EC 4JH1-T EL (Ver1) PDF

FOR SERVICE TRAINING
4JH1-T ENGINE
Engine Management System Operation & Diagnosis
Applicable Model
Model Year Vehicle Model Destination
2003, 2004 TFR/TFS Thailand
ISUZU MOTORS LIMITED

TFR/S 4JH1-T Engine V5 System - 1
INTRODUCTION & OUTLINE

1. Air Cleaner Case
2. Intake Air Temperature
(IAT) Sensor
3. Engine Coolant
Temperature (ECT)
Sensor
4. Engine Control Module
(ECM)
5. Fuel Injection Pump
6. EGR Valve
1 2 3 4 5 6
The 4JH1-T engine with direct injection and eight overhead valves. The hart of the system is a Denso V5
injection pump that can deliver injection pressure of up to 100MPa at delivery valves.
This engine management system is combination with EGR valve and catalytic converter has enabled to
meet Euro 2 (Thai Level 5) emission level.
FEATURE OF V5 INJECTION PUMP
With the worldwide increase in demand for further

restrictions on exhaust gas emissions, the level of
exhaust emission control performance demanded
from diesel engines and the injection pumps used
with them is becoming higher every year.
The electronically controlled high pressure injection
pump ECD-V5, newly introduced for use in direct
diesel engines, responds to such demands.
The high pressure injection pump itself carries
sensors and actuators as well as a memory with
pump specific data. The data in the pump ROM
(PROM) is adapted to the specific pump it is fitted to
and can not be replaced as separate component.
Another feature of this pump is a called solenoid spill
valve (SPV) that controls injection quantity. The
solenoid spill valve (SPV) has replaced of the
previously used control sleeve and is controlled by
high voltage driver inside the electrical drive unit
(EDU).
The engine control module (ECM) uses the timing
control valve (TCV) to control the injection timing.
1. Solenoid Spill Valve (SPV)

2. Timing Control Valve (TCV)
3. Cam Plate
4. Pump Camshaft Position (CMP) Sensor Pulser
5. Roller Ring
6. Pump Camshaft Position (CMP) Sensor
7. Fuel Temperature (FT) Sensor
8. Pump ROM
SYSTEM OUTLINE
The engine control system is made up of the following electrical components: sensors, engine control
module (ECM), electrical drive unit (EDU) and actuators.
1. Sensors
Measure the engine conditions and driving conditions electronically and send output electrical signals to
engine control module (ECM).
2. ECM
Receive the electrical signals from the sensors and output electrical signals to actuators and EDU.
3. EDU
According to the electrical signal from the ECM, produce the high electrical current and send output to
the solenoid spill valve (SPV) to perform the fuel injection.
Injection Volume Control Schematic

1. Various Sensor Inputs
2. ECM
3. EDU
4. Pump ROM
6. To Injection Nozzle
Injection Timing Control Schematic

1. Various Sensor Inputs
2. ECM
3. Pump ROM
5. Timer Piston
ENGINE CONTROL MODULE
The engine control module (ECM) is located on the

cylinder head cover via the bracket. There are two
types of different control modules. One is for
automatic transmission and another is for manual
transmission. They have another engine control
calibration each other to perform optimum engine
running.
The ECM achieves the following functions.
1. Fuel Injection Volume Control

Calculate optimum fuel injection volume based on
engine speed and accelerator position and etc. to
control the solenoid spill valve (SPV).
2. Fuel Injection Timing Control

Control the electrical signal to drive the timing control
J1 Port J2 Port valve (TCV), depending on the engine conditions, to
have the optimum fuel injection timing.
3. Idling Speed Control

Always secure the stable state of the engine idling
speed even if the engine condition changes.
4. Idling Vibration Control

Reduce engine vibration due to cylinder-to-cylinder
torque fluctuation caused by cylinder-to-cylinder
variation in fuel injection amount and nozzle opening
pressure.
5. Exhaust Gas Re-Circulation Control

Control the rate of exhaust gas to recirculate to
reduce NOx.
6. Fail Safe Function

Control the engine with the values memorized in the
ECM if any failure occurs in system components.
7. Diagnosis Function
Memorize failures in parts or control systems if any
failure occurs in system components, and let a driver
or a serviceman know the existence of failures.
The engine control module (ECM) constantly
monitors the data form various sensors. It controls
the systems that affect vehicle performance. And it is
designed maintain exhaust emission levels and fuel
efficiency. And it performs the diagnostic function of
the system. The function can recognize operational
problems, and warn to the driver through the check
engine lamp. And store diagnostic trouble code
(DTC). DTCs identify the problems to aid the
technician in making repair.
ELECTRICAL DRIVE UNIT
The electrical drive unit (EDU) is located on the

engine cylinder block left side back of the fuel
injection pump via a bracket. The EDU is an engine
controller that controls the solenoid spill valve (SPV)
on the injection pump. It improves response of the
solenoid spill valve (SPV) by high voltage and high
electrical current. Because the engine is two stage
combustion that performed low emission.
The EDU communicates with the engine control
module (ECM). A broken or loose EDU may be
unstable engine speed or engine stall because the
EDU decides the actual fuel injection.
3 EDU Internal
1. Battery Voltage Feed
2. ECM
3. EDU
1 4 6
4. DC/DC Converter
5. Control Circuit
5 6. Solenoid Spill Valve (SPV)
2
A The EDU terminal 22 receives the injection

command signal from the ECM terminal J1-34. To
confirm this command signal has been given to the
solenoid spill valve (SPV), the ECM terminal J1-33
receives a feed back signal from the EDU terminal 25
CH1 for every injection.
0V
CH1: Feedback Signal / CH2: Command Signal

Measurement Terminal: CH1: J1-33(+) / CH2: J1-34(+)
CH2 GND(-)
0V
Measurement Scale: CH1: 5V/div / CH2: 5V/div
10ms/div
Measurement Condition: Engine Idle Speed (A)
Approximately 2000rpm (B)
B
CH1
0V
CH2
0V
Related DTC
Symptom
Code DTC Name DTC Setting Condition Fail-Safe (Back Up) Suspected Cause
Code
P0251 8 EDU/SPV System The phase between SPV relay off. z EDU command signal is open circuit.
Error command signal from z EDU feedback signal is open circuit,
ECM and return signal short to ground or short to battery or
from EDU is wrong ignition voltage.
width. z EDU malfunction.
z ECM malfunction.
P1630 1 SPV Output Signal SPV operating signal SPV relay off. z EDU command signal is short to ground.
Stuck High (EDU feedback signal) z EDU malfunction.
high stuck fail is z ECM malfunction.
present.
2 SPV Output Signal SPV operating signal z EDU command signal is short to battery
Stuck Low (EDU feedback signal ) or ignition voltage.
low stuck fail is present. z EDU malfunction.
z ECM malfunction.
BREAKER BOX
The engine control module (ECM) and other
connectors have water proof connector and special
terminal. Waterproof terminal does not allow to use
back prove. In addition, the ECM special terminal
can not let regular digital voltage meter prove to
1 access, because terminal shape is very fin pin type.
In order to prevent damage of female terminal and
2 connector itself, the breaker box and adapter is the
3 most suitable special tool.
1. Breaker Box
2. Harness Adapter
3. Engine Control Module (ECM)
Breaker Box Connection Type "A" for Open Circuit

Check, Short to Ground Check and Short to Battery
Check.
Breaker Box Connection Type "B" for Power, Signal

Check Between the ECM and Electrical
Components.
ECM CONNECTOR PIN ASSIGNMENT & OUTPUT SIGNAL
J01 Port: View Looking Into ECM Case
Signal or Continuity Tester Position

B/Box Wire Engine ECM
Pin No. Pin Function Key SW Off Key SW On Engine Idle Range (+) (-)
No. Color 2000rpm Connection
Approx.
Approx.
Pump Camshaft Position Sensor 67Hz by
J01-01 1 RED - - 23Hz by Connect AC V 1 17
(+) wave form or
wave form
approx. 0.9V
J01-02 2 No Connection - - - - - - - - -
J01-03 3 No Connection - - - - - - - - -
J01-04 4 No Connection - - - - - - - - -
J01-05 5 No Connection - - - - - - - - -
J01-06 6 No Connection - - - - - - - - -
J01-07 7 No Connection - - - - - - - - -
J01-08 8 No Connection - - - - - - - - -
EGR #1 is not operated:

EGR Vacuums Solenoid Valve WHT/ Less than 10 - 14V
J01-09 9 10 - 14V Connect DC V 9 GND
#1 RED 1V EGR #1 is operated: Less
than 1V
EGR #2 is not operated:

EGR Vacuums Solenoid Valve WHT/ Less than 10 - 14V
J01-10 10 10 - 14V Connect DC V 10 GND
#2 BLK 1V EGR #2 is operated: Less
than 1V
J01-11 11 No Connection - - - - - - - - -
J01-12 12 No Connection - - - - - - - - -
J01-13 13 No Connection - - - - - - - - -
Less than
J01-14 14 MAP Sensor Power Supply GRN Approx. 5V Connect DC V 14 62
1V
J01-15 15 No Connection - - - - - - - - -
J01-16 16 No Connection - - - - - - - - -
Pump Camshaft Position Sensor Continuity

J01-17 17 GRN - - - Connect Ohm 17 GND
(-) with ground

J01-18 18 No Connection - - - - - - - - -
J01-19 19 No Connection - - - - - - - - -
J01-20 20 No Connection - - - - - - - - -
J01-21 21 No Connection - - - - - - - - -
J01-22 22 No Connection - - - - - - - - -
Approx.
Approx.
67Hz by
J01-23 23 Crank Position Sensor Signal WHT - - 23Hz by Connect AC V 23 GND
wave form or
wave form
approx. 1.4V
J01-24 24 No Connection - - - - - - - - -
SPV relay is
Less than
J01-25 25 Timing Control Valve (TCV) YEL activated: 10 Wave form Connect DC V 25 GND
1V
- 14V
WHT/ Less than

J01-26 26 EGR EVRV 10 - 14V Wave form Connect DC V 26 GND
ORN 1V
J01-27 27 No Connection - - - - - - - - -
MT: 2.3 -
2.6V at EGR
1.6 - 1.9V at
presser 53 -
GRN/ Less than EGR
J01-28 28 EGR Pressure Sensor Signal Approx. 4.8V 58Kpa / AT: Connect DC V 28 113
YEL 1V pressure 40
4.7 - 4.9V at
- 45Kpa
EGR presser
98 - 102Kpa
J01-29 29 No Connection - - - - - - - - -
J01-30 30 No Connection - - - - - - - - -
J01-31 31 No Connection - - - - - - - - -
J01-32 32 No Connection - - - - - - - - -
Electrical Drive Unit (EDU

J01-33 33 VIO - - Wave form Connect AC V 33 GND
Return)
Electrical Drive Unit (EDU
J01-34 34 BRN - - Wave form Connect AC V 34 GND
Command)
J01-35 35 No Connection - - - - - - - - -
J01-36 36 No Connection - - - - - - - - -
Continuity
J01-37 37 ECM Ground BLK - - - Connect Ohm 37 GND
with ground
Continuity
J01-38 38 ECM Ground BLK - - - Disconnect Ohm 38 GND
with ground
J01-39 39 No Connection - - - - - - - - -
J01-40 40 No Connection - - - - - - - - -
Fuel Temperature (FT) Sensor WHT/ Less than 25deg. C: Approx. 3.3V / 40 deg. C:
J01-41 41 Connect DC V 41 45
Signal GRN 1V Approx. 2.6V
Engine Coolant Temperature Less than 25deg. C: Approx. 3.7V / 50 deg. C:

J01-42 42 WHT Connect DC V 42 45
(ECT) Sensor Signal 1V Approx. 2.5V / 80 deg. C: Approx. 1.2V
J01-43 43 No Connection - - - - - - - - -
J01-44 44 No Connection - - - - - - - - -

Fuel Temperature (FT) & Engine

Continuity
J01-45 45 Coolant Temperature (ECT) GRY - - - Disconnect Ohm 45 GND
with ground
Sensor (5 Volt Return)
J01-46 46 No Connection - - - - - - - - -
J01-47 47 No Connection - - - - - - - - -
J01-48 48 No Connection - - - - - - - - -
ORN/
J01-49 49 PUMP PROM - - - - - - - -
GRN
ORN/
J01-50 50 PUMP PROM - - - - - - - -
BLU
J01-51 51 No Connection - - - - - - - - -
J01-52 52 No Connection - - - - - - - - -
J01-53 53 No Connection - - - - - - - - -
Continuity
with ground
Continuity
with ground
J01-56 56 No Connection - - - - - - - - -
J01-57 57 No Connection - - - - - - - - -
Less than Approx.

J01-58 58 MAP Sensor (Signal) GRN Approx. 2.3V 2.3 - 2.7V Connect DC V 58 62
1V 2.3V
J01-59 59 No Connection - - - - - - - - -
Intake Air Temperature (IAT) GRN/ Less than

J01-60 60 25deg. C: Approx. 3.6V Connect DC V 60 113
Sensor Signal RED 1V
J01-61 61 No Connection - - - - - - - - -
Continuity
J01-62 62 MAP Sensor (5 Volt Return) GRY - - - Connect Ohm 62 GND
with ground
J01-63 63 No Connection - - - - - - - - -
J01-64 - No Connection - - - - - - - - -
J02 Port: View Looking Into ECM Case

RED/ Less than

J02-01 64 ECM Main Relay 10 - 14V Connect DC V 64 GND
GRN 1V
RED/
J02-02 65 Battery Voltage Feed 10 - 14V Connect DC V 65 GND
WHT
Throttle Position Sensor #1 Less than

J02-03 66 YEL Approx. 5V Connect DC V 66 GND
Power Supply 1V
J02-04 67 No Connection - - - - - - - - -
J02-05 68 No Connection - - - - - - - - -
J02-06 69 No Connection - - - - - - - - -
A/C Compressor Relay (A/T GRN/

J02-07 70 Less than 1V Connect DC V 70 GND
Only) RED
J02-08 71 No Connection - - - - - - - - -
J02-09 72 No Connection - - - - - - - - -
J02-10 73 No Connection - - - - - - - - -
Approx.
Approx.
23Hz by
Engine Speed Output Signal (To BLK/ 67Hz by
J02-11 74 - - wave form Connect AC V 74 GND
Tachometer) RED wave form or
or approx.
approx. 6.1V
6.0V
J02-12 75 No Connection - - - - - - - - -
J02-13 76 No Connection - - - - - - - - -
Throttle Position Duty Signal to RED/ Approx. 100Hz by wave form (Idle: Off
J02-14 77 - - - - -
TCM (A/T Only) WHT duty 10% / WOT: Off Duty 90%)
BLU/
J02-15 78 ECM Main Relay 10 - 14V Less than 1V Connect DC V 78 GND
RED
BLK/
J02-16 79 Spill Valve Relay 10 - 14V Less than 1V Connect DC V 79 GND
GRN
RED/ Less than

J02-17 80 ECM Main Relay 10 - 14V Connect DC V 80 GND
GRN 1V
J02-18 81 No Connection - - - - - - - - -

RED/
J02-19 82 Battery Voltage Feed 10 - 14V Connect DC V 82 GND
WHT
EGR Pressure Sensor Power Less than

J02-20 83 GRN Approx. 5V Connect DC V 83 113
Supply 1V
J02-21 84 No Connection - - - - - - - - -
J02-22 85 No Connection - - - - - - - - -
ECM main
relay is
activated:
Less than
WHT/
J02-23 86 Intake Solenoid Valve 1V / ECM 10 - 14V Connect DC V 86 GND
BLU
Main Relay
is not
activated:
10 - 14V
J02-24 87 No Connection - - - - - - - - -
J02-25 88 No Connection - - - - - - - - -
J02-26 89 No Connection - - - - - - - - -
J02-27 90 No Connection - - - - - - - - -
J02-28 91 No Connection - - - - - - - - -
RED/ Less than In reverse: 10 -14V

J02-29 92 Transmission Reverse Switch Connect DC V 92 GND
YEL 1V Other than reverse: Less than 1V
J02-30 93 No Connection - - - - - - - - -
J02-31 94 No Connection - - - - - - - - -
BRN/ Less than Lamp is turned on: Less than 1V

J02-32 95 Check Engine Lamp Connect DC V 95 GND
YEL 1V Lamp is turned off: 10 - 14V
Throttle Position Sensor #2 (5 Continuity

J02-33 96 RED - - - Disconnect Ohm 96 GND
Volts Return) with ground
J02-34 97 No Connection - - - - - - - - -

J02-35 98 WHT Approx. 5V Connect DC V 98 96
Power Supply 1V

J02-36 99 BLK Approx. 0.2 - 0.4V 0.3 - 0.6V Connect DC V 99 96
(Signal) 1V

J02-37 100 GRN Approx. 0.2 - 0.4V 0.7 - 1.1V Connect DC V 100 112
(Signal) 1V
J02-38 101 No Connection - - - - - - - - -
J02-39 102 No Connection - - - - - - - - -
Speed Meter (Vehicle Speed) BLK/ Approx. 14.5Hz by wave form or approx.
J02-40 103 - Connect AC V 103 GND
Signal YEL 6.3V at vehicle speed 20km/h
J02-41 104 No Connection - - - - - - - - -
J02-42 105 No Connection - - - - - - - - -


J02-43 106 No Connection - - - - - - - - -
RED/ Less than In neutral (A/T: P or N): 10 - 14V / Other

J02-44 107 Neutral Switch Connect DC V 107 GND
GRN 1V than neutral (A/T: P or N): Less than 1V
A/C request switch is turned on: 10 - 14V

GRN/ Less than
J02-45 108 A/C Request Signal / A/C request switch is turned off: Less Connect DC V 108 GND
BLK 1V
than 1V
J02-46 109 No Connection - - - - - - - - -
J02-47 110 No Connection - - - - - - - - -
J02-48 111 No Connection - - - - - - - - -
Throttle Position Sensor #1 (5 Continuity

J02-49 112 BLU - - - Disconnect Ohm 112 GND
Volts Return) with ground
EGR Pressure and Intake Air

Continuity
J02-50 113 Temperature (IAT) Sensor (5 GRY - - - Disconnect Ohm 113 GND
with ground
Volts Return)
J02-51 114 No Connection - - - - - - - - -
WHT/ Less than

J02-52 115 Key Switch 10 - 14V Connect DC V 115 GND
GRN 1V
J02-53 116 No Connection - - - - - - - - -
J02-54 117 Data Link Connector GRN - - - - - - - -
J02-55 118 No Connection - - - - - - - - -
J02-56 119 No Connection - - - - - - - - -
J02-57 120 No Connection - - - - - - - - -
J02-58 121 No Connection - - - - - - - - -
J02-59 122 No Connection - - - - - - - - -
J02-60 123 No Connection - - - - - - - - -
BLK/ Less than

J02-61 124 Diagnosis Check Switch 10 - 14V Connect DC V 124 GND
GRN 1V
J02-62 125 No Connection - - - - - - - - -
J02-63 126 No Connection - - - - - - - - -
J02-64 - No Connection - - - - - - - - -
EDU CONNECTOR PIN ASSIGNMENT & OUTPUT SIGNAL MEASUREMENT
View Looking Into EDU Case

B/Box Wire Engine EDU
SPV relay is
not activated:
BLK/ Less than Less than 1V
4 - Spill Valve Relay 10 - 14V Connect DC V 4 GND
RED 1V SPV relay is
activated: 10
- 14V
SPV relay is
not activated:
BLK/ Less than Less than 1V
7 - Spill Valve Relay 10 - 14V Connect DC V 7 GND
RED 1V SPV relay is
activated: 10
- 14V
Continuity
12 - EDU Ground BLK - - - Disconnect Ohm 12 GND
with ground
BLK/ Approx. 1 -
14 - Spill Valve (+) - - - Disconnect Ohm 14 20
WHT 2 Ohm
Continuity
17 - EDU Ground BLK - - - Disconnect Ohm 17 GND
with ground
BLK/
20 - Spill Valve (‐) - - Wave form Connect - - -
BLU
EDU Command Signal from Continuity

22 34 BRN - - - Disconnect Ohm 22 34
ECM J1-34 with ECM
EDU Return Signal to ECM J1- Continuity
25 33 VIO - - - Disconnect Ohm 25 33
33 with ECM
TFR/S 4JH1-T Engine V5 System -15
ELECTRICAL COMPONENTS
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR
The manifold absolute pressure (MAP) sensor is a

strain gage. A pressure strains the resistance on the
silicon base. At that time the resistance value
changes. And it changes voltage. In other word it
measures a pressure value. It is installed to the
intake manifold. Output voltage of the MAP sensor is
low as pressure is low. The engine control module
(ECM) monitors the voltage on the signal line and
calculates a fuel volume of main injection, an
injection timing.
Characteristic of MAP Sensor -Reference- The characteristic of the MAP sensor is displayed in
5
the graph. Calculated absolute pressure can be
4.5 found on the Tech 2 by unit KPa. Also, output voltage
can be found on the Tech 2, which is measured on
4 the ECM terminal J1-58. Note that the ignition key
Output Voltage (V) (Tech 2 Reading)
3.5
On position with engine not run condition, it will be
displayed nearly barometric pressure. When the
3 engine is idle speed, it will be displayed slight
vacuum condition.
2.5
Ignition On: Approximately 100KPa & 2.3volt
2
Idle speed at 700rpm (After warm-up):
1.5
Approximately 98kPa & 2.2volts
2000rpm (No-load): Approximately 101KPa & 2.4volts
1
0.5
0
20 40 60 80 100 120 140 160 180 200
Manifold Absolute Pressure (KPa) (Tech 2 Reading)
MAP Sensor Pin Assignment

View Looking Sensor Side Connector 1. MAP Sensor Low Reference to ECM Terminal J1-62
2. MAP Sensor Output Signal to ECM Terminal J1-58
3. MAP Sensor +5V Reference from ECM J1-14
3
Related DTC
Symptom
Code
P0105 1 MAP Sensor Circuit MAP sensor output The ECM uses 110 Kpa z +5V reference circuit is short to battery or
High Voltage voltage is more than condition as substitute. ignition voltage.
4.98V. z Signal circuit is short to battery or ignition
voltage.
z Low reference circuit is open circuit.
z Sensor internal circuit is open circuit or
short circuit.
z ECM malfunction.
2 MAP Sensor Circuit MAP sensor output z +5V reference circuit is open circuit,
Low Voltage voltage is less than 0.05 short to ground circuit.
V. z Signal circuit is open circuit, short to
ground circuit.
z Sensor harness connector is poor
connection.
short circuit.
z ECM malfunction.
INTAKE AIR TEMPERATURE (IAT) SENSOR
The intake air temperature (IAT) sensor is installed to

the intake duct. It is a variable resistor. The IAT
sensor measures the temperature of the air entering
the engine. The engine control module (ECM)
supplies 5-volts to the IAT signal circuit and a ground
for the IAT low reference circuit. When the IAT sensor
is cold, the sensor resistance is high. When the air
temperature increases, the sensor resistance
decreases. With high sensor resistance, the ECM
detects a high voltage on the IAT signal circuit. With
lower sensor resistance, the ECM detects a lower
voltage on the IAT signal circuit.
The ECM uses to this value to calculate a fuel
volume of main injection, an injection timing.
The characteristic of the IAT sensor is displayed in

Characteristic of IAT Sensor -Reference-
100,000 the graph. Calculated intake air temperature can be
found on the Tech 2 by unit deg. C or deg. F. The
output voltage can be measured on the ECM
terminal J1-60.
10,000
20deg. C: Approximately 3.8volts
Reistance (Ohm)
1,000
100
10
-40 -20 0 20 40 60 80 100 120 140
Temperature (deg. C)
IAT Sensor Pin Assignment

View Looking Sensor Side Connector 1. IAT Sensor Output Signal to ECM Terminal J1-60
2. IAT Sensor Low Reference to ECM Terminal J2-50
2
Related DTC
Symptom
Code
P0110 1 Intake Air IAT sensor output The ECM uses 60 deg. z Signal circuit is open circuit, short to
Temperature (IAT) voltage is more than C condition as battery or ignition voltage.
Sensor Circuit High 4.92 V. substitute. z Low reference circuit is open circuit.
Voltage z Sensor internal is open circuit.
connection.
z ECM malfunction.
2 Intake Air IAT sensor output z Signal circuit is short to ground circuit.
Temperature (IAT) voltage is less than 0.04 z Sensor internal circuit is short circuit.
Sensor Circuit Low V. z ECM malfunction.
Voltage
ENGINE COOLANT TEMPERATURE (ECT) SENSOR
The engine coolant temperature (ECT) sensor is

installed to the coolant stream on the thermo housing.
It is a variable resistor. The ECT sensor measures
the temperature of the engine coolant. The engine
control module (ECM) supplies 5-volts to the ECT
signal circuit and a ground for the ECT low reference
circuit. When the ECT sensor is cold, the sensor
resistance is high. When the air temperature
increases, the sensor resistance decreases. With
high sensor resistance, the ECM detects a high
voltage on the ECT signal circuit. With lower sensor
resistance, the ECM detects a lower voltage on the
ECT signal circuit.
injection volume, injection timing and EGR control,
etc.
Characteristic of ECT Sensor -Reference- The characteristic of the ECT sensor is displayed in
100,000 the graph. Calculated coolant temperature can be
found on the Tech 2 by unit deg. C or deg. F. The
output voltage can be measured on the ECM
terminal J1-42.
10,000
Reistance (Ohm)

1,000
100
10
-40 -20 0 20 40 60 80 100 120 140
View Looking Sensor Side Connector

ECT Sensor Pin Assignment
1. ECT Sensor Low Reference to ECM Terminal J1-45
2. ECT Sensor Output Signal to ECM Terminal J1-42
2
Related DTC
Symptom
Code
P0115 1 Engine Coolant ECT sensor output The ECM uses 80 deg. z Signal circuit is open circuit, short to
Temperature (ECT) voltage is more than C condition as battery or ignition voltage.
Sensor Circuit High 4.92 V. substitute. z Low reference circuit is open circuit.
Voltage z Sensor internal is open circuit.
connection.
z ECM malfunction.
2 Engine Coolant ECT sensor output z Signal circuit is short to ground circuit.
Temperature (ECT) voltage is less than 0.04 z Sensor internal circuit is short circuit.
Sensor Circuit Low V. z ECM malfunction.
Voltage
FUEL TEMPERATURE (FT) SENSOR
The fuel temperature (FT) sensor is installed to the

injection pump assembly. It is a variable resistor. The
FT sensor measures the temperature of the fuel. The
engine control module (ECM) supplies 5-volts to the
FT signal circuit and a ground for the FT low
reference circuit. When the FT sensor is cold, the
sensor resistance is high. When the air temperature
increases, the sensor resistance decreases. With
high sensor resistance, the ECM detects a high
voltage on the FT signal circuit. With lower sensor
resistance, the ECM detects a lower voltage on the
FT signal circuit.
injection volume.
The characteristic of the FT sensor is displayed in

Characteristic of FT Sensor -Reference-
100,000 the graph. Calculated fuel temperature can be found
on the Tech 2 by unit deg. C or deg. F. The output
voltage can be measured on the ECM terminal J1-
41.
10,000
Reistance (Ohm)

1,000
100
10
-40 -20 0 20 40 60 80 100 120 140

FT Sensor Pin Assignment
1. FT Sensor Low Reference to ECM Terminal J1-45
2. FT Sensor Output Signal to ECM Terminal J1-41
2
Related DTC
Symptom
Code
P0180 1 Fuel Temperature FT sensor output The ECM uses 40 deg. z Signal circuit is open circuit, short to
(FT) Sensor Circuit voltage is more than C condition as battery or ignition voltage.
High Voltage 4.89 V. substitute. z Low reference circuit is open circuit.
z Sensor internal is open circuit.
connection.
z ECM malfunction.
2 Fuel Temperature FT sensor output z Signal circuit is short to ground circuit.

(FT) Sensor Circuit voltage is less than 0.04 z Sensor internal circuit is short circuit.
Low Voltage V. z ECM malfunction.
CRANKSHAFT POSITION (CKP) SENSOR
The crankshaft position (CKP) sensor is installed to

the engine front cover and fixed with a bolt. The CKP
sensor uses a hall element. It outputs two pulse
signals per 360 deg. crankshaft angle. The engine
control module (ECM) monitors the TDC (Top Dead
Center) of the cylinder and calculates a timing of
injection.
Calculated signal can be found on the Tech 2 as

engine speed unit RPM. The reference waveform of
the CKP sensor is displayed on the left. The output
signal can be measured on the ECM terminal J1-23.
Measurement Terminal: J1-23(+) GND(-)

0V Measurement Scale: 2V/div 10ms/div
Measurement Condition: Approximately 2000rpm
CKP Sensor Pin Assignment

1. CKP Sensor Low Reference to Engine Ground
2. CKP Sensor Output Signal to ECM Terminal J1-23
3. CKP Sensor +12V Feed from ECM Main Relay
1
2
3
Related DTC
Symptom
Code
P0335 4 Crankshaft Position No or missing pulse TCV feed back control z CKP sensor harness open circuit, short
Sensor No Signal detected consecutively. disabled. to ground or short to voltage circuit.
z Poor connector connection.
z CKP sensor malfunction.
z Pulse sensing gap incorrect.
z Pulser malfunction.
z Electrical interference.
z Magnetic interference.
z ECM malfunction.
8 Crankshaft Position Incorrect pulse detected z CKP sensor harness open circuit, short
Sensor Insufficient consecutively. to ground or short to voltage circuit.
Activity z Poor connector connection.
z ECM malfunction.
PUMP CAMSHAFT POSITION (CMP) SENSOR
The pump camshaft position (CMP) sensor is

installed to the injection pump assembly. It uses to
combine with the pulser ring, which is attached to the
main shaft of the injection pump. The pulser ring has
51 hollows with 3 missing at 3 locations and 4
missing at 1 location, enabling the pulser rotation
angle to be detected at 11.25 deg. CA intervals. The
engine control module (ECM) counts electric pulses
and calculates fuel injection timing.
Pump Camshaft Position (CMP) Sensor

1. Permanent Magnet
2. Coil
3. Pulser Ring
4. No Pulser Part (Missing Part)

injection pump speed unit RPM. The reference
waveform of the pump CMP sensor is displayed on
the left CH1. The output signal can be measured on
CH1
0V
the ECM terminal J1-1.
This analogue pump CMP sensor signal is converted
by the ECM into a square wave signal as displayed
on the left CH2. This signal is sent from the ECM
CH2 terminal J2-11 to the tachometer in the instrument
0V cluster, transmission control module (TCM) and
transfer case control module (TCCM).
CH1: Pump CMP Sensor / CH2: Engine Speed Signal

Measurement Terminal: CH1: J1-1(+) / CH2: J2-11(+)
GND(-)
Measurement Scale: CH1: 2V/div / CH2: 10V/div
5ms/div
Note that engine speed display in the Tech 2 means

CKP sensor output signal. However, engine speed
signal from the ECM to other components is based
on pump CMP sensor output signal.
Pump CMP Sensor Pin Assignment

View Looking Sensor Side Connector 1. CMP Sensor (-) to ECM Terminal J1-17
2. CMP Sensor (+) to ECM Terminal J1-1
Related DTC
Symptom
Code
P0370 4 Pump Camshaft Incorrect or no pulse The ECM uses CKP z CMP sensor harness open circuit, short
Sensor No Signal detected consecutively. signal as substitute and to ground or short to voltage circuit.
uses throttle position z Poor connector connection.
between 6.5 and 20%. z CMP sensor malfunction.
z ECM malfunction.
VEHICLE SPEED (VS) SENSOR
The vehicle speed (VS) sensor is a magnet rotated

M/T 2WD, 4WD & A/T 4WD
by the transmission output shaft. The VS sensor
uses a hall element. It interacts with the magnetic
field treated by the rotating magnet. It outputs pulse
signal. The 12-volts operating supply from the
“meter” fuse. The engine control module (ECM)
calculates the vehicle speed by the VS sensor.
The 2WD model fitted with automatic transmission,
vehicle speed sensor signal is transmitted from the
transmission control module (TCM) to the ECM via
the speed meter.
A/T 2WD

vehicle speed unit km/h or MPH. The reference
waveform of the VS sensor is displayed on the left.
The output signal can be measured on the ECM
terminal J2-40.
0V
Measurement Scale: 5V/div 50ms/div
Measurement Condition: Approximately 20km/h
VS Sensor Pin Assignment

View Looking Sensor Side Connector (M/T 2WD, 4WD & A/T 4WD model)
(M/T 2WD, 4WD & A/T 4WD) 1. VS Sensor +12V Feed from IG SW via Meter Fuse
2. VS Sensor Low Reference to Engine Ground via
Speed Meter
3. VS Sensor Output Signal to ECM Terminal J2-40
(A/T 2WD model)

1 1. VS Sensor Output Signal to TCM Terminal B-13
2 2. VS +12V Feed from Back Up Fuse
3 3. VS Sensor Low Reference to Engine Ground via
(A/T 2WD) Speed Meter
Related DTC
Symptom
Code
P0500 1 Vehicle Speed z Vehicle speed is The ECM controls z VSS signal circuit open, short to ground
Sensor Signal Too more than 240 km/h. 20km/h condition as or short to voltage circuit.
High z Fuel quantity is less substitute. z VSS malfunction.
than 5 mm3/st. z Speed meter malfunction.
z TCM malfunction (AT 2WD).
z ECM malfunction.
4 Vehicle Speed z Vehicle speed is 0 z VSS signal circuit open, short to ground
Sensor Signal km/h. or short to voltage circuit.
Circuit Too Low z Engine speed is more z VSS malfunction.
than 1600 rpm. z Speed meter malfunction.
z Clutch switch is not z TCM malfunction (AT 2WD).
fail. z ECM malfunction.
z Other than neutral
gear.
z Fuel quantity is more
than 36 mm3/st.
8 Vehicle Speed z Other than neutral z VSS signal circuit open, short to ground
Sensor Insufficient gear. or short to voltage circuit.
Activity z VSS signal error. z VSS malfunction.
z Speed meter malfunction.
z ECM malfunction.
THROTTLE POSITION SENSOR (TPS)
The throttle position sensor (TPS) is mounted on the

throttle body assembly. The sensor is made up of two
individual sensors within one housing. The engine
control module (ECM) compares both output signals.
As the throttle valve opens, the output voltage
increases so that the output voltage should be high.
The ECM calculates engine load based on the
throttle position and engine speed and controls fuel
injection volume, an injection timing.
Characteristic of TPS -Reference- The characteristic of the TPS 1 & 2 is displayed in

5
the graph. Calculated throttle angle can be found on
4.5 the Tech 2 by unit %. Also, output voltage can be
found on the Tech 2, which is measured on the ECM
4 terminal J2-36 & J2-37.
Output Voltage (V) (Tech2 Reading)
3.5 Position 0%: Approximately 0.59volts on TPS1

TPS 1
Approximately 0.27volts on TPS2
3
Position 50%: Approximately 1.80volts on TPS1
2.5
Approximately 0.88volts on TPS2
Position 100%:Approximately 3.20volts on TPS1
2 Approximately 1.58volts on TPS2
TPS 2
1.5
0.5
0
0 10 20 30 40 50 60 70 80 90 100
Throttle Position (%) (Tech2 Reading)
10ms
The analogues TPS signal is converted by the ECM
into a pulse wave signal (100Hz Duty Signal). This
Voltage
converted signal is sent from the ECM terminal J2-14

to the transmission control module (TCM) terminal
A-16.
Time
1ms
Throttle Position 0%: Off Duty 10%
Throttle Position 50%: Off Duty 50%
10ms Throttle Position 100%: Off Duty 90%
Voltage
Time
9ms
TPS Pin Assignment

View Looking Sensor Side Connector 1. TPS 1 Output Signal to ECM Terminal J2-37
TPS 1 TPS 2 2. TPS 1 +5V Reference from ECM Terminal J2-3
3. TPS 1 Low Reference to ECM Terminal J2-49
4. TPS 2 +5V Reference from ECM Terminal J2-35
5. TPS 2 Low Reference to ECM Terminal J2-33
6. TPS 2 Output Signal to ECM Terminal J2-36
1 4
2 5
3 6
Related DTC
Symptom
Code
P1120 1 Throttle Position TPS 1 output voltage The ECM uses 7 % (AT) z TPS 1 +5V reference circuit is short to
Sensor 1 High more than 4.93 V. or 5 % (MT) condition as battery or ignition voltage.
Voltage substitute. z TPS 1 signal circuit is short to battery or
ignition voltage.
z TPS 1 low reference circuit is open
circuit.
z TPS 1 internal circuit is open circuit or
short circuit.
z ECM malfunction.
Note: TPS 1 is internal to TPS assembly.
4 Throttle Position TPS 1 output voltage z TPS 1 +5V reference circuit is open
Sensor 1 Low less than 0.202 V. circuit, short to ground.
Voltage z TPS 1 signal circuit is open circuit, short
to ground.
z TPS 1 harness connector is poor
connection.
short circuit.
z ECM malfunction.
8 Throttle Position TPS 1 signal error in z TPS 1 signal circuit is high resistance.
Sensor 1 comparison with TPS 2. z TPS Malfunction.
Insufficient Activity z ECM malfunction.
Note: TPS 1 & TPS 2 are internal to TPS

assembly.
P1122 1 Throttle Position TPS 2 output voltage The ECM uses 7 % (AT) z TPS 2 +5V reference circuit is short to
Sensor 2 High more than 4.93 V. or 5 % (MT) condition as battery or ignition voltage.
Voltage substitute. z TPS 2 signal circuit is short to battery or
ignition voltage.
circuit.
short circuit.
z ECM malfunction.
4 Throttle Position TPS 2 output voltage z TPS 2 +5V reference circuit is open
Sensor 2 Low less than 0.202 V. circuit, short to ground.
Voltage z TPS 2 signal circuit is open circuit, short
to ground.
connection.
short circuit.
z ECM malfunction.
8 Throttle Position TPS 2 signal error in z TPS 2 signal circuit is high resistance.
Sensor 2 comparison with TPS 1. z TPS Malfunction.
Insufficient Activity z ECM malfunction.
Note: TPS 1 & TPS 2 are internal to TPS

assembly.
FUEL INJECTION & TIMING CONTROL

FUEL PRESSURE FEED AND INJECTION CONTROL
SOLENOID SPILL VALVE (SPV) CONTROL
The solenoid spill valve (SPV) is located in the
middle of the passage connecting the pump chamber
and the plunger pressure chamber. The valve is a
normal open type by the operation of the spool spring
(return spring) in the solenoid spill valve, and closes
when its coil is energized. A direct acting solenoid
valve has been adopted to achieve high response
and high spilling performance.
1. Valve Body
2. Spool Valve
3. Spring
4. Coil
5. Core
6. Armature
7. Spill Port
8. Fuel Return
9. Plunger
View Looking Valve Side Connector Solenoid Spill Valve (SPV) Pin Assignment
1. Solenoid Spill Valve (SPV) (-) to EDU Terminal 14
2. Solenoid Spill Valve (SPV) (+) to EDU Terminal 20
2
Suction Process
When the plunger moves down, the fuel enters the
pressure chamber.
Distribution Port: Closed

Solenoid Spill Valve (SPV): Open (No Energized)
1- a. Solenoid Spill Valve (SPV) (Open)

2. Roller
3. Face Cam Plate
4. Pump Chamber
5. Plunger
6. Distribution Port
7. Pressure Chamber
8. Injection Nozzle
Injection Process
Turning and rising, the plunger compresses and
feeds the fuel.
Distribution Port: Closed

Solenoid Spill Valve (SPV): Closed (Energized)
1-b. Solenoid Spill Valve (SPV) (Closed)

2. Roller
3. Face Cam Plate
End of Injection Process

As soon as the solenoid spill valve (SPV) is
deenergized, it opens. The pressurized fuel
remaining in the plunger chamber is compressed
back to the pump chamber, completing the pressure
feed cycle.
Distribution Port: Open

Solenoid Spill Valve (SPV): Open (No Energized)
1-a. Solenoid Spill Valve (SPV) (Open)

2. Roller
3. Face Cam Plate
Fuel Cutoff Process

While the fuel cutoff process, the current does not
flow to the solenoid spill valve, thus allowing the spill
port to remain open. Therefore, the fuel is not
pumped even when the plunger ascends.
FUEL INJECTION QUANTITY CONTROL

Correcting the basic fuel injection quantity calculated
based on the engine condition (accelerator pedal
opening, engine speed, etc.) in response to the
engine coolant temperature, fuel temperature, intake
air temperature and manifold pressure, etc., the
engine control module (ECM) transmits the optimum
output signal to the solenoid spill valve (SPV) via
electrical drive unit (EDU). The pump ROM on the
pump outside, it memories correction data for
injection quantity and timing to establish a high
precision for compensate pump deviation.
1. Various Sensor Inputs (MAP Sensor, TP Sensor,

CMP Sensor, ECT Sensor, FT Sensor, IAT Sensor)
2. ECM
3. EDU
4. Pump ROM
6. To Injection Nozzle
The cam position of the cam plate determines the

fuel injection start timing. Fuel injection stops after
the solenoid spill valve (SPV) is deenergized (open)
and the pressurized fuel spills out (is released) into
the pump chamber. Consequently, the ECM controls
the fuel injection quantity by adjusting the fuel
injection end timing.
1-a. Solenoid Spill Valve (Open)

2. Roller
3. Face Cam Plate
1. Start of Injection
2. End of Injection
3. Injection
4. Fuel Injection Volume Increase
5. Cam Lift
7. Cylinder
SOLENOID SPILL VALVE OPENING TIMING

1. Pump Camshaft Position
(CMP) Sensor Signal
Command
3. SPV Close
4. SPV Open
5. Plunger Lift (Cam Lift)
6. Pilot Injection Angle
7. Main Injection Angle
8. Pilot Injection
9. Main Injection
The pump camshaft position (CMP) sensor is used to

determine the solenoid spill valve (SPV) opening
timing. The cam angle that corresponds to cam lift is
determined as follows.
z The cam lift is determined by the rotation angle of

the rotor, which rotates in one unit with the pulser,
and this rotation is in turn detected by the pump
CMP sensor.
z The rotation angle of the rotor is detected by the

rotation angle of pulser, which can be determined
from the pump CMP sensor signal output (signal
pulse per the cam angle of 11.25 deg.).
z The engine control module (ECM) uses the pump

CMP sensor signal output to determine the
solenoid spill valve (SPV) opening timing
(injection end timing) by the number of teeth.
1 Actual solenoid spill valve (SPV) operation and

0V relation to the pump CMP sensor and command
signal are visible on the left waveform.
2 1. Crankshaft Position (CKP) Sensor Signal

0V 2. Pump Camshaft Position (CMP) Sensor Signal
4. Solenoid Spill Valve (SPV) Command Signal form
ECM
Measurement Terminal: 1:J1-23(+) / 2:J1-1(+) /

3:EDU20(+) / 4:J1-34(+) GND(-)
3 Measurement Scale: 1:5V/div / 2:500mV/div /
0V 3:50V/div / 4:5V/div 2ms/div
4
0V
PILOT INJECTION
A B To realize the engine noise reduction at low engine
speed, pilot injection is applied to this system. The
pilot injection is only activated around the engine idle
CH1
0V speed.
The CH1 on the left waveform shows the engine
control module (ECM) command signal to the
electrical drive unit (EDU). According to this signal,
the EDU actuates the solenoid spill valve (SPV) as
CH2. The first pulse (A) is pilot injection. After
CH2 approximately 16ms, next pulse (B) is sent for main
0V injection.
Measurement Terminal: CH1:J1-34 (+) / CH2:EDU20(+)

GND(-)
Measurement Scale: CH1: 5V/div / CH2:50V/div
5ms/div
PUMP ROM
The V5 injection pump is fitted with a programmable
read only memory (ROM) to establish a high
precision. Due to unavoidable pump component
variations, deviations in the timing control as well as
the fuel quantity control occur. To compensate for
these manufacturing deviations, correction data is
memorized in the pump test bench at the factory.
The information of correction data is sent from the
pump ROM (PROM) to the engine control module
(ECM) via a serial communication line. This
communication is done only when the ignition switch
is turned On during a short period.
View Looking PROM Side Connector

Pump ROM (PROM) Pin Assignment
1. PROM +5V Reference from ECM Terminal J1-50
2. PROM Low Reference to Engine Ground
2 1 3. Not Used
4. PROM Output Signal to ECM Terminal J1-49
4 3
Related DTC
Symptom
Code
P0505 3 SPV System High z Engine idling z The ECM controls z EDU/SPV harness open or short circuit.
(*1) Idle RPM (Positive condition. fuel quantity based z SPV malfunction.
Divination) z Engine rpm error on default value (limit z EDU malfunction.
(Engine idle speed - fuel quantity ; 15 z ECM malfunction.
Desired engine mm3/st ).
speed ) is more than z The ECM stops idling
180 rpm. feedback.
Above conditions are
met for 30 seconds.
5 SPV System Low z Engine idling z The ECM controls z EDU/SPV harness open or short circuit.
Idle RPM (Negative condition. fuel quantity based z SPV malfunction.
Divination) z Engine rpm error on default value (limit z EDU malfunction.
( Desired engine idle fuel quantity ; 25 z ECM malfunction.
speed - engine mm3/st ).
180 rpm. feedback.
met for 30 seconds.
P1651 0 Pump ROM z Data line anytime low. PROM communication z PROM harness open circuit, short to
(*2) Communication z Data line anytime disabled. ground circuit, short to battery or ignition
Error high. voltage circuit.
z Start pattern error. z PROM malfunction.
z Parity error. z ECM malfunction.
Stable one of above
conditions is detected
10 continuous cycle.
(*1): P0505 does not recover in the same ignition cycle. To verify the repair, the vehicle should be operated at
least three (3) ignition cycles. (One cycle: Key Off - Key On - Engine On in idle for 30 seconds – Key Off)
least eleven (11) ignition cycles. (One cycle: Key Off - Key On - Engine On in idle for 30 seconds – Key Off)
FUEL INJECTION TIMING CONTROL
The engine control module (ECM) calculates the

desired fuel injection timing from various sensor
inputs and transmits a signal to the timing control
valve (TCV) to determine the optimum fuel injection
timing.
7. Various Sensor Inputs (MAP Sensor, TP Sensor,

CKP Sensor, CMP Sensor, ECT Sensor, IAT Sensor)
8. ECM
9. Pump ROM
11. Timer Piston
TIMING CONTROL VALVE (TCV)

The timing control valve (TCV) is installed in the fuel
injection pump. According to the signals from the
engine control module (ECM), the valve open/close
the fuel passage between the timer piston high-
pressure chamber side (4) and low-pressure
chamber side (5). When the coil (3) is energized, the
spring (2) is compressed by moving core (1), thus the
fuel passage opens. Current that flows to the stator
core is duty controlled by ECM, and as longer the ON
time (time which ECM terminal TCV is grounded),
the longer is the length of the valve opening time.
1. Moving Core
4 2. Spring
3. Coil
5 4. From High Pressure Chamber
5. To Low Pressure Chamber (Timer Piston)
The timing control valve opening is controlled by the

ratio of ON/OFF duration (duty ratio) of the current
supplied to the coil by the ECM.
A longer ON duration produces a longer valve
1 opening duration.
0V 1. Longer On Duty (Timer Advance)

2. Shorter On Duty (Timer Retard)
Measurement Scale: 10V/div 10ms/div
2
0V
TCV Pin Assignment

View Looking Valve Side Connector 1. +12V Feed from SPV Relay
2. Duty Signal Control to ECM Terminal J1-25
INJECTION TIMING CONTROL METHOD

1. Fuel Inlet
2. Orifice
3. Roller Ring
4. Pump Inner Pressure
Chamber
5. Timer High Pressure
Chamber
6. Timer Piston
7. Timer Low Pressure
Chamber
8. Timing Control Valve
(TCV)
9. ECM
10. Timer Advance
11. Timer Retard
To control the injection timing, the fuel pressure of

the timer low-pressure chamber (7) that is applied to
the timer piston (5) is regulated by varying the length
of time in which the timing control valve (TCV) (8) is
open, thus moving the roller ring (3). When the length
of time in which the TCV (8) is open is long, the
volume of fuel that bypasses from the pump inner-
pressure chamber (4) to the timer low-pressure
chamber (7) increases, causing the pressure in the
timer low-pressure chamber (7) to increases. As a
result, the timer piston (6) moves in the retard
direction (11). When the length of time in which the
TCV (8) is open is short, the timer piston moves in
the advance direction (10).
CALCULATION OF FUEL INJECTION TIMING

The injection timing is controlled by changing the
position of timer piston and the cam ring connected
with it (the position determines the injection start
timing). Since the injection start timing advances with
the injection end timing, the injection quantity is not
affected by changes in the injection start timing. The
pump camshaft position (CMP) sensor is installed to,
and therefore moves with the cam ring. Even when
the cam ring position is changed, the relationship
between the cam lift and pump cam position pulses
(a relationship that affects the injection quantity
control) keeps the constant.
1. Pump Camshaft Position (CMP) Sensor

2. Pulser (51 teeth)
3. No Pulser Section
4. Timer Piston
5. Roller Ring
6. Drive Shaft
The actual injection timing is determined by the

following method.
On the engine side, the compression TDC position
has a relationship with the crankshaft position (CKP)
sensor signal. On the pump side, the injection
waveform has a relationship with the pump cam shaft
position (CMP) pulses. The actual injection timing,
therefore is determined by calculating the phase
difference 1 between the CKP sensor signal and
pump CMP sensor signal.
1. Actual Engine Top Dead Center (TDC)

2. Crankshaft Position (CKP) Sensor Signal
3. Pump Camshaft (CMP) Sensor Signal
4. Injection Waveform
5. Engine Side
6. Injection Pump Side
Related DTC
Symptom
Code
P0216 1 TCV Control z Request signal is Off z The ECM controls z TCV harness short to battery or ignition
(*1) System High from ECM. final fuel quantity voltage.
Voltage z Actual output signal is based on default z TCV malfunction.
On. value ( Final fuel z ECM malfunction.
quantity less than 25
3 TCV Control z TCV duty output is mm3/st). z TCV harness malfunction.
System Malfunction more than 0%. z TCV solenoid z TCV malfunction.
Fuel Timing z Timing error (desired- disabled. z ECM malfunction.
Positive Deviation final) is more than -10 z Injection pump timing device malfunction.
deg. CA.
met for 40 seconds.
4 TCV Control z Request signal is On z TCV harness open circuit or short to

System Low from ECM. ground circuit.
Voltage z Actual output signal is z TCV malfunction.
Off. z ECM malfunction.
5 TCV Control z TCV duty output is z TCV harness malfunction.

System Malfunction less than 255%. z TCV malfunction.
Fuel Timing z Timing error (desired- z ECM malfunction.
Negative Deviation final) is more than 10 z Injection pump timing device malfunction.
deg. CA.
met for 40 seconds.
least three (3) ignition cycles. (One cycle: Key Off - Key On - Engine On in idle for 30 seconds – Key Off)
EGR (EXHAUST GAS RE-CIRCULATION)

The exhaust gas re-circulation (EGR) system
reduces the temperature of the combustion
temperature. This results in reducing nitrogen oxide
(NOx) emissions. The amount of EGR is controlled
by two EGR valves which is operated by vacuum
control through the two vacuum switching valve
(VSV) and a electrical vacuum regulating valve
(EVRV). The engine control module (ECM) sends
electrical signals to the VSV #1, #2 and EVRV
depending on following inputs.
z Engine speed
z Coolant temperature
z Fuel injection quantity
z Throttle position
The system is activated from engine coolant

temperature more than 20deg. C. And, it will be
started from engine idle speed.
EGR System Construction Parts

1. VSV #1
2. VSV #2
3. EVRV
4. EGR Pressure Sensor
5. Front EGR Valve
6. Rear EGR Valve
7. ECM
8. Vacuum Pump
9. Vacuum Hose with Blue Stripe
10. Vacuum Hose with White Stripe
EGR VSV
EGR vacuum switching valve (VSV) is located on the

right side engine compartment. There are two VSV
are existing on this system. VSV #1 has responsible
to front EGR valve together with EVRV. VSV #2 has
responsible to rear EGR valve. Both VSV are On/Off
switching type valve.
View Looking VSV Side Connector

VSV #1 Pin Assignment
1. +12V Feed from ECM Main Relay
2. Solenoid Control to ECM Terminal J1-9
VSV #2 Pin Assignment

View Looking VSV Side Connector 1. +12V Feed from ECM Main Relay
2. Solenoid Control to ECM Terminal J1-10
EGR EVRV
EGR electric vacuum regulating valve (EVRV) is also

located on the right side engine compartment. The
EVRV is shaped to control vacuum applied to the
diaphragm chamber of the EGR valve based on duty
signal sent from the ECM. The duty ratio is the time
that the EVRV is opened to one EVRV operating
cycle. A duty ratio change of 0% to appropriate
percentage is EGR valve lift control.
EVRV Pin Assignment

View Looking EVRV Side Connector 1. +12V Feed from ECM Main Relay
2. Duty Signal Control to ECM Terminal J1-26
EGR PRESSURE SENSOR
The EGR pressure sensor is a strain gage. A

pressure strains the resistance on the silicon base.
At that time the resistance value changes. And it
changes voltage. In other word it measures a
vacuum pressure value. It is installed to the vacuum
hose between VSV #1 and front EGR valve. Output
voltage of the EGR pressure sensor is low as
pressure is low. The engine control module (ECM)
monitors the voltage on the signal line to feed back
the applied vacuum pressure to the front EGR valve
via the EVRV control.
When the accelerator pedal is stepped on, the EVRV
operating duty changes to control the EGR valve lift.
If the EVRV operating duty indicated 0%, the EGR
pressure will be displayed barometric pressure
(approximately 100KPa at sea level).
Characteristic of EGR Pressure Sensor -Reference-

The characteristic of the EGR pressure sensor is
5 displayed in the graph. Calculated EGR valve control
vacuum pressure can be found on the Tech 2 by unit
4.5 KPa. Also, output voltage can be found on the Tech 2,
which is measured on the ECM terminal J1-28. Note
4
that the engine with key On position, it will displayed
Output Voltage (V) (Tech 2 Reading)
3.5 nearly barometric pressure. And, it will close to

manifold absolute pressure (MAP) sensor reading
3 pressure.
2.5 Ignition On: Approximately 100KPa & 4.75volts

Idle speed at 700rpm (After warm-up):
2
Approximately 42KPa & 1.7volts
1.5
0.5
0
15 30 45 60 75 90 105
Manifold Absolute Pressure (KPa) (Tech 2 Reading)

EGR Pressure Sensor Pin Assignment
1. Sensor Low Reference to ECM Terminal J2-50
2. Sensor Output Signal to ECM Terminal J1-28
3. Sensor +5V Reference from ECM J2-20
3
Related DTC
Symptom
Code
P0400 1 EGR EVRV Circuit EGR EVRV circuit short z EVRV disabled. z EGR EVRV circuit short to voltage circuit.
Signal Too High to voltage circuit. z The ECM controls z EGR EVRV malfunction.
EGR pressure 25 z ECM malfunction.
KPa condition as
substitute.
4 EGR EVRV Circuit EGR EVRV circuit open z EGR EVRV circuit open or short to
Signal Too Low or short to ground ground circuit.
circuit. z EGR EVRV malfunction.
z ECM malfunction.
P0405 1 EGR Valve EGR valve pressure z EGR disabled. z Disconnected EGR hose.
Pressure Sensor sensor output voltage is z The ECM controls z +5V reference circuit is short to battery or
Circuit High Voltage more than 4.98 V (104.4 EGR pressure 25 ignition voltage.
Kpa). Kpa condition as z Signal circuit is short to battery or ignition
substitute. voltage.
z Low reference circuit is open circuit.
short circuit.
z ECM malfunction.
4 EGR Valve EGR valve pressure z +5V reference circuit is open circuit,
Pressure Sensor sensor output voltage is short to ground circuit.
Circuit Low Voltage less than 0.48 V (11.3 z Signal circuit is open circuit, short to
Kpa). ground circuit.
connection.
short circuit.
z ECM malfunction.
P1404 1 EGR VSV 1 Circuit EGR VSV 1 circuit short EGR VSV 1 disabled. z EGR VSV 1 circuit short to voltage
Signal Too High to voltage circuit. circuit.
z EGR VSV 1 malfunction.
z ECM malfunction.
4 EGR VSV 1 Circuit EGR VSV 1 circuit open z EGR VSV 1 circuit open or short to
circuit. z EGR VSV 1 malfunction.
z ECM malfunction.
P1405 1 EGR VSV 2 Circuit EGR VSV 2 circuit short EGR VSV 2 disabled. z EGR VSV 2 circuit short to voltage
Signal Too High to voltage circuit. circuit.
z ECM malfunction.
4 EGR VSV 2 Circuit EGR VSV 2 circuit open z EGR VSV 2 circuit open or short to
circuit. z EGR VSV 2 malfunction.
z ECM malfunction.
DIAGNOSIS WITH TECH 2

IF NO CODES ARE SET
Refer to F1: Data Display and identify the electrical faults that are not indicated by trouble code.
Refer to "SYMPTOM DIAGNOSIS".
IF CODES ARE SET

1. Record all trouble codes displayed by Tech 2 and check id the codes are intermittent.
2. Clear the codes.
3. Drive the vehicle for a test to reproduce the faulty status.
4. Check trouble codes again using the Tech 2.
5. If no codes is displayed by test driving, the fault is intermittent. In this case, refer to "DIAGNOSIS
AIDS".
6. If a code is present, refer to DTC Chart for diagnosis.
7. Check trouble codes again using the Tech 2.
TECH 2 CONNECTION
1. PCMCIA Card
2. Loop Back Connector
3. SAE 16/19 Connector
4. DLC Cable
5. Tech2
Data Link Connector Location

TECH 2 OPERATING FLOW CHART (START UP)
Press “ENTER” key. Select “(TF/UC)”.
Select “F0: Diagnostic”. Select “F0: Powertrain”.
Select “(3) 2003” or later. Select “4JH1-T Denso”.
Select “4JH1-T Denso” in Vehicle Identification menu and the following table is displayed in the Tech 2
screen.
F0: Diagnostic Trouble Code

F0: Diagnostic Trouble Code The purpose of the "Diagnostic Trouble Codes"
F0: Read DTC Infor By Priority mode is to display stored trouble code in the ECM.
F1: Read DTC Infor As Stored By ECU When "Clear DTC Information" is selected, a "Clear
F2: Clear DTC Information
DTC Information", warning screen appears. This
screen informs you that by cleaning DTC's "all stored
F1: Data Display
DTC information in the ECM will be erased". After
F2: Snapshot clearing codes, confirm system operation by test
driving the vehicle.
F3: Miscellaneous Test
F0: EGR Pulse Ratio Test F1: Data Display
F1: Engine Speed (RPM) Control The purpose of the "Data Display" mode is to
F2: Injection Timing continuously monitor data parameters.
F3: Spill Valve Relay Test The current actual values of all important sensors
and signals in the system are display through F1
F4: Programming mode. See the "Typical Scan Data" section.
F0: Program VIN
F1: Lock ECU F2: Snapshot
"Snapshot" allows you to focus on making the
condition occur, rather than trying to view all of the
data in anticipation of the fault.
The snapshot will collect parameter information
around a trigger point that you select.
F3: Miscellaneous Test:

The purpose of "Miscellaneous Test" mode is to
check for correct operation of electronic system
actuators.
F4: Programming (Factory Use Only)

The purpose of "Programming" is to program VIN in
the ECM and lock the programmed data.
* Symptom Code
Read DTC Infor As Stored By ECU This number or alphabet means identification of the
malfunction. Each DTC includes plural symptoms,
P0105 Present such as DTC P0105 has two kinds of symptom code
(1) Manifold Absolute Pressure (MAP) (1) and (2). DTC chart (check procedure) is
Sensor Circuit High Voltage
separated depending on the symptom code.
Symptom Code
MISCELLANEOUS TEST
The state of each circuit can be tested by using
miscellaneous test menus. Especially when DTC
cannot be detected, a faulty circuit can be diagnosed
by testing each circuit by means of these menus.
Even DTC has been detected, the circuit tests using
these menus could help discriminate between a
mechanical trouble and an electrical trouble.
Connect Tech 2 and select "Powertrain", "4JH1-T
Denso” & "Miscellaneous Test".
F0: EGR Pulse Ratio Test

When the Tech 2 is operated, "EGR Pulse Ratio"
increases to 95% or decreases to 5%. The circuit is
normal if the "EGR Pressure" is changed in
accordance with this operation.
1. Press "Active" key. Then, EGR valve pulse ratio is

changed. (EGR pressure is changed at the same
time)
2. Press "Inactive" key. Then, EGR valve pulse ratio
is changed. (EGR pressure is changed at the
same time)
3. Press "Quit" Key.
F1: Engine Speed (RPM) Control

When the Tech 2 is operated, "Desired Engine Idle
Speed" increases or decreases 50rpm-by-50rpm.
The circuit is normal if engine speed is changed in
1. Press "Increase" key. Then, desired engine idle

speed is increases 50rpm-by-50rpm. (Engine
speed and final fuel rate are changed)
2. Press "Decrease" key. Then, desired engine idle
speed is decreases 50rpm-by-50rpm. (Engine
speed and final fuel rate are changed)
F2: Injection Timing

When the Tech 2 is operated, TCV duty ratio
increases or decreases 5%-by-5%. The circuit or
TCV is normal if "Fuel Injection Timing" is changed in
1. Press "Increase" key. Then, fuel injection timing is

retarded step-by-step. (Engine sound is changed)
2. Press "Decrease" key. Then, fuel injection timing is
advanced step-by-step. (Engine sound is
changed)
F2: Spill Valve Relay Test

When the Tech 2 is operated, SPV relay signal turns
ON or OFF. The circuit is normal if clicking sound is
generated in accordance with this operation when
key switch is turned ON.
1. Press "Active" key. Then, spill valve relay is

activated. (Engine can start)
2. Press "Inactive" key. Then, spill valve relay is
deactivated. (Engine stops immediately)
TYPICAL SCAN DATA & DEFINITIONS

Use the typical values table only after the On-Board Diagnostic System check has been completed, no
DTC(s) were noted, and you have determined that the On-Board Diagnostic are functioning properly.
Tech2 values from a properly running engine may be used for comparison with the engine you are
diagnosing.
Condition: Vehicle stopping, engine running, air conditioning off & after warm-up (Coolant temperature
80-85 deg. C, Intake air & fuel temperature 25-30 deg. C)
Tech 2 Parameter Units Idle 1500rpm 2000rpm Description
This displays the key switch status indicated by

On12V/ the ECM with key switch signal. This should
1 Ignition Status On 12V On 12V On 12V
Off0V display "Off 0V" at key OFF and "On12V" at key
ON.
This displays the system voltage measured by

2 System Voltage V 10 - 15 10 - 15 10 - 15
the ECM at ignition feed.
This displays the air conditioner request signal.

3 A/C Request On/Off Off Off Off This should display "On" when the air
conditioner switch is switched on.
This displays operating status for the Check

4 Check Engine Lamp On/Off Off Off Off Engine Lamp. This should display "On" when
the Check Engine Lamp is turned on.
This displays operating status for the ECM main

Active/
5 Main Relay Active Active Active relay. This should display "Active" when the key
Inactive
switch is turned on and while engine is running.
This displays operating status for the spill valve

Active/ relay. This should display "Active" when the key
6 Spill Valve Relay Active Active Active
Inactive switch is turned on and while engine is running.
The TPS 1 output voltage is displayed. This data

7 Throttle Position Sensor 1 V 0.5 - 0.7 0.7 - 0.9 0.7 - 1.1
is changing by accelerator operating angle.
The TPS 2 output voltage is displayed. This data

8 Throttle Position Sensor 2 V 0.2 - 0.4 0.3 - 0.5 0.3 - 0.6
is changing by accelerator operating angle.
Throttle position operating angle is measured by

the ECM from throttle position output voltage 1 &
9 Throttle Position Sensor % 0 6-8 9 - 12 2. This should display 0% at idle and 99 - 100%
at full throttle.
The MAP sensor output voltage is displayed.

10 Manifold Absolute Pressure V 2.1 - 2.5 2.1 -2.5 2.2 - 2.7
This data is changing by inlet manifold pressure.
The MAP (Kpa) is measured by ECM from MAP

11 Manifold Absolute Pressure Kpa 97 - 102 100 - 105 102 - 108 output voltage. This data is changing by inlet
manifold pressure.
The ECT sensor output voltage is displayed.

This data is changing by coolant temperature.
12 Engine Coolant Temperature V 1.1 - 1.35 1.1 - 1.35 1.1 - 1.35 When the coolant temperature is cold, output
voltage is high. When the coolant temperature is
hot, out put voltage is low.
Tech 2 Parameter Units Idle 1500rpm 2000rpm Description

The ECT is measured by ECM from ECT sensor
output voltage. This data is changing by coolant
deg. C /
13 Engine Coolant Temperature 80 – 85 80 - 85 80 - 85 temperature. When the engine is normally warm
deg. F
upped, this data displays approximately 80 deg.
C.
The IAT is measured by ECM from IAT sensor

deg. C /
14 Intake Air Temperature 25- 30 25- 30 25- 30 output voltage. This data is changing by intake
deg. F
air temperature.
The FT is measured by ECM from FT sensor

deg. C /
15 Fuel Temperature 25 - 30 25 - 30 25 - 30 output voltage. This data is changing by fuel
deg. F
temperature.
EGR EVRV Duty Cycle 60 - 65 48 - 52 48 - 52 This displays the duty signal from the ECM to
16 %
Value of ( ) shows AT model. (60 - 65) (0) (0) control the EGR flow amount.
The EGR pressure sensor output voltage is

EGR Pressure 1.6 - 1.9 2.3 - 2.6 2.3 - 2.6
17 V displayed. This data is changing by EVRV
Value of ( ) shows AT model. (1.6 - 1.9) (4.7 - 4.9) (4.7 - 4.9)
operation.
The EGR pressure (Kpa) is measured by ECM

EGR Pressure 40 - 45 53 - 58 53 - 58
18 Kpa from EGR pressure output voltage. This data is
Value of ( ) shows AT model. (40 - 45) (98 - 102) (98 - 102)
changing by EVRV operation.
This displays calculated actual injection timing

based on CKP signal and pump cam signal. The
19 Fuel Injection Timing deg. CA 25 - 29 25 - 29 30 - 33
ECM controls TCV duty ratio to meet desired
injection timing from the ECM.
This displays desired injection timing from the

ECM. The ECM compensates for fuel injection
20 Desired Fuel Injection Timing deg. CA 25 - 29 25 - 29 30 - 33
timing by throttle position and various sensor
signal.
The final fuel rate (fuel quantity) is made from

basic quantity, full quantity and deceleration
21 Final Fuel Rate Mm3/stk 6-9 7 - 10 7 - 11
value. This displays commanded value from the
ECM.
This displays injection pump speed. The

22 Injection Pump Speed rpm 337 - 363 720 - 755 995 - 1005 injection speed is measured by ECM from the
pump cam sensor.
The engine speed is measured by ECM from the

23 Engine Speed rpm 675 - 725 1440 - 1510 1990 - 2010
CKP sensor.
The desired engine idle speed that the ECM

commanding. The ECM compensates for
24 Desired Engine Idle Speed rpm 700 700 700 various engine loads based on engine coolant
temperature.
Not This displays input signal from the vehicle speed

Not Not Not
25 Vehicle Speed Sensor Signal Received/ sensor. When the vehicle speed pulse is
Received Received Received
Received generated, signal is received.
This displays vehicle speed. The vehicle speed

km/h /
26 Vehicle Speed 0 0 0 is measured by ECM from the vehicle speed
MPH
sensor.
ECM DIAGNOSTIC TROUBLE CODE (DTC) TABLE

Related Related
Flash Symptom
Code MIL DTC Name DTC Setting Condition Fail-Safe (Back Up) Recovery Condition Suspected Cause ECM Pin Multiple
Code Code
No. DTC
34 P0105 1 ON MAP Sensor Circuit MAP sensor output The ECM uses 110 Kpa MAP sensor output z +5V reference circuit is short to J01-14/ P1120/
High Voltage voltage is more than condition as substitute. voltage is less than 4.84 battery or ignition voltage. J01-58/ P1122/
4.98V. V. z Signal circuit is short to battery or J01-62 P1635
ignition voltage.
z Low reference circuit is open
circuit.
z Sensor internal circuit is open
circuit or short circuit.
z ECM malfunction.
2 ON MAP Sensor Circuit MAP sensor output MAP sensor output z +5V reference circuit is open J01-14/ P1122/
Low Voltage voltage is less than 0.05 voltage is more than 0.73 circuit, short to ground circuit. J01-58 P1635
V. V. z Signal circuit is open circuit, short
to ground circuit.
connection.
z ECM malfunction.
23 P0110 1 ON Intake Air IAT sensor output voltage The ECM uses 60 deg. C IAT sensor output voltage z Signal circuit is open circuit, short J01-60/ P0405
Temperature (IAT) is more than 4.92 V. condition as substitute. is less than 4.88 V. to battery or ignition voltage. J02-50
Sensor Circuit High z Low reference circuit is open
Voltage circuit.
connection.
z ECM malfunction.
2 ON Intake Air IAT sensor output voltage IAT sensor output voltage z Signal circuit is short to ground J01-60 -
Temperature (IAT) is less than 0.04 V. is more than 0.06 V. circuit.
Sensor Circuit Low z Sensor internal circuit is short
Voltage circuit.
z ECM malfunction.
Related Related
Flash Symptom
Code Code
No. DTC
14 P0115 1 ON Engine Coolant ECT sensor output The ECM controls 80 ECT sensor output z Signal circuit is open circuit, short J01-42/ P0180
Temperature (ECT) voltage is more than 4.92 deg. C condition as voltage is less than to battery or ignition voltage. J01-45
Sensor Circuit High V. substitute. 4.88V. z Low reference circuit is open
Voltage circuit.
connection.
z ECM malfunction.
2 ON Engine Coolant ECT sensor output ECT sensor output z Signal circuit is short to ground J01-42 -
Temperature (ECT) voltage is less than 0.04 voltage is more than 0.06 circuit.
Sensor Circuit Low V. V. z Sensor internal circuit is short
Voltage circuit.
z ECM malfunction.
15 P0180 1 ON Fuel Temperature FT sensor output voltage The ECM controls 40 FT sensor output voltage z Signal circuit is open circuit, short J01-41/ P0115
(FT) Sensor Circuit is more than 4.89 V. deg. C condition as is less than 4.88 V. to battery or ignition voltage. J01-45
High Voltage substitute. z Low reference circuit is open
circuit.
connection.
z ECM malfunction.
2 ON Fuel Temperature FT sensor output voltage FT sensor output voltage z Signal circuit is short to ground J01-41 -
(FT) Sensor Circuit is less than 0.04 V. is more than 0.06 V. circuit.
Low Voltage z Sensor internal circuit is short
circuit.
z ECM malfunction.
Related Related
Flash Symptom
Code Code
No. DTC
46 P0216 1 ON TCV Control System z Request signal is Off z The ECM controls No recovery during same z TCV harness short to battery or J01-25 -
High Voltage from ECM. final fuel quantity ignition cycle. ignition voltage.
z Actual output signal is based on default z TCV malfunction.
On. value ( Final fuel z ECM malfunction.
quantity less than 25
3 ON TCV Control System z TCV duty output is mm3/st). Timing error (desired- z TCV harness malfunction. J01-25 -
Malfunction Fuel more than 0%. z TCV solenoid final) is less than 5 z TCV malfunction.
Timing Positive z Timing error (desired- disabled. deg.CA . ( In case timing z ECM malfunction.
Deviation final) is more than -10 error; less than 0 deg.CA) z Injection pump timing device
deg. CA. Above condition is met for malfunction.
Above conditions are met 40 seconds.
for 40 seconds.
4 ON TCV Control System z Request signal is On No recovery until z TCV harness open circuit or short J01-25 -
Low Voltage from ECM. condition match for 2 to ground circuit.
z Actual output signal is seconds. z TCV malfunction.
Off. z ECM malfunction.
5 ON TCV Control System z TCV duty output is Timing error (desired- z TCV harness malfunction. J01-25 -
Malfunction Fuel less than 255%. final) is less than -5 z TCV malfunction.
Timing Negative z Timing error (desired- deg.CA . ( In case timing z ECM malfunction.
Deviation final) is more than 10 error; less than 0 deg.CA) z Injection pump timing device
deg. CA. Above condition is met for malfunction.
Above conditions are met 40 seconds.
for 40 seconds.
61 P0251 8 ON EDU/SPV System The phase between SPV relay off. No recovery during same z EDU command signal is open J01-33/ P0505
Error command signal from ignition cycle. circuit. J01-34
ECM and return signal z EDU feedback signal is open
from EDU is wrong width. circuit, short to ground or short to
battery or ignition voltage.
z EDU malfunction.
z ECM malfunction.
Related Related
Flash Symptom
Code Code
No. DTC
43 P0335 4 ON Crankshaft Position No or missing pulse TCV feed back control No recovery until z CKP sensor harness open circuit, J01-23 -
Sensor No Signal detected consecutively. disabled. condition match for 3 short to ground or short to voltage
seconds. circuit.
z ECM malfunction.
8 ON Crankshaft Position Incorrect pulse detected No recovery until z CKP sensor harness open circuit, J01-23 -
Sensor Insufficient consecutively. condition match for 119 short to ground or short to voltage
Activity crank counts. circuit.
z ECM malfunction.
41 P0370 4 ON Pump Camshaft Incorrect or no pulse The ECM uses CKP No recovery until z CMP sensor harness open circuit, J01-01/ P0335
Sensor No Signal detected consecutively. signal as substitute and condition match for 5 short to ground or short to voltage J01-17/
uses throttle position seconds. circuit. J01-37
between 6.5 and 20%. z Poor connector connection.
z CMP sensor malfunction.
z ECM malfunction.
32 P0400 1 ON EGR EVRV Circuit EGR EVRV circuit short z EVRV disabled. No recovery during same z EGR EVRV circuit short to voltage J01-26 -
Signal Too High to voltage circuit. z The ECM controls ignition cycle. circuit.
EGR pressure 25 z EGR EVRV malfunction.
KPa condition as z ECM malfunction.
substitute.
4 ON EGR EVRV Circuit EGR EVRV circuit open No recovery until z EGR EVRV circuit open or short to J01-26 P0405/
Signal Too Low or short to ground circuit. condition match for 3 ground circuit. P1404/
seconds. z EGR EVRV malfunction. P1405
z ECM malfunction.
Related Related
Flash Symptom
Code Code
No. DTC
26 P0405 1 ON EGR Valve Pressure EGR valve pressure z EGR disabled. No recovery during same z Disconnected EGR hose. J01-28/ P1120/
Sensor Circuit High sensor output voltage is z The ECM controls ignition cycle. z +5V reference circuit is short to J02-20/ P1122/
Voltage more than 4.98 V (104.4 EGR pressure 25 battery or ignition voltage. J02-50 P1620
Kpa). Kpa condition as z Signal circuit is short to battery or
substitute. ignition voltage.
z Low reference circuit is open
circuit.
z ECM malfunction.
4 ON EGR Valve Pressure EGR valve pressure z +5V reference circuit is open J01-28/ P1620/
Sensor Circuit Low sensor output voltage is circuit, short to ground circuit. J02-20 P1120
Voltage less than 0.48 V (11.3 z Signal circuit is open circuit, short
Kpa). to ground circuit.
connection.
z ECM malfunction.
24 P0500 1 ON Vehicle Speed z Vehicle speed is The ECM controls 20 No recovery during same z VSS signal circuit open, short to J02-40 -
Sensor Signal Too more than 240 km/h. km/h condition as ignition cycle. ground or short to voltage circuit.
High z Fuel quantity is less substitute. z VSS malfunction.
than 5 mm3/st. z Speed meter malfunction.
z ECM malfunction.
4 ON Vehicle Speed z Vehicle speed is 0 z VSS signal circuit open, short to J02-40 -
Sensor Signal Circuit km/h. ground or short to voltage circuit.
Too Low z Engine speed is more z VSS malfunction.
than 1600 rpm. z Speed meter malfunction.
z Clutch switch is not z TCM malfunction (AT 2WD).
fail. z ECM malfunction.
z Other than neutral
gear.
Fuel quantity is more than
36 mm3/st.
8 ON Vehicle Speed z Other than neutral z VSS signal circuit open, short to J02-40 -
Sensor Insufficient gear. ground or short to voltage circuit.
Activity z VSS signal error. z VSS malfunction.
z Speed meter malfunction.
z ECM malfunction.
Related Related
Flash Symptom
Code Code
No. DTC
63 P0505 3 ON SPV System High z Engine idling z The ECM controls Engine rpm error z EDU/SPV harness open or short J01-33/ P0251
Idle RPM (Positive condition. fuel quantity based (Desired engine idle circuit. J01-34
Divination) z Engine rpm error on default value (limit speed-engine speed) is z SPV malfunction.
(Engine idle speed - fuel quantity ; 15 less than -90 rpm. z EDU malfunction.
Desired engine mm3/st ). Above condition is met for z ECM malfunction.
speed ) is more than z The ECM stops idling 30 seconds.
180 rpm. feedback.
Above conditions are met
for 30 seconds.
5 ON SPV System Low z Engine idling z The ECM controls z EDU/SPV harness open or short J01-33/ P0251
Idle RPM (Negative condition. fuel quantity based circuit. J01-34
Divination) z Engine rpm error on default value (limit z SPV malfunction.
( Desired engine idle fuel quantity ; 25 z EDU malfunction.
speed - engine mm3/st ). z ECM malfunction.
180 rpm. feedback.
Above conditions are met
for 30 seconds.
35 P0560 1 ON System Voltage Too Battery voltage more than No fail-safe function. No recovery until z Charge system malfunction. J02-01/ -
High 16 V for 30 seconds. condition match z Battery jump start cable J02-15/
misconnect. J02-17
z ECM malfunction.
2 ON System Voltage Too System voltage is less z Battery power feed harness open J02-01/ -
Low than 8.3 V for 30 circuit or short to ground circuit. J02-15/
seconds. z ECM ground harness open or poor J02-17
connection.
z Battery malfunction.
z ECM main relay malfunction.
z Charge system malfunction.
z ECM malfunction.
55 P0601 0 ON ECM Checksum Memory area error. Engine control disabled. No recovery during same z ECM malfunction. - -
Error ignition cycle.
Related Related
Flash Symptom
Code Code
No. DTC
21 P1120 1 ON Throttle Position TPS 1 output voltage The ECM uses 7 % (AT) No recovery until z TPS 1 +5V reference circuit is J02-03/ -
Sensor 1 High more than 4.93 V. or 5 % (MT) condition as condition match for 4.4 short to battery or ignition voltage. J02-37/
Voltage substitute. seconds. z TPS 1 signal circuit is short to J02-49
circuit.
z TPS 1 internal circuit is open circuit
or short circuit.
z ECM malfunction.
Note: TPS 1 is internal to TPS

assembly.
2 ON Throttle Position TPS 1 output voltage less z TPS 1 +5V reference circuit is J02-03/ P0405/
Sensor 1 Low than 0.202 V. open circuit, short to ground. J02-37 P1620
Voltage z TPS 1 signal circuit is open circuit,
short to ground.
connection.
or short circuit.
z ECM malfunction.

assembly.
8 ON Throttle Position TPS 1 signal error in No recovery until z TPS 1 signal circuit is high J02-37/ P0105/
Sensor 1 Insufficient comparison with TPS 2. condition match for 5.2 resistance. J02-35 P0405/
Activity seconds. z TPS Malfunction. P1122/
z ECM malfunction. P1620/
P1635
Related Related
Flash Symptom
Code Code
No. DTC
33 P1122 1 ON Throttle Position TPS 2 output voltage The ECM uses 7 % (AT) No recovery until z TPS 2 +5V reference circuit is J02-33/ -
Sensor 2 High more than 4.93 V. or 5 % (MT) condition as condition match for 4.4 short to battery or ignition voltage. J02-35/
Voltage substitute. seconds. z TPS 2 signal circuit is short to J02-36
circuit.
or short circuit.
z ECM malfunction.

assembly.
2 ON Throttle Position TPS 2 output voltage less z TPS 2 +5V reference circuit is J02-35/ P0105/
Sensor 2 Low than 0.202 V. open circuit, short to ground. J02-36 P1635
Voltage z TPS 2 signal circuit is open circuit,
short to ground.
connection.
or short circuit.
z ECM malfunction.

assembly.
8 ON Throttle Position TPS 2 signal error in No recovery until z TPS 2 signal circuit is high J02-37/ P0105/
Sensor 2 Insufficient comparison with TPS 1. condition match for 5.2 resistance. J02-35 P0405/
Activity seconds. z TPS Malfunction. P1120/
z ECM malfunction. P1620/
P1635
31 P1404 1 ON EGR VSV 1 Circuit EGR VSV 1 circuit short EGR VSV 1 disabled. No recovery during same z EGR VSV 1 circuit short to voltage J01-09 -
Signal Too High to voltage circuit. ignition cycle. circuit.
z ECM malfunction.
4 ON EGR VSV 1 Circuit EGR VSV 1 circuit open z EGR VSV 1 circuit open or short to J01-09 P0400/
Signal Too Low or short to ground circuit. ground circuit. P0405/
z EGR VSV 1 malfunction. P1405
z ECM malfunction.
Related Related
Flash Symptom
Code Code
No. DTC
37 P1405 1 ON EGR VSV 2 Circuit EGR VSV 2 circuit short EGR VSV 2 disabled. No recovery during same z EGR VSV 2 circuit short to voltage J01-10 -
Signal Too High to voltage circuit. ignition cycle. circuit.
z ECM malfunction.
4 ON EGR VSV 2 Circuit EGR VSV 2 circuit open z EGR VSV 2 circuit open or short to J01-10 P0400/
Signal Too Low or short to ground circuit. ground circuit. P0405/
z EGR VSV 2 malfunction. P1404
z ECM malfunction.
47 P1589 8 ON Transmission Switch Neutral switch and No fail-safe function. No recovery during same z Switch circuit short to voltage J02-29/ -
Malfunction reverse switch signal ignition cycle. circuit. J02-44
inputted "On" at the same z Switch malfunction.
time. z ECM malfunction.
12 P1620 1 ON 5V Reference Circuit 5V reference circuit 1 5V reference circuit 1 No recovery until z TPS 1 or EGR valve pressure J02-03/ P0405/
1 High Voltage voltage more than 5.3 V. disabled. condition match for 0.5 sensor +5V reference circuit short J02-20 P1120/
seconds. to battery or ignition voltage. P1122
z TPS 1 malfunction.
z EGR valve pressure sensor
malfunction.
z ECM malfunction.
2 ON 5V Reference Circuit 5V reference circuit 1 z TPS 1 or EGR valve pressure J02-03/ P0405/
1 Low Voltage voltage less than 4.1 V. sensor +5V reference circuit short J02-20 P1120
to ground circuit.
z EGR valve pressure sensor
malfunction.
z ECM malfunction.
76 P1625 1 ON Main Relay Circuit ECM main relay circuit ECM main relay Off. No recovery until z ECM main relay malfunction. - -
High Voltage short to voltage circuit. condition match for 1.5 z ECM malfunction.
seconds.
4 ON Main Relay Circuit ECM main relay circuit z ECM main relay circuit open or J02-15 -
Low Voltage open or short to ground short to ground circuit.
circuit. z ECM main relay malfunction.
z ECM malfunction.
Related Related
Flash Symptom
Code Code
No. DTC
62 P1630 1 ON SPV Output Signal SPV operating signal SPV relay off. No recovery during same z EDU command signal is short to J01-34 -
Stuck High (EDU feedback signal) ignition cycle. ground.
high stuck fail is present. z EDU malfunction.
z ECM malfunction.
2 ON SPV Output Signal SPV operating signal z EDU command signal is short to J01-34 -
Stuck Low (EDU feedback signal ) battery or ignition voltage.
low stuck fail is present. z EDU malfunction.
z ECM malfunction.
64 P1631 1 ON Spill Valve (SPV) SPV relay circuit short to SPV relay off. No recovery during same z SPV relay malfunction. - -
Relay Circuit High voltage circuit. ignition cycle. z ECM malfunction.
Voltage
4 ON Spill Valve (SPV) SPV relay circuit open or No recovery until z SPV relay circuit open or short to J02-16 -
Relay Circuit Low short to ground circuit. condition match for 3 ground circuit.
Voltage seconds. z SPV relay malfunction.
z ECM malfunction.
13 P1635 1 ON 5V Reference 2 5V reference circuit 2 5V reference circuit 2 No recovery until z TPS 2 or MAP sensor +5V J01-14/ P0105/
Circuit High Voltage voltage more than 5.3 V. disabled. condition match for 0.5 reference circuit short to battery or J02-35 P1120/
seconds. ignition voltage. P1122
z MAP sensor malfunction.
z ECM malfunction.
2 ON 5V Reference 2 5V reference circuit 2 z TPS 2 or MAP sensor +5V J01-14/ P0105/

Circuit Low Voltage voltage less than 4.1 V. reference circuit short to ground J02-35 P1122
circuit.
z MAP sensor malfunction.
z ECM malfunction.
44 P1651 0 ON Pump ROM z Data line anytime low. PROM communication No recovery until z PROM harness open circuit, short J01-49/ -
Communication Error z Data line anytime disabled. condition match for next to ground circuit, short to battery or J01-50
high. ignition cycle. ignition voltage circuit.
z Start pattern error. z PROM malfunction.
z Parity error. z ECM malfunction.
Stable one of above
conditions is detected 10
continuous cycle.
Related Related
Flash Symptom
Code Code
No. DTC
65 P1662 1 ON Idle Port VSV Circuit Idle port VSV circuit short Idle port VSV disabled. No recovery during same z VSV circuit short to voltage circuit. J02-23 -
Signal Too High to voltage circuit. ignition cycle. z VSV malfunction.
z ECM malfunction.
4 ON Idle Port VSV Circuit Idle port VSV circuit open z VSV circuit open or short to ground J02-23 -
Signal Too Low or short to ground circuit. circuit.
z VSV malfunction.
z ECM malfunction.
77 P1690 1 OFF Check Engine Lamp Check engine lamp circuit Lamp disabled. No recovery during same z ECM malfunction. - -
Circuit High Voltage short to voltage circuit. ignition cycle.
4 OFF Check Engine Lamp Check engine lamp circuit No recovery until z Check engine lamp circuit open or J02-32 -
Circuit Low Voltage open or short to ground condition match for 3 short to ground circuit.
circuit. seconds. z Check engine lamp malfunction.
z ECM malfunction.
MULTIPLE DTC SETS & TROUBLE SHOOTING AIDS
When the MAP sensor harness J1-58 short to battery or ignition voltage, following DTCs is may stored.
z P0105 (1) (MAP Sensor Circuit High Voltage)
z P1635 (1) (5V reference 2 Circuit High Voltage)
z P1120 (8) (TPS 1 Insufficient Activity)
When the MAP sensor harness J1-14 or TPS harness J2-35 short to battery or ignition voltage, following
DTCs is may stored.
z P0105 (1) (MAP Sensor Circuit High Voltage)
z P1635 (1) (5V Reference 2 Circuit High Voltage)
When the MAP sensor harness J1-14 or TPS harness J2-35 short to ground, following DTCs is may
stored.
z P0105 (2) (MAP Sensor Circuit Low Voltage)
z P1635 (2) (5V Reference 2 Circuit Low Voltage)
z P1122 (2) (TPS 2 Low Voltage)
When the EGR pressure sensor harness J2-20 or TPS harness J2-3 short to battery or ignition voltage,
following DTCs is may stored.
z P0405 (1) (EGR Pressure Circuit High Voltage)
z P1620 (1) (5V Reference Circuit 1 High Voltage)
When the EGR pressure sensor harness J2-20 or TPS harness J2-3 short to ground, following DTCs is
may stored.
z P0405 (4) (EGR Pressure Circuit Low Voltage)
z P1620 (2) (5V Reference 1 Circuit Low Voltage)
z P1120 (2) (TPS 1 Low Voltage)
When the ECM main relay is failed, following DTCs is may stored.
z P0400 (4) (EGR EVRV Circuit Signal Too Low)
z P0405 (4) (EGR Pressure Circuit Low Voltage)
z P1404 (4) (EGR VSV 1 Circuit Signal Too Low)
z P1405 (4) (EGR VSV 2 Circuit Signal Too Low)
z P0560 (2) (System Voltage Too Low)
z P0335 (4) (Crank Position Sensor No Signal)
When the ECM main relay is failed during engine running, following DTC is may stored.
z P0560 (2) (System Voltage Too Low)
When the EDU harness J1-33 open, short to battery or ignition voltage or short to ground during engine
running, the engine is stopped and following DTC is may stored.
z P0251 (8) (EDU/SPV System Error)
When the EDU harness J1-34 open during engine running, the engine is stopped and following DTC is
may stored in the next cranking.
z P0251 (8) (EDU/SPV System Error)
When the EDU harness J1-34 short to battery voltage during cranking or engine running, the engine is
stopped and following DTC is may stored.
z P1630 (1) (SPV output Signal Stuck High)
When the EDU harness J1-34 short to ground during cranking or engine running, the engine is stopped
and following DTC is may stored.
z P1630 (2) (SPV Output Signal Stuck Low)
SYMPTOM DIAGNOSIS
PRELIMINARY CHECKS
Before using this section, perform the "On-Board Diagnostic (OBD) System Check" and verify all of the
following items:
z The engine control module (ECM) and check engine lamp (MIL=malfunction indicator lamp are
operating correctly.
z There are no Diagnostic Trouble Code(s) stored.
z Tech 2 data is within normal operating range. Refer to Typical Scan Data Values.
z Verify the customer complaint and locate the correct symptom in the table of contents. Perform the
procedure included in the symptom chart.
VISUAL/PHYSICAL CHECK
Several of the symptom procedures call for a careful visual/physical check. This can lead to correcting a
problem without further checks and can save valuable time. This check should include the following
items:
z ECM grounds for cleanliness, tightness and proper location.
z Vacuum hoses for splits, kinks, and proper connection. Check thoroughly for any type of leak or
restriction.
z Air intake ducts for collapsed or damaged areas.
z Air leaks at throttle body mounting area, MAP sensor and intake manifold sealing surfaces.
z Wiring for proper connections, pinches and cuts.
INTERMITTENT
Important: An intermittent problem may or may not turn on the check engine lamp (MIL=malfunction
indicator lamp) or store a Diagnostic Trouble Code. Do NOT use the Diagnostic Trouble Code (DTC)
charts for intermittent problems.
The fault must be present to locate the problem. Most intermittent problems are cased by faulty electrical
connections or wiring. Perform a careful visual/physical check for the following conditions.
z Poor mating of the connector halves or a terminal not fully seated in the connector (backed out).
z Improperly formed or damaged terminal.
z All connector terminals in the problem circuit should be carefully checked for proper contact tension.
z Poor terminal-to-wire connection. This requires removing the terminal form the connector body to
check.
z Check engine lamp (MIL=malfunction indicator lamp) wire to ECM shorted to ground.
z Poor ECM grounds. Refer to the ECM wiring diagrams.
Road test the vehicle with a Digital Multimeter connected to a suspected circuit. An abnormal voltage
when the malfunction occurs is a good indication that there is a fault in the circuit being monitored.
Using Tech 2 to help detect intermittent conditions. The Tech 2 have several features that can be used to
located an intermittent condition. Use the following features to find intermittent faults:
To check for loss of diagnostic code memory, disconnect the MAP sensor and idle the engine until the
check engine lamp (MIL=malfunction indicator lamp) comes on. Diagnostic Trouble Code P0105 should
be stored and kept in memory when the ignition is turned OFF.
If not, the ECM is faulty. When this test is completed, make sure that you clear the Diagnostic Trouble
Code P0105 from memory.
An intermittent check engine lamp (MIL=malfunction indicator lamp) with no stored Diagnostic Trouble
Code may be caused by the following:
z Check engine lamp (MIL=malfunction indicator lamp) wire to ECM short to ground.
z Poor ECM grounds. Refer to the ECM wiring diagrams.
Check for improper installation of electrical options such as light, cellular phones, etc. Check all wires
from ECM to the ignition control module for poor connections.
Check for an open diode across the A/C compressor clutch and check for other open diodes (refer to
wiring diagrams in Electrical Diagnosis).
If problem has not been found, refer to ECM connector symptom tables.
z Check the "Broadcast Code" of the ECM, and compare it with the latest Isuzu service bulletins and/or
Isuzu EEPROM reprogramming equipment to determine if an update to the ECM's reprogrammable
memory has been released.
This identifies the contents of the reprogrammable software and calibration contained in the ECM.
If the "Broadcast Code" is not the most current available, it is advisable to reprogram the ECM's
EEPROM memory, which may either help identify a hard-to find problem or may fix the problem.
The Service Programming System (SPS) will not allow incorrect software programming or incorrect
calibration changes.
FAULTY SYMPTOM & DEFINITION

1. Engine Cranks But Will Not Run
Definitions: Engine cranks, but will not run. (The engine never start.)
2. Hard Start Symptom

Definitions: Engine cranks, but does not start for a long time. Does eventually start, or may start and then
immediately stall.
3. Rough, Unstable, or Incorrect Idle, Stalling Symptom
Definitions: Engine runs unevenly at idle. If severe,

the engine or vehicle may shake. Engine idle speed
rpm
may vary in RPM. Either condition may be severe
enough to stall the engine.
X
Rough Idle
Stall
time
4. Surges and/or Chugs Symptom
Definitions: Engine power variation under steady

rpm throttle or cruise. Feels like the vehicle speeds up
and slows down with no charge in the accelerator
pedal.
Surge
time
5. Hesitation, Sag, Stumble Symptom
Definitions: Momentary lack of response as the

Stumble accelerator is pushed down. Can occur at any
rpm
vehicle speed. Usually most pronounced when first
trying to make the vehicle move, as from a stop sign.
Sug
May cause the engine to stall if severe enough.
Hesitation
time
6. Cuts Out, Misses Symptom
Definitions: Steady pulsation or jerking that follows

rpm engine speed; usually more pronounced as engine
load increases.
time
7. Lack of Power, Sluggish or Spongy Symptom

Definitions: Engine delivers less than expected power. Attempting part-throttle acceleration results in
little or no increase in vehicle speed.
8. Poor Fuel Economy Symptom

Definitions: Fuel economy, as measured by an actual road test, is noticeably lower than expected. Also,
economy is noticeably lower than it was on this vehicle at one time, as previously shown by an actual
road test. (Larger than standard tires will cause odometer readings to be incorrect, and that may cause
fuel economy to appear poor when it is actually normal.)
9. Excessive White Smoke
10. Excessive Black Smoke

WIRING DIAGRAM
ENGINE CONTROL MODULE (ECM)
RELAY, FUSE & SLOW BLOW FUSE LOCATION

X-5: Spill Valve Relay
X-13: ECM Main Relay
X-14: A/C Compressor
Relay
EB-1: ECM (15A)

EB-2: ECM/B (10A)
EB-3: Spill Valve (15A)
C-6: Engine (15A)

C-7: Back Up (15A)
C-10: Meter (15A)
C-19: Meter +B (10A)
ELECTRICAL HARNESS LOCATION

CHECK SHEET
SPECIAL TOOLS
Tech2
Breaker Box
5-8840-0285-0
High Impedance Multimeter
5-8840-0385-0
Connector Test Adapter Kit
5-8840-0279-0
Vacuum Pump With Gauge
Issued by
ISUZU MOTORS LIMITED

SERVICE MARKETING DEPARTMENT
Tokyo, Japan
COPYRIGHT-ISUZU MOTORS LIMITED
SBT-TM-TF4JHE-D-1-04 (version 1)
January 2004
THE RIGHT IS RESERVED TO MAKE CHANGES AT ANY TIME WITHOUT NOTICE.

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FOR SERVICE TRAINING

ISUZU MOTORS LIMITED

INTRODUCTION & OUTLINE

FEATURE OF V5 INJECTION PUMP

With the worldwide increase in demand for further

1. Solenoid Spill Valve (SPV)

Injection Volume Control Schematic

Injection Timing Control Schematic

ENGINE CONTROL MODULE

The engine control module (ECM) is located on the

1. Fuel Injection Volume Control

2. Fuel Injection Timing Control

3. Idling Speed Control

4. Idling Vibration Control

5. Exhaust Gas Re-Circulation Control

6. Fail Safe Function

ELECTRICAL DRIVE UNIT

The electrical drive unit (EDU) is located on the

A The EDU terminal 22 receives the injection

CH1: Feedback Signal / CH2: Command Signal

Breaker Box Connection Type "A" for Open Circuit

Breaker Box Connection Type "B" for Power, Signal

ECM CONNECTOR PIN ASSIGNMENT & OUTPUT SIGNAL

J01 Port: View Looking Into ECM Case

Signal or Continuity Tester Position

EGR #1 is not operated:

EGR #2 is not operated:

Pump Camshaft Position Sensor Continuity

Signal or Continuity Tester Position

WHT/ Less than

Electrical Drive Unit (EDU

Engine Coolant Temperature Less than 25deg. C: Approx. 3.7V / 50 deg. C:

Signal or Continuity Tester Position

Fuel Temperature (FT) & Engine

Less than Approx.

Intake Air Temperature (IAT) GRN/ Less than

J02 Port: View Looking Into ECM Case

Signal or Continuity Tester Position

RED/ Less than

Throttle Position Sensor #1 Less than

A/C Compressor Relay (A/T GRN/

RED/ Less than

Signal or Continuity Tester Position

EGR Pressure Sensor Power Less than

RED/ Less than In reverse: 10 -14V

BRN/ Less than Lamp is turned on: Less than 1V

Throttle Position Sensor #2 (5 Continuity

Throttle Position Sensor #2 Less than

Throttle Position Sensor #2 Less than

Throttle Position Sensor #1 Less than

J02-38 101 No Connection - - - - - - - - -

J02-39 102 No Connection - - - - - - - - -

J02-41 104 No Connection - - - - - - - - -

J02-42 105 No Connection - - - - - - - - -

Signal or Continuity Tester Position

J02-43 106 No Connection - - - - - - - - -

RED/ Less than In neutral (A/T: P or N): 10 - 14V / Other

A/C request switch is turned on: 10 - 14V

J02-46 109 No Connection - - - - - - - - -