (called brake
torque) to make the motor stop immediately. Here the rubber brush is just reset to the
bottom edge of the windshield.
The maintenance personnel can look for the fault of wiper circuit according to the
wiper working principle and variable speed control wiring diagram.
a. Main components
Designation Quantity Mounting position
Connecting rod assembly 1 Bottom edge of front windshield
Wipe rod and brush assembly (left) 1 Front windshield
Wipe rod and brush assembly (right) 1 Front windshield
Rain wiper motor assembly 1 Inside the cab
Washer jug assembly 1 Inside the cab
Water pipe assembly 1 Inside the cab
Nozzle assembly 2 Cab front panel
Control switch (combined switch) 1 On steering column
10
Wiper relay 2 Inside the cab fuse box
b. Functional requirements
I. Three operation modes of high speed, low speed and intermittent
II. Automatic reset function of wiper rod
III. Interval of intermittent operation can be adjusted
IV. Linked control of washer and wiper
c. Circuit design
Slow speed relay

High speed relay
High
speed Slow Wiper motor
speed
Motor
Washer
motor
Diode
Combined
switch
Earth
8 .Washer
Dust or dirt may get onto the windshield glass during the driving. To ensure good sight
of the driver, most vehicles have windshield glass washer.
11
When the washing engine armature is powered on, it turns in the permanent magnetic
field. When the armature shaft turns, it drives the pump shaft via coupling, so the
pump rotor also rotates. The pump rotor pumps the washing liquid from the pot to the
wind shield via the outlet hose and the nozzle. In the meantime, the wiper blade
swings to remove the dirt on the wind shield glass.
To use the washer, switch on the washing pump before the wiper. The continuous
work time of washing pump should not exceed 5s, interval not be less than 10s. When
there is no washing liquid in the pot, do not switch on the washing pump. Otherwise,
the motor may be damaged.
9. Headlamp
The headlamp of this vehicle is anti-glare combination lamp. The bulb is twin filament
type (long-distance beam/short-distance beam). When long-distance beam is
switched on, the long-distance beam indicator on the dashboard illuminates at the
same time. Lamp switch and change is operated from the group switch.
If the lamp is not ON, please check in the following sequence.
Ste
Inspection content Method
p
Check if the fuse is If the fuse is blown, replace it after the cause is
1
blown found. If not, check the next item.
Turn on the lamp switch to see if the headlamp relay
Check if the lamp relay
2 operates. Or use a universal meter to check if the
operates normally
relay terminal is OK.
If the result of the above checks is acceptable,
Check the headlamp
3 please check if the bulb is damaged. If not, check
bulb
the next step.
Check if the wiring Check if all the terminals are reliably connected
4
connectors are reliable according to the wiring diagram.
Check the combined Check if the lamp switch on the group switch can be
5
switch (lamp switch) normally turned on
12
Main power supply
Headlamp
circuit
Short-distance Long-distance
beam relay beam relay
Left Headlamp Right

Short-
distance Long-
headlamp long-dista Short-
distance Long- headlamp
beam distance beam distance
beam nce beam beam
indicator
Small Short- Combined

lamp distance
Headl
amp Lamplight
Flicker
beam Lamplight
switch
switch
switch
10 .Front small lamp

The front small lamp of this vehicle (width lamp) is combined lamp, i.e., front small
lamp on the lower part and direction lamp on the upper part. Check for fault according
to the small lamp operating circuit:
Power supply→ Fuse → Relay coil→Combined switch→Earth
→Relay contact →Front small lamp→Earth
The trouble shooting method is the same with that of front lamp. The difference is that
you need to check the small lamp relay when you check the relay.
11. License lamp

The license lamp is on the plate support on the rear of the vehicle. The license lamp is
ON when the lamplight switch is in any position.
The trouble shooting method is the same with that of small lamp.
13
License lamp
To replace the bulb, remove
one screw fixing the lens.
Check for fault according to the license lamp operating circuit:

Power supply→ Fuse → Relay coil→Combined switch→Earth
→Relay contact→License lamp→Earth
12. Direction signal lamp and hazard warning lamp

The direction lamp and front small lamp is combined. It is on the top of the combined
lamp. The light color is yellow. The operating circuit of the direction lamp is shown
below:
Power supply → Fuse → Flasher ---→Combined switch ----→Left and right direction lamp→Earth
---→Left and right direction lamp→Earth
---→Warning switch
The direction lamp circuit should be checked according to the circuit diagram. When
the vehicle is at fault or there is other danger, turn on the warning switch. The bulbs of
the direction lamp flicker at the same time to give a warning. The trouble shooting
method is the same as above.
13. Rear combination lamp
Rear lamp is a combined lamp with brake lamp, reversing lamp and direction lamp at
the bottom of the rear of the vehicle on both left and right. The color is red. The rear
lamp control switch is on the lamp switch of the combined switch. Its circuit is:
Power supply → Fuse → Relay coil→Combined switch→Earth
→ Relay contact→Rear lamp→Earth
Note: The rear lamp use the same relay with front small lamp. It also share the same
fuse with front small lamp, license lamp, fog lamp and instrument lamp. The
maintenance personnel should pay attention to this in maintenance. The trouble
shooting method of rear lamp is the same with that of front small lamp.
Rear combination lamp

To replace the bulb,
unscrew the four bolts
fixing the lens.
14
14 .Reversing lamp and switch
Reversing lamp position is the same with that of rear lamp. The reversing lamp light is
white in color. The reversing lamp works together with the reverse gear switch
mounted on the gearbox. Its operating circuit is:
Power supply→Fuse→Reverse gear switch→Reversing lamp→Earth
Note: the reversing lamp shares the same fuse with brake lamp and roof lamp. Please
pay attention to this in maintenance and repair.
15. Interior lamp and switch 150

The interior lamp is at the middle of the upper edge of the front windshield of the cab.
It has two switches, one is the roof lamp composite switch and the other is the door
post switch installed on the left door post of the cab. Its operating circuit is:
Power supply → Fuse → Interior lamp → Interior lamp switch → Earth

→ Door post switch → Earth
Interior lamp switch

circuit diagram
OFF ON
Interior lamp
Door switch
Interior lamp switch position

15
ON ←OFF→ Door
16. Brake lamp and switch

Brake lamp position is the same with that of rear lamp. The brake lamp light is red and
the brightness is higher than that of rear lamp. The brake lamp works together with the
brake lamp switch mounted on the brake pedal. Its operating circuit is:
Power supply→ Fuse→Brake switch→Brake lamp→Earth
Note: the brake lamp shares the same fuse with reversing lamp and roof lamp. Please
pay attention to this in maintenance and repair.
17. Parking brake lamp and switch

Parking brake switch is integrated with parking brake control lever. When the manual
control lever is lifted, the parking brake switch is ON. Here the parking brake indicator
on the dashboard turns ON. Let down the manual control lever, and the parking brake
switch is OFF and the parking brake indicator is OFF. Its operating circuit is:
Power supply→Fuse →Parking brake indicator→Parking brake switch →Earth
Parking brake indicator sign on the dashboard:
P
18 Fog lamp and switch

The fog lamp is combined with the headlamp and its light color is yellow. The working
principle of fog lamp is: when you drive on a foggy day, first switch on any lamp on the
combined switch and then press the fog lamp switch to turn it on. Turn off the lamp
switch on the combined switch or the fog lamp switch to turn off the fog lamp.
Fog lamp operating circuit:
Power supply → Fuse → Relay coil→ Combined switch→Earth
→ Relay contact →Fog lamp switch →Fog lamp→ Earth
Note: The fog lamp shares the same fuse with the front small lamp, rear lamp, license
lamp and instrument lamp. The maintenance personnel should pay attention to it in
16
repair.
19. Electric horn

The electric horn of this vehicle is dual tone (high and low tone) electric horn. It is
fitted on No. 1 girder on the chassis in the middle of the front bumper. Its operating
circuit is:
Power supply → Fuse → Horn relay coil →Horn button→Earth
→ Relay contact →Horn →Earth
Note: The contact of horn button is an elastic joint on the combined switch that keeps
effective connection with the button contact iron ring on the steering wheel. Pay
attention to the connection state of the contact in maintenance.
Electric horn:
Relay：Horn Wiring diagram
Switch
：Horn
Horn
Horn specifications:
Structural Diaphragm Sound level Base frequency Volume range
shape diameter mm dB (A) range Hz fitting (dual tone)
Disc type >115 105~125 250~650 4: 5
If the horn does not sound or sounds
abnormally when you press the horn
button, check the line and battery voltage
before the following items:
1. Check if the fuse is blown. At the same
time, check if the wire connection is tight.
2. If both the fuse and connector can
operate in normal sequence, remove the
horn from the steering wheel and
short-circuit the horn switch guide line
terminal and the steering shaft thread.
a. No sound --- Poor contact between horn
contact of the combined switch and the
steering wheel bottom.
17
b. Sound --- The horn switch is at fault.
3. If the horn sounds without stop, the
source of trouble may be the horn switch
or bad reset contact ring.
20. Vacuum alarm
When the vacuum pressure in the vacuum cylinder exceeds certain value, the
pressure contact on the vacuum horn closes to complete the circuit. The vacuum
alarm buzzer and alarm lamp on the dashboard is switched on to warn the driver to
find out the cause.
The vacuum abstraction is carried out by the vacuum pump on the generator. The
maintenance personnel should pay attention to this in repair.
Alarm lamp identification:
！
21 .Various relays
The relays for this vehicle include lamp relay, horn relay, warm air relay, starting relay
and preheating relay. As the lamp, horn and warm air does not consume high current,
relay of the same specification is used for these current consumers. The solenoid
switch of the starter and heating plug consumes high current, so they use special
purpose relays that are installed in the chassis electric box. From left to right, starting,
preheating, horn, air conditioner and braking relay.
22 .Combined switches
The combined switch is a switch integrating power, start, lamp, wiper, washer and
direction lamp. There are many lines together, so faults are likely to occur here. It will
help the maintenance personnel a lot to know about the structure of the combined
switch in electric trouble shooting.
Combined switch structural diagram
1. Ignition switch working position conduction diagram
Contact code
ACC ON R ST P1 P2 R1 Remark
and power B B1 R2
220W 240W 60W 220W 40W 40W 60W s
Working gear
Wire color B L BY BR BW LY LW L R Y
Specification mm² 5.0 3.0 3.0 3.0 3.0 1.0 1.0 1.0 0.75 0.75
18
LOCK 〇〇
ACC 〇〇〇〇
ON 〇〇〇〇〇
START 〇〇〇〇〇〇 Automa
tic reset
Power Key in 〇〇
switch
Key out 〇
2 Lamp switch beam selection and overtaking signal conduction diagram

Contact code BT E J B BH HU
Rated power 80W 120W 10W 150W 150W
OFF
〇〇〇 Overtaking
〇〇
Small lamp
〇〇〇 Overtaking
Gear
Short-distanc 〇〇〇〇
Headlamp
e beam 〇〇〇〇〇〇 Overtaking
Long-distance 〇〇
〇〇
beam
19
3 Direction switch, warning switch, exhaust brake switch and horn conduction
diagram
Contact code TL TB TR B1 F B2 EX ER HO
Rated power 72W 144W 72W 120W 120W 120W
Warning Direction
switch switch
L 〇〇〇〇
OFF OFF 〇〇
R 〇〇〇〇
ON OFF 〇〇〇〇〇
Exhaust OFF
brake
ON 〇
switch
Horn 〇
4 Wiper switch and water spraying switch
Water
Wiping 11 E1 12 AS L H E2 W E3
spraying
OFF 〇〇
INT 〇〇〇〇
OFF
LO 〇〇
HI 〇〇
OFF INT 〇〇
ON
LO HI
EZ
20
23. Combined instrument
Instrument
Disassembling and reassembling
Disassembling sequence:
1. Transparent top cover 6.Pointer component
2. Instrument decorative ring A 7.Gauge plate
3. Instrument decorative ring B 8.Middle cover
4. Black frame 9.Circuit board parts
5. Reset rod 10.Bottom cover
Disassembling sequence:
Follow the reverse order of disassembling to reassemble.
21
1 Instrument indicator:
No. Designation Function Color
1 Engine oil pressure alarm ON when the engine oil pressure is too Red
lamp low
2 Charging indicator ON when the battery discharges Red
3 Parking brake alarm lamp ON when the parking brake is switched Red
on
4 Preheat indicator ON during the preheating Yellow
5 Exhaust brake indicator ON when the exhaust brake is switched Yellow
on
6 Left/right direction indicator ON when the direction lamp is switched Green
on
7 Beam indicator lamp ON when the headlamp is switched on Blue
8 Fog lamp indicator ON when the fog lamp is switched on Yellow
9 Hazard alarm lamp indicator ON when the hazard alarm is switched Red
on
10 Fuel oil level alarm lamp ON when the fuel oil level is low Yellow
11 Small lamp indicator ON when the small lamp is switched on Yellow
12 Door open alarm lamp ON when the door is open Red
13 ABS alarm lamp ON when the ABS system is at fault Yellow
14 Brake fault alarm lamp ON when the brake is at fault or the Red
brake fluid is low
1) Main component installation

Main component Model Mounting position
Combined Stepping motor type Under dashboard
instrument
Speed Middle of combined instrument
meter/odometer Electronic
Odometer sensor On gearbox output shaft
Engine oil pressure Varistor type On engine oil pipe
sensor
Water temperature Thermister On engine water inlet pipe
22
sensor
Fuel oil sensor Varistor type Inside oil tank
23
2) Indicator and warning switch:
Engine oil pressure indicator switch
Wiring diagram
Indicator switch position
Switch specification
Working pressure: 0.3- 0.5 KSC.
When the oil pressure is as low as the
switch action pressure, the indicator
is ON.
24
Vacuum alarm switch
Alarm buzzer Wiring diagram
Its position is the inner side of the left
pedal in the cab.
Switch：Vacuum
Switch specification
Stamping sign: 350
Negative pressure (mm hg): 320- 380
Note: The switch has working negative

pressure mark. Make sure that you
replace it with switch of the same
negative pressure when necessary.
ON Parking
arking brake switch
Wiring diagram
OFF
Switch
25
2 Technical requirements:
Technical requirements of combined instrument
3801910D800 Combined instrument assembly
The basic deviation requirements are as follows:
Basic deviation
Indicated speed 20 40 60 80 100 120 140 160
Km/h
Speedometer
Allowable +5 +5 +5 +5 +6 +7
(stepping motor ±3
deviation Km/h 0 0 0 0 0 0
type)
Transmitting 1:637 Interface mode Sensor type
ratio
Indicated mark E 1/2 F
Basic resistance 97 32.5 6
Fuel gauge (Ω)
(stepping motor Allowable ±16 ±6.5 ±3
type) deviation (Ω)
Sensor Designation Fuel oil Model RG1164B1
sensor
Indicated mark C (50) 100 H (115)
(℃)
Water Basic resistance 230 40.4 26.4
temperature (Ω)
gauge Allowable ±30 ±5 ±1.5
(stepping motor deviation (Ω)
type) Sensor Designation Water Model WG1371
temperature
sensor
All alarm indication systems of 3801910D800 instruments conform to GB4094 - 1999

Signs of automobile controls, indicators and signal devices.
DJY7121-1.6-20;DJY7141-1.6-20;DJY7121A-1.6-20 combined socket is adopted for
the instruments.
24 .CD player
A single disk dual track CD player is mounted on this vehicle. The L channel speaker
is mounted in the left door and the R channel speaker is mounted in the right door.
If you find that some functions do not work, please read carefully the operation
instructions in the manual first before you send it for repair. You can check the player
26
according to the following table. It will help you fix the trouble.
Please send the player to the maintenance service station if the fault cannot be fixed.
Do not disassemble the player to repair it by yourself.
General situation
The player does not work and there is no display.
·Check the fuse connection of the player and vehicle
·Check the voltage.
The player works but there is no sound or the sound is very low
·Raise the volume.
·Check the front and rear, left and right balance setting of the horn.
·Check the antenna and connection.
Horn volume lowers by itself
·The internal safety circuit can prevent the internal temperature from exceeding
certain value.
·Raise the volume after the temperature is lowered.
Reception
Cannot get the channel:
·Check if the antenna is fully drawn and if the connection is right.
·Check if the negative terminal (brown line) is grounded (chassis).
·Please use manual tuning if the signal is too weak.
Poor reception:
·Some vehicle (such as Volkswagon and SEAT) needs a 12 V antenna on the top.
Please consult your dealer if there is 12 V power supply to this antenna.
CD
CD ERROR is displayed:
·Check if the CD is correctly inserted, and make sure that the CD is not broken or dirty.
Distortion of sound
·CD cannot be read, damaged or dirty.
CD player out of operation:
·Moisture may condensate on the laser magnetic head when it is very cold. Turn it to
radio reception for about 5 minutes to let the moisture evaporate.
NO CD or NO DISC is displayed.
27
·Check if there is CD in the CD player.
25. Idle speed boost device

A solenoid valve called idle speed boost device is fitted on the rear end (left side of the
chassis) of the vacuum pump on the engine. When the engine is at idle speed and the
air conditioner is switched on, it boosts the idle speed of 700r/min to 850±50r /min, so
that the power generation meets the requirements of the air-conditioner. Its functional
diagram is as follows:
Connecting rubber tube2 Vacuum membrane box Engine throttle lever
Wire1
Drawbar
Wire2
Connecting rubber tube1

Vacuum
pump pipe
Solenoid valve DF156(Suction voltage<9V, Release voltage>1V)
When the air conditioner is switched on, the solenoid valve of the idle speed boost
device operates so that rubber tube 1 and rubber tube 2 is connected. With the
vacuum membrane, the fuel up lever is pushed by the push rod to the fuel up direction,
so that the engine idle is raised to 850±50r /min. The wiring diagram is as follows:
Compressor
Fuse Air conditioner switch electromagnetic clutch
28
Idle speed boost valve
26. Exhaust brake controller

Exhaust brake switch
1. Wiring diagram
Acceleration Clutch
switch switch
Alarm
buzzer
Magnetic
valve
Vacuum
switch
2. Switching diagram
ON OFF
3. Accelerator and clutch switch:

Maximum stroke: 4mm;
Working stroke: 2.0-2.8mm.
OFF
Max. travel
4.Position of exhaust brake solenoid valve

(left arrow)
29
27. Electrical device
Disassembly of line bundle connector:
Please always both hands to cut the
connector. Drawing the connector with
single hand will result in rupture of the
wire terminal.
Note: press the lock plates on both sides
before drawing out the connector to cut.
Connection of line bundle connector:

Wrong
Clench both sides (male and female) of the
connector and make sure that the connector
terminal pins match and align with the
holes. Press both sides of the connector
carefully until you hear a clear click.
Correct
Wrong Inspection of line bundle connector:

Use circuit tester to check the connector
Probe continuity. Insert test probe from side of
the connector wire
Do not insert the test probe in connector

open end
30
Correct
Probe
31
Inspection of fuse line:
Fuse line
The fuse line is fitted on battery positive
Starter
switch
terminal and starter switch B terminal
If there is over current, the fuse is blown to
protect the main power supply from being
overloaded. Please use universal meter to
check the continuity of the circuit.
Starter motor
Pin Disassembly of wire terminal

Barb 1. Insert a pin into the open end of the
Wire
connector shell
2. Press the barb (facing the connector wire
side) and pull the wire on the connector
wire side.
Terminal
Open end
Insertion of wire terminal:

Barb Wire
1. Check if the barb is completely open.
2. Insert the terminal from connector wire
side and press it until the barb fixes it
firmly.
3. Pull the wire gently to reset the terminal.
Terminal
Wrong Precautions of line bundle arrangement:

Use jacket or sleeve to protect the line
bundle and avoid direct contact with sharp
edge or surface.
Correct
32
Wrong There should be sufficient clearance between
the line bundle and bracket. Use ethylene
sleeve and clip to protect the line bundle and
avoid direct contact.
Correct
Sleeve
Clamp
The line bundle between the engine and chassis

should be long enough to avoid abrasion or
damage owing to vibration.
Wrong
Correct
Normal Damaged Fuse:

Fuse is the most used circuit protection of
vehicle circuit. When there is over current in
the circuit，the fuse is blown to prevent the high
current from damaging other parts in the circuit.
Find out the cause of overload current and solve
the problem before you replace the fuse.
Use new fuse of the same ampere to replace the
original one. Otherwise, there will be line
burning or other serious damage to the circuit.
Circuit breaker:
Breaker is a protective device to open the
circuit when the load current exceeds the rated
breaker capacity.
If there is short circuit or other form of
overload, the over current will open the circuit
on both sides of the breaker. When the circuit
is open, the breaker button pops up.
Push
33
Air heating & air conditioning equipment
Generator
Disassembling and reassembling
Troubleshooting
34
General
1. Air conditioner refrigeration cycle

1.1 main parts of refrigeration system
Refrigeration cycle system of integrated air conditioner (warming and cooling) of JAC
vehicle mainly consists of compressor, compressor exhaust hose, condenser
assembly, reservoir, HP hose, F type expansion valve, evaporator assembly, and LP
hose. The reservoir assembly includes internal drier and filter etc., as well as HP/LP
pressure switches, sight mirror and fusible plug installed on casing.
1.2 Refrigerating principle
The compressor sucks in and compresses low temperature, low pressure refrigerant
gas to generate high temperature, high pressure refrigerant gas, which will be sent to
condenser via HP hose for condensing, releasing heat to air passing condenser and
being condensed to high pressure medium temperature liquid. This liquid flows to the
reservoir where impurities in refrigerant are filtered and water content is removed, and
then flows to expansion valve via HP hose, where it is changed to low pressure, low
temperature liquid-gas mixture by throttling and depressurizing effect of the valve, and
then enters the evaporator. This mixed refrigerant will evaporate in the evaporator and
absorb heat from air inside vehicle and flowing pass the evaporator to become
superheated gas, which will enter compressor for next refrigeration cycle. Air inside
vehicle passing the evaporator will discharge heat to the evaporator and become cold
air. In addition, since temperature of evaporator surface is lower than air dew point,
water vapor in air will condense to become dew that will be drained outside the vehicle,
hence reducing temperature and humidity of air inside vehicle. Fig.1 shows air
conditioning refrigeration schematic diagram.
Expansion Reservoir
valve
Evaporator Condenser
Compressor
Fig.1 Air conditioning refrigeration schematic diagram
35
2. Air conditioning warming cycle
2.1 Main parts of warming system
Warming cycle system of integrated air conditioner (warming and cooling) of JAC
vehicle mainly consists of warm air blower, engine, water pump, water valve, water
tank and pipelines etc.
2.2 Warming principle
By means of a water pump, hot coolant of engine is pumped into warm air blower core,
where heat exchange occurs to release heat to air inside vehicle. Later, this coolant
returns to the water tank and enters next warming cycle.
Water pump Warm air

(water tank) blower core
Engine Water valve
Fig.2 Air conditioning warming schematic diagram
3. Electric control
3.1 Main parts of electric control
The electric control mainly consists of power supply switch, electromagnetic clutch,
controller, defrosting thermistor, defrosting temperature controller, HP/LP pressure
switches, electric control box, governing resistor, and connection harness etc.
3.2 Electric control principle
The controller is the control center of air conditioning (refrigerating and warming parts).
Electronic elements in the electric control box are used to control On/Off of
refrigerating and warming, and adjustment of AC fan rotation speed and temperature.
The power supply switch is used to control driving power of the air conditioning. This
switch is a mina part of the controller and functions to turn AC on or off (also referred
to as A/C switch). At gears 1, 2, 3 and 4, refrigeration will be executed.
3.2.1 Temperature control
The defrosting thermistor is a control element that senses temperature of discharged
air from evaporator. It directly converts temperature to electric signal and transmits
36
this signal to the defrosting temperature controller inside electric control box. The
defrosting temperature controller receives electric signal from defrosting thermistor
and control On/Off of compressor EM clutch according to set parameters (i.e. On/Off
of air conditioning refrigeration cycle), so as to control temperature inside the vehicle.
The electric control box is the execution center of air conditioning control. It receives
commands from controller and feedback electric information from defrosting
thermistor, and uses internal relays to control On/Off of compressor clutch.
3.2.2 Pressure protection control
The HP/LP pressure switch is a safety part used to ensure safe operation of
refrigeration system. When the high pressure is ≥3.14MPa or low pressure is
≤0.2MPa, this switch will be turned off, disengaging compressor clutch and stopping
the refrigeration system. When system high pressure falls to 2.5MPa or system low
pressure rises to 0.23MPa, this switch will be turned on, engaging compressor clutch
and starting the refrigeration system.
1. Technical parameters
S/N General item Sub-item Parameter
Code R134a
1 Cooling medium
Amount of filling 0.85kg
Code PAG56
2 Refrigerating oil
Amount of filling 150g
Model 5H14
3 Compressor Voltage 12V
Displacement 138cm3/r
Condenser heat sinking
9000W
capacity
Condenser with
4 Voltage 12V
reservoir assembly
Maximum current 15A
Air flow 1800m3/h
Refrigerating capacity 3900W
Heating capacity 4000W
Front evaporator/
5 Voltage 12V
heater assembly
Maximum current 18A
Air flow 350m3/h
Disconnected at
High pressure protection
2-state pressure ≥3.14Mpa
7 characteristics
switch Connected at ≤2.5Mpa
Low pressure protection Disconnected at
37
characteristics ≤0.2Mpa
Connected at ≥0.23Mpa
2. Structure of main parts of air conditioning
2.1 Heating equipment, blower equipment and evaporator
1
7
3
5
1. Lower cover; 2. Fuse and relay box; 3. Ventilating air duct; 4. Evaporator; 5. Blower;
6. Heating equipment; 7. Instrument stand
For removal of heating equipment, blower and evaporator from instrument stand,
follow this sequence: 1. lower cover 2. fuse and relay box 3. →ventilating air duct→ 4.
evaporator →5. blower → 6. heating equipment.
38
Sequence of assembling is the reverse of this sequence. For tightening torques, refer
to the table below:
Tightening torque (N·m)

Diameter of thread (mm) Pitch (mm) Standard
Maximum Minimum
value
6 1 9 12 6
8 1.25 23 26 16
8 1 25 28 17
10 1.5 59 75 37
10 1.25 63 79 45
10 1 64 80 46
12 1.75 95 111 73
12 1.5 97 113 75
12 1.25 99 115 78
Important operation-assembling
● To assembly blower, prevent water leakage.
Sealant Butyl rubber (none-dry type)
Air conditioning panel

● Turn mode handle to left most (FACE direction);
● Turn temperature lever to left most (COLD
direction);
● Turn inner/outer air control lever to left most
Control cable “A”
(INSIDE direction)
Control cable “B”
● Hang control cable “C” on blower clip, press

butterfly nut to bottom and fix cable on clip;
Air heater ● Hang control cable “B” on heater clip, press
butterfly nut to bottom and fix cable on clip.
Control cable “C”

Hang control cable “C” on blower clip, press
butterfly nut to bottom and fix cable on clip
39
Blower
2.2 Structure of condenser assembly
1. Condenser damping pad sleeve; 2. Hex flanged face nut;

3. Pad; 4. Condenser core;
5. Condenser damping pad; 6. Condensing fan assembly;
7. Bolt combination
Important operations
1. When removing pipe from each device, avoid damaging connecting nut or the pipe.
2. Cover pipe port with plastic cloth to avoid ingress of dust in pipe.
40
2.3 Disassembling and assembling of compressor
Disassembling sequence: Assembling sequence:

1. Pipe 4. Compressor
2. Belt 3. Idler
3. Idler 2. Belt
4. Compressor 1. Pipe
Important operations
1. To remove pipe from each device, avoid damaging connecting nut or the pipe.
2. Cover pipe port with plastic cloth to avoid ingress of dust in pipe.
Operation prompts
1.1 To avoid accidents and ensure safety of relevant personnel, non-discipline
personnel must not perform disassembling or repair.
1.2 Use of open flame or smoking is prohibited.
1.3 Always wear working clothes during working. Ensure intact protective devices.
1.4 Perform operation in a weld ventilated environment.
1.5 Before starting the engine, confirm that there is no tool, measuring instrument or
other part on moving and rotating parts, and parts through which electric current flows.
1.6 Before start of engine, blow horns to warn operating workers and confirm safety.
1.7 To check electric lines, take care not to touch terminals or other parts through
which electric current flows; otherwise short circuit may occur due to human body or
41
other part.
1.8 Use fuses of rated capacity. Avoid burning of electric devices such as relay and
fire.
1.9 When using hose and hard pipeline, take care to avoid leakage of gas.
1.10 Thoroughly clean dust at hose or hard pipeline connecting part and inside
pipelines; prevent gas leakage and abnormal operation.
1.11 Avoid water or oil etc. on fan, fan motor or V belt, so as to prevent damage and
fire.
1.12 Before shutdown of air conditioner is confirmed, do not touch belt or fan to avoid
injury.
1.13 Do not place refrigerant cans on engine or radiator, so as to prevent serious
accident.
1.14 Do not subject refrigerant cans to direct sunshine, moisture, or temperatures
exceeding 40℃, so as to prevent serious accident. Store these cans at a cool and dry
place.
1.15 Store refrigerant cans where no fierce collision with other hard matter or iron
ware etc. will occur, so as to avoid serious accident.
1.16 When handling refrigerant gas, wear protective goggles to avoid injury of eyes. In
case such gas enters the eye, timely wash with large amount of clear water to prevent
frostbite; if serious, go to hospital at once.
Items that must be inspected before AC system maintenance or diagnosis
2.1 Visually check hoses for damage and friction.
2.2 Ensure that condenser fins are not blocked by insects, impurities and dirt etc.,
2.3 And that fins have no apparent falling.
2.4 Correct operating direction of condenser fan.
2.5 No overheating of engine water tank.
2.6 Check tension of driving belt and for damage.
2.7 Operation of compressor.
2.8 Check for clogging of evaporator drain hose.
2.9 Check free action of switch at each air outlet.
2.10 Check if blower and evaporator fan can operate at specified fan speed.
2.11 Check that there is no apparent refrigerant leakage or oily dirt on device or
pipeline connector.
42
Troubleshooting
Blower motor rotates but no

hot air comes out from
outlet
Check water
hose
YES Hose sharp twisting,

bending or clogging
Replace
No air comes out from defroster

outlet
Check connecting pipe

between defroster &
heater
YES Wear
Replace
Check defroster door & control
cable
YES Replace &

adjust
43
Blower speed cannot be
adjusted
Check electric connector
YES Disconnect
Replace
Check control switch
YES Faulty
Replace
Blower motor not rotating
Check fuse
YES Faulty
Replace
Check circuit & connector
YES Open or
disassemble
Replace
Check switch circuit
YES Incorrect
Replace
Check engine motor
YES Faulty
Replace
44
High blower motor noise
Check blower motor bearing
YES Broken
Replace
Cold air blown out intermittently
Check magnetic clutch
YES Slipping or not operating
Replace
Check expansion valve
YES Faulty
Replace
Check wiring
YES Faulty
Repair
45
Insufficient cooling
Check condenser
Check driving belt Clean or

replace
YES Slipping
Check compressor Replace
YES Faulty
Replace
Check expansion
valve
YES Faulty
Replace
Check thermostat
YES Faulty
Replace
Check coolant
YES Insufficient or
excessive
Adjust
46
Electrical Equipment
I. Identification of the Electrical Diagram 164
II. Name and Purpose of the Electrical Appliances of the Complete Vehicle
165
-1-
I. Identification of the Electrical Diagram
1. Identification of the Wire Code
The wire specifications and colors used in the wiring diagram are distinguished by different
codes. Since the regulations for the color code of the vehicle electric wires in every country are
different at present, the users and the maintenance personnel of JAC Product should identify the
wires according to the Color Code of Wires in the Electrical Equipment Maintenance Guidance of
Jianghuai Automobile.
Example: 0.5GR
0.5---------- the section of the electric wire conductor is 0.5mm2
G------------the base color of the insulating layer is green
R------------the ribbon is red
Section of the Electric Wire Conductor -Base color of the Insulating Layer Ribbon
0.5 G R
Ribbon
Base color
Section
2. Identification of Electrical Elements
The electrical elements in the JAC Vehicle Electrical Diagram are expressed according to the
usual and commonly-used patterns. Please refer to the Commonly-used Vehicle Electrical Graphic
Symbols for the details.
-2-
Storage Battery Set Fuse Wire Relay Flasher Button Switch
Electromagnetic Illuminating Lamp,

Valve Electric Horn Indicating Lamp Loudspeaker Fuel Gauge
Combined Lamp Buzzer General Symbol for Radio-cassette Thermometer

Manual Switch Player
Semiconductor
Motor Voltage Regulator Twin-filament Lamp Ammeter
Diode
Figure 1 Commonly-used Vehicle Electrical Graphic Symbols
II. Name and Purpose of the Electrical Appliances of the Complete Vehicle
1. Storage Battery
1.1 Description of Storage Battery
The storage battery is a reversible low voltage DC power supply, which can not only convert
the chemical energy to the electric energy, but also convert the electric energy to the chemical
energy. The storage battery is the heart of the vehicle electric system. When the engine doesn’t
generate, the storage battery provides all the electric energy for the electric equipments.
Comparing to the traditional storage batteries, the maintenance-free storage battery provided
by JAC possesses the following advantages:
a. Need no water or a little water in use;
b. With less self discharge;
c. With a long service life;
d. Clean and safety;
e. With little internal resistance and a good starting performance.
1.2 Charge and Discharge Characteristics of the Storage Battery
1.2.1 Discharge Characteristics
The discharge characteristics of the storage battery indicate the regular pattern of the
terminal voltage, the electromotive force and the electrolyte density of the storage battery varying
with the time during the constant current discharge process.
The discharge process can be divided into 3 phases:
a. the starting phase
b. the stabilizing phase
c. the rapid-decline phase
-3-
1.2.2 Charge Characteristics
The charge characteristics of the storage battery indicate the regular pattern of the terminal
voltage, the electromotive force and the electrolyte density of the storage battery varying with the
time during the constant current charge process.
The phenomenon of storage battery with enough power is:
a. The terminal voltage rises to the maximum and stop increasing within 2 hours
b. The electrolyte density rises to the maximum and stop increasing within 2 hours
c. Plenty of bubbles are being intensely released, like “boiling”
1.3 The Maintenance of the Storage Battery
a. Observe the outside surface of the storage battery and check if there are cracks and
electrolyte leakage;
b. Check if the storage battery is firmly installed on the vehicle, the electric pile shakes and
the wiring connection is fastened;
c. Frequently remove the dirt and dust on the storage battery and the oxides on the electric
pile and the electric wire ends, wipe the electric fluid and dirt on the upper part and the
outside surface of the storage battery, and dredge the air vent on the charging cover;
d. Periodically check the electrolyte density and level of the storage battery;
e. In cold weather, pay attention to adopting the cold-proof measures to the storage battery,
the extremely low temperature will cause capacity decline and even frost damage to the
storage battery;
f. Frequently check the discharge degree of the storage battery. If the degree is lower than
the specified standard, immediately conduct battery charging. If the color of the charging
state indicator of the storage battery is discovered as grey or white, the storage battery
should be charged in time.
Storage Battery Check:
OK 1. Check if the wiring column is loose and corrosive
Head of Keep the contacts reliably connected, remove all
column
the tracks of corrosion and always keep the
Color Charge battery contacts clean
indication rod 2. Check the charging state indicator
If the charging state indicator of the storage
Ball box Electrolyte is not
battery turns green, it means that it is fully
Density enough; replace charged; if it turns grey, it means that it needs to
ball battery be charged; if it turns white, it means that the
State indicator of storage battery storage battery should be replaced.
2. Starter
2.1 Description of the Starter
The function of the starter is to convert the electric energy of the storage battery to the
mechanical energy, and drive the engine to operate. The starter used in this vehicle type is 12V
DC series motor, which is composed of 3 parts as: (1) the DC series motor: the function is to
convert the electric energy of the storage battery to the mechanical energy, and produce torque; (2)
the transmission mechanism, also called as the meshing mechanism: the function is to make the
driving gear of the starter meshed into the flywheel gear of the engine, and transfer the torque of
the starter to the engine crank when the engine starts; and it can make the driving gear of the
starter and the flywheel gear of the engine automatically disengage after the engine starts; (3) the
control unit: the function is to connect and disconnect the circuit between the starter and the
-4-
storage battery.
Structure Diagram of the Starter

Adjusting Gasket
Return Spring Electromagnetic Switch
Movable Iron Core
Screw
Fork Conducting Plate
Electric Brush
Clutch
Driving Gear
Intermediate Bearing Plate Armature Commutator Magnetic Pole
2.2 Working circuit of the Starter

Power Fuse Wire Combined Fuse Wire Starting Relay Coil Grounding
Supply Switch (Starting)
Fuse Wire Starting Relay Starter Grounding
Contact
If there are malfunctions in the starting circuit, the maintenance personnel should conduct
examination and maintenance according to the circuit indicated in the working circuit diagram of
the starter.
2.3 Common Malfunction Cause and Troubleshooting of the Starter
2.3.1 Possible Causes for the Starter Failure:
a. The electric storage of the storage battery is not enough, the electric wire contact is loose or
the pole column is too dirty.
b. The contact of the starter electromagnetic switch is burnt or is not closed up because of
improper adjustment.
c. The magnetic field winding or the armature winding is broken, shorted out or grounded.
d. The insulating electric brush is grounded, or the electric brush is stuck in the brush rocker
and the spring breaks up.
e. The sucking coil in the magnetic switch is broken or shorted out.
f. The contact of the starting relay cannot be closed up, the contact is burnt or with greasy dirt,
or the contact of protective relay is burnt or with greasy dirt.
2.3.2. If the starter operates powerlessly while the electric storage of the storage battery and the
circuit is normal, the possible causes are:
a. The commutator is too dirty.
b. Over-wearing and the insufficient spring pressure of the electric brush causes poor contact.
c. There is partial short circuit in the magnetic field winding and the armature winding.
d. The switch contact of the starter is burnt.
e. The assembly of the engine is too tight or the temperature is too low, which causes excessive
-5-
rotational resistance.
2.3.3. The driving gear and the flywheel gear of the starter cannot be meshed and operate with the
sound of clashing, the possible causes are:
a. The driving gear or the flywheel gear of the starter is worn out or broken.
b. The switch is closed up too early, and the starter has already rotated before the driving gear of
the starter is meshed.
3. Generator
The AC generator is the main power supply of the vehicle. It is actually an autonomous
three-phase synchronous generator. There are 3 windings which are separated by 120º electric
angle on the stator core of the generator. The ends of the 3 windings are connected in the shape
which is usually called Y connection. The rotator is wound by the exciting winding. The rotator
winding will produce magnetic field when DC goes through. When the engine drives the rotator
to rotates, the magnetic force line of the rotator and the fixed stator three-phase winding form a
relative cutting movement, and then the three-phase alternating electromotive force is generated
from the three-phase winding, which is also called AC. All currents used in the vehicle circuit are
the directive current, and the alternating current generated by the AC generator can only be used
after rectification. The rectification is mainly completed by the silicon rectifier inside the
generator. The rectifier transforms the alternating current into the directive current by the
three-phase bridge full-wave rectification circuit, which is composed of several silicon diodes.
The silicon rectification shunt AC generator is adopted for this vehicle type. It is composed
of the three-phase AC motor and the silicon diode rectifier. Conduct the ground connection with
the negative pole (grounding), be sure not to ground the wrong pole, otherwise it will cause
damage to the generator.
Ro
tat Elec Storage
or trica Battery
Wi l
ndi Equ
ng ipm
Stator ents
Winding
AC Generator Rectifier
Figure 2 Circuit Diagram of AC Generator
4. Air Conditioning and Heating System
4.1 Air Conditioner Refrigeration Circulation

4.1.1 Major Components and Parts of the Refrigeration System
-6-
N721 narrow-body air conditioner refrigeration circulation system is mainly composed of the
compressor, condenser, air suction pipe, exhaust pipe, liquid pipe, evaporator, type H expansion
valve and blower.
4.1.2 Refrigeration Principle
The compressor intakes and compresses the refrigerant gas of low temperature and low
pressure, and turns it into the refrigerant gas of high temperature and high pressure. The
refrigerant gas of high temperature and high pressure is sent to the condenser through the high
pressure hose for condensation, it releases heat to the air in the condenser and then be condensed
to liquid of high pressure and medium temperature, which flows to the receiver. In the receiver,
the refrigerant is filtered and dehydrated. Then it flows to the expansion valve through the high
pressure hose, and turns into the gas-liquid mixture of low pressure and low temperature and
enters the evaporator after being throttled and depressurized by the expansion valve. The
gas-liquid mixture refrigerant of low pressure and low temperature evaporates in the evaporator,
and absorbs the heat from the in-vehicle air passing the evaporator. Then it evaporates to be the
overheated air and enters the compressor to begin the next refrigeration circulation in cycles. The
in-vehicle air passing the evaporator releases heat to the evaporator and turns into cold air. At the
same time, since the temperature on the surface of the evaporator is lower than the air dew point,
the moisture in the air is condensed to be dew and is discharged out of the vehicle. Thereby the
temperature and the humidity are lowered. Figure 1 is the Schematic Diagram of Air Conditioner
Refrigeration
The expansion valve: allows the
膨胀阀：允许制冷剂迅
refrigerant to rapidly expand to be
the liquid of low temperature and
速膨胀成低温低压液体 The evaporator: absorbs heat
low pressure
蒸发器：从周围环境吸
from the surrounding and
收热量使制冷剂变为气
evaporates the refrigerant to be
gas (and the surrounding is
体（同时环境被冷却）
cooled down at the meanwhile)
鼓风机：给蒸
The blower:
鼓风机
Blower Storage Battery
外部或内部循环空气
adds pressure to
发器加压，向
the evaporator
车内提供冷空
and provide cold
气
air in the vehicle
压缩机：由发动机通过
The compressor: It is driven
v型皮带驱动，将由蒸
by the engine through V-belt.
发器传出的制冷剂转变
It turns the refrigerant, which
is transferred by the
成高压高温气体，并提
evaporator, into the gas of
供给冷凝器，装有电磁
high pressure and high
离合器以便压缩机停止
temperature, and provides it to
运转
the condenser. The
Drier receiver: Remove the electromagnetic clutch is
储液/干燥罐：清除制
moisture and the dust in the equipped to stop the
refrigerant and keep the
冷剂中的水汽和灰尘杂 compressor from operating
refrigerant in abundant supply
质并保持制冷剂充足
The condenser: It is installed in front of
冷凝器：装在散热器前面，冷
the radiator. It condenses the refrigerant
却高温高压制冷剂，在这里制
of high temperature and high pressure.
冷剂被风扇和车辆行驶形成的
Here, the refrigerant is condensed to be
风冷却成高压液体
high pressure liquid by the wind formed
by the blower and the vehicle driving.
Figure 3 Schematic Diagram of Air Conditioner Refrigeration

4.2 Air Conditioner Heating Circulation
4.2.1 Major Components and Parts of the Heating System
N721 narrow-body air conditioner heating circulation system is mainly composed of the
-7-
heating tank, blower, engine (the water tank and water pump) and heater pipeline.
4.2.2 Heating Principle
Utilize the water pump to pump the hot refrigerant liquid into the heater core body, through
which the heat exchange is conducted. The heat is released to the in-vehicle air. And after that the
refrigerant liquid returns to the engine and begins the next heating circulation.
Radiat
Warm Air or Engine Water Jacket
Blower
Water Pump
Figure 4 Schematic Diagram of Plumbing Type Heating Circulation

4.3 Electrical Control
4.3.1 Major Components and Parts of the Electrical Control Part
The electrical control part is mainly composed of the power switch, electromagnetic clutch,
controller, defrosting thermal resistance, defrosting temperature controller, high and low voltage
pressure switch, electric control box, speed regulation resistance and connecting harness.
4.3.2 Electrical Control Principle
The controller is the controlling hub of the air conditioner refrigeration and heating. By
controlling the electric elements in the electric control box, it controls the turn-on and turn-off of
the refrigeration and heating system, as well as the rotating speed and the temperature adjustment
of the air condition blower.
The power switch is used to control the driving power of the air conditioner. It is one of the
major components of the controller with the function of turning on or off the air conditioner (also
called A/C switch). It performs refrigeration when pressing the gear of 1, 2, 3 and 4.
4.3.2.1 Temperature Control
The defrosting thermal resistance is the controlling element which inducts the temperature
on the air-out surface of the evaporator. It directly transforms the temperature into electric signal
and transfers it to the defrosting temperature controller in the electric control box. By receiving
the electric signal sent from the defrosting thermal resistance, the defrosting temperature
controller controls the turn-on and turn-off of the electromagnetic clutch of the compressor
according to the designated parameters (which means controlling the ON/OFF of the air
conditioner refrigeration circulation) in order to control the temperature inside the vehicle.
The electric control box is the execution hub of the air conditioner control. It receives the
command of the controller and the electric information fed back by the defrosting thermal
resistance, and controls the turn-on and turn-off of the compressor clutch through the internal
relay.
-8-
4.3.2.2 Pressure Protection Control
The high and low voltage pressure switch is a security component to ensure the safety
operation of the refrigeration system. When the high voltage is ≥3.14MPa or the low voltage is
≤0.2MPa, the high and low voltage pressure switch is off, the compressor clutch is cut off and the
refrigeration system stop operation; when the high voltage of the system pressure declines to
2.5MPa or the low voltage of the system rises to 0.23MPa, the high and low voltage pressure
switch is on, the compressor clutch is closed up and the refrigeration system works.
Technical parameters:
No. General Item Sub-item Item Parameters
Code R134a
1 Refrigerant
Input Quantity (500±20)g
Code PAG46
2 Refrigeration Oil
Input Quantity (140±10)ml
Type 8103010LD010
3 Compressor Voltage 12V
Displacement 143cm3/r
Heat Dissipation Capacity of Condenser ＞8000W
Condenser Voltage 12V
4
Assembly Rated Current 12A
Blowing Rate ＞1800m3/h
Refrigerating Capacity 4200W
Heating Capacity 5400W
5 HVAC Assembly Voltage 12V
Rated Current 20A
Blowing Rate 470m3/h
Cut off when≥3.14MPa
High Voltage Protection Feature
Binary Pressure Connect when≤2.55MPa
6
Switch Cut off when≤0.196MPa
Low Voltage Protection Feature
Connect when≥0.216MPa
4.4 Structure of the Major Components and Parts of the Air Conditioner
4.4.1 Blower Assembly
-9-
1. Motor assembly of blower; 2. Fixed support of air duct; 3. Speed regulation resistance
assembly; 4. Cross-recessed large semi-circle tapping screw; 5. Blower housing assembly; 6.
Filter screener; 7. External and internal air valve assembly; 8. External and internal air valve
control mechanism; 9. Hexagon flange face nut; 10. Fixed support of blower; 11. Subassembly of
hexagon bolt, spring washer and plain washer
4.4.2 HVAC Assembly
1. Evaporator core body assembly; 2.Heater core body assembly; 3. Fixed support 1 of heating
and refrigerating unit; 4. Fast nut; 5. Subassembly of hexagon bolt, spring washer and plain
washer; 6. Fixed support of the protection plate under the instrument desk; 7.Temperature damper
adjusting mechanism; 8. Fixed washer of CAM component; 9. Mode damper adjusting
- 10 -
mechanism; 10. Electronic temperature controller assembly; 11. Housing assembly; 12. Mode
adjusting damper I; 13. Mode adjusting damper II; 14. Temperature adjusting damper; 15. Air
suction transition pipe; 16. Liquid transition pipe; 17. Expansion valve; 18. Air intake housing of
heating and refrigerating unit; 19. Cross-recessed large semi-circle tapping screw; 20.Expansion
valve shield; 21. Cab sealing plate; 22. Fixed housing of connecting pipeline of the heater; 23.
Right fixed support 2 of heating and refrigerating unit; 24. Weeping pipe of evaporator
4.4.3 Condenser and Bracket Assembly
1. Condenser core body assembly; 2. Blower assembly of condenser; 3. Hexagon flange face nut;
4. Hexagon flange face bolt; 5. Right bracket assembly of condenser; 6. Left bracket assembly of
condenser; 7. Shock pad bushing; 8. Condenser shock pad; 9. Pressure switch
4.4.4 Compression Device
- 11 -
1. Compressor belt; 2. Compressor assembly; 3. Compressor bracket; 4. Hexagon flange face bolt
4.4.5 Controller of Air Conditioner
1. Integrated instrument 5. A/C Switch

2. Controller regulation assembly 6. Instrument desk assembly
3. Control panel 7. Each control knob
4. Adjusting knob of internal and 8 Each adjusting wiredrawing
external circulation
4.4.6 Foundation Duct Device
1. Right duct of foundation wind; 2.Intermediate duct of foundation wind; 3. Left duct of
foundation wind
4.4.7 Refrigeration Pipeline Device
- 12 -
Cond
enser
Evaporator
Compres
sor
1. Air suction pipe assembly; 2. Exhaust pipe assembly; 3. Liquid pipe assembly
4.4.7 Heating Pipeline
1. Engine water inlet pipe assembly; 2. Double hole pipe clamp; 3. Engine water outlet pipe
assembly; 4.Heater steel pipe assembly; 5. Heater water inlet pipe assembly; 6. Heater water
outlet pipe; 7. Steel belt spring clip; 8. Hexagon flange face bolt; 9. Hexagon flange face nut
4.5 Operation Cautions

1. To prevent accidents and ensure the personnel safety, the non-professional should not
disassemble or perform maintenance.
2. It is forbidden to use open fire and smoke.
3. Wear working clothes during operation and ensure that the protection devices are in
good condition.
4. Conduct the operation under the conditions of good ventilation.
5. Before starting the engine, ensure that there are no tools, measuring instruments and
- 13 -
other components or parts on the components which are moving, rotating and with
electric current flowing through.
6. Before starting the engine, sound the bugle to warn the workers in operation and ensure
the safety.
7. When examining the electric circuit, pay attention to not touching the components with
electric current flowing through, like the terminals. Short circuit might be caused by the
body or other component.
8. Use the rated fuse wire. Prevent burning the electric element such as the relay and
causing fire.
9. Be careful when using the pipelines of hose and hard pipe, prevent gas leakage.
10. Thoroughly clean the connecting part and the pipelines of hose and hard pipe, prevent
gas leakage and abnormal operation.
11. The fan, fan motor and V-belt should not be stained with water or oil, so as to prevent
damage and fire disaster.
12. Before confirming that the air conditioner has stopped operating, do not touch the belt
and blower, so as to prevent injuries.
13. Do not put the refrigerant tank on the engine or the radiator, so as to prevent serious
accidents.
14. Do not put the refrigerant tank at places under direct sunshine, with moisture and with
temperature over 40℃, so as to prevent serious accidents. The tank should be stored at
cool and dry places.
15. Store the refrigerant tank at places without bumping against other hard and iron objects,
so as to prevent serious accidents.
16. When operating with the refrigerant gas, wear protection glasses to prevent eye injury. If
the refrigerant gas enters the eyes, rinse the eyes with plenty of clean water to prevent
frozen injury. Immediately go to the hospital and get treatment in case of serious injury.
- 14 -
4.6 Items required to be inspected before the Damaged and blocked fin
maintenance and diagnosis of the air condition
system: Not overheated engine
1. Visually inspect the hose and check if

there is damage and friction.
2. Ensure that the condenser fin is not
blocked by obstacles as the insects,
impurities and dirt, and the fin is not Plugged hose
inversed.
3. The operation direction of the condenser Damaged and plugged contact
blower is right.
4. The engine/ water tank is not over
heated.
5. Check the tension force of the driving
belt to see if there is damage.
Plugged drain pipe
6. Check if the compressor works.
7. Check if the drain hose of evaporator is
Normal belt tension
plugged.
8. Check if each air outlet can be open and
closed normally.
9. Check if the blower and evaporating
blower can operate at regulated wind
speed gear. All-open air outlet
10. There is no obvious refrigerant leakage

and oil dirt on the element or the
connecting part of pipelines.
- 15 -
4.7 Periodical Maintenance
Note: ★ indicates inspecting, adjusting, repairing and replacing if necessary; when replacing the
refrigerant oil, replace with new oil according to the regulation of compressor.
Maintenance Period
Maintenance Item Content Dail Week Monthl Quarte Yearl
y ly y rly y
Refrigera Observe from the liquid
Refrigeration System
nt sight-glass to see if the liquid ★

quantity flows with bubbles
Check the hose and see if there is
★
crack and damage
Check each connecting part and
Pipeline ★
see if there is leakage
Check each fixed clip and see if
★
it is loose or damaged
Refrigera
Replace the refrigerant oil ★
nt oil
Compressor
Check the belt tension degree and

Belt ★
see if it is worn
Compres
Check if the bolt is loose and the
sor ★
support is damaged
support
Condenser
Condense Check if it is plugged by dirt, and

★
r core clean it when necessary
Blower Check if the operation is normal,
★
motor check if there is abnormal sound
Water
inlet and
Evaporator
Check if the clip is loose ★

outlet
pipes
Blower Check if the operation is normal,
★
motor if there is abnormal sound
Control Check if the electric element is in
★
box good condition
Plug and
Check if the thread end, the plug ★
and socket is loose or has fallen
socket
Electric element
off
Pressure Check if the pressure of high and ★
switch low voltage is normal
Temperat
Check if the wind speed of 3 ★
ure
gears is normal
control
Electrom
Check if it can be closed up and
agnetic ★
disconnected normally.
clutch
- 16 -
4.8 Malfunction Diagnosis
The blower motor rotates, but

without hot wind coming through
the outlet
Check the water hose
Normal
The hose is sudden-twisted,
bent, plugged or damaged
Replacement
No wind coming out from the defroster

outlet
Check the connecting pipes of

the defroster and the heater
Normal Worn
Replacement
Check the defroster door and the

control cable
Normal Replacement
and adjustment
- 17 -
The speed of blower cannot be adjusted
Check the electric contact
Normal Disconnected
Replacement
Check the control switch
Normal Malfunction
Replacement
The blower motor does not rotate
Check the fuse wire
Normal Malfunction
Replacement
Check the circuit and contact
Normal Open or disassemble
Replacement
Check the switch circuit
Normal Incorrect
Replacement
Check the engine motor
Normal Malfunction
Replacement
- 18 -
The blower motor is with loud noise
Check the bearing of blower motor
Normal Fractured
Replacement
With cold wind coming out discontinuously
Check the magnetic clutch
Normal Slipping or not working
Replacement
Check the expansion valve
Normal Malfunction
Replacement
Check the wire connection
Normal Malfunction
Repair
- 19 -
Not sufficient refrigeration
Check the condenser
Check the driving belt Clean or replace
Normal Slip
Check the compressor Replacement
Normal Malfunction
Replacement
Check the expansion valve
Normal Malfunction
Replacement
Check the thermostat
Normal Malfunction
Replacement
Check the refrigerant
Normal Insufficient or too much
Adjustment
- 20 -
5. Electric Preheating
The engine of this vehicle type adopts the mode of electric preheating to preheat the engine
in the cold season. The heating wire is controlled by ECU. Every time of starting, ECU will
decide whether to start the electric preheating and control the operation time according to the
outside condition (the temperature).
If the preheating performance is found not good, firstly check whether the electric circuit is
connected. If the circuit is normal, use the multimeter to measure the heating wire and check if it
is in good condition, and replace the burnt electric heater.
6. Various Relays
The relays for this vehicle types include: the light relay, horn relay, heater relay, starting
relay and preheating relay. Since the electric current used in the light, horn and heater is not large,
the relays used for these devices are of smaller specifications. The electric current for the
electromagnetic switch of the starter is relatively large, so the specific relay is adopted and put in
the electric box on the chassis.
7. Wiring Harness Device

Disassembling of the wiring harness connector:
Please always disconnect the connector by both
hands. Unplugging the connector with one hand will
cause the fracture of the wire terminal.
Note: Push the locking plates at the both sides and
then unplug the plug to disconnect.
Connection of the wiring harness connector:

Firmly grab both sides of the wire connector
Incorrect
(positive and negative), confirm that the stitches of
the connector match with the stitch holes and the
both sides are mutually aligned. Carefully press the
both sides of the connector until you hear a clear
Correct sound of “click”.
Incorrect
Check of the wiring harness connector:
Use the circuit testing instrument to check the
Probe continuity of the connector. Insert the test probe at
the wire side of the connector.
Do not insert the test probe into the open end of the
connector.
- 21 -
Correct
Probe
Check of the fusible circuit:

Fusible circuit
The fusible circuit is installed in the positive
Starter connector of the storage battery and the connector of
switch starter switch B
If the excessive current flows into the circuit, the fuse
wire will melt to protect the main power supply from
Starter motor being overloaded. Please use the multimeter to check
the continuity of the connector circuit.
Disassembling of the wire stitch:

Pin 1. Insert the pin into the open end of the wire
Barb
Wire connector housing
2. Press the barb (towards the wire side of the
connector), and pull the wire at the wire side of
connector.
Open end Terminal
Inserting the wire stitch:

Barb Wire
1. Check if the barb of stitch is fully open.
2. Insert the stitch at the wire side of connector, and
press the stitch till the stitch barb is tightly
buckled.
3. Gently pull the wire and reset the stitch.
Terminal
- 22 -
Notes for wiring harness layout:
Incorrect
Use the protective jacket or sleeve to protect the
wiring harness, avoid it from directly contacting the
sharp edge or surface;
Correct
There should be enough space between the wiring

Incorrect
harness and other stuff such as the support, and use
the ethylene sleeve and clip to protect the wiring
harness and avoid direct contact;
Correct Sleeve
Clip
The length of the wiring harness between the engine

and the chassis should be long enough to prevent the
wiring harness from being abraded or damaged by
various vibrations.
Incorrect
Correct
Fuse wire
Normal Damaged
The fuse wire is the most common circuit protection
form in the vehicle circuit. In the circuit, when there
is overloaded current passing by, the fuse wire will
be fused to avoid strong current causing damage to
other parts in the circuit
Before replacing the fuse wire, find out the reason
which causes the overloaded current, and solve the
problem.
The replaced fuse wire should be of the same
amperage as the original one. Otherwise it will cause
the circuit burning or other serious damages to the
circuit.
Instrument shield
� Remove the instrument shield, be careful not to
scratch other panels
- 23 -
� Remove the connecting parts of the electric
switch, emergency buttons and the wiring
harness of the vehicle body.
Important
Work——
Work—— Disassembling
——Disassembling
Fuse wire box and relay box
� After disassembling the instrument desk frame,
remove the fuse wire box and relay box which
are installed on the frame, and then remove the
wiring harness.
� Remove all the plug connectors which are

connected to the wiring harness of the vehicle
body.
� Remove the bolts, and be careful not to scratch
the surfaces of other components.
Important Work-Assembling
� Install the wiring harness of vehicle body on the
pipe beam of the instrument desk, fix the fuse
wire and relay box at corresponding positions,
and fix the wiring harness by wire clip. After
checking the electric wiring harness or the wire
clip, connect the connectors of the wiring
harnesses of the vehicle body and chassis.
- 24 -
Air conditioner panel
� Thread the control wire into the instrument
panel, and then firmly assemble the air
conditioner panel.
� Rotate the mode switch knob to the leftmost
(towards FACE)
� Rotate the temperature control knob to the
leftmost (towards COLD)
� Pull the internal and external cycle rod to the
leftmost (towards INSIDE)
Control wiredrawing
“A”
Control wiredrawing � After hanging the control wiredrawing “A” on
“B” the grabber of the blower, pull the butterfly valve
to the “full” position, then fix the electric cable
onto the clip.
� After hanging the control wiredrawing “B” on
Warm air the grabber of the heater, pull the butterfly valve
blower to the lowest position, then fix the electric cable
onto the clip.
Control wiredrawing “C”
� After hanging the control wiredrawing “C” on

the grabber of the blower, pull the butterfly valve
to the “full” position, then fix the electric cable
onto the clip.
Warm air
blower
E Connect the electric wiring harness at the following

positions:
B C A Antenna cable
B Radio
H C Blower switch
D D Cigarette lighter
G
A E Instrument
F Clutch switch, brake switch, throttle cock,
G Fog lamp switch, warning switch, preheating
I switch
H Combined switch
I Washer pot
- 25 -
8. Rotation Speed Sensor
The rotation speed signal is taken from the rotation speed output signal of W terminal of the
generator. The output waveform is the sine wave.
9. Wiper and Washer System

9.1 Working Principle of Wiper
Through the linkage mechanism, the electric wiper converts the motor rotation into the
swing motion of the major and minor wiping arms and plates, and then performs glass wiping.
The working mode of the wiper of this vehicle includes three gears such as Low-speed,
High-speed and Intermittent.
Through the speed regulation switch, the wiper performs wiping at variable speeds by
changing the wiping motor circuit. The speed regulation control circuit is indicated as the
following figure, the control process is as the following:
a) Wiping at Low-speed: when the power switch is on, and the speed regulation switch is
connected to Gear “I”, the current flows from the positive pole of storage battery → power
switch →fuse wire → electric brush B3 → armature → electric brush B1→speed regulation
switch Gear “I” grounding → the negative pole of storage battery.
b) When the speed regulation switch is connected to Gear “II”, the current flows from the
positive pole of storage battery → power switch →fuse wire → electric brush B3 → armature
→ electric brush B2→speed regulation switch Gear “II” grounding → the negative pole of
storage battery. Since the electric brush B2 is bias by one angle, the motor rotates at a high
speed and drives the wiping plate swinging fast.
c) Stop and reset. The automatic reset mechanism of the motor wiper is indicated as Figure (b).
There are copper rings 7 and 9 embedded in the turbine 8, which is made of nylon. The copper
rings are separated into 2 parts. The copper ring 9 with lager area is connected to the motor
shell and grounded. The contact blades 3 and 5 are made of phosphor copper sheet or other
elastic materials. There are contact points 4 and 6 at the rivet points. Since the contact points 3
and 5 are elastic, when the turbine 8 rotates, the contact points 4 and 6 keep contacting with
the end surface of the turbine 8 (including the copper rings 7 and 9).
Circuit Diagram of Speed Regulation Control of Wiper
1-Power switch；2-Fuse wire；3、5-Self-return contact blade；4、6-Contact point；

7、9- Self-return slip ring (copper ring)；8-Turbine；10- Armature；11- Permanent magnet
When the speed regulation switch of wiper is pulled to Gear “0” (STOP), if the wiping plates
- 26 -
do not stop at the bottom line of the windshield, the turbine will rotate and connect with the
contact point 6 and the copper ring 9, then the current will flow to the armature. At this moment,
the electric current flows from the positive pole of storage battery → power switch →fuse wire →
electric brush B1 → speed regulation switch → contact blade 5 → contact point 6 →copper ring 9
→ grounding → the negative pole of the storage battery, and it forms the loop. The motor rotates
at low speed till the turbine rotates to the position indicated as (a) in the figure, when the contact
points 4 and 6 are connected to the copper ring 7.
When the contact points 4 and 6 are connected to the copper ring 7, under the inertial force
of the armature rotation, the motor generates in the engine mode instead of stopping immediately.
Since the direction of the electrodynamic force produced by the armature winding is opposite to
the direction of the external power voltage, the electric current flows from the electric brush B3
→ contact blade 3 → contact point 4 → copper ring 7 → contact point 6 →contact blade 5 →
speed regulation switch → electric brush B1. It forms the loop and produces the torque (which is
also called as brake torque). The motor immediately stops rotating and the wiping plate is
properly reset at the bottom line of the windshield.
The maintenance personnel can find out the malfunctions of the wiper circuit according to
the working principle of wipers and the circuit diagram of speed regulation control.
9.2 Usage of Washer
When driving the vehicle, the windshield glass will be stained with dirt or impurities. Most
of the vehicles are equipped with the windshield washer to provide the driver with good vision.
When the armature of washing motor is switched on, the armature winding is forced to rotate
in the magnetic field of permanent magnet. When the armature rotates, the coupling drives the
water pump shaft and pump rotor to rotate at the same time. The pump rotor pumps the washing
liquid in the liquid pod out to the water outlet hose. And the washing liquid will be sprayed to the
windshield by the sprayer in front of the windshield. At the same time, the wiper operates and the
wiping plate swings to wipe and clean the dirt on the windshield.
When using the washer, the washer pump should be switched on first, and then the wiper.
The continuous operation hour of the washer pump should not exceed 5s, and the intermittent l
time should not be less than 10s. When the washing liquid in the pod is used up, to avoid causing
damage to the washing motor, please do not switch on the washer pump for idling.
9.3 Circuit Diagram of Wiper Washing System
When there is circuit malfunction, non-operation or abnormal operation in the wiper washing
system, the maintenance personnel can conduct the malfunction troubleshooting according to the
system circuit diagram.
- 27 -
Contact
co d e
W ip e
r
W ash
er
W ater
sp ra y
W iper
Intermittent intermittent
R eset re la y
M otor
Low - H ig h-
sp eed sp eed
R eset
Wiper Motor Washer Motor
9.4 Examination of the Wiper and Washer System

Step Measurement Normal Result Abnormal Result
Switch the ignition device The wiper operates at low-speed. The washer fails to
to ON, place the washer The washer sprays to the work.
switch at ON position. windshield glass when the
washer is switched on. After
1
being switched off, the washer
stops working, and the wiper
returns to the stop position after
wiping for 2-4 times.
Place the wiper switch at After a full-range wiping, the The intermittent
the position of intermittent wiper pauses for 1-22 seconds, operation mode of
2
operation. and then continues the next wiper is abnormal.
round of wiping.
Place the wiper switch at The wiper continues to operate The wiper fails to
3 the position of low-speed. at low-speed. work in the
low-speed mode.
Place the wiper switch at The wiper operates at The wiper fails to
4 the position of high-speed high-speed. work in the
(HI). high-speed mode.
Place the wiper switch at The wiper returns to the stop The wiper fails to
the position of OFF. position at low-speed. stop, or the wiping
5
plate is not reset
when stop.
- 28 -
9.5 Diagnostic Program of the Wiper/Washer System
Malfunction mode: No matter which gear the wiper switch is placed at,
the wiper and washer fail to work.
Step Disposal Method Yes No
1 Check the fuse wire of wiper, is the fuse wire broken? To Step3 Step 2
Disassemble the wiper switch. Check if there are To Step 5 To Step 4
abnormalities in the switch such as burning and fracture.
2 Use the digital multimeter to measure and check if the wire
is connected or not. Measure the voltage of the connector
and the wiper switch to see if the voltage is normal.
3 Replace the damaged fuse wire. To Step 2
Please check the instrument harness from the fuse wire to To Step 5
4
the wiper switch. Repair it if necessary.
Ensure that the contact between the wiper switch and the To Step 6
wire harness connector is in good condition?
Separate the wire harness from the wiper motor. Check the
5
wiper switch and the instrument harness from the fuse wire
to the wiper motor according to the circuit diagram. Repair
the harness if necessary.
Check the wiper motor and repair it if necessary. Ensure To Step 7 —
that the wiper motor is good. Ensure that the contact
6
between the wiper motor and the connector is in good
condition.
Please check the grounding wire of the wiper motor in the To Step 8
7
wire harness of the instrument panel, repair it if necessary.
8 If the system is in good condition?
Malfunction mode: The operation fails at High-speed Gear

Separate the wire harness connector from the wiper motor. To Step 2 To Step 3
1 Use the digital multimeter to measure the voltage of the
side stitch of wire harness, and see if the voltage is normal?
Check the internal structure of the wiper motor, replace or
2
repair it if necessary.
Disassemble the wiper switch and check; ensure that it is in
3 good condition. Check the instrument panel from the wiper
switch to the wiper motor, repair it if necessary.
Malfunction mode: Fail to operate at Low-speed Gear.

Separate the wire harness connector from the wiper motor. To Step 2 To Step 3
1 Use the digital multimeter to measure the voltage of the
Check the internal structure of the wiper motor, replace or
2
repair it if necessary.
- 29 -
Disassemble the wiper switch and check; replace or repair it To Step 4
3
if necessary. Ensure the wiper switch is in good condition.
4 Check the instrument harness from the wiper switch to the
wiper motor. Repair it if necessary.
Malfunction mode: Fail to operate at Intermittent Gear
Remove the wiper relay, pull the ignition device to ON To Step 4 To Step 2
position, and pull the wiper switch to the intermittent gear.
1
Use the digital multimeter to measure the voltage of the
Disassemble the wiper switch and check, and ensure that it To Step 3
2 is in good condition. Otherwise, replace or repair it if
necessary.
Please check the instrument harness from the wiper switch To Step 7
3
to the wiper relay. Repair it if necessary.
Please check the grounding of the relay. Is the wire well To Step 6 To Step 5
4
grounded?
Please repair the grounding wire and ensure that it is well
5
grounded.
Please replace the wire relay. Is the system in good
6
condition?
Please check the instrument harness from the wiper switch To Step 8 To Step 10
7
to the relay, ensure that there is no problem.
Disassemble the new wiper relay, use the digital multimeter To Step
8
to measure the voltage of the relay. Is the voltage normal? 10
Please check the instrument harness. Repair it if necessary. To Step
9
Ensure that there is no problem. 10
Please check the instrument wire harness from the relay to
the wiper motor. Repair the instrument panel if necessary;
10
ensure that there is no problem with it. Is the system in
good condition?
Malfunction: The wiping plate fails to be reset normally

Disassemble the wiper switch and check the internal To Step
1 structure. Repair or replace it if necessary. Ensure that there 2
is no problem with it.
Disconnect the wiper motor connector; use the digital To Step To Step 3
2 multimeter to measure the voltage of the side stitch of the 4
wire harness. Is the voltage normal?
Check the instrument harness from the fuse wire to the wiper To Step
3 motor according to the circuit diagram. Ensure that there is 4
no problem with it.
Disassemble the wiper motor and check the structure. Repair
4
or replace it if necessary. The system is in good condition.
- 30 -
Malfunction: The wiper fails to stop.
1 Check the fuse wire and see if it is in good condition? To Step 2 To Step 3
2 Replace the damaged fuse wire. To Step 3
Disassemble the wiper switch; use the digital multimeter to To Step 5 To Step 4
3
measure the voltage of the switch. Is the voltage normal?
Please check the instrument harness from the fuse wire to To Step 5 To Step 6
4
the wiper switch. Repair it if necessary.
Please check the internal structure of the wiper switch, To Step 10
replace or repair it if necessary.
5
Ensure that there is no problem with it. Is the system in
good condition?
Please separate the connector from the wiper motor, pull the To Step 7 To Step 10
ignition switch to “ON” and place the wiper switch to
6 High-speed Gear. Use the digital multimeter to measure the
voltage of the stitch in the connector (at the side of wire
harness). Is the voltage normal?
Please check the instrument harness from the wiper switch To Step 8 To Step 9
7 to the relay.
Ensure that there is no problem with it.
Please use the digital multimeter to ensure whether the
8
grounding wire is well grounded.
Remove the wiper motor. Replace or repair it. The system is To Step 10
9
in good condition.
Check the instrument wire harness from the wiper switch to
the wiper motor according to the circuit diagram. Repair it if
10
necessary. Ensure that there is no problem with it. Is the
system in good condition?
Malfunction: The washer fails to work.

Disassemble the wiper/washer switch; pull the ignition
switch to “ON”;
1 Use the digital multimeter to measure the voltage of the To Step 3 To Step 2
stitch at the original position of the switch. Is the voltage
normal?
Please check the instrument harness from the fuse wire to
2 the wiper/washer switch. Repair it if necessary. Ensure that To Step 3
there is no problem with it.
Please check the internal structure of the wiper switch.
3 Repair or replace it if necessary. Ensure that there is no To Step 4
problem with it. Is the system in good condition?
Assemble the wiper/washer switch; separate the washer
4 motor connector, pull the wiper/washer switch to “WASH”. To Step 6 To Step 5
Use the digital multimeter to measure the voltage of the
- 31 -
stitch at the washer motor connector (at the side of wire
harness). Is the voltage normal?
Check and repair the harness from the wiper/washer to the
5 To Step 6
washer motor according to the circuit diagram.
Check the instrument wire harness from the wiper motor to
6 the wiper/washer switch according to the circuit diagram. Is To Step 7
it in good condition?
Please replace the washer motor. Is the system in good
7
condition?
10. Barometer Sensor

The function of the barometer sensor is to transform the gas pressure signal in the air
reservoir into the electric signal. The combination instrument will present the electric signal on
the instrument panel. The gas pressure in the air reservoir can be read through the panel. When the
pressure is lower than 0.4MPa, the low-pressure alarm will ring to remind the driver to identify
the causes.
11. Combined Switch

The combined switch is a general switch integrated by the light, wiper, washer and turn lamp.
It contains many circuits and all the circuits are centralized. So there are relatively more
malfunctions. It will help a lot with the examination and maintenance of the vehicle circuit
malfunction, if the maintenance personnel know about the structure of the combined switch.
Structure Diagram of Each Switch of the Combined Switch
1) Guiding Diagram of Light Switch, Light Variation and Overtaking Signal
Terminal Terminal
Green
Gear Gear Red and and Yellow
yellow yellow
Upper
Lower Headl
amp
Overtaki Headl
amp
Rated
Rated
working
working
current
current
2) Guiding Diagram of Steering Switch
- 32 -
Terminal
Gear
Steer to
the left L
Change to
the left laneL
Straight N
Change to the
right lane R
Steer to
the right R
Rated
working
current
3) Water Wiping Switch and Spraying Switch

Terminal
Gear
Terminal
Gear
Washing
Rated
working
current Rated
working
current
12. Combination Instrument
(1) Disassembling and Reassembling
- 33 -
Order of disassembling：
Pointer components of odometer and
1 Transparent upper cover 8
tachometer
Pointer components of fuel gauge and
2 Black frame 9
barometer
Trimming ring of mileage and Pointer components of water
3 10
rotational speed thermometer
Trimming ring of fuel oil and air
4 11 Intermediate shell
pressure
Trimming ring of water
5 12 Circuit board
thermometer
6 Reset rod 13 Bottom shell
7 Panel
Order of reassembling:
Conduct the reassembling according to the opposite order of disassembling.
(2) Buzzer of Instrument Indicating Lamp:

No. Name Function Color
Charge and discharge
1 Lit when the generator fails to generate Red
indicator lamp
Lit when the warning lamp is switched
2 Warning indicator lamp Red
on
3 Oil pressure alarm Lit when the oil pressure is low Red
4 Fuel oil alarm Lit when the fuel oil level is low Yellow
Lit when there is malfunction in the
5 Engine check Yellow
engine
6 Small lamp indicator Lit when the small lamp is switched on Green
7 Upper beam indicator Lit when the upper beam is switched on Blue
Lit when the back fog lamp is switched
8 Back fog lamp indicator Yellow
on
Lit when the left steering lamp is
9 Left steering indicator Green
switched on
10 Right steering indicator Lit when the right steering lamp is Green
- 34 -
switched on
Buzz when the gas pressure in the air
11 Buzzer alarm Red
reservoir is lower than 0.4MPa
12 ABS Alarm Lit when there is malfunction in ABS Yellow
13 Door open indicator Lit when the door is not closed Red
Lit when there is much moisture in the
14 Sedimentation water Red
fuel filter
15 Exhaust braking Lit when the exhaust brake works Green
16 Parking brake Lit when the parking brake works Red
17 Preheating indicator Lit when the preheating works Yellow
Rear-view mirror Lit when the rear-view mirror defrosting
18 Yellow
defrosting works
Lit when the water temperature is too
19 Water temperature alarm Red
high
Electric-adjusting Lit when the electric-adjusting
20 Green
headlamp indicator headlamp works
(3) Confirmation and Installation of the Major Components

Major Component Type Location of Installation
Combination
Stepping motor type Under the instrument board
instrument
At the intermediate part of the
Speedometer/odometer
All-electronic type combination instrument
Odometer sensor On the transmission output shaft
Engine oil pressure
Variable resistance type At the engine oil pipeline
sensor
Water temperature
Thermal resistance type At the water inlet pipe of the engine
sensor
At the right upper part of the
Water thermometer Stepping motor type
combination instrument
Fuel oil sensor Variable resistance type Inside the oil tank
At the right lower part of the
Fuel gauge Stepping motor type
In the middle of the combination
Tachometer Stepping motor type
instrument
At the left lower part of the
Barometer (Deleted) Stepping motor type
(4) Indicator and Alarm Switch
- 35 -
Indicator switch of the engine oil pressure
Circuit diagram
Position of the indicator switch
Specification of switch
Working pressure: 0.3—0.5kg/cm2
The indicator is lit when the oil pressure
declines to the switch functioning pressure.
Barometer sensor
- 36 -
Parking braking switch
Connected Circuit diagram
Disconnected
Switch
(5) Technical Requirements:

3820100LD010 Combination Instrument Assembly
The basic requirements of error are as the following:
Basic Error
Indicating Speed 20 40 60 80 100 120 140 160
Speedometer Km/h
(Stepping Permissible error +5 +5 +5 +5 +6 +7
±3
motor type) Km/h 0 0 0 0 0 0
Transmission ratio 1:640 Interface mode Sensor type
Indicating scale E 1/2 F
Fuel Gauge Base resistance(Ω) 110 32.5 3
(Stepping Permissible error(Ω) ±5 ±2 ±2
motor type) Supporting sensor Name Fuel oil Type RG1164B1
sensor
Indicating scale(℃) C(50) 110 H(115)
Water Base resistance(Ω) 226 31.1 26.4
thermometer Permissible error(Ω) ±30 ±2 ±1.5
(Stepping Supporting sensor Name Water Type WG1371
motor type) temperature
sensor
Electr Nominal rotational 1000 2000 3000 4000 5000

onic speed(r/min)
Tacho Permissible error (r/min) ±100 ±100 ±150 ±200 ±250
meter Reference frequency(Hz) 177 354 530 707 884
Signal The signal is taken from the engine terminal W, the
logarithm of the engine pole is 6.
Product standards QC/T727 the Instruments for Automotive and
Motocycle
The alarm indicating system of the instrument 3820100LD100 is in accordance with the
symbols indicated in GB4094-1999 Symbols for Vehicle Control, Indicators and Signal Device.
- 37 -
13. CD Player
The stereo of this vehicle is the single-disc double-track CD player with the function of
USB_MP3. The left channel speak of the CD player is installed in the left door; the right channel
speaker is installed in the right door.
If you found that some function of the vehicle stereo fails to work, before you send it for
maintenance, please carefully read the operation indication in the instruction book, and conduct
the examination according to the following table. It will help you solve the malfunction.
If the malfunction cannot be solved, please send the machine to the service station for
maintenance. Please don’t disassemble the machine or maintain it by yourself.
General situation
The host machine fails to function and display.
· Check if the fuse connector of the host machine and the vehicle is loose.
The host machine functions, but without or with little sound.

· Up the volume.
· Check the settings of the left and right balance of the speaker.
· Check if the contact of the speaker plug is in good condition.
Radio
Not receiving the station you want:
· Check if the antenna is fully unfolded and correctly connected.
· The signal of the required radio station is too week, please manually adjust.
· Check if the antenna plug is fully connected with the connecting plug of the host
machine.
Poor receiving capability:

CD
The CD display shows “CD ERROR”:
· Check if the disc is correctly placed, and the disc is not damaged or dirty.
Sound distortion
· Fail to read the disc; the disc is damaged or dirty.
CD play fails to work:
· When the weather is too cold, there might be moisture condensed on the laser head. Turn
the host machine to radio mode and run for about 5 minutes to evaporate the moisture.
Mode conversion fails to function
· Check if the CD disc is placed in the player.
Disc input fails
· Check if there is disc inside the machine already;
Notes: When play the newly-bought disc in, check if the white pad in the center of disc has
been taken off.
This player is not applicable for 6-inch disc.
USB
Fail to read USB flash disc:
· Check if the song format in the USB flash disc is correct. This machine only supports
the format of MP3 and WMA.
- 38 -
· Check if the connection of the interface of USB flash disc is good.
Remarks: When the USB flash disc fails to be read, refresh it by the computer or conduct the
virus check.
Cab Assembly
1. Front Wall Components
Disassembling and Assembling
Disassembling Order Assembling Order
1. Front bumper assembly ▲5. Exterior rear-view mirror

2. Face shield 4. Upper side plate of front wall
7. Lower side plate of front wall 3. Outer plate of front wall
6. Headlamp 6. Headlamp
3. Outer plate of front wall 7. Lower side plate of front wall
4. Upper side plate of front wall 2. Face shield
5. Exterior rear-view mirror 1. Front bumper assembly
- 39 -
1 2 Important Work-Disassembling
Face shield
a) Remove the tapping screw in the
central part of the face shield;
b) Push the exposed part of 5 upper
bayonets of the face shield from the
state shown in “Figure 1” to the state
shown in “Figure 2”in sequence. The
bayonets will automatically fall off;
c) Pull the face shield, including the
bayonets at the lower part, out from the
installation hole.
Headlamp
When replacing the bulbs of the upper beam
Rear cover
lamp, lower beam lamp and width lamp, the
replacement can be conducted after removing
the rear cover. There is no need to disassemble
the whole lamp.
Side plate bayonet III of front wall
Upper sealing strip of side plate of front wall
Side plate bayonet II of front wall (alphabet)
Upper side plate of front wall
Limit structure of the M6 bolt mounting

upper and lower side hole
plates of front wall Side plate bayonet I M6 bolt mounting
of front wall
M6 bolt mounting
M6 bolt mounting
lower sealing strip of
Lower side plate side plate of front wall
of front wall
Side plate bayonet I
of front wall
M6 bolt mounting M6 bolt mounting
Assembling order:
� Install caps of the side plate bayonet III of front wall and side plate bayonet II of front
wall onto the vehicle body;
� Install buckles of bayonet II of front wall onto the side plate of front wall;
� Install the mounted upper side plate of front wall onto the vehicle body by the bayonet,
and tightly press the dual bayonet;
� (When installing the headlamp) Use M6 cross pan-headed bolt to fix the upper side
- 40 -
plate and headlamp with the sheet metal; (totally 1 mounting hole for both
installation)
� After the headlamp installation
� Install the side plate bayonet I of front wall onto the vehicle body;
� Assemble the lower and upper side plates of front wall with the vehicle body;
� Adjust the state;
� Use two M6 cross pan-headed bolts to fix the lower side plate of front wall and the headlamp
support.
2. Front Windshield Glass
Sectional drawing
1. Front windshield glass 2. Lower rubber strip of front windshield 3. Upper rubber strip of front windshield 4. Inner rubber strip of front
windshield 5. Front windshield buckle
Disassembling order Assembling order

▲1. Front windshield glass ▲5. Stopper of front windshield
2. Lower rubber strip of front windshield 4. Lower rubber strip of front windshield
3. Upper rubber strip of front windshield 3. Upper rubber strip of front windshield
4. Inner rubber strip of front windshield 2. Inner rubber strip of front windshield
5. Stopper of front windshield 1. Front windshield glass
Important Work-Disassembling
Front windshield glass
a) Tear the sealing strip off from the
upper flange and angles of the
vehicle flange. And then, gently
pull the glass out, and take it out.
Notes: Not to scratch the glass
surface.
- 41 -
b) Use the petrol to wash off the
sealant on the vehicle.
Range to paste sealant Front windshield glass
� As indicated in the left figure, paste
the edge with enough sealant, with the
diameter of about 10mm.
Insufficiency of sealant will cause
leakage.
� It is required that the glass adhesive
should cover the rubber strips around
glass with the width of 1~2mm.
Sealant single-component
polyurethane glass adhesive
Windshield glass assembly

� Adhere the windshield glass to the
front windshield flange of the cab
body.
� Use the rubber hammer to knock the

Rubber Windshield glassgently, make the vehicle body
hammer glass
flange fullycontacted with the sealing
Sealing strip strip.
Vehicle
body flange
- 42 -
3. Rear Windshield Glass

▲3. Rear windshield assembly ▲1. Rear windshield glass
2. Rubber strip of rear windshield 2. Rubber strip of rear windshield
1. Rear windshield glass 3. Rear windshield assembly
- 43 -
Rear windshield assembly
� Tear the sealing strip off from the
upper flange and angles of the vehicle
flange. And then gently pull the glass
out and take it out.
Be careful not to scratch the coating
surface or glass.
Sealing strip Important Work-Assembling

Sealing strip
� The glass should be placed with the
Center trademark at the left bottom, adjust
the center of glass to be aligned with
the joint beneath the sealing strip.
Left Right
Joint
Sealing strip
� Thread the rope of Ф5-6mm into the
flange. After circling for one round,
make it coincide at the bottom center
of glass.
Rope
Rear windshield assembly

推 � Adjust the glass to the center of the
vehicle windshield window, press the
glass from the outside, and then pull
the rope to the center of glass from
the inside. Install the rubber strip of
拉 rear windshield to the vehicle body
flange.
The rubber strip should not be
twisted or unfit with the vehicle rear
windshield body, so as to avoid water
leakage.
- 44 -
� Knock the glass gently with the
Windshield rubber hammer to make the vehicle
Rubber
hammer glass flange fully contacted with the
Sealing
sealing strip.
strip
Vehicle body
flange
4. Instrument Desk
15
3
21
8
1
14
9 2
V
16
5
7
4
13
6
19
12
10
20
18
17
- 45 -
Disassembling Reassembling

1. Instrument panel shield 21. Air conditioner, heater
2. Electrical switch on the instrument panel shield 20. Pipe beam
3. Cover of clutch oil can 19. Wash pot
4. Sundries box of instrument panel 18. Fuse wire box, relay box
5. Lower guard board of passenger area 17. Harness
6. Air conditioner control panel 16. Clutch oil can
7. Radio 15. Frame body of instrument panel, defrosting duct
shield, sundries box and duct
8. Left lower guard board of control area 14. Combination instrument
9. Hand throttle knob 13. Right cover plate of passenger area
10. Right lower guard board of control area (including 12. Cigarette lighter
fuse wire cap)
11. Electrical switch on right lower guard board of 11. Electrical switch on right lower guard board of
control area control area
12. Cigarette lighter 10. Right lower guard board of control area (including
fuse wire cap)
13. Right cover plate of passenger area 9. Hand throttle knob
14. Combination instrument 8. Left lower guard board of control area
15. Frame body of instrument panel, defrosting duct 7. Radio
shield, sundries box and duct
16. Clutch oil can 6. Air conditioner control panel
17. Harness 5. Lower guard board of passenger area
18. Fuse wire box, relay box 4. Sundries box of instrument panel
19. Wash pot 3. Cover of clutch oil can
20. Pipe beam 2. Electrical switch on the instrument panel shield
21. Air conditioner, heater 1. Instrument panel shield
Electrical
switch
Instrument Shield
� Remove the instrument shield, be careful
not to damage other panels.
� Remove the connecting parts of the
Instrume
electrical switch, emergency button and
nt shield vehicle electric harness.
Emergency
button
- 46 -
6 and 7, air conditioner panel and radio (or
Radio CD player)
� Disconnect each connector of the radio
(or CD player) and the control wire of air
conditioner.
� Remove the radio (or CD player) and air
conditioner panel.
Screw

� After disassembling of instrument panel
frame, remove the fuse wire and relay
Fuse wire box installed on the frame, and then,
and relay remove the harness.
box
Pipe beam of instrument panel

Braking oil can and
� To remove the fixed part of braking oil
hose
can from the pipe beam of instrument
panel, loosen the hose first to drain the
oil in the braking oil can first. Otherwise
the braking oil will overflow.
- 47 -
� Remove all the plug connectors
connected to the vehicle body harness.
Frame and harness,
relay, and fuse wire � Remove the bolts, be careful not to
scratch the surface of other components.
Fuse wire
box and relay
box � Install the vehicle body harness to the
pipe beam of instrument panel, and fix
the fuse wire and relay box at the
corresponding positions. Fix the harness
with wire clip. After check the harness or
wire clip, connect the connectors of the
vehicle body harness and the chassis
harness.
1 Pipe beam of instrument panel

2
� Mount and tighten bolts to the hole 1-2
indicated in the figure, and tighten it.
� Install the pipe beam to the steering
column, mount and tighten the bolts.
� Connect the plug connector of electric
harness with the combined switch.
Torque N·m 8~10
- 48 -
� Install the braking oil can on the pipe
beam of instrument panel,
A B
� Tighten the nuts at A and B position.
� Connect the braking oil can and hose and
tighten up.
Torque N·m 5~11

� Thread the control wire into the
instrument panel, and then firmly
assemble the air conditioner panel.
� Rotate the mode switch knob to the
leftmost (towards FACE)
Screw � Rotate the temperature control knob to
the leftmost (towards COLD)
� Pull the internal and external cycle rod to
the leftmost (towards INSIDE)
Control
wiredrawing “A”
Control
� After hanging the control wiredrawing
wiredrawing “B” “A” on the grabber of the blower, pull the
butterfly valve to the “full” position, then
fix the electric cable onto the clip.
Warm air blower “B” on the grabber of the heater, pull the
butterfly valve to the lowest position,
then fix the electric cable onto the clip.
Control wiredrawing “C”

“C” on the grabber of the blower, pull the
butterfly valve to the “full” position, then
fix the electric cable onto the clip.
Blower
- 49 -
Radio (or CD player)
Radio
� After installing the radio in the
instrument panel, respectively connect
the electric harness connector and the
antenna cable to the back of radio.
Ensure firm assembling to avoid
vibration.
Screw
Air
conditioner
panel
F E Connect the electric wiring harness at
following positions:
B C A Antenna cable
B Radio
H C Blower switch
D D Cigar lighter
G
A E Instrument
F Clutch switch, brake switch, throttle
cock,
I G Fog lamp switch, warning switch,
preheating switch
H Combined switch
I Washer pot
- 50 -
5. Ceiling Trimming
4
3
4 2

4 .Bayonet installation of ceiling trimming 1. Ceiling trimming assembly
- 51 -
2 .Pressure plate assembly of ceiling trimming 4. Bayonet installation of ceiling trimming
3. Connection of pressure plate with bayonet of 3. Connection of pressure plate with bayonet of
ceiling trimming ceiling trimming
4. Bayonet installation of ceiling trimming 2. Pressure plate assembly of ceiling trimming
1. Ceiling trimming assembly 1. Bayonet installation of ceiling trimming
6. Ceiling Sundries Box

1. Bayonet of ceiling sundries box 1. Side upper support assembly
2. Ceiling sundries box assembly 2. Fixed support of ceiling sundries box
3. Fixed support of ceiling sundries box 3. Ceiling sundries box assembly
4. Side upper support assembly 4. Bayonet of ceiling sundries box
7. Vehicle Door
Vehicle Door Disassembling
- 52 -
16
Left door
assembly
3
12 13
15
5 11
7
10 14
17
6 9
18
8
Disassembling order
17. Sealing strip of the lower panel strip of 9. Vehicle door sealing diaphragm
vehicle door
16. Vehicle door sealing strip (including the door 8. Lower section of rear glass guide slot of
buffer gasket and installation technique hole vehicle door
blocking of steering lamp)
15. Vehicle door ash pan assembly 7. Outer buckle assembly of vehicle door
18. Rocker handle assembly 6. Vehicle door lock assembly
14. Inner buckle of vehicle door 5. Vehicle door glass assembly
12. Vehicle door buckle 4. Window regulator assembly (electrical
window regulator assembly)
14. Rocker handle 3. Outer weather strip of vehicle door glass
13. Inner buckle assembly of vehicle door 2. Vehicle door glass sealing strip
12. Cover plate of big handrail of vehicle door 1. Vehicle door harness assembly
11. Big handrail of vehicle door
10. Door guard board assembly (inner trimming
assembly of electric vehicle door)
- 53 -
Reassembling
16
2
Left vehicle door
assembly 3
12 13
15
5 11
7
10 14
17
6 9 18
8
Assembling order
▲1. Vehicle door harness assembly ▲14. Inner buckle of vehicle door
2. Sealing strip of vehicle door glass 15. Vehicle door ash pan assembly
▲3. Outer weather strip of vehicle door glass 16. Vehicle door sealing strip (including the
door buffer gasket and installation
technique hole blocking of steering lamp)
4. Window regulator assembly (electrical 17. Sealing strip of the lower panel strip of
window regulator assembly) vehicle door
Additional remarks: It is required to be
installed when assembling the door guard
board
▲5. Vehicle door glass assembly 18. Rocker handle assembly
▲6. Vehicle door lock assembly
7. Outer buckle assembly of vehicle door
▲8. Lower section of rear glass guide slot of
vehicle door
▲9. Vehicle door sealing diaphragm
10. Door guard board assembly (inner
trimming assembly of electric vehicle
- 54 -
door)
▲11. Big handrail of vehicle door
12. Cover plate of big handrail of vehicle
door
13. Inner buckle assembly of vehicle door
Vehicle door sealing strip
� Use the buffer stopper to fix the joint
round holes of the vehicle door
sealing strip with the maximum Z
value.
� Clip the bayonet of rubber strip to the
fixed hole of vehicle door in
clockwise direction.
Sealing strip of the lower panel strip of

vehicle door
� Fix the bayonet closest to the white
mark on the sealing strip of the lower
panel strip of vehicle door to the
bayonet of the lower panel strip of
vehicle door with the maximum X
value
� Fix the other bayonets in sequence.
Vehicle door sealing diaphragm

� Place the sealing adhesive around the
areas required to be sealed within the
vehicle door.
� Concentrically locate the hole
positions on the sealing diaphragm
and the hole positions on the vehicle
body. Tightly stick the sealing
diaphragm to the vehicle door.
- 55 -
Structural Disassembling of Vehicle Door Body Assembly
2
8
5
6 3
9 4
1
1. Outer plate of front vehicle door 7. Front glass guide slot assembly of front
vehicle door
2. Inner plate of front vehicle door 8. Rear glass guide slot assembly of front
vehicle door
3. Stiffener of Inner plate of front vehicle door 9. Anti-collision beam assembly of front
vehicle door
4. Stiffener of vehicle door lock
5. Nut plate of big handrail of front vehicle
door
6. Hinge plate assembly of left front vehicle
door
- 56 -
8. Hinge Assembly and Limit Stopper Assembly of Vehicle Door
Disassembling
1. Vehicle body assembly 7. Hinge pin circlip of vehicle door limit

stopper
2. Vehicle door body assembly 8. Mounting support of vehicle door limit
stopper and the mounting bolt
3. Upper hinge assembly of vehicle door and
the mounting bolt
4. Lower hinge assembly of vehicle door and
the mounting bolt
5. Limit stopper body assembly of vehicle door
and the mounting bolt
6. Hinge pin of vehicle door limit stopper
57
Reassembling
1. Vehicle body assembly ▲7. Hinge pin circlip of vehicle door limit stopper
2. Vehicle door body assembly ▲8. Mounting support of vehicle door limit stopper and
the mounting bolt
▲3. Upper hinge assembly of vehicle door and the
mounting bolt
▲4 Lower hinge assembly of vehicle door and the
mounting bolt
▲5. Limit stopper body assembly of vehicle door
and the mounting bolt
▲6. Hinge pin of vehicle door limit stopper
58
Vehicle door hinge
� By mounting the bolt (Level 8.8), fix the
upper hinge assembly of vehicle door to
the vehicle door assembly, and ensure a
certain tightening torque;
� By mounting the bolt (Level 8.8), fix the
lower hinge assembly of vehicle door to
the vehicle door assembly, and ensure a
certain tightening torque;
� Pre-install the vehicle door assembly
(attached with the vehicle door hinge
assembly) to the vehicle body. Adjust the
clearance and surface difference between
the vehicle door assembly and the vehicle
body assembly to meet the design
requirements. And then, firmly mount the
bolt (Level 8.8), and ensure a certain
tightening torque.
Torque N·m 25
Vehicle door limit stopper

� Use the limit stopper mounting nuts to
install the vehicle door limit stopper body
to the vehicle door body assembly;
� Use the elastic washer bolts to install the
mounting support of vehicle door limit
stopper to Column A of the vehicle body;
� Open, close and move the vehicle door,
align the holes in the arm rod of vehicle
door limit stopper with the holes in the
mounting support, insert the limit stopper
hinge pin from the top down, and then
clip with the circlip of the limit stopper
hinge pin.
Torque N·m 9
59
Glass regulator assembly of vehicle window
� Firstly, install the glass regulator
assembly to the vehicle door, and then
install the glass to the bracket of glass
regulator.
� Then install the lower guide slot of
vehicle door glass, and adjust the glass to
smooth regulation.
Vehicle door lock assembly

� Ensure that the locking and opening rod is
reliably jointed with the outer handrail of
vehicle door, and the locking and opening
wiredrawing is reliably jointed with the
inner handrail of vehicle door.
Torque N·m 9
Inner handler assembly

a After the vehicle door lock assembly is
�
installed, respectively clip the

wiredrawing “a” and “b” of the vehicle
lock assembly into the clip slots “c” and
“d” of the inner handler assembly.
c d b
� Ensure that there is a certain space for the
inner handler assembly on the inner
trimming plate of vehicle door.
60
Outer handler assembly
� Respectively insert the rods “a” and “b”
of vehicle door lock assembly into the
positions “c” and “d” of the outer handler
assembly, tightly spin the protective
sleeve.
b a
c
a
d
c
Rocker handler
� Adjust the handler to the position
indicated in the left figure, forming an
angle of 5° to the horizontal line, all part
of the vehicle window glass should be
raised.
61
9. Seat

3. Cross pan-headed tapping screw 1. Expansion buckle of floor trim strip
2. Carpet trim strip 2. Carpet trim strip
1. Expansion buckle of floor trim strip 3. Cross pan-headed tapping screw
4. Carpet assembly 4. Carpet assembly
11. Double seat 5. Three-point safety belt assembly
10. Driver’s seat 6. Safety belt buckle assembly of driver’s seat
9. Safety belt buckle assembly of passenger’s seat 7. Safety belt buckle assembly of additional
intermediate seat
8. Safety belt assembly of additional intermediate seat 8. Safety belt assembly of additional intermediate
seat
62
7. Safety belt buckle assembly of additional 9. Safety belt buckle assembly of passenger’s seat
intermediate seat
6. Safety belt buckle assembly of driver’s seat 10. Driver’s seat
5. Three-point safety belt assembly 11. Double seat
10. Seat Safety Belt
Seat device

5. Safety belt buckle assembly of passenger’s seat ▲1.Three-point safety belt assembly
4. Safety belt assembly of additional intermediate seat 2. Safety belt buckle assembly of driver’s seat
3. Safety belt buckle assembly of additional 3. Safety belt buckle assembly of additional
intermediate seat intermediate seat
2. Safety belt buckle assembly of driver’s seat 4. Safety belt assembly of additional intermediate seat
1. Three-point safety belt assembly 5. Safety belt buckle assembly of passenger’s seat
63
Three-point safety belt assembly
Install the fixed part of seat safety belt to
Column B.
Pay attention to the installation direction of
Seat safety belt
the fixed part of seat safety belt.
Part Part Torque N·m 30~50
Hemming
Forward
Part
Seat safety
belt
Hemming
Forward
Part Part
11. Cab Turnover and Locking Mechanism
Turnover Mechanism
1
5
6
5
Disassembling Assembling
64
▲1. Strut assembly ▲6. Torsion bar
2. Snap ring ▲5. Left and right bearing seat
▲3. Torsion bar arm assembly ▲4. Axle tube assembly
4. Axle tube assembly ▲3. Torsion bar arm assembly
5. Left and right bearing seat 2. Snap ring
6. Torsion bar 1. Strut assembly
Strut assembly
� Separate the strut assembly from the cab
assembly and vehicle frame.
(Notes: It can also be disassembled from the
hinge pin at the joint of the upper bearer and
upper strut.)
Torsion bar assembly
Align with the
marked � Remove the snap ring;
� Turn the cab to angle of 50° (the pre-torsion
angle of torsion bar), unload the torque
force;
� Slightly loosen the mounting bolt of the
torsion bar;
� Remove the adjusting bolt 1 of torsion bar
and the mounting bolt 2 of the bar arm;
� Remove the torsion bar arm assembly and
lower the cab.
(Note: Before lowering the cab, remove the
mounting bolt of torsion bar arm in the rear
part.
Mark Important Work-Assembling
alignment
Torsion bar
� Install the axle tube assembly with the left
and right bearing seats.
� Insert the torsion bar into the axle tube, and
align the mark I on the torsion bar with the
mark I on the axle tube assembly. After
assembling ensure that the end surface of
torsion bar is leveled with the end surface of
bearing tube.
65
Left and right bearing seats
� Insert the fixed bolt of front support into the
tube of vehicle frame, turnover the left and
right bearing seats before installation
Torque (N·m) 150~170
Left and right bearing seat

� Align the cab guide pin with the left and
right supporting beams, lower and fix the
cab.
Torque(N·m) 60~70
Left and right bearing seat

Align with the � Lean the cab, align the mark I of torsion bar
marked position
arm assembly with the mark I of torsion bar
and install. Tighten the screw 1. After fixing
the bolt 2 to the designated position, lower
the cab, and test the tilting force. Adjust the
bolt 2 to make the tilting force meet the
requirement, and tighten the bolt 2.
Torque (N·m) 60~70
Locking Mechanism
1
5 2 4 3 4
Disassembling Assembling
66
1. Rear supporting bearer assembling ▲7. Handler
2. Short pull rod ▲6. Control mechanism
3. Long pull rod assembly ▲5. Left /right assemblies of locking mechanism
4. Auxiliary latch hook pull rod 4.Auxiliary latch hook pull rod
5. Left/right assemblies of locking mechanism ▲3. Long pull rod assembly
6. Control mechanism ▲2. Short pull rod
7. Handler ▲1. Rear supporting bearer assembling
3 1
4 4
3
2 3
2
1
1
Handler, control mechanism, left/right assembly of locking mechanism

� Install the handler, control mechanism, left/right assembly of locking mechanism on the rear
bracket of the cab according to the assembling order indicated in the figure.
Torque (N·m) 13.7~23.5
67
Assemblies of short and long pull rods
� Paint the lubricating grease on the contact surface
of the long and short pull rods;
� Install the two ends of long pull rod to the axle pins
of the left and right locking mechanism, install the
wave gasket and gasket successively at the right
side and fix them by lockpin.
(Notes: The join sequence at the right side is: the
right locking mechanism——long pull rod
assembly——wave gasket——plain
gasket——safety pin)
� Respectively install the gaskets at the handler hinge
pin and the left long pull rod assembly.
� nstall the short pull rod at the left side
(groove-shaped surface faces out), successively
install the wave gasket and gasket, and use the
hinge pin to tighten.
(Notes: The join sequence of the connectors of short
Short
pull rod
Auxiliary
hook pull rod
latch and long pull rods is: the long pull rod——plain
Long
pull rod
gasket——short pull rod——wave gasket——plain
gasket——safety pin
The join sequence of the control mechanism and short
pull rod is: control mechanism——plain
gasket——short pull rod——wave gasket——plain
gasket——safety pin )
Check and Adjustment

� Pull the handler of the cab
B：Open position
locking mechanism from
2 1 Position A to Position B. Adjust
the adjusting nuts 1 and 2 of the
Ａ：Locking position
long pull rod, make hinge pins of
the left and right locking
mechanisms reach the same
position, and lock the adjusting
nuts.
68
Table of Contents
01 Circuit Diagram Instructions Definition of Control Unit Pin·
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Internal Logo for Electrical Circuit ·
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Guide Wire Color Description ·
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Common Disconnection Methods for Connectors ·
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Circuit Test·
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Measurement of Voltage & Current ·
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Measurement of Resistance & Diode ·
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Trouble Shooting ·
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·66
02 Electrical Box 10 Circuit Diagram of Lighting Signal System ·
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·73
Cab Electrical Box ·
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·87
Fuse Type ·
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Fuse Function/Component ·
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Distribution of Cab Electrical Box Plug ·
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Electrical Box and Power Supply Locations ·
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03 Ground Wire
Ground Wire Point - General Chart ·
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04 Control Unit
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Location Distribution of Control Unit ·
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I
II
Circuit Diagram Instructions 01
Wiper main relay
ECU relay
JAC 1
01 Circuit Diagram Instructions
Reading Diagram
No. Reading Diagram
1 B1: representing the power line which supplies power to cab electrical box through electrical box fuse SF02 of chassis.
3 IGN2: supply line for gear ON of ignition switch
4 Skip sign: representing method for skip within system; 32 representing the line is directly connected to wire harness of wire size 32.
5 Wire color & wire diameter: representing method for wire color & wire diameter; BrR representing the wire is brown red and its diameter is 0.5 mm.
6 Component name: representing the name of the component.
Internal circuit: representing the wire is internal circuit of module or assembly and only for the reference of the tendency of internal circuit; in case of repairing,
7
please replace the assembly as suggested.
8 GROUND: ground wire; other than ground wire connection itself in electrical circuit, all wire harness should be grounded through this wire.
Reference coordinate of electrical circuit: reference coordinate; each wire has its own coordinate setting for the convenience of finding and positioning of wire
9
harness; each system has its own coordinate system
10 Plug terminal: representing method for plug; B09-10 representing number 10 pin of plug B09.
Ground point: definition of ground point; G005 representing the wire get grounded to vehicle body through ground wire point G005; refer to distribution diagram
11
of ground wire points for specific positions.
Skip information: representing component name connected with wire harness and corresponding plug terminal; the component to be connected is not main part in
12
its system
13 Circuit drawing No.: description of circuit drawing No.; it is used to distinguish different drawings.
Page break sign: description of connection of previous page and next page; representing the wire harness to be connected to same code of previous page or next
14
page.
Fuse information: F35 15A representing that the wire harness passes through fuse with code F35 and maximum current value 15 A. Refer to electrical box for
15
specific position of fuse F35.
16 ACC: supply line for gear ACC of ignition switch.
17 IGN1: supply line for gear ON of ignition switch.
2 JAC
Internal Logo for Circuit Diagram
Non-detachable type guide wire jointing Component internal guide wire connection Component connector connection
(usually used in the wire harness) (non-detachable)
Wire harness connector connection Crossed guide wires, no joint at the Twisted pair: guide wires twisted together
crossing
JAC 3
Shielded wire: Fuse/blown fuse: Battery:

One measure preventing electromagnetic One sheet metal that will be blown under large Storing chemical energy and converting it
interference of other equipments. current, so as to interrupt current and prevent to electrical energy to provide direct current
the circuit from damage. for all kinds of electrical components on
vehicle.
Ground wire point: Resistance: Speaker:

Point connected on the metal part of Electrical element with fixed resistance value Electrical device which will generate sound
vehicle body to provide current loop for can reduce voltage to specified value. wave when current passes through.
circuit.
4 JAC
Variable resistance: Capacitance: Diode:

One kind of controllable electrical resistor Storage cell of small size for storing voltage Semiconductor which only allows one-way
with rated value of variable resistance; it is temporarily circulating of current
also referred to as voltage divider or
variable resistor.
Luminescence diode(LED)： Bulb: Switch:

Give out light with current but will not Current passes through light filament and gets Turn on or off electrical circuit to allow or
generate heat when giving out light it warming up and giving out light. stop current passing through.
JAC 5
Starter: Motor: Cigarette lighter/heater strip:

Starting engine Converting electrical energy to mechanical One resistance heating element
energy.
Relay: Double-throw relay: Solenoid valve:

Usually meaning the switch controlled Having current passing through either One kind of electromagnetic coil which
electronically; current will generate group of contact in two groups of contact; can generate magnetic field when current
magnetic field when passing through coil, current may pass through the relay. passes through; it is used to move metal
which will turn on or off attached switch. plunger etc.
6 JAC
Term Abbreviations Description of Guide Wire Color

ABS Anti-lock Brake System B Black
A/C Air Conditioner O Orange
AT Automatic Transmission Bl Blue
MT Manual Transmission P Pink
OBD On-board Diagnostic System Br Brown
CAN-L Controller Area Network signal line CAN-L R Red
CAN-H Controller Area Network signal line CAN-H G Green
LIN Local Intranet V Purple
B+ Battery Power Supply Gr Gray
IGN Ignition Switch Power Supply Y Yellow
ECU Engine Control Unit Lg Light green
APM Electronic Acceleration Pedal W White
EGR Exhaust Gas Recirculation Solenoid Valve BG Black Green
GPS On-board Global Position System Br G Brown Green
GND Ground Wire
DEF Demister
JAC 7
Connector
Representing the connectors connected to parts and components
Figure (letter) in the drawing represents pin No.
Attached list below the drawing: Description of connector (code, name, color and
position of connector)
Name Front left combination light

Color Black
Position Rear part of front combination
light on left side
Representing the connectors connecting wire harness (physical drawing)
Do pull out main body of connector when pulling connector, and do not pull wire
harness.
Note: before pulling out connector, check the type of connector to be disconnected
Male connector
8 JAC
Common Disconnection Methods for Connectors
Press down the unlock key ① of

engine control unit connector
plug- arrow A -pull open along
direction of arrow B, and then
disconnect connector plug.
Installation method is in the
reverse order of disassembly.
JAC 9
Circuit Test
Measurement of Voltage
— Red multimeter or voltmeter pen selects voltage/ohm measuring jack while black pen selects
return circuit jack.
— Set function selection switch of multimeter or voltmeter to DC voltage gear.
— Connect testing probe (polarity of testing probe is exchangeable).
— Read out voltage value on display screen of multimeter or voltmeter.
Measurement of Current
— Red multimeter or ammeter pen voltage measuring jack while black pen selects return circuit
jack.
— Set function selection switch of multimeter or voltmeter to DC voltage gear.
— Connect multimeter or ammeter to circuit to be tested in series (connect red positive electrode
test prod on high potential side of circuit and black negative electrode test probe on low
electrical potential side).
Ammeter — Read out current value in multimeter.
10 JAC
Circuit Test
Measurement of Resistance
— Red multimeter or ohmmeter pen selects voltage/ohm measuring jack while black pen selects
return circuit jack.
— Set function selection switch of multimeter or ohmmeter on ohm block.
— Connect test prod of multimeter or ohmmeter onto resistance or coil to be tested to test its
resistance value (when measuring, ensure resistance or coil to be electrically neutral).
Ohmmeter
Measurement of Diode
— Red multimeter or ohmmeter pen voltage measuring jack while black pen selects return circuit
jack.
— Set function selection switch of multimeter or ohmmeter on diode testing gear.
— Test the access state on two sides of diode. If one direction of diode is accessible while breaks
off after exchanging test prod, it indicates the diode is in good condition.
— If two directions of diode are accessible, it indicates the diode is punctured if two directions
are inaccessible, it indicates the diode is open.
JAC 11
Circuit Test
Troubleshooting
Electrical appliances work abnormally
1) Find out trouble with test light
— As the circuit shown in the drawing, get one terminal of test light grounded
and test two ends of fuse with another terminal; if test light goes on, it
indicates fuse is trouble free
— Establish one return circuit on position A of connector with test light and
storage battery. If test light goes on, it indicates position A of connector is
trouble free.
— Establish one return circuit on position B of connector with test light and
storage battery. If test light goes on after turning on circuit switch in the
drawing, it indicates position A of connector and switch are trouble free.
— Establish one return circuit on position C of connector with test light and
storage battery. If test light and electrical equipments work after turning on
circuit switch in the drawing, it indicates position C of connector and
electrical equipments are trouble free.
— Check circuit ground wire.
2) Find out trouble with multimeter
— Set function selection switch of multimeter on -off testing gear.
— Get red multimeter pen grounded.
— Same as finding out trouble with trouble light, connecting red multimeter pen
on different connecting position to test the voltage.
— Determine trouble point according to whether multimeter displays voltage.
12 JAC
Electrical Box 02
Cab Electrical Box Fuse Type

Specifications Fuse Color Type
30A Silver grey Fuse wire
20A Yellow Fuse wire
15A Red Fuse wire
10A Green Fuse
Relay Type
Component Code Name
X1 Brake light relay
X2 Blower relay
X3 Wiper relay
X4 Electric door lock relay
X5 -
X6 Wiper high/ low speed relay
X7 Horn relay
X8 Wiper main relay
X9 Fog light relay
X10 Auxiliary relay layout
X11 Door lock
X12 Electric car and window relay
X13 Low beam relay
X14 -
X15 High beam relay
X16 Small light relay
JAC 13
02 Electrical Box
Fuse Function/Component Fuse Function/Component

Rated Rated
No. Name in Circuit Diagram Function /Component No. Name in Circuit Diagram Function /Component
Value Value
01 Cab electrical box fuse F1 10A Auxiliary brake 23 Cab electrical box fuse F23 - -
02 Cab electrical box fuse F2 7.5A Engine control unit Ignition switch power
24 Cab electrical box fuse F24 10A
Instrument cluster、Audio supply
03 Cab electrical box fuse F3 15A 25 Cab electrical box fuse F25 15A Horn power supply
control unit power supply
04 Cab electrical box fuse F4 - - 26 Cab electrical box fuse F26 15A Flasher power supply
05 Cab electrical box fuse F5 15A Fog light power supply Position light power
06 Cab electrical box fuse F6 30A Electric windows power supply supply
Small light relay / high beam Switch lighting of
07 Cab electrical box fuse F7 10A relay / low beam relay control instrument desk
terminal power supply Rear position light
08 Cab electrical box fuse F8 15A Wiper motor/washer motor 29 Cab electrical box fuse F29 10A license light power
Front left low beam light power supply
supply 30 Cab electrical box fuse F30 30A Blower power supply
10 Cab electrical box fuse F10 15A Cigarette lighter power supply
Front right low beam light
power supply
Mounted brake light power
supply
13 Cab electrical box fuse F13 - -
Front left high beam light power
supply
Front right high beam light
power supply
Electric car and window relay
control terminal power supply
17 Cab electrical box fuse F17 10A Generator power supply
18 Cab electrical box fuse F18 10A Instrument cluster
19 Cab electrical box fuse F19 - -
20 Cab electrical box fuse F20 7.5A Engine control unit
Wiper relay control terminal
power supply
22 Cab electrical box fuse F22 10A Audio control unit
14 JAC
Electrical Box 02
Distribution of Cab Electrical Box Plug Chassis Electrical Box
JAC 15
02 Electrical Box
Fuse Type Fuse Function/Component

Specifications Fuse Color Type Rated
No. Name in circuit diagram Function /component
60A Brown Fuse wire value
50A Red Fuse wire 01 Chassis electrical box fuse SF01 50A Starter power supply
40A Blue Fuse wire 02 Chassis electrical box fuse SF02 50A Cab electrical box power supply
30A Purple Fuse wire 03 Chassis electrical box fuse SF03 60A Cab electrical box power supply
25A Gray Fuse 04 Chassis electrical box fuse SF04 60A Cab electrical box power supply
20A Yellow Fuse 05 Chassis electrical box fuse SF05 30A Ignition switch power supply
15A Blue Fuse 06 Chassis electrical box fuse SF06 40A Ignition switch power supply
10A Red Fuse Preheating controller power
07 Chassis electrical box fuse SF10 60A
supply
Relay Type 08 Chassis electrical box fuse SF11 60A Fuel filter heating power supply
Component Code Name 09 Chassis electrical box fuse SF12 40A ABS control unit power supply
X17 Start relay 10 Chassis electrical box fuse F31 20A Compressor power supply
X18 - 11 Chassis electrical box fuse F32 25A ABS control unit power supply
X19 Fuel heating relay Engine control unit power
12 Chassis electrical box fuse F33 10A
X20 ECU relay supply
X21 A/C relay Engine control unit power
13 Chassis electrical box fuse F34 15A
X22 A/C relay supply
Engine control unit power
X23 A/C relay 14 Chassis electrical box fuse F35 15A
supply
X26 A/C relay
X27 -
X28 Dryer relay (optional)
X29 -
X30 -
16 JAC
Electrical Box 02
Electrical Box and Power Supply Locations
1-Chassis electrical box 2-Cab electrical box 3-Battery
JAC 17
03 Ground Wire Point
Ground Wire Point-General Chart

Distribution of Ground Wire Point
Name
Position
G001 Left side of front cross beam of chassis
G002 Right side of front cross beam of chassis
G003 Middle side of front cross beam of chassis
G004 Floor below left side of instrument desk
G005 Floor below right side of instrument desk
G006 Upper part of rear side of engine
Middle part of chassis cross beam on rear
G007
side of engine
Rear part of left longitudinal beam of
G008
chassis; near spare tire
Right side of middle part of chassis; near
G009
storage battery
18 JAC
Ground Wire Point 03
Position Distribution of Ground Wire Point
G001: Left side of front cross beam of G002 ： Right side of front cross beam of G003: Middle side of front cross beam of
chassis chassis chassis
G004: Floor below left side of instrument G005：Floor below right side of instrument G006: Upper part of rear side of engine
desk desk
JAC 19
03 Ground Wire Point
Location Distribution of Ground Wire Point
G007: Middle part of chassis cross beam G008: Rear part of left longitudinal beam of G009: Right side of middle part of chassis;
on rear side of engine chassis; near spare tire near storage battery
20 JAC
Control Unit 04
General Chart of Control Unit

No. Control Unit
01 Instrument cluster
02 Engine control unit
03 Preheating plug controller
04 Audio control unit
05 A/C control panel
06 ABS control unit
JAC 21
04 Control Unit
Location Distribution of Control Unit
1-Instrument cluster 2-Engine control unit 3-Preheating plug control unit

Left side of instrument desk Left side of front part of chassis; left side Left side of front part of chassis and near
of engine chassis electric box
4-Audio control unit 5-A/C control unit 6-ABS control unit

Middle of instrument desk Middle of instrument desk Middle of front part of chassis
22 JAC
Control Unit 04
Definition of Control Unit Pin A-Engine Control Unit

Pin No. Wire Color Connection
C: 94 - core plug connection. Left side of front part of chassis; left side of engine
C96-01 RG Main relay power supply
C96-02 B Ground wire
C96-03 RY Main relay power supply
C96-05 RY Main relay power supply
C96-07 N/A N/A
C96-08 N/A N/A
C96-09 N/A N/A
C96-10 N/A N/A
C96-11 N/A N/A
C96-12 RB Air flow signal
C96-13 N/A N/A
C96-14 N/A N/A
C96-15 N/A N/A
C96-16 N/A N/A
C96-17 N/A N/A
C96-18 N/A N/A
C96-19 YR Speed sensor input signal
C96-20 V Air intake temperature signal
C96-21 LgY EGB switch signal
C96-22 RG Power supply 2 of electronic accelerator pedal
C96-23 YB EGR solenoid valve power supply
C96-24 N/A N/A
JAC 23
04 Control Unit

C96-25 N/A N/A
C96-26 N/A N/A
C96-27 RW Power supply for differential pressure sensor
Power supply 1 for electronic accelerator
C96-28 BlW
pedal
C96-29 WB Signal of exhaust brake relay
C96-30 W Loop operation
C96-31 WB Signal of EGR solenoid valve
C96-32 N/A N/A
C96-33 N/A N/A
C96-34 N/A N/A
C96-35 N/A N/A
C96-36 N/A N/A
C96-37 BG A/C controller signal
C96-38 RBl Brake switch signal
C96-39 WB EGR solenoid valve ground wire
C96-40 N/A N/A
C96-41 N/A N/A
C96-42 N/A N/A
C96-43 N/A N/A
C96-44 WY Diagnosis wire K
C96-45 N/A N/A
C96-46 G Ignition switch power supply
C96-47 BlO Main relay control signal
C96-48 B Ground wire signal of vehicle speed sensor
C96-49 N/A N/A
C96-50 N/A N/A
C96-51 N/A N/A
C96-52 N/A N/A
24 JAC
Control Unit 04

C96-53 N/A N/A
C96-54 W Loop operation
C96-55 LgR Input signal of clutch switch
C96-56 N/A N/A
C96-57 GR Preheating time feedback signal
C96-58 RY Signal 1 of electronic accelerator pedal 2
C96-59 G Differential pressure sensor
C96-60 RBl Ground wire 1 of electronic accelerator pedal 2
C96-61 N/A N/A
C96-62 N/A N/A
C96-63 BlB Air flow sensor ground wire
C96-64 N/A N/A
C96-65 N/A N/A
C96-66 N/A N/A
C96-67 BlB Ground wire1 of electronic accelerator pedal
C96-68 N/A N/A
C96-69 WB Control signal of turbocharger
C96-70 YW Trouble light for engine system
C96-71 YBl OBD Trouble light
C96-72 N/A N/A
C96-73 N/A N/A
C96-74 N/A N/A
C96-75 N/A N/A
C96-76 N/A N/A
C96-77 BlB Signal of oil-water separator
C96-78 B Brake switch signal
C96-79 N/A N/A
C96-80 B Differential pressure sensor ground wire
JAC 25
04 Control Unit

C96-81 BG Signal 1 of electronic accelerator pedal
C96-82 N/A N/A
C96-83 N/A N/A
C96-84 N/A N/A
C96-85 N/A N/A
C96-86 N/A N/A
C96-87 N/A N/A
C96-88 N/A N/A
C96-89 N/A N/A
C96-90 W Preheating relay control signal
C96-91 WR Signal of preheating indicator
C96-92 N/A N/A
C96-93 N/A N/A
C96-94 N/A N/A
B: 60- core plug connection. Left side of front part of chassis; left side of engine
E13-01 VB Cylinder 3 injector high potential signal
E13-02 WY Cylinder 2 injector high potential signal
E13-03 N/A N/A
Exhaust gas recirculation solenoid valve
E13-04 YR
signal
E13-05 N/A N/A
E13-06 W Common rail pressure sensor power supply
Power supply for boost pressure temperature
E13-07 R
sensor
E13-08 L Camshaft position sensor
E13-09 N/A N/A
E13-10 N/A N/A
26 JAC
Control Unit 04

E13-11 N/A N/A
E13-12 N/A N/A
E13-13 W Crankshaft position sensor signal
E13-14 B Crankshaft position sensor ground wire
E13-15 N/A N/A
E13-16 W Cylinder 1 injector high potential signal
E13-17 LW Cylinder 4 injector high potential signal
E13-18 N/A N/A
E13-19 LB Exhaust gas recirculation solenoid valve signal
E13-20 N/A N/A
E13-21 N/A N/A
E13-22 LB A/C controller signal
E13-23 N/A N/A
E13-24 N/A N/A
E13-25 N/A N/A
E13-26 N/A N/A
E13-27 N/A N/A
E13-28 LR Ground wire of boost pressure temperature sensor
E13-29 N/A N/A
E13-30 N/A N/A
E13-31 GBr Cylinder 2 injector low potential signal
E13-32 N/A N/A
E13-33 RY Cylinder 4 injector low potential signal
E13-34 N/A N/A
E13-35 G Camshaft position sensor
E13-36 N/A N/A
E13-37 Y Coolant temperature sensor signal
E13-38 N/A N/A
JAC 27
04 Control Unit

E13-39 N/A N/A
E13-40 GL Common rail pressure sensor ground wire
E13-41 N/A N/A
E13-42 N/A N/A
E13-43 N/A N/A
E13-44 N/A N/A
E13-45 N/A N/A
E13-46 BrY Cylinder 3 injector low potential signal
E13-47 WG Cylinder 1 injector low potential signal
E13-48 N/A N/A
E13-49 N/A N/A
E13-50 RB Coolant temperature sensor ground wire
E13-51 N/A N/A
E13-52 GW Common rail pressure sensor signal
Temperature signal of boost pressure
E13-53 Gr
temperature sensor
Pressure signal of boost pressure temperature
E13-54 V
sensor
E13-55 N/A N/A
E13-56 N/A N/A
E13-57 LB Camshaft position sensor
E13-58 N/A N/A
E13-59 N/A N/A
E13-60 LB Control signal of fuel meter unit
28 JAC
Control Unit 04
Definition of Control Unit Pin A-Instrument Cluster

C: 32-core plug connection. left side of instrument desk
B36-01 R Instrument cluster power supply
B36-02 B Instrument cluster ground wire
B36-03 N/A N/A
B36-04 N/A N/A
B36-05 N/A N/A
B36-06 N/A N/A
B36-07 N/A N/A
B36-08 B Exhaust brake signal ground wire
B36-09 Lg Exhaust brake signal
B36-10 W Rear fog light signal
B36-11 W Warning light
B36-12 B Lighting signal ground wire
B36-13 LgR Door light
B36-14 WR High beam indicator signal
B36-15 WR Left steering signal
B36-16 BR Right steering signal
B36-17 GO Instrument cluster power supply
B36-18 B Speed signal ground wire
B36-19 YR Speed signal
B36-20 GBr Speedometer sensor power supply
B36-21 BW Speed signal
B36-22 YB Water temperature signal
B36-23 LgW Fuel signal
B36-24 BO Air pressure gauge A
JAC 29
04 Control Unit

B36-25 WO Air pressure gauge B
B36-26 GB Air pressure signal ground wire
B36-27 GY Air pressure signal power supply
B36-28 N/A N/A
B36-29 N/A N/A
B36-30 N/A N/A
B36-31 N/A N/A
B36-32 N/A N/A
B: 32- plug connection. left side of instrument desk
B37-01 WG Generator indicator signal
B37-02 Bl Oil pressure switch
B37-03 WR Engine inspection signal
B37-04 GB Engine inspection signal
B37-05 BlR Brake fluid level warning switch signal
B37-06 PB Driver seat belt switch signal
B37-07 N/A N/A
B37-08 Bl ABS signal indicator ground wire
B37-09 RBl Signal if door is not closed
B37-10 YW Discharge fault alarm signal
B37-11 B Signal of oil-water separator
B37-12 BG Signal of oil-water separator
B37-13 Y Parking brake switch
B37-14 N/A N/A
B37-15 N/A N/A
30 JAC
Control Unit 04

B37-17 P Signal of cab tumbler switch
B37-18 N/A N/A
B37-19 N/A N/A
B37-20 N/A N/A
B37-21 YBI Signal ground wire of preheating indicator
B37-22 GB Signal of preheating indicator
B37-23 N/A N/A
B37-24 N/A N/A
B37-25 V Urea liquid level warning signal
B37-26 N/A N/A
B37-27 N/A N/A
B37-28 N/A N/A
B37-29 N/A N/A
B37-30 N/A N/A
B37-31 N/A N/A
JAC 31
04 Control Unit
Definition of Control Unit Pin A-Audio Control Unit

B: 16 - core plug connection. Middle of instrument desk
B42-01 N/A N/A
B42-02 N/A N/A
B42-03 Br Left speaker +
B42-04 Gr Right speaker +
B42-05 N/A N/A
B42-06 N/A N/A
B42-07 G ACC power supply
B42-08 R Power supply
B42-09 LG Audio main device switch lighting light
B42-10 N/A N/A
B42-11 Y Right speaker -
B42-12 N/A N/A
B42-13 N/A N/A
B42-14 GB Left speaker -
B42-15 N/A N/A
B42-16 B Ground wire
32 JAC
Control Unit 04
Definition of Control Unit Pin A-ABS Control Unit

B: 38-plug connection. Middle of front part of chassis
C95-01 W ABS pump power supply
C95-02 N/A N/A
C95-03 N/A N/A
C95-04 V Signal of EBD indicator
C95-05 N/A N/A
C95-06 GR Front right wheel speed sensor
C95-07 N/A N/A
C95-08 N/A N/A
C95-09 N/A N/A
C95-10 N/A N/A
C95-11 N/A N/A
C95-12 N/A N/A
C95-13 B ABS pump ground wire
C95-14 N/A N/A
C95-15 N/A N/A
C95-16 N/A N/A
C95-17 W K wire
C95-18 Br Front right wheel speed sensor
C95-19 W Rear right wheel speed sensor
C95-20 G Rear left wheel speed sensor
C95-21 Y Front left wheel speed sensor
C95-22 N/A N/A
C95-23 N/A N/A
C95-24 N/A N/A
Power supply of ABS pressure regulating
C95-25 W
valve
JAC 33
04 Control Unit
Definition of Control Unit Pin A-ABS Control Unit

C95-26 N/A N/A
C95-27 N/A N/A
C95-28 N/A N/A
C95-29 L Signal of ABS indicator
C95-30 RL Brake switch signal (normally on)
C95-31 V Rear right wheel speed sensor
C95-32 RBl ABS control unit power supply
C95-33 O Rear left wheel speed sensor
C95-34 B Front left wheel speed sensor
C95-35 N/A N/A
C95-36 N/A N/A
C95-37 N/A N/A
C95-38 B ABS control unit ground wire
34 JAC
Control Unit 04
Definition of Control Unit Pin A-Control Unit for Preheating Plug

B: 5 core plug connection. Left side of front part of chassis and near chassis
electric box
1 B Ground wire
2 BIB Engine control unit
3 GB Power supply
4 N/A N/A
5 GR Engine control unit
C: 6-core plug connection. Left side of front part of chassis and near chassis
electric box
7 R Preheating plug 1#
8 Y Preheating plug 2#
9 Gr Preheating plug 3#
10 BI Preheating plug 4#
11 N/A N/A
12 N/A N/A
JAC 35
05 Circuit Diagram of Power Supply System
36 JAC
Circuit Diagram of Power Supply System 05
Blower
relay
Instrument cluster
JAC 37
Horn High Low

relay beam beam
relay relay
Ignition
Clock switch Instrument
spring cluster
38 JAC
Main brake switch Preheating

IGN SW
controller ABS ABS
Reserved IGN SW
Reserved controller controller
Cab Electrical box
Chassis Electrical box
Starter relay
Brake light relay
Battery, generator Starter

Ground wire controller
Front left combination light ECU

(Low beam) ABS control unit
JAC 39
Chassis electrical box
Oil-water separator heating switch ECU ECU
ECU relay
A/C relay
Warning
Heating of switch of Deputy brake Instrument
oil-water oil-water switch cluster B
separator separator
40 JAC
Chassis electrical box
Condenser fan A/C Pressure

motor switch
A/C relay A/C relay A/C relay
JAC 41
Name B01 Name B02 Name B03

Code B01 Code B02 Code B03
Attached Attached wire harness Cab wire harness Attached wire harness Cab wire harness
Cab wire harness
wire harness In cab electrical In cab electrical
Position Position
Position In cab electrical box box box

Attached wire harness Cab wire harness Attached wire harness Cab wire harness Attached wire harness Cab wire harness
In cab electrical In cab electrical In cab electrical
Position Position Position
box box box
42 JAC

Position In cab electrical box Position In cab electrical box In cab electrical
Position
box

In cab electrical In cab electrical In cab electrical
box box box
JAC 43
Name B14 Cab and chassis wire harness Cab and chassis wire harness
Name Name
Code B14 jointing plug A jointing plug A
Attached wire Code CM02 Code CM02
Cab wire harness
harness harness Attached Attached
Chassis wire harness Cab wire harness
Position In cab electrical box wire harness wire harness
Position In front side cover plate of cab In front side cover plate of
Position
cab
Cab and chassis wire harness Cab and chassis wire harness Cab and chassis wire harness
Name Name Name
jointing plug B jointing plug B jointing plug C
Code CM03 Code CM03 Code CM04
Attached wire Attached wire Attached
Chassis wire harness Cab wire harness
harness harness wire Chassis wire harness
In front side cover plate of In front side cover plate of harness
Position Position
cab cab Position In front side cover plate of cab
44 JAC
Cab and chassis wire Chassis and engine wire Chassis and engine wire
Name Name Name
harness jointing plug C harness jointing plug harness jointing plug
Code CM04 Code EM01 Code EM01
Attached Attached Attached wire
Cab wire harness Engine wire harness Chassis wire harness
wire harness wire harness harness
In front side cover plate of Position Left side of engine Position Left side of engine
Position
cab
JAC 45
06 Circuit Diagram of Start Charging System
Cab electrical box
Cab electrical box
Starting relay
Starter
46 JAC
Circuit Diagram of Start Charging System 06

Attached wire Attached wire Attached wire
Cab wire harness Cab wire harness Cab wire harness
harness harness harness
Position In cab electrical box Position In cab electrical box Position In cab electrical box
Name B09 Name Ignition Switch Name Starter

Code B09 Code B26 Code C71
Cab wire harness Cab wire harness Chassis wire harness
Steering column at the left
Position In cab electrical box Position Position Below left side of engine
of instrument desk
JAC 47
06 Circuit Diagram of Start Charging System
Name Generator power supply Name Engine indicator Name Starter

Code C75 Code C78 Code C93
Chassis wire harness Chassis wire harness Chassis wire harness
Near generator on right side Near generator on right side of
Position Position Position Below left side of engine
of engine engine
Name Name Name
jointing Plug B jointing plug B jointing plug C
Chassis wire harness Cab wire harness Chassis wire harness
In front side cover plate of
Position Position In front side cover plate of cab Position In front cover plate of cab
cab
48 JAC
Circuit Diagram of Start Charging System 06
Cab and chassis wire harness

Name
jointing plug C
Code CM04
Attached wire
Cab wire harness
harness
Position In front cover plate of cab
JAC 49
07 Circuit Diagram of Engine System
Oil-water
ECU relay
separator
heating
switch B
Auxiliary relay layout
Heating of oil-water Heating of oil-water

separator A separator B
50 JAC
Circuit Diagram of Engine System 07
Right combination switch Warning switch of oil-water separator A Warning switch of oil-water separator B
Crankshaft position sensor

Instrument Instrument
cluster B cluster B
JAC 51
Heating plug
Crankshaft position Boost pressure and temperature sensor
sensor
52 JAC
A/C pressure switch

Instrument cluster B Air flow
Air Flow meter
Meter Electronic acceleration pedal
Instrument cluster
Differential pressure sensor
JAC 53
54 JAC


JAC 55
Name Auxiliary brake switch Name Electronic acceleration pedal Name Diagnostic interface
Cab wire harness Cab wire harness Cab wire harness
Below left side of instrument Below left side of instrument
Position Position Position In cab electrical box
desk desk
Name Right combination switch Name Differential pressure sensor Name Air flow meter
Code B57 Code C51 Code C52
Cab wire harness Chassis wire harness Chassis wire harness
Rear steering column on left Inner side of battery in the On air intake manifold of
side of instrument desk middle of chassis right side of engine
56 JAC
Name Preheating plug Name Speedometer sensor Name Exhaust brake solenoid valve
Attached Attached wire Attached wire
wire harness harness harness
Inside middle part fuel tank of
Position On middle cylinder body of engine Position Above rear side of gearbox Position
chassis
Oil-water separator heating Oil-water separator warning

Name Oil-water separator heater A Name Name
switch A switch A
Attached Attached wire Attached wire
Position Near left side oil tank of chassis Position Near left side oil tank of chassis Position Near left side oil tank of chassis
JAC 57
Preheating controller power

Name Name Preheating controller A Name Preheating controller B
supply
Position Rear part of left side of engine Position Rear part of left side of engine Position Rear part of left side of engine
Oil-water separator heating

Name Engine control unit Name Oil-water separator heater B Name
switch B
Near left side oil tank of
Position Left side of engine Position Position Near left side oil tank of chassis
chassis
58 JAC
Oil-water separator warning Boost pressure and temperature

Name Name Name Common rail pressure sensor
switch B sensor
Code C99 Code E01 Code E02
Chassis wire harness Engine wire harness Engine wire harness
Near left side oil tank of On air intake manifold of left Front side of middle part of
chassis side of engine engine cylinder body
Name Cooling temperature sensor Name Camshaft position sensor Name Nozzle 1
Code E03 Code E04 Code E05
Engine wire harness Engine wire harness Engine wire harness
Front side of engine cylinder
Position Position In front of right side of engine Position Left part of engine cylinder head
body
JAC 59
Name Nozzle 2 Name Nozzle 3 Name Nozzle 4

Left part of engine cylinder
Position Left part of engine cylinder head Position Position Left part of engine cylinder head
head
Name Crankshaft Position Sensor Name VNT control solenoid valve Name EGR solenoid valve
Joint of gearbox on right side of Rear side of middle part of
Position Position Position Rear part of left side of engine
engine engine
60 JAC
Cab and chassis wire harness

Name Oil mass counter Name Engine control unit Name
jointing plug A
Code E12 Code E13 Code CM02
Engine wire harness Engine wire harness Chassis wire harness
Position front part of left side of engine Position Left side of engine Position In front side cover plate of cab
Name Name Name
jointing plug A jointing plug C jointing plug C
Cab wire harness Chassis wire harness Cab wire harness
Position In front side cover plate of cab Position In front cover plate of cab Position In front cover plate of cab
JAC 61
Chassis and engine wire harness Chassis and engine wire harness
Name Name
jointing plug jointing plug
Code EM01 Code EM01
Attached Attached
Engine wire harness Chassis wire harness
wire harness wire harness
Position Left side of engine Position Left side of engine
62 JAC
Circuit Diagram of Audio System 08
Cigarette lighter
Left door speaker Front door speaker
JAC 63
08 Circuit Diagram of Audio System
Name Cigarette lighter lighting Cigarette lighter power Name Cigarette lighter ground wire
Name
Code B39 supply Code B41
Attached wire harness Cab wire harness Code B40 Attached wire
Cab wire harness
Middle of instrument Attached wire harness
Position Cab wire harness
desk harness Position Middle of instrument desk
Position Middle of instrument desk
Name Audio main device Name Left door speaker Name Front door speaker
Code B42 Code D04 Code D08
Attached wire harness Cab wire harness Attached wire harness Left door wire harness Attached wire harness Right door wire harness
Position Middle of instrument desk Position Lower side of left door Position Lower side of right door
64 JAC
Circuit Diagram of Audio System 08
Cab and left door wire Cab and left door wire harness Cab and right door wire harness
Name Name Name
harness jointing plug jointing plug jointing plug
Code DM01 Code DM01 Code DM02
Attached wire Attached wire Attached
Left door wire harness Cab wire harness Right door wire harness
harness harness wire harness
Below left side of Below left side of instrument Position Below right side of instrument desk
Position Position
instrument desk desk
Cab and right door wire

Name
harness jointing plug
Code DM02
Attached wire
Cab wire harness
harness
Below right side of instrument
Position
desk
JAC 65
09 Circuit Diagram of Instrument Cluster
Coolant
level Urea Air Fuel Speedom Water
meter pressure gauge Tachomet eter temperat
warning gauge er ure gauge
Instrument cluster
66 JAC
Circuit Diagram of Instrument Cluster 09
Braking fault
Seat belt
Oil pressure
Vacuum
tube
Generator
JAC 67
Right steering
Preheating
Left steering
ECU
C96-47
68 JAC
Name Vacuum tube Name Air pressure gauge sensor A Name Brake fluid level warning switch
Attached wire Cab wire harness Attached wire Attached wire
Cab wire harness Cab wire harness
Left side of front cross beam of Below middle part of instrument Middle part of right side of
chassis board instrument desk
Name Air pressure gauge sensor B Name Instrument cluster A Name Instrument cluster B
Attached wire Attached wire Cab wire harness Attached wire Cab wire harness
Cab wire harness
Below middle part of instrument Position Left side of instrument desk Position Left side of instrument desk
Position
board
JAC 69
Name Speedometer sensor Name Fuel gauge sensor Name Oil pressure switch
Attached Attached wire Chassis wire harness Attached wire Chassis wire harness
Chassis wire harness
Position Above rear side of gearbox Position On left side fuel tank of chassis Position Below left side of engine cylinder
body
Name Parking brake system Name Cab tumbler switch Name Front left door light switch
Code F03 Code F04 Code F05
Attached wire Left floor wire harness Attached wire Left floor wire harness Attached wire Left floor wire harness
Position In auxiliary instrument desk Position Near locking device of cab Position Rear edge of front left door
70 JAC
Name Driver's seat belt Name Front right door light switch Name Water temperature sensor
Code F06 Code F07 Code C77
Attached wire Left floor wire harness Attached wire Right floor wire harness Attached wire Chassis wire harness
Position Right side of driver' seat Position Rear edge of front right door Position Front part of engine cylinder head
Name Cab and chassis wire harness Name Cab and chassis wire harness Name Cab and left floor wire harness
jointing plug C jointing plug C jointing plug
Code CM04 Code CM04 Code FM01
Attached wire Chassis wire harness Attached wire Cab wire harness Attached wire Cab wire harness
Position In front cover plate of cab Position In front cover plate of cab Position Bottom left of instrument desk
JAC 71
Name Cab and left floor wire harness Name Cab and right floor wire harness Name Cab and right floor wire harness
jointing plug jointing plug jointing plug
Code FM01 Code FM02 Code FM02
Attached wire Left floor wire harness Attached wire Cab wire harness Attached wire Right floor wire harness
Position Bottom left of instrument desk Position Below right side of instrument Position Below right side of instrument
desk desk
72 JAC
Circuit Diagram of Lighting Signal System 10
Instrument cluster
JAC 73
10 Circuit Diagram of Lighting Signal System
Ceiling light
Fog light
Front left fog lamp
Front right fog lamp

Instrument Instrument cluster
cluster
B36-16
Front right fog lamp

74 JAC
75
10
Circuit Diagram of Lighting Signal System
High Beam
Front right combination light
High beam relay
High Beam
Front left combination light
Front right
combination light
Front left combination
light
JAC
JAC
Low Beam
Low beam relay
Low Beam
Front left combination light
Circuit Diagram of Lighting Signal System
Backup Light
Backup Light
10
76
Contact No.
JAC 77

Attached wire Cab wire harness Attached wire Cab wire harness Attached wire Cab wire harness

Code BD01 Code B08 Code B09
78 JAC

Attached Cab wire harness Attached wire Cab wire harness Attached wire Cab wire harness
Name B14 Name Front left combination light Name Front left fog Light
Attached Cab wire harness Attached wire Cab wire harness Attached wire Cab wire harness
Position In cab electrical box Position Left side of front cross beam of Position Left side of front cross beam of
chassis chassis
JAC 79
Adjusting motor of front left Name Left combination switch Name Main brake switch
Name
combination light Code B27 Code B28
Code B25 Attached wire Attached wire
Attached wire harness harness
Cab wire harness
harness Rear steering column on left side Position Below left side of instrument desk
Position
Left side of front cross beam of of instrument desk
Position
chassis
Adjusting switch of front Name Rear fog light switch Name Danger warning switch
Name
headlamp Code B34 Code B45
Code B31 Attached wire Attached wire
Attached wire harness Cab wire harness harness harness
Switch group on left side Switch group on left side of Position Middle of instrument desk
Position Position
of instrument desk instrument desk
80 JAC
Front right combination light

Name Name Front right combination light
Name Flasher adjusting motor
Code B55
Code B48 Code B54
Attached wire
Attached wire Attached wire Cab wire harness
Cab wire harness Cab wire harness harness
harness harness
Right side of front cross beam of
Position In cab electrical box Right side of front cross beam Position
Position chassis
of chassis
Name Front right left fog light Name Clock spring Name Diode
Attached wire harness Cab wire harness Attached wire harness Cab wire harness Attached wire Cab wire harness
Right side of front cross Rear steering column on harness
Position Position
beam of chassis left side of instrument desk Position Middle of instrument desk
JAC 81
Name Horn
Name Backup switch Name Left turning light
Code C70
Code C79 Code D02
Attached wire
Chassis wire harness Attached wire Chassis wire harness Attached wire left door wire harness
harness
harness harness
Middle position of front cross
Position Position Above rear side of gearbox Position Lower side of left door
beam of chassis
Name Right turning light Name Front left door light switch Name Front right door light switch
Code D03 Code F05 Code F07
Attached wire Right wire harness Attached wire Left floor wire harness Attached wire
Right floor wire harness
Position Lower side of right door Position Rear edge of front left door Position Rear edge of front right door
82 JAC
Name Rear left combination light Name Rear right combination light
Name Ceiling light
Code R10 Code R12
Code R04
Attached wire Attached wire
Attached wire Container wire harness terminal Container wire harness terminal
Ceiling light wire harness harness harness
harness
Left side of rear cross beam of Right side of rear cross beam of
Position Right above cab Position Position
chassis chassis
Cab and chassis wire harness jointing Cab and chassis wire harness Cab and chassis wire harness
Name Name Name
plug A jointing plug A jointing plug C
Chassis wire harness Cab wire harness Chassis wire harness
Position In front side cover plate of cab Position In front side cover plate of cab Position In front cover plate of cab
JAC 83
Cab and left door wire harness Cab and left door wire harness
Cab and chassis wire harness Name Name
Name jointing plug jointing plug
jointing plug C
Code DM01 Code DM01
Code CM04
Attached Attached wire
Attached wire left door wire harness Cab wire harness
Cab wire harness wire harness harness
harness
Below left side of instrument Below left side of instrument
Position In front cover plate of cab Position Position
desk desk
Cab and right door wire harness Cab and right door wire harness
Name Name Cab and left floor wire harness
jointing plug jointing plug Name
jointing plug
Code DM02 Code DM02
Code FM01
Attached Attached
Right door wire harness Cab wire harness Attached
wire harness wire harness Cab wire harness
wire harness
Below right side of instrument Below right side of instrument
Position Position Position Bottom left of instrument desk
desk desk
84 JAC
Cab and left floor wire harness Cab wire harness and right floor wire Cab wire harness and right floor
Name Name Name
jointing plug harness jointing plug wire harness jointing plug
Code FM01 Code FM02 Code FM02
Left floor wire harness Cab wire harness Right floor wire harness
Position Bottom left of instrument desk Position Below right side of instrument desk Position Below right side of instrument desk
Chassis and container wire harness Chassis and container wire harness
Name Name Cab and ceiling light wire harness
jointing plug jointing plug Name
jointing plug
Code SM01 Code SM01
Code RM01
Attached wire Attached wire
Chassis wire harness side Container wire harness terminal Attached wire
harness harness Cab wire harness
harness
On left side chassis frame of spare On left side chassis frame of spare
Position Position Position Below right side of instrument desk
tire tire
JAC 85
Cab and ceiling light harness

Name
jointing plug
Code RM01
Attached wire
Ceiling light wire harness
harness
Below right side of instrument
Position
desk
86 JAC
Circuit Diagram of Electric Door Window System 11
Power window switch of left door
Power window switch of right door

JAC 87
11 Circuit Diagram of Electric Door Window System

Attached Cab wire harness Attached Cab wire harness Attached Cab wire harness
wire harness wire harness wire harness

88 JAC
Circuit Diagram of Electric Door Window System 11
Name Power window switch of left door Name Power window switch of left door Name Power window switch of right
Code D05 Code D06 door
Attached wire Left door wire harness Attached wire Left door wire harness Code D09
harness harness Attached wire Right door wire harness
Position Lower side of left door Position Upper part of left door middle harness
part Position Lower side of right door
Name Power window switch of right Name Cab and left door wire harness Name Cab and left door wire harness
door jointing plug jointing plug
Code D10 Code DM01 Code DM01
Attached wire Right door wire harness Attached Left door wire harness Attached wire Cab wire harness
harness wire harness harness
Position Upper part of right door middle Position Below left side of instrument desk Position Below left side of instrument desk
part
JAC 89
11 Circuit Diagram of Electric Door Window System
Name Cab and right door wire Name Cab and right door wire
harness jointing plug harness jointing plug
Code DM02 Code DM02
Attached Right door wire harness Attached Cab wire harness
Position Below right side of instrument Position Below right side of instrument
desk desk
90 JAC
Circuit Diagram of Wiper and Washer System 12
Wiper main relay
JAC 91
12 Circuit Diagram of Wiper and Washer System
92 JAC
Circuit Diagram of Wiper and Washer System 12

Attached Cab wire harness Attached wire Cab wire harness Attached wire harness Cab wire harness
wire harness harness Position In cab electrical box
Position In cab electrical box Position In cab electrical box
Name B14 Windshield wiper Name Wiper motor

Name
Code B14 intermittent controller Code B52
Attached wire Code B49 Attached wire harness Cab wire harness
Cab wire harness
harness Attached wire In front of right
Cab wire harness
Position In cab electrical box harness Position lower side of
Middle part of right side of Instrument desk
Position
instrument desk
JAC 93
12 Circuit Diagram of Wiper and Washer System
Name Washing motor Name Right combination switch

Code B53 Code B57
Attached Cab wire harness Attached Cab wire harness
Position Below right side of instrument Position On steering column on left
desk side of instrument desk
94 JAC
Circuit Diagram of A/C system 13
JAC 95
13 Circuit Diagram of A/C system
Blower relay
Condenser fan motor
96 JAC

Name B05 Name B08 Name A/C control panel

Position In cab electrical box Position In cab electrical box Position Middle of instrument desk
JAC 97
Name A/C speed regulation switch Name Electronic thermostat Name Blower speed regulation resistance
Position Middle of instrument desk Position In cab electrical box Position Below right side of instrument
desk
Name Air blower Name Diode A Name A/C compressor

Code B51 Code B59 Code C76
Attached wire Cab wire harness Attached wire Cab wire harness Attached wire Chassis wire harness
Position Below right side of instrument Position Middle of instrument desk Position Right side of engine cylinder
desk body
98 JAC
Name Condenser fan motor Name A/C pressure switch Name Engine control unit
Attached wire Chassis wire harness Attached wire Chassis wire harness Attached wire Chassis wire harness
Position Left side of middle part of chassis Position Near condenser on middle part of Position Left side of engine
chassis
Name Engine control unit Name Chassis and engine wire harness Name Chassis and engine wire harness
Code E13 jointing plug jointing plug
Attached wire Engine wire harness Code EM01 Code EM01
harness Attached wire Engine wire harness Attached wire Chassis wire harness
Position Left side of engine harness harness
Position Left side of engine Position Left side of engine
JAC 99
Name Cab and chassis wire harness Name Cab and chassis wire harness
jointing plug C jointing plug C
Code CM04 Code CM04
Attached Chassis wire harness Attached Cab wire harness
Position In front cover plate of cab Position In front cover plate of cab
100 JAC
Circuit Diagram of ABS 14
Instrument
cluster Instrument cluster
B37-08
Front left wheel speed Front right wheel Rear left wheel speed Rear right wheel speed
sensor speed sensor sensor sensor
JAC 101
14 Circuit Diagram of ABS
Name Front left wheel speed sensor Name Front right wheel speed sensor Name Rear right wheel speed sensor
Attached wire Chassis wire harness Attached wire Chassis wire harness Attached wire Chassis wire harness
Position Front left wheel side Position Front right wheel side Position Rear left wheel inner side
Name Rear left wheel speed sensor Name ABS control unit Name Cab and chassis wire harness
Code C84 Code C95 jointing plug A
Attached wire Chassis wire harness Attached wire Chassis wire harness Code CM02
harness harness Attached wire Chassis wire harness
Position Rear left wheel inner side Position Rear side of front cross beam of harness
chassis Position In front side cover plate of cab
102 JAC
Circuit Diagram of ABS 14
Name Cab and chassis wire harness Name Cab and chassis wire harness Name Cab and chassis wire harness
jointing plug A jointing plug C jointing plug C
Attached wire Cab wire harness Attached wire Chassis wire harness Attached wire Cab wire harness
Position In front side cover plate of cab Position In front cover plate of cab Position In front cover plate of cab
JAC 103
ABS Maintenance Guide
Thanks for using APG ABS products. Before checking ABS, please
carefully read this "ABS Maintenance Guide”. If you have any doubt
during maintenance, please contact with APG. Telephone: 0571-82764676
ABS harness connector pin definition
Serial Number:APG-ABS-05
ABS harness connector
Page 1 of 1
Zhejiang Asia-Pacific
Mechanical &Electronic Co., Ltd
Pin definition
Pin NO. Pin function Parameter requirements

1 Leftward front wheel
Resistance R＝1300-2000Ω
2 sensor
3
4 MCU power supply Turning the ignition switch to “ON” could power to the 12 voltage (through 5A fuse).
5 Leftward rear wheel
6 sensor
7 K-line Signal line for failure diagnosis

8、24 Ground wire Connected to battery “-” pole.
9 Power supply of solenoid/relay is connected to the battery “+” (through 20A fuse).
Power wire
25 Power supply of ABS motor is connected to the battery “+” (through 20A fuse).
12V:ABS indicator lamp ON with on driving ability;
16 ABS lamp signal output
0V:ABS indicator lamp OFF, max. sink current: 10mA
With the ignition switch at “ON” gear, if the brake pedal is depressed, the 12V voltage can
18 Braking signal
be generated. Whereas releasing the pedal could disappear the voltage.
19 Rightward front wheel
20 sensor
22 Rightward rear wheel

23 sensor
17
25
10
9
1 2 3
Connector on failure diagnosis instrument and pin definition
Failure diagnosis instrument adopts ODB-II connector and has three invalid lines, namely Pin16 as the 12V power
supply “+”, 4 or 5 as the ground line and 7 or 9 as the signal line (pin function is depend on manufacture.)
Failure diagnosis instrument function

A: Read ECU information
The actuator-related information can be read under this command.
B: Read actuator failure information
The last failure code stored in actuator can be read under this command. If the ABS is at warning status before
diagnosis, current failure code can be read, or else the last failure code will appear.
C: Delete actuator failure information
The current failure code and all stored failure codes can be cleared under this command. If the failure is existed in
system, after it being repowered and self-checked, the related failure code will be developed and then stored.
D: Actuator unit test
Actuator operation will be tested under this command.
E: DataStream test
Four-wheel speed and parking status etc can be read under this function. Its initial value is 3Km/h.
F: Quit diagnosis function
The diagnosis function can be quitted under this command. After the failure is successfully cancelled, please select
this function to ensure failure is completely off.
ABS failure code, inspection area and method description

1. Sensors
Failure code and displayed information

Failure Failure description Displayed inspection area
Failure type
code displayed in Chinese
Leftward front
00283
wheel-speed signal
Rightward front
00285 Sensor connector, ABS harness connector,
wheel-speed signal Open Exceeding
harness, sensor clearance, ring gear, sensor , ECU
Leftward rear circuit tolerance range
00290 assembly
wheel-speed signal
Rightward rear
00287
wheel-speed signal
A: Vehicle-speed sensor signal open-circuit
Cause: the relative wheel-speed sensor resistance was too high, which had been detected by ABS system.
Troubleshooting:
Signal open-circuit of wheel-speed sensor
Remember the failure

code, clear it and then
quit diagnosis
Repower it to let the

failure code appear again
If it is previous failure
code, the troubleshooting
is over.
Deenergize it, extract the

main harness connector,
then use the multimeter to
measure the
failure-code-related sensor
resistance.
Dismantle the Disconnect the sensor

failure-code-related connector to measure its
sensor resistance.
Two persons apply 98N or less force

to pull the sensor at opposite Check the vehicle
Replace sensor
direction and simultaneously body harness
measure the sensor resistance.
Resistance is
normal
Replace sensor Consult APG
Repower it for self-check,

ABS warning lamp goes
out
Clear the failure code,

quit diagnosis
Troubleshooting is
over
Precautions:
I. Before replacing or dismantling the sensors, please carefully confirm vehicle
sensor layout. During operation, please take note of the sensor wiring around the
movable area. Too tight sensor wiring will snap the sensor harness during
vehicle traveling.
II. Please replace the snapped or damaged front-wheel-speed sensor probe, during
which the dust cover should be improved to prevent the gravel or mud from
getting in. Otherwise, the sensor probe will be damaged again.
III. Also replace the wear or impacted rear-wheel-speed sensor probe, during which
the clearance between the sensor probe and ring gear of wheel speed should be
checked for normal value and ensure no other part interferes the normal
clearance.
Note: the following picture is only used as reference, whereas the actual vehicle will prevail.
ABS connector
ABS assembly
Leftward front
sensor connector
Rightward front
sensor connector
Leftward
rear sensor
connector
Rightward
rear sensor
connector
1. Disconnect the sensor connector
Measure the resistance of main connector (leftward front

sensor pin is shown in picture.)
2. Check whether the multimeter is normal( if the knob

is turned to 2kΩ, 0kΩ should be displayed.)
4. Normal resistance of sensor (if the knob is turned to

3. The two pens should be respectively connected the two
2kΩ, please refer to “ABS harness connector pin
ends of sensor connector.
definition” for displayed value.)
B. Wheel-speed sensor signal exceeding tolerance range
Cause: the wheel-speed signal inputted into the related sensor was higher than or lower than other wheel-speed signal,
which had been tested by ABS system.
Troubleshooting:
Wheel-speed sensor signal exceeding tolerance range
Remember failure code,

clear it and then quit
diagnosis
Repower it and then the

failure will appear again
during vehicle traveling.
If it is previous failure code,

the troubleshooting is over.
Connect the diagnosis

instrument and enter into
"read datastream"
Straight travel at
constant speed
Remember wheel
speed that is different
Stop vehicle, shut down

engine and disconnect the
main harness connector
Check related sensor

for short-circuit, wear Replace sensor
probe or snap etc.
Check whether the vehicle harness

circuit is shorted. Check the sensor
clearance. Ensure the ring gear are
well installed with no tooth lost etc.
Dismantle Eliminate
related sensor related failure
Two persons apply 98N or less to pull

the sensor in opposite direction and
simultaneously measure the resistance
of sensor.
Measured
resistance value is
normal.
Replace sensor Consult APG
Repower it for self-check,

ABS warning lamp goes
out
Clear the failure code,

quit diagnosis
Troubleshooting is
over
How to effectively use the datastream test function of diagnosis instrument
A; Used to test the clearance between the wheel-speed sensor probe and ring gear.
Test principle: the clearance between the sensor probe and ring gear should be designed to be 0.3mm-0.7mm. The
machining accuracy or proper installation will lead to the deviation of clearance value. If current value is less than min.
limit, gear clash will occur (if not, it does not effect this system.); if current value is higher than max. limit, the more
highly the clearance value increases, the higher the min. value at which the wheel speed sensor can detect is.
Test method: start engine to connect the failure diagnosis instrument and enter into its datastream test function. When
vehicle is stopped, four-wheel speed will be initialized to be 0km/h, in such case, you can ignore the possible run-out of
wheel-speed data. The vehicle should straight travel on flat road by slowly releasing the clutch. Then the
four-wheel-speed date should simultaneously increase. The run-out range is allowed to be 1km/h. If one wheel speed is
greatly lower than that of other wheels, please increase the vehicle speed until the wheel reaches the normal speed, which
indicates the clearance of wheel sensor increases. The more highly the vehicle speed gets, the larger the sensor clearance
is. Under the same conditions, if the wheel speed stays the same rather than increases, that indicates the sensor clearance
is too large (such as the sensor is out of the mounting position) or the sensor harness is open-circuit or short-circuited.
B: Used to test the intermittent short-circuited or open-circuit wheel-speed sensor/harness.
Test principle: because of the relative displacement between the vehicle body and suspension caused by the sharp turn,
emergency accelerating or braking, any improper installation of sensor and harness will make them bear the pulling force,
which will cause the intermittent short circuit or open circuit. In such case, ABS-control computer will not receive the
wheel-speed signal for short time and then the computer will determine this wheel is locked or is to be locked. Under
non-diagnosis model, if conditions are met, ABS will automatically control the action. Therefore, during the datastream
test, the intermittent short-circuited or open-circuit wheel-speed sensor/harness will be analyzed by checking the logic
change of four-wheel speed.
Test method: start the engine to connect the failure diagnosis instrument and then enter into the datastream test function.
Under all kinds of traveling conditions, if some wheel speed suddenly drops by too high value, that indicates intermittent
short circuit or poor connection is existed.
2. Supply voltage of motor
Failure Failure description Failure Displayed inspection area
code displayed in Chinese type
Supply voltage of ABS Battery, accessory circuit for charging, motor fuse, connector,
00301 /
motor harness, HCU assembly ,ECU assembly
Supply voltage of motor (namely return pump)

Cause: supply voltage of motor was abnormal, which had been detected by ABS system.
Troubleshooting:
Remember the failure

code, clear it and quit
diagnosis
Repower it, and the

failure code will appear
again during traveling.
If it is previous failure code,

troubleshooting is over.
Deenergize it, extract Check the plug-in ABS

assembly for normal
main connector and operation.
measure the voltage.
Poorly Reconnect the ABS

Power supply harness of Motor fuse is
connected to motor is short-circuited or
assembly of original
blown vehicle, repower it for
ground poorly connected. self-check.
Ensure the Check the power

ground wire is supply harness of Replace motor fuse Replace ABS Replace ABS
well connected. motor assembly. assembly.
Repower it for
self-inspection, ABS
warning lamp goes out.
Clear the failure

code, quit diagnosis
Troubleshooting is
over
The left is ABS harness connector and the right is ECU plug, as Measure supply voltage of motor
shown in figure.
Display the measured voltage ( not less than 10V, the Selected voltage range (the recommended voltage range should
recommended range should not be less than 20V) be not less than 20V)
3. Supply voltage of solenoid valve relay
Failure Failure description displayed Failure Displayed inspection area
code in Chinese type
Battery, accessory circuit for charging, safety fuse, connector,
00302 Supply voltage of ABS valve /
harness, ECU assembly
Supply voltage of solenoid valve relay

Cause: supply voltage of solenoid valve relay was abnormal, which had been detected by ABS system.
Troubleshooting:
Supply voltage of solenoid valve relay
Remember the failure code,

diagnosis
Repower it and the failure

will appear during vehicle
traveling.
code, the troubleshooting
is over.
Deenergize it, extract

the main harness Use plug-in ABS
connector and then assembly for inspection
measure the voltage
Poorly
connected to Power supply harness of Relay fuse is Reconnect the ABS of
original vehicle for
ground
relay is poorly connected or
disconnected.
blown self-check
Ensure that Check the power

Replace the fuse of Replace the
ground wire is supply harness of Poorly connected
relay ABS assembly
well connected. relay
Repower it for
self-check, ABS warning
lamp goes out.
Clear the failure

code, quit diagnosis
Troubleshooting is
over
The left is ABS harness connector and the right is ECU plug, as Measure the supply voltage of solenoid valve relay.
shown in above figure.
Display the measured voltage（not less than 10V, Selected voltage range（it is recommended that the range is not
measurement range of 20V is recommended) less than 20V)
4. Battery voltage
Failure Failure description Displayed inspection area
Failure type
code displayed in Chinese
Battery, accessory circuit for charging, starting voltage change
00532 Battery voltage /
of generator, ECU assembly
Battery voltage
Cause: during ignition, battery voltage was not insufficient for long time, which had been detected by ABS system.
Troubleshooting:
Battery voltage
Remember failure code,

diagnosis
Repower it and then the

failure appears again
during traveling.
code, troubleshooting
will be over.
Measure the
battery voltage
Lower than Replace the

10V or not? battery
Measure battery
voltage during
startup
Lower than
10V or not?
Check whether the plug-in

ABS assembly is normal
Check whether the Reconnect the ABS of

ground wire is well original vehicle, repower
connected. it for self-inspection
Ensure the
Replace the Poorly
ground wire is
ABS assembly connected
well connected.
Power it for
self-inspection, ABS
warning lamp OFF
Cancel the failure code,

quit the diagnosis
Troubleshooting is
over
Supply voltage of
solenoid valve relay
5. Power-on failure with vehicle parked

Operation: stop vehicle and then turn the power supply switch from the OFF to ON.
Normal: ABS indicator lamp goes out after 2s. Abnormal: ABS indicator lamp constantly is ON.
Inspection procedures and points:
Step I: use the diagnosis instrument to read the failure code and failure type stored in the actuator and then clear the
failure code. If ABS indicator lamp constant is ON after vehicle is started, perform the step II and step III. If there is no
failure, carry out the step IV by using the diagnosis instrument.
Step II: if the read failure code is only “(00255)ECU coil drive failure”, please replace with new actuator.
Step III: according to the read failure code and failure type, use the multimeter to check the electric feature of faulted
part of ABS harness connector so as to locate the failure point.
Step IV: use the multimeter to check all electrical features of ABS harness connector so as to locate the fault point.
Repair finish: use the diagnosis instrument to clear the failure code stored in actuator again.
Phenomenon:
A: during step I, if failure diagnosis instrument or its wiring is normal but could not be connected, it is highly possible
not to power the ABS controller;
B: during step I, if what the failure diagnosis instrument reads is no failure, it is highly possible that the ABS indicator
lamp is out of ABS controller control. Check whether the partial harness between the output connector of ABS actuator
indicator lamp to instrument indicator lamp is well connected. With the switch turned to ON, respectively connect the
ABS harness connector 16 pin to 12V power supply and then to ground to check whether ABS indicator lamp is normal.
C: during step I, if what the failure diagnosis instrument reads is power supply voltage that will appear again if engine is
started after the failure code is cancelled, in such case, the ABS indicator lamp is not constantly ON or does not go on
during vehicle traveling, these indicate the power supply voltage is constantly low during ignition. Please troubleshoot
and this failure does not affect the ABS normal operation under traveling status.
6. Dynamic traveling failure

ABS is normal under power-on condition with vehicle parked, whereas the ABS indicator lamp will go on if vehicle
speed reaches to 10Km/h.
Inspection procedures and points:
Step I: stop vehicle, connect the diagnosis instrument and then use it to read the failure code and failure type stored in
actuator.
A: if the deviation value of sensor is high, it is highly possible that the sensor is short-circuited or clearance between the
sensor and ring gear is too high.
B: in case of failing to power the motor, it is highly possible that its power wire is poorly connected.
Step II: in case of sensor type failure, please connect the diagnosis instrument to perform the datastream test function.
Slowly release the clutch and then straight move the vehicle. After that, if one vehicle speed is obviously different from
other wheels, and its speed is zero at low-speed range and then becomes normal after vehicle speed is increased, this
indicates the clearance between this wheel sensor and ring gear is too large. Under the same conditions, if its speed
always stays at low speed, this indicates the wheel sensor harness is short-circuited. (For concrete method, please refer to
the application of datastream function)

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CityStar 3

Version No.[ JAC-2013050101N3301]

Main parameters of 1041 series trucks

Company Vehicle Type Main Code from

Company Code Name：HFC------represents JAC motor

World Manufacturer Identification

The mechanic performance table of bolts in China

Quality Grade( mark) 6.8 8.8 9.8 10.9 12.9

Yield limit σ s max (MPa) 480 640 720 940 1100

Corresponding to Hyundai standards 4T 6T 7T 8T 10T

1 steering wheel tightening nut

Perforation bolt： according to the

7 brake draw bench equipment

T206 series tire nut(inner)（M20X1.5） 518-598

T206 series tire nut(outer)（M30X1.5）

T4 series tire nut 540-670

11 front leaf spring pin N、T、Z：190-260

12 Rear leaf spring pin N、T、Z：190-260

13 front spring pin locking bolt

Rear spring pin locking bolt

Clutch platen bolt((10.9 class ）：

clutch 19 Clutch pipeline According to the pipe drawing

20 Cabin titling mechanism M10:41-51 M12:75-96 M16:182-222

22 Door locks 9-11

cabin 23 Safety belt M12：75-96

24 engine titling torsion arm

25 cabin support rod up M8:17-28 down M10:37-75

26 cabin front support bolt M14×1.5: 99-115

connection bolt of Cabin titling

28 electric plugs 6-8(wide cabin)

Chapter I Technical Characteristics of Engine .......................................................................................................... 11

Chapter I Technical Characteristics of Engine

Environment temperature Above 5℃ Above -5℃ Above -10℃ Above -25℃

The diesel filter embodies the fuel-water separation function:

II. Engine Oil

Notice: Make sure to horizontally park the vehicle while

Section II Main Technical Specification of Engine

Section III Performance Curve of Engine

Section IV Main Checking and Adjustment Parameters

Section V Tightening Torque for Critical Bolts of Engine

☆ Comparison Table of Tightening Torque for Critical Bolts

No. Description N．m

No. Description N．m

☆ Comparison Table for Standard Bolt Specification and Tightening Torque

M22×1.5 256~422 370~555 433~649

Section VI Main Fitting Clearances and Allowable Wear Limits of Engine

Outside diameter of tappet Φ13 −−00..010

Section VII Specification of Main Attachments and Accessories

Chapter II Maintenance for Main Structures of Engine

Section I Disassembly of Engine Assembly

II. Disassembly Procedure

2. Disassemble the belt, air conditioner

a. Use an open-end wrench to remove the fixing nuts of

3. Disassemble the exhaust system.

a. Disassemble the fixing bolts of turbocharger lubricating

b. Remove the exhaust pipe shield.

c. Remove the EGR cooler.

d. Remove the exhaust pipe and turbocharger assembly.

a. Loosen the conical nut at fuel injector end and the