Toyota Camry 2007-2009 Service Manual - Power_Steering

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POWER STEERING – POWER STEERING SYSTEM

POWER STEERING SYSTEM

PRECAUTION

NOTICE:
When disconnecting the cable from the negative (-)
battery terminal, initialize the systems after the cable is
reconnected (See page IN-43).

1. HANDLING PRECAUTIONS FOR STEERING SYSTEM

(a) Care must be taken when replacing parts. Incorrect

replacement may affect the performance of the
steering system and result in driving hazards.

2. HANDLING PRECAUTIONS FOR SRS AIRBAG
SYSTEM

(a) The vehicle is equipped with SRS (Supplemental

Restraint System), such as airbags. If service
operation is not carried out properly, in a step by
step fashion, sudden deployment of the airbags
may result in serious injury. Before servicing
(including removal or installation of parts, inspe ction
or replacement), be sure to read the precautionary
notice for the supplemental restraint system (See
page RS-1).

3. PRECAUTIONS FOR REMOV AL, INST ALLA TION AND
REPLACEMENT OF ELECTRONIC MOTOR POWER
STEERING COMPONENTS

(a) Be sure to turn the front wheels straight ahead when

removing and installing the power steering link
assembly.

(b) If disconnecting the steering intermediate shaft sub-

assembly and the power steering link assembly, be
sure to put matchmarks before starting the
operation.

(c) After replacing the power steering link assembly or

power steering ECU assembly, clear the rotation
angle sensor calibration value, initialize the rotation
angle sensor, and calibrate torque sensor zero point
(See page PS-13).

PS–1

PS

PS

PS–2

POWER STEERING – POWER STEERING SYSTEM

POWER STEERING SYSTEM

Symptom Suspected Area See page

Steering is heavy.

Steering effort differs between right and left or is
uneven.

While driving, steering effort does not change in
accordance with vehicle speed or the steering wheel
does not return properly.

A knocking (or cranking) sound occurs when turning
the steering wheel back and forth while power steering
is in operation.

Noise occurs when turning the steering wheel during
low speed driving.

A high-pitched sound (squeaking) occurs when turning
the steering wheel slowly with the vehicle stopped.

The steering wheel vibrates and noise occurs when
turning the steering wheel from lock to lock.

PROBLEM SYMPTOMS TABLE

HINT:
Use the table below to help determine the cause of the
problem. The numbers indicate likely causes of the problem
in descending order. Check each part in order. If necessary,
repair or replace faulty parts.

1. Front tires (Improperly inflated, unevenly worn) TW-3

2. Front wheel alignment (Incorrect) SP-4

3. Front suspension (Lower ball joint) SP-24

4. Steering column assembly SR-35

5. Torque sensor (Built into steering link assembly) -

6. Power steering motor -

7. Speed sensor -

8. Skid control ECU -

9. Battery and power source system -

10. Power steering ECU power source voltage and relay -

11. Power steering ECU PS-68

1. Calibration of turning angle sensor output and torque sensor
zero point is not completed

2. Front tires (Improperly inflated, unevenly worn) TW-3

3. Front wheel alignment (Incorrect) SP-4

4. Front suspension (Lower ball joint) SP-24

5. Power steering link assembly PS-58

6. Torque sensor (Built into steering link assembly) -

7. Steering column assembly SR-35

8. Power steering motor -

9. Power steering ECU PS-68

1. Front suspension (Lower ball joint) SP-24

2. Speed sensor -

3. Skid control ECU -

4. Combination meter -

5. Engine speed detection circuit -

6. Torque sensor (Built into steering link assembly) -

7. Power steering motor -

8. Power steering ECU PS-68

1. Front suspension (Lower ball joint) SP-24

2. Steering intermediate shaft -

3. Power steering link assembly PS-58

1. Power steering link assembly PS-58

2. Steering column assembly SR-35

1. Power steering motor

1. Power steering link assembly PS-58

2. Steering column assembly SR-35

PS-13

-

POWER STEERING – POWER STEERING SYSTEM

ON-VEHICLE INSPECTION

1. CHECK STEERING EFFORT (TORQUE)
NOTICE:
Some service operations affect the SRS airbags. Be
sure to read the precautionary notice for the SRS
airbags before servicing (See page RS-1).

(a) Stop the vehicle on a level, paved surface and align

the wheels straight ahead.

(b) Disconnect the cable from the negative (-) battery

terminal.

CAUTION:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner
activation.

(c) Remove the steering pad (See page RS-344).
(d) Connect the cable to the negative (-) battery

terminal.

(e) Using a torque wrench, check if the steering wheel

set nut is properly tightened.

Torque: 50 N*m (510 kgf*cm, 37 ft.*lbf)

(f) Turn the power switch on (READY) so that the

power steering is available.

PS–3

C132536

(g) Turn the steering wheel 90 degrees to the right and

check steering effort (torque) while turning. Check in
the opposite direction using the same manner.

Steering effort (Reference):

6.0 N*m (60 kgf*cm, 53 in.*lbf) or less

Inspect the power steering system if the value is not

within the specified range (See page PS-1).
(h) Align the front wheels straight ahead.
(i) Disconnect the cable from the negative (-) battery

terminal.
(j) Install the steering pad (See page RS-346).
(k) Connect the cable to the negative (-) battery

terminal.
(l) Clear the DTCs (See page RS-41).
(m) Perform initialization.

NOTICE:

Some systems need initialization after

reconnecting the cable to the negative battery

terminal (See page IN-43).

(n) Inspect the airbag warning light (See Page RS-33).

PS

PS

PS–4

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

ELECTRONIC POWER STEERING
SYSTEM

PRECAUTION

1. NOTICE FOR INITIALIZATION

(a) When disconnecting the negative (-) battery

terminal, initialize the following systems after the
terminal is reconnected.

System Name See procedure

SFI System (See page IN-43)

2. HANDLING PRECAUTIONS

(a) When handling the electronic parts:

(1) Avoid any impact to electronic parts such as

ECUs and relays. Replace these parts with new
ones if dropped or subjected to a severe blow.

(2) Do not expose any electronic parts to high

temperature or humidity.

(3) Do not touch the connector terminals in order to

prevent deformation or malfunctions due to
static electricity.

(4) If the power steering ECU assembly has been

replaced with a new one, initialize the rotation
angle sensor value and calibrate the torque
sensor zero point (See page PS-13).

(b) When handling the power steering link assembly:

(1) Avoid any impact to the power steering link

assembly, especially to the motor or torque
sensor. Replace these parts with new ones if
dropped or subjected to a severe blow.

(2) Do not pull on the wire harness when moving the

power steering link assembly.

(3) If the power steering link assembly has been

replaced with a new one, clear the rotation angle
sensor calibration value, initialize the rotation
angle sensor value, and calibrate the torque
sensor zero point (See page PS-13).

(c) When disconnecting and reconnecting the

connectors:
(1) Turn the power switch on (IG), center the

steering wheel, and turn the power switch off
again before disconnecting the connectors
related to the electronic power steering system.

(2) Ensure that the power switch is off before

reconnecting the connectors related to the
electronic power steering system. After
reconnection, center the steering wheel and turn
the power switch on (IG).

NOTICE:
Do not turn the power switch on (IG) when
the steering wheel is not centered.

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

(3) If the above operations are not carried out

properly, the steering center point (zero point)
will deviate, which may lead to a difference in
steering effort between right and lef t. If there is a
difference in steering effort between right and
left, perform steering zero point calibration (See
page PS-13).

3. PRECAUTIONS FOR CAN COMMUNICATION

(a) CAN communication is used to receive information

from the skid control ECU, power steering ECU,

hybrid vehicle control ECU, and steering angle

sensor and to transmit warnings to the combination

meter. It is also used for communication between

terminals Tc and Ts of the DLC3. If there are any

problems in the CAN communication lines, DTCs

indicating communication line malfunctions are

output.
(b) Perform troubleshooting for communication line

problems if CAN communication DTCs are output.

Be sure to start troubleshooting on the electronic

power steering system only when data

communication is normal.
(c) Temporary fixing or rep air with byp ass wiring, etc. is

impossible because the length and path of each

CAN communication line is specified.

PS–5

Bypass Wire

F045104E02

4. BUS LINE REPAIR

(a) After repairing the bus line with solder, wrap the

repaired part with electrical tape.

NOTICE:

• The CANL bus line and CANH bus line must
be installed together all the times.
When installing, make sure to twist them.
CAN bus lines are likely to be influenced by
electrical noise if they are not twisted.

• The difference in length between the CANL
bus line and CANH bus line should be 100
mm (3.937 in.) or less.

• Leave approximately 80 mm (3.150 in.) loose
in the twisted wires around the connector.

(b) Do not use bypass wiring between the connectors.

NOTICE:
The ability of the twisted bus lines to resist
interference will be lost if bypass wiring is used.

C106492E01

PS

PS–6

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

PARTS LOCATION

HYBRID VEHICLE CONTROL ECU

POWER STEERING LINK

- TORQUE SENSOR

- POWER STEERING MOTOR

- ROTATION ANGLE SENSOR

COMBINATION METER

- PS WARNING LIGHT

POWER STEERING ECU

SKID CONTROL ECU

PS

DLC3

MAIN BODY ECU (INSTRUMENT PANEL J/B)

B150822E01

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

SYSTEM DIAGRAM

PS–7

Motor Rotation
Angle Sensor

Torque Sensor

Skid Control ECU

Power Steering ECU Assembly

- Motor Relay

- Power Source Relay

- Motor Current Sensor

- Temperature Sensor

EPS Motor

CAN

Steering Angle Sensor

Hybrid Vehicle Control ECU

Combination Meter

Main Body ECU (Instrument Panel J/B)

Transmitting ECU

(transmitter)

Hybrid Vehicle Control ECU Power Steering ECU Assembly T/M variation information signal CAN

Receiving ECU Signals Communication method

PS

B139367E01

PS–8

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

Transmitting ECU

(transmitter)

Hybrid Vehicle Control ECU Power Steering ECU Assembly Ready signal CAN
Hybrid Vehicle Control ECU Power Steering ECU Assembly Ambient temperature signal CAN
Hybrid Vehicle Control ECU Power Steering ECU Assembly Intake air temperature signal CAN

Hybrid Vehicle Control ECU Power Steering ECU Assembly

Hybrid Vehicle Control ECU Power Steering ECU Assembly
Hybrid Vehicle Control ECU Power Steering ECU Assembly TC terminal condition CAN

Skid Control ECU Power Steering ECU Assembly
Skid Control ECU Power Steering ECU Assembly Additional torque target signal CAN

Skid Control ECU Power Steering ECU Assembly Vehicle speed (SP1) status signal CAN
Skid Control ECU Power Steering ECU Assembly Target steering angle signal CAN

Skid Control ECU Power Steering ECU Assembly
Skid Control ECU Power Steering ECU Assembly Vehicle speed (SP1) signal CAN

Skid Control ECU Power Steering ECU Assembly Test mode signal CAN
Skid Control ECU Power Steering ECU Assembly VSC controlling signal CAN

Skid Control ECU Power Steering ECU Assembly ABS controlling signal CAN
Steering Angle Sensor Power Steering ECU Assembly
Steering Angle Sensor Power Steering ECU Assembly +B open circuit signal CAN

Steering Angle Sensor Power Steering ECU Assembly Sensor malfunction signal CAN
Steering Angle Sensor Power Steering ECU Assembly Steering angle signal CAN

Steering Angle Sensor Power Steering ECU Assembly

Steering Angle Sensor Power Steering ECU Assembly

Main Body ECU

(Instrument Panel J/B)

Power Steering ECU Assembly Skid Control ECU EPS pinion angle invalid signal CAN
Power Steering ECU Assembly Skid Control ECU

Power Steering ECU Assembly Skid Control ECU
Power Steering ECU Assembly Hybrid Vehicle Control ECU EPS idle up request signal CAN

Power Steering ECU Assembly Skid Control ECU EPS torque sensor value signal CAN
Power Steering ECU Assembly Skid Control ECU EPS pinion angle signal CAN
Power Steering ECU Assembly Skid Control ECU EPS assisting current signal CAN
Power Steering ECU Assembly Combination Meter EPS light ON request signal CAN
Power Steering ECU Assembly Combination Meter EPS diagnostic information signal CAN

Receiving ECU Signals Communication method

Engine variation information
signal

Vehicle destination information
signal

Output command value (to EPS)
signal

Target steering angle and
additional torque valid signal

Data continuity (valid/invalid)
signal

Zero point memory (in sensor)
valid/invalid signal

Zero point (stored in steering
angle sensor) signal

Power Steering ECU Assembly Vehicle model signal CAN

EPS assisting current invalid
signal

EPS torque sensor value invalid
signal

CAN

CAN

CAN

CAN

CAN

CAN

CAN

CAN

CAN

PS

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

PS–9

SYSTEM DESCRIPTION

1. DESCRIPTION

(a) The EPS system generates assist torque to assist

steering effort through the operation of the motor
installed on the power steering link assembly.
The direction and amount of power assistance are
determined by signals from the torque sensor, and
controlled in accordance with vehicle speed. As a
result, steering effort is controlled to be light during
low speed driving and moderately high during high
speed driving.

2. FUNCTIONS OF COMPONENTS

Components Function

Calculates degree of assistance needed based on steering torque and
vehicle speed. Drives the motor based on motor electric angle

Power Steering ECU Assembly

Torque Sensor Detects steering effort generated when the steering wheel is turned.
Power Steering Motor
Hybrid Vehicle Control ECU Transmits ready signal to the power steering ECU.

obtained from the motor rotation angle sensor.
Boosts battery voltage to generate motor drive voltage.
Restricts power assistance to protect the system if the motor and ECU

overheat.

Located coaxially with the rack shaft. Its rotation is converted to the
rectilinear motion of the steering rack via the ball screw nut and ball.

PS

PS–10

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

3. OPERATION EXPLANATION

Torque Sensor Portion:

Input Shaft

To Power Steering ECU
Assembly

Output Shaft

Torsion Bar

Torque Sensor

PS

Power Steering Motor Portion:

From Power
Steering ECU
Assembly

Ball Screw
Nut

Ball

Steering Rack

Power Steering Motor

To Power Steering ECU
Assembly

Motor Rotation
Angle Sensor

C106460E02

(a) The torque sensors is mounted on the input shaft to

the main shaft and on the output shaft to the pinion
shaft. The input and output shafts are joined by a
torsion bar.

(b) If the steering wheel is turned, the torsion bar twists,

resulting in a difference in the rotation angle
detected by the torque sensor. The power steering
ECU assembly calculates torque based on this
difference.

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

(c) The power steering ECU assembly calculates

proper assisting torque, according to vehicle speed,
based on the torque obtained in the previous step.
Then the ECU controls the motor drive circuit in
order to allow it to generate assisting torque.

(d) A ball screw nut is attached to the motor shaft. It

converts the rotational motion of the motor into the
rectilinear motion of the steering rack via the ball.

(e) The assisting force generated in the above process

will reduce the steering effort required by the driver.

PS–11

PS

PS–12

1

NEXT

2

NEXT

3

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

HOW TO PROCEED WITH
TROUBLESHOOTING

Perform troubleshooting according to the following flowchart.
HINT:

• For further details, see the page given.

• *: Use the intelligent tester.

VEHICLE BROUGHT TO WORKSHOP

CUSTOMER PROBLEM ANALYSIS

CHECK DTC AND FREEZE FRAME DATA*

NEXT

4

NEXT

5

6

NEXT

(a) Record the DTCs and freeze frame data.

CLEAR DTC AND FREEZE FRAME DATA*

PROBLEM SYMPTOM CONFIRMATION

SYMPTOM DOES NOT OCCUR (GO TO STEP

6)

SYMPTOM OCCURS (GO TO STEP 7)

SYMPTOM SIMULATION

PS

CHECK DTC*

7

(a) Recheck for DTCs.

HINT:

• Refer to the diagnostic trouble code chart if any DTCs
are output.

• If any CAN communication system DTCs are output,
perform troubleshooting on the CAN communication
system first (See page CA-7).

8

NEXT

9

NEXT

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

PROBLEM SYMPTOMS TABLE

DTC CHART

PS–13

• If communication to the power steering ECU
assembly is not established through the intelligent
tester, inspect terminals SIL of the DLC3 and power
steering ECU assembly, and inspect the IG circuit of
the power steering ECU assembly.

NORMAL SYSTEM CODE IS OUTPUT : GO T O
STEP 8

TROUBLE CODE IS OUTPUT: GO TO STEP 9

10

NEXT

11

NEXT

12

NEXT

13

NEXT

END

CIRCUIT INSPECTION*

IDENTIFICATION OF PROBLEM

REPAIR OR REPLACE

CONFIRMATION TEST

PS

PS–14

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

CALIBRATION

1. ROTATION ANGLE SENSOR VALUE INITIALIZATION
AND TORQUE SENSOR ZERO POINT CALIBRATION
NOTICE:
Clear the rotation angle sensor calibration value,
initialize the rotation angle sensor value, and
calibrate the torque sensor zero point if any of the
following has occurred:

• The power steering ECU assembly has been

replaced.

• The power steering link assembly has been

replaced.

• Steering effort differs between left and right.

(a) Inspection before calibration

(1) Connect the intelligent tester (with CAN VIM) to

the DLC3.
(2) Turn the power switch on (IG).
(3) Turn the intelligent tester on.
(4) Select "IG SUPPLY" from the data list.
(5) Check the IG power supply voltage on the tester

screen.

PS

DLC3

Intelligent Tester

C131977E01

Tester Display Measurement Item/Range Inspection Condition Reference Value

IG SUPPLY

ECU power source voltage/

Min.: 0 V, Max.: 25.5 V

Power switch on (IG) 10 to 14 V

Standard voltage:

10 to 14 V
NOTICE:
If the IG power supply voltage is 10 V or less,
calibration cannot be performed. In this case,
charge or replace the battery, and then
perform calibration.

DLC3

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

Intelligent Tester

C131977E01

PS–15

(b) Rotation angle sensor calibration value clear,

rotation angle sensor value initialization, and torque
sensor zero point calibration.

NOTICE:

• If DTC C1516 (Torque Sensor Zero Point
Adjustment Incomplete) is stored, the torque
sensor zero point cannot be calibrated. Clear
the DTC before starting calibration.

• If DTC C1526 (Rotation Angle Sensor
Initialization Incomplete) is stored, the
rotation angle sensor value cannot be
initialized. Clear the DTC before starting
initialization.

(1) Connect the intelligent tester (with CAN VIM) to

the DLC3.
(2) Turn the power switch on (IG).
(3) Turn the intelligent tester on.
(4) Select "TRQ SENSOR ADJ".
(5) Follow the procedures on the tester display to

clear the rotation angle sensor calibration value,

initialize the rotation angle sensor value, and

calibrate the torque sensor zero point.

NOTICE:

• When initializing the rotation angle sensor
value, observe the following to stabilize
sensor voltage:
After turning the power switch on (IG),
wait for at least 2.5 seconds before
turning the steering wheel. Do not turn the
steering wheel quickly.

• The steering wheel will vibrate during
torque sensor zero point calibration. Do
not touch the steering wheel while it is
vibrating or for 2 seconds after it stops.

PS

PS–16

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

PROBLEM SYMPTOMS TABLE

ELECTRONIC POWER STEERING SYSTEM

Symptom Suspected Area See page

1. Front tires (Improperly inflated, unevenly worn) TW-3

2. Front wheel alignment (Incorrect) SP-4

3. Front suspension SP-24

4. Power steering link assembly PS-61

Steering is heavy.

Steering effort differs between right and left, or is
uneven.

While driving, steering effort does not change in
accordance with vehicle speed, or the steering wheel
does not return to its centered position easily.

Friction sounds occur when turning the steering wheel
during low speed driving.

High-pitched sounds (squeaking) occur when turning
the steering wheel slowly with the vehicle stopped.

The steering wheel vibrates and noise occurs when
turning the steering wheel with the vehicle stopped.

PS warning light remains on. PS warning light remains on PS-50
PS warning light does not come on. PS warning light does not come on PS-54

5. Steering column assembly SR-35

6. Battery and power source system -

7. Power source voltage of power steering ECU assembly PS-50

8. Power steering ECU assembly PS-68

9. Vehicle condition (The steering wheel is turned from left to
right repeatedly with the vehicles stopped or a heavy load is
continuously applied to the vehicle)

1. Power steering ECU assembly (Steering center point is not
recorded correctly)

2. Front tires (Improperly inflated, unevenly worn) TW-3

3. Front wheel alignment (Incorrect) SP-4

4. Front suspension SP-24

5. Power steering link assembly PS-61

6. Steering column assembly SR-35

7. Power steering ECU assembly PS-68

1. Speed sensor BC-273

2. Skid control ECU BC-289

3. Power steering link assembly PS-61

4. Power steering ECU assembly PS-68

1. Power steering link assembly PS-61

2. Power steering ECU assembly PS-68
Power steering link assembly PS-61

1. Power steering link assembly PS-61

2. Steering column assembly PS-68

-

PS-13

PS

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

TERMINALS OF ECU

1. TERMINALS OF ECU

PS–17

A66 A68

A67

HINT:
The power steering ECU assembly uses waterproof
connectors. Therefore, voltage or waveforms cannot be
checked with the connectors connected to the vehicle.

Terminal No. (Symbols) Wiring Color Terminal Description

A66-2 (CANH) B High-level CAN bus line
A66-3 (CANL) W Low-level CAN bus line

A66-4 (PIG) W Power source

A66-5 (PGND) B Power ground

A66-9 (IG) O IG power source

A67-1 (RZG) W Rotation angle sensor power source circuit ground

A67-2 (SRZG) BR Rotation angle sensor shield ground

A67-3 (RZV) G Rotation angle sensor power source
A67-4 (TRQV) P Torque sensor power source
A67-6 (TQG1) L Torque sensor power source circuit ground
A67-7 (RZSN) B SIN phase input signal (Rotation angle sensor)
A67-8 (RZCS) R COS phase input signal (Rotation angle sensor)

A67-9 (INSN) B SIN phase input signal (Torque sensor input shaft side)

A67-10 (INCS) R COS phase input signal (Torque sensor input shaft side)

A67-11 (OUSN) W SIN phase input signal (Torque sensor output shaft side)
A67-12 (OUCS) G COS phase input signal (Torque sensor output shaft side)
A67-13 (TQG2) Y Torque sensor detection circuit ground

A68-1 (V) R V phase motor output

A68-2 (U) B U phase motor output

A68-3 (W) W W phase motor output

C116647E02

A66

2. INSPECT WIRE HARNESS SIDE CONNECTOR

A68

A67

PS

C116648E02

PS–18

Terminal No. (Symbols) Wiring Color Terminal Description Condition Specified Conditi on

A66-4 (PIG) - A66-5 (PGND) W - B Power source Always 10 to 14 V

A66-5 (PGND) - Body ground B - Body ground Power ground Always Below 1 Ω

A66-9 (IG) - A66-5 (PGND) O - B IG power source Power switch on (IG) 10 to 14 V
A68-2 (U) - A68-3 (W)/A68-1 (V) B - W/R U phase motor output Always Below 1 Ω
A68-3 (W) - A68-2 (U)/A68-1 (V) W - BR W phase motor output Always Below 1 Ω

A68-1 (V) - A68-2 (U)/ A68-3 (W) R - B/W V phase motor output Always Below 1 Ω

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

DIAGNOSIS SYSTEM

CG

SG

CANH

SIL

1. CHECK DLC3

(a) The vehicle's ECU uses ISO 15765-4 for

communication protocol. The terminal arrangement
of the DLC3 complies with SAE J1962 and matches
the ISO 15765-4 format.

CANL

Symbols (Terminal No.) Terminal Description Condition Specified Condition

SIL (7) - SG (5) Bus "+" line During transmission Pulse generation
CG (4) - Body ground Chassis ground Always Below 1 Ω
SG (5) - Body ground Signal ground Always Below 1 Ω

BAT (16) - Body ground Battery positive Always 10 to 14 V

CANH (6) - CANL (14) CAN bus line

CANH (6) - CG (4) HIGH-level CAN bus line

CANL (14) - CG (4) LOW-level CAN bus line

CANH (6) - BAT (16) HIGH-level CAN bus line

CANL (14) - BAT (16) LOW-level CAN bus line

BAT

H100769E16

Power switch off
Power switch off
Power switch off
Power switch off
Power switch off

*

*

*

*

*

54 to 69 Ω
200 Ω or higher
200 Ω or higher

6 kΩ or higher
6 kΩ or higher

NOTICE:
*: Before measuring the resistance, leave the
vehicle as is for at least 1 minute and do not
operate the power switch, any other switches or
the doors.

If the result is not as specified, the DLC3 may have
a malfunction. Repair or replace the harness and
connector.

PS

DLC3

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

Intelligent Tester

C131977E01

B150816

(b) Connect the cable of the intelligent tester (with CAN

VIM) to the DLC3, turn the power switch on (IG) and
attempt to use the intelligent tester. If the screen
displays a communication error message, a
problem exists in the vehicle side or tester side.
HINT:

• If communication is normal when the tool is
connected to another vehicle, inspect the DLC3
on the original vehicle.

• If communication is still impossible when the tool
is connected to another vehicle, the problem is
probably in the tool itself. Consult the Service
Department listed in the tool's instruction manual.

2. P/S WARNING LIGHT

(a) Check that the PS warning light comes on when the

power switch is turned on (IG) and goes off in
approximately 3 seconds.
If the warning light does not come on or remains on,
inspect the PS warning light circuit.

Trouble Area See Procedure

PS warning light circuit (Remains on) PS-50
PS warning light circuit (Does not come

on)

PS-54

PS–19

DLC3

DTC CHECK / CLEAR

1. CHECK FOR DTCs

(a) Connect the intelligent tester (with CAN VIM) to the

DLC3.
(b) Turn the power switch on (IG).
(c) Turn the intelligent tester on.
(d) Read the DTCs by following the display on the

intelligent tester.

HINT:

Refer to the intelligent tester operator's manual for

further details.

Intelligent Tester

C131977E01

PS

PS–20

DLC3

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

2. CLEAR DTCs

(a) Connect the intelligent tester (with CAN VIM) to the

DLC3.
(b) Turn the power switch on (IG).
(c) Turn the intelligent tester on.
(d) Clear the DTCs by following the display on the

intelligent tester.

HINT:

Refer to the intelligent tester operator's manual for

further details.

Intelligent Tester

C131977E01

PS

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

FREEZE FRAME DATA

1. FREEZE FRAME DATA
NOTICE:

• It is difficult to show the specified values

(judgement values) clearly because freeze frame
data values change significantly due to
differences in measurement conditions,
surroundings, or vehicle conditions. For this
reason, there may be a problem even when the
values are within specifications.

• T urn the power switch on (IG) and p ark the vehicle

on level ground. Check the freeze frame data by
using the intelligent tester.

(a) Connect the intelligent tester (with CAN VIM) to the

DLC3.

(b) Turn the power switch on (IG) and check the freeze

frame data by following the prompts on the
intelligent tester's display screen.

PS–21

DLC3

Intelligent Tester

Tester Display Item Description/Range Inspection Condition Reference Value

SPD

ENGINE REV

MOTOR ACTUAL

COMMAND VALUE

STR ANGL VEL

THERMISTOR TEMP

PIG SUPPLY

IG SUPPLY

STR SENS SIG

TRQ1

C131977E01

Vehicle speed from meter/
Min.: 0 km/h (0 mph), Max.: 300
km/h (186 mph)

Engine revolution/
Min.: 0 rpm, Max.: 12.800 rpm

Amount of current to motor/
Min.: -128 A, Max.: 127 A

Demanded amount of current to
motor/
Min.: -128 A, Max.: 127 A

Steering angle speed/
Min.: -4.096 deg/sec, Max.: 4.064
deg/sec

ECU substrate temperature/
Min.: -50°C, Max.: 205°C

Power source voltage to activate
motor/
Min.: 0 V, Max.: 25.5 V

ECU power source voltage/
Min.: 0 V, Max.: 25.5 V

Steering angle sensor signal
status/
OK or NG

Torque sensor 1 rotation angle/
Min.: 0 deg, Max.: 360 deg

1. Vehicle is stopped

2. V ehicle is driven at a constant
speed

Engine is running at a constant
speed

Power steering is in operation

Power steering is in operation

Steering wheel is turned

Power switch on (IG) -

Power steering is in operation 10 to 14 V

Power switch on (IG) 10 to 14 V

--

Steering wheel is turned

1. 0 km/h (0 mph)

2. No significant fluctuation

No significant fluctuation
Value changes in proportion to

steering effort
Value changes in proportion to

steering effort

Value changes in proportion to
steering speed

Value changes from 0 to 360°
every 22.5° of steering angle

PS

PS–22

Tester Display Item Description/Range Inspection Condition Reference Value

TRQ2

TRQ1 ZERO VAL

TRQ2 ZERO VAL

STEERING TORQU

MOTOR ROTATE

COMMAND VALUE 2

PIG2 VOLTAGE

MOTOR VOLTAGE

MTR TERMINAL (U)

MTR TERMINAL (V)

MTR TERMINAL (W)

IG ON/OFF TIMES

MTR OVERHEAT

MTR LOW POWER

ENG REV INTER

STR ANGL INTER

SPD SIG INVALID

BATTERY VOLTAGE

PS ASSIST SIG

# CODES

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

Torque sensor 2 rotation angle/
Min.: 0 deg, Max.: 360 deg

Zero point value of torque sensor
1/
Min.: 0 deg, Max.: 360 deg

Zero point value of torque sensor
2/
Min.: 0 deg, Max.: 360 deg

Steering torque/
Min.: -7.0 N*m, Max.: 7.0 N*m

Motor rotation angle/
Min.: 0 deg, Max.: 360 deg

Demanded amount of current to
motor 2/
Min.: -128 A, Max.: 127 A

Motor drive voltage/
Min.: 0 V, Max.: 64 V

Motor power source voltage/
Min.: 0 V, Max.: 64 V

Motor terminal voltage (U phase)/
Min.: 0 V, Max.: 64 V

Motor terminal voltage (V phase)/
Min.: 0 V, Max.: 64V

Motor terminal voltage (W phase)/
Min.: 0 V, Max.: 64 V

Number of times IG switch is
turned on after DTC detection/
Min.: 0 time, Max.: 255 times

Continuous overheat prevention
control record/
REC or UNREC

PIG power source voltage drop
record/
REC or UNREC

Record of power revolution signal
interruption/
REC or UNREC

Record of steering angle sensor
signal interruption/
REC or UNREC

Record of vehicle speed signal
invalid/
REC or UNREC

Battery voltage/
Min.: 0 V, Max.: 25.5 V

Power steering assist signal/
ON or OFF

Number of detected DTCs when
freeze frame data is stored/
Min.: 0, Max.: 255

Steering wheel is turned

Steering wheel is not turned
(without load)

Steering wheel is not turned
(without load)

Steering wheel is turned

Steering wheel is turned

--

Power steering is in operation 27 to 34 V

Power steering is in operation 27 to 34 V

Power steering is in operation 0 to 34 V

Power steering is in operation 0 to 34 V

Power steering is in operation 0 to 34 V

--

--

--

--

--

--

- 10 to 14 V

Power switch on (IG) -

--

Value changes from 0 to 360°
every 22.5° of steering angle

Values differ depending on
vehicle

Values differ depending on
vehicle

Value changes in proportion to
steering effort

Value changes from 0 to 360°
every 5° of steering angle

PS

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

FAIL-SAFE CHART

If a problem occurs in the electronic power steering system,
the PS warning light will come on in the combination meter
and steering power assistance will be stopped, fixed at a
particular point, or decreased simultaneously to protect the
system.

DTC No. Malfunction Fail-safe

C1511
C1512
C1513
C1521
C1522
C1523
C1524
C1528 Motor Rotation Angle Sensor Malfunction
C1531
C1532
C1555 Motor Relay Welding Failure

C1533 ECU Malfunction

C1534 ECU Malfunction

C1541 Vehicle Speed Signal Malfunction
U0129 Lost Communication With Skid Control ECU

Torque Sensor Circuit Malfunction

Motor Circuit Malfunction

ECU Malfunction

Power assistance stops.

System overheat prevention control continues
without using the substrate temperature
sensor.

Torque sensor zero point and rotation angle
sensor calibration value are set to the default
values.

Amount of power assistance is fixed for a
speed of 100 km/h (62 mph).

PS–23

HINT:
The amount of power assistance may be decreased to
prevent the motor and ECUs from overheating if the steering
wheel is continuously turned when the vehicle is either
stopped or driven at a low speed, or if the steering wheel is
kept at either full lock position for a long time. In that case, the
amount of power assistance will return to normal if the
steering wheel is not turned for approximately 10 minutes
with the engine idling.

PS

PS–24

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

DATA LIST / ACTIVE TEST

1. DATA LIST

HINT:
By accessing the data list displayed on the intelligent
tester, values of switches, sensors and other related
parts can be checked without removing any parts.
Reading the data list is the first step in troubleshooting
and is one method to shorten labor time.

(a) Connect the intelligent tester (with CAN VIM) to the

DLC3.
(b) Turn the power switch on (IG).
(c) Operate the intelligent tester according to the steps

on the display and select the data list.

PS

DLC3

Intelligent Tester

Tester Display Measurement Item/Range Normal Condition Reference Value

SPD

ENGINE REV

MOTOR ACTUAL

COMMAND VALUE

STR ANGL VEL

THERMISTOR TEMP

PIG SUPPLY

IG SUPPLY

STR SENS SIG

TRQ1

TRQ2

TRQ1 ZERO VAL

C131977E01

Vehicle speed from meter/
Min.: 0 km/h (0 mph), Max.: 300
km/h (186 mph)

Engine revolution/
Min.: 0 rpm, Max.: 12.800 rpm

Amount of current to motor/
Min.: -128 A, Max.: 127 A

Demanded amount of current to
motor/
Min.: -128 A, Max.: 127 A

Steering angle speed/
Min.: -4.096 deg/sec, Max.: 4.064
deg/sec

ECU substrate temperature/
Min.: -50°C, Max.: 205°C

Power source voltage to activate
motor/
Min.: 0 V, Max.: 25.5 V

ECU power source voltage/
Min.: 0 V, Max.: 25.5 V

Steering angle sensor signal
status/
OK or NG

Torque sensor 1 rotation angle/
Min.: 0 deg, Max.: 360 deg

Torque sensor 2 rotation angle/
Min.: 0 deg, Max.: 360 deg

Zero point value of torque sensor
1/
Min.: 0 deg, Max.: 360 deg

1. Vehicle is stopped

2. V ehicle is driven at a const ant
speed

Engine is running at a constant
speed

Power steering is in operation

Power steering is in operation

Steering wheel is turned

Power switch on (IG) -

Power steering is in operation 10 to 14 V

Power switch on (IG) 10 to 14 V

--

Steering wheel is turned

Steering wheel is turned

Steering wheel is not turned
(without load)

1. 0 km/h (0 mph)

2. No significant fluctuation

No significant fluctuation
Value changes in proportion to

steering effort
Value changes in proportion to

steering effort

Value changes in proportion to
steering speed

Value changes from 0 to 360°
every 22.5° of steering angle

Value changes from 0 to 360°
every 22.5° of steering angle

Values differ depending on
vehicle