Model Outline Engine Chassis

Engine Chassis
Body Body Electrical
Steering
EPS (Electric Power Steering)
– Motor drives the rack directly

Resolver
R l Type
T
Torque Sensors

Steering Gear Unit

• Burushless Motor
Rotational Angle • Reduction Mechanism
Sensor
[Specifications]
Type Vehicle Speed Sensing Type
G
Gear R
Ratio
ti (O
(Overall)
ll) ?
No. of Turns Lock to Lock ?
Rack Stroke [mm in.)] ?
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
System Diagram
VGRS ECU BEAN (Instrument Panel Bus)

Engine
i J/C No. 2
J/C No. 1 Gateway ECU
ECU

Skid Control CAN

PS Warning
ECU Light
EPS ECU
P/S
Temp. Sensor
Torque DLC3 Boost Converter
Sensors
EPS Motor Battery (12V)
Drive (28V)

Rotation Angle
g
Sensor
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Torque Sensor (Resolver Type)
– Torque sensor detects the twist of torsion bar, changes it into the
electric signal, and outputs it to EPS ECU

Main Shaft (Input

Shaft)
Torsion Bar

Resolver 1 to EPS ECU

Resolver
l 2

Pinion Shaft (Output

Shaft) Rack Shaft
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Torque Sensor (Resolver Type)
– Torque sensor consists of resolver 1, 2 and torsion bar
– Resolver 1 of rotor portion is fixed to main shaft, resolver 2 of rotor
portion is fixed to pinion shaft.
shaft

Main Shaft (Input

Torsion Shaft)
Bar
Resolver 1 (Stator
Portion)

Resolver 1 (Rotor
Portion)

Resolver 2 Pinion Shaft Resolver 2 (Stator

(R t P
(Rotor Portion)
ti ) (Output Shaft) Portion)
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Torque Sensor (Resolver Type)
– Resolvers of rotor portion generate a relative angle difference of a
twist of the torsion bar

Main Shaft (Input

Shaft)

Resolver 1 (Rotor
Portion)
o o )

Resolver 2
(Rotor Portion)

Pinion Shaft
(O t t Sh
(Output Shaft)
ft)
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Torque Sensor (Resolver Type)
– Characteristic of resolver

Exciting Detection
4
Coil Coil

2
1 3

4
2
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Torque Sensor (Resolver Type)
– Detection method of torque sensor
Stator Portion Rotor Portion Stator Portion

Signal A

Signal B
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Torque Sensor (Resolver Type)
– Detection method of torque sensor
Stator Portion Rotor Portion Stator Portion

Signal A

Signal B
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Torque Sensor (Resolver Type)
– Detection method of torque sensor
Stator Portion Rotor Portion Stator Portion

Signal A

Signal B
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Torque Sensor (Resolver Type)
– One resolvor outputs two signals with which the phase lagged 90
degrees to detect a relative angle
Output
Resolver (Rotor Signal (V)
Portion)

Signal
i lA
t

Signal B
t

AUTO
Resolver (Stator
MANUA P ti )
Portion)
L
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Torque Sensor (Resolver Type)
– Resolver of rotor portion outputs the straight signal, when resolver of
stator portion stayed
Output
Resolver (Rotor Signal (V)
Portion)

Signal
i lA
t

Signal B
t

Resolver (Stator
P ti )
Portion)
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Torque Sensor (Resolver Type)
– When vehicle is driven straight, resolver 1 and 2 output the signals of
the same signal
[Resolver 1 Output Signal] [Resolver 2 Output Signal]

t t

t t
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Torque Sensor (Resolver Type)
– When steering is turned, relative angle difference is created between
the resolver 1 and 2 of rotor portion
[Resolver 1 Output Signal] [Resolver 2 Output Signal]

t t

t t
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Torque Sensor (Resolver Type)
– EPS ECU decides assist voltage to a EPS motor from difference in
relative position of resolver 1 and 2

θ
θ1

θ = θ 1 - θ2
EPS ECU

Assist Voltage
θ2
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Motor (Brushless Type)
– Motor is concentric with rack shaft, and consists of rotation angle
sensor, stator and rotor

Coil
Rotation Stator
A l S
Angle Sensor
Motor

Magnet
Rack Shaft
Rotor
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Motor (Brushless Type)

Coil
Protrusion for
Rotation Angle
Sensor
Stator

Rack Shaft

Rotor with Magnet

g Rotation Angle
S
Sensor
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Reduction Mechanism
– Movement of motor travels to ball screw reduction gear, via balls, to
gear that is created on rack shaft

Ball Screw Reduction Gear

Ball
Rack Shaft
Rotor
Ball screw reduction gear is fixed to rotor
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Reduction Mechanism
– Ball is circulating the inside of the ball screw reduction gear by the
ball director
– Ball screw reduction gear has four ball directors

Ball Director

Ball Screw Reduction

Gear

Ball Director

B ll
Ball
Ball Screw
Reduction Gear
Rack Shaft Rotor

Ball screw reduction gear is fixed to rotor

 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Rotation Angle Sensor (Resolver Type)
– Detects the rotation angle of the motor for preventing torque
fluctuations
Rotation Angle Sensor Output
Signal (V)

Signal
i lA
t

Signal B
t
Rotor
Rack
Shaft Protrusion
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
EPS Operation
– Relationship between the steering torque and the assist power
current output

Low

Assist Power Vehicle

Current Output Speed

High

Steering Torque
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
EPS Operation
– There are the following functions in assist control
Item Function
Calculates
l l the
h assist current from
f the
h steering torque value
l and
d
Basic Control
the vehicle speed, and actuates the motor
Inertia Compensation Improves the starting movement of the motor when the driver
Control starts to turn the steering wheel
During the short interval between the time the driver fully turns
Recovery Control the steering wheel and the wheels try to recover, this control
assists the recovery force
Regulates the amount of assist when the driver turns the steering
Damper Control wheel while driving at high speeds, thus damping the changes in
the yaw rate of the vehicle body
Boosts the battery voltage in the EPS ECU. It maintains 0 volts
when the driver does not turn the steering wheel or the vehicle is
V lt
Voltage B
Boostt Control
C t l b i
being d
driven
i straight.
t i ht It effects
ff t variable
i bl control
t l between
b t 27 to
t 34
volts in accordance with the load, when the driver is turning the
steering wheel.
Estimates the motor temp. based on the amperage and the current
System
y Overheat
duration . If the temp.
temp exceeds the standard,
standard it limits the
Protection Control
amperage to prevent the motor from overheating
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Diagnosis
– When malfunction occurs in EPS system, EPS ECU controls
following control;
• Turns on P/S warning light and fail-safe operation
DTC No. Detection Item P/S
C1511 / 11
C1512 / 11 Torque sensor malfunction
lf Illuminate
ll
C1513 / 11
C1515 / 15 Torque sensor zero point adjustment undone Illuminate
C1516 / 16 T
Torque sensor zero point
i t adjustment
dj t t incomplete
i l t Ill
Illuminate
i t
C1521 / 25
C1522 / 25
Motor malfunction Illuminate
C1523 / 24
C1524 / 24
C1525 / 17 Rotation angle sensor output initialization undone Illuminate
C1526 / 18 Rotation angle sensor output initialization incomplete Illuminate
C1528 / 12 Motor rotation angle sensor malfunction Illuminate
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Diagnosis

DTC No. Detection Item P/S

C1531 / 25
C1532 / 25
ECU malfunction Illuminate
C1533 / 25
C1534 / 25
C1541 / 13 Vehicle speed signal malfunction Illuminate
C1551 / 25 IG power source voltage malfunction Illuminate
C1552 / 22 PIG power supply voltage malfunction Illuminate
C1554 / 23 Power supply relay failure Illuminate
C1555 / 25 Motor relay welding failure Illuminate
C1567 / 44 Lost communication with VGRS ECU? Illuminate
C1581 / 26 Assist map number un-writing Illuminate
U0073 / 49 Control module communication bus off Illuminate
U0104 / 45 Lost communication with cruise control module ⎯
U0105 / 41 Lost communication with fuel injector control module ⎯
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Diagnosis

DTC No. Detection Item P/S

Lost communication with anti-lock brake system (ABS)
U0121 / 42 Illuminate
control module
U0122 / 42 ⎯
U0130 / 44 Lost communication with steering effort control module ⎯
U0405
0 0 / 45 ⎯
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Fail safe
Fail-safe

DTC No. Detection Item Fail-safe Operation

C1511 / 11
C1512 / 11 Torque sensor malfunction Prohibit steering assist control
C1513 / 11
C1521 / 25
C1522 / 25
Motor malfunction Prohibit steering assist control
C1523 / 24
C1524 / 24
Motor rotation angle sensor
C1528 / 12 Prohibit steering assist control
malfunction
C1531 / 25
Prohibit steering assist control
C1532 / 25
Protection function which EPS
C1533 / 25 EPS ECU malfunction ECU is canceled. And steering
assist control is continued
Amount of power assist is fixed
C1534 / 25
for a 62.5 mph (100 km/h)
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Fail safe
Fail-safe

DTC No. Detection Item Fail-safe Operation

Amount of power assist is fixed
C1541 / 13 Vehicle speed signal malfunction
for a 62.5 mph (100 km/h)
IG power source voltage
C1551 / 25 Prohibit steering assist control
malfunction
PIG power supply voltage
C1552 / 22 Prohibit steering assist control
malfunction
C1554 / 23 Power supply relay failure Prohibit steering assist control
C1555 / 25 Motor relay welding failure Prohibit steering assist control
Lost communication with VGRS
C1567 / 44
ECU?
C1581 / 26 Assist map number un-writing
Control module communication bus Amount of power assist is fixed
U0073 / 49
off for a 62.5 mph (100 km/h)
Lost communication with cruise
U0104 / 45
control module
Lost communication with fuel
U0105 / 41 Prohibit steering assist control
injector control module
 Model Outline Engine Chassis
Engine Chassis
Body Body Electrical
Steering
Fail safe
Fail-safe

DTC No. Detection Item Fail-safe Operation

Lost communication with anti-lock
Amount of power assist is fixed
U0121 / 42 brake system (ABS) control
for a 62.5 mph (100 km/h)
module
U0122 / 42
Lost communication with steering
U0130 / 44
effort control module
U0405 / 45
Assist current to the motor is
⎯ •Motor overheating
limited until temperature falls
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Perform the initialization and calibration of EPS system in the
following cases
Remove, install or Using the Hand-held Tester or
replacing Intelligent Tester-II

• Steering Wheel
• Steering column
assy
• Steering gear assy

Click!

EPS ECU

Replace the new one Using

i the
h SST

NOTE: These operation cannot be performed when the DTCs are

Click!
outputted except C1515 / C1525
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the Hand-held tester

TRQ SENSOR ADJUST CAUTION TRQ SENSOR ADJUST

This function is used for the Check the following

following conditions. initial conditions.
-“Gear ASSY” or “EMPS ECU” -No DTCs except
was exchanged.
exchanged C1515/C1525/C1581 * NOW PROCESSING *
-Difference of steering control effort were detected.
from left to right exists. -Vehicle is stopped.
-Power Switch is ON,
READY or Engine idling.
PRESS [ENTER]
PRESS [ENTER]
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the Hand-held tester

TRQ SENSOR ADJUST TRQ SENSOR ADJUST TRQ SENSOR ADJUST

Turn Power Switch -Check PS warning -Turn the steering

OFF and ON. light is ON. wheel to the left
-Center the steering wheel. greater than
45 degrees
degrees.
-Turn the steering
back to the center.

PRESS [ENTER] PRESS [ENTER] PRESS [ENTER]

 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the Hand-held tester

TRQ SENSOR ADJUST TRQ SENSOR ADJUST TRQ SENSOR ADJUST

-Turn the steering -Center the steering wheel.

wheel to the right -Remove hands from the steering
greater than wheel.
45 degrees
degrees. * NOW PROCESSING * The steering wheel
-The
-Turn the steering will vibrate.
back to the center. -Do not touch during vibration.
TIME REMAINING:

[30 ] SEC
SEC. PRESS [ENTER]
PRESS [ENTER]
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the Hand-held tester

TRQ SENSOR ADJUST TRQ SENSOR ADJUST TRQ SENSOR ADJUST

Press [ENTER]
after the steering
vibration has
stopped
stopped. * NOW PROCESSING * COMPLETE

TIME REMAINING:

[ 4 ] SEC
SEC.
PRESS [ENTER] PRESS [ENTER]
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the intelligent tester-II

Select
Chassis
↓
EPS
↓
Utility
↓
Torque Sensor
Adjustment

Click!
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the intelligent tester-II
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the intelligent tester-II
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the intelligent tester-II
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the intelligent tester-II
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the intelligent tester-II
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the intelligent tester-II
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the intelligent tester-II

10
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the intelligent tester-II

10
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the intelligent tester-II
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the intelligent tester-II
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the intelligent tester-II

10
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the intelligent tester-II
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the intelligent tester-II
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– If DTCs are outputted except C1515 / C1525
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the SST (09083-18040)
1. Initialization of EPS ECU
1. Connect terminals Tc,Ts and CG 2. Disconnect and connect terminal
and turn the ignition switch to ON Tc 20 times within 20sec.

CG

3. Confirm the P/S warning light

Ts Tc indicates

P/S

4 Turn the
4. h ignition
i i i switch
i h to OFF
O
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the SST (09083-18040)
2. Calibration of motor rotation angle sensor
1. Connect terminals Ts and CG 2. Turn the steering 45 degree
and turn the ignition switch to ON or more (both side)

CG N

Ts
 Model Outline THS-II
Engine Chassis
Engine Chassis
Body Body Electrical
Service Point (Steering)
Initialization and Calibration
– Using the SST (09083-18040)
3. Calibration of torque sensor
1. Connect terminal Tc after 2. Confirm the P/S warning light
calibration of motor rotation blinks
angle sensor

CG
P/S

3. Disconnect SST and turn the

Ts ignition switch to OFF