Infiniti G37 Coupe. Manual - part 271

BRC-58

< COMPONENT DIAGNOSIS >

[VDC/TCS/ABS]

C1142 PRESS SENSOR

NO

>> Replace stop lamp switch.

3.

CHECK STOP LAMP SWITCH CIRCUIT

1.

Disconnect ABS actuator and electric unit (control unit) connector.

2.

Connect stop lamp switch connector.

3.

Check voltage between ABS actuator and electric unit (control unit) harness connector terminal and
ground.

Is the inspection result normal?

YES

>> Replace ABS actuator and electric unit (control unit).

NO

>> Repair or replace malfunctioning components.

Component Inspection

INFOID:0000000001635098

1.

CHECK DATA MONITOR

On “DATA MONITOR”, select “PRESS SENSOR” and check the brake fluid pressure.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Go to diagnosis procedure. Refer to 

BRC-57, "Diagnosis Procedure"

.

Special Repair Requirement

INFOID:0000000001635099

1.

ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION

Always perform the neutral position adjustment for the steering angle sensor, when replacing the ABS actua-
tor and electric unit (control unit). Refer to 

BRC-8, "ADJUSTMENT OF STEERING ANGLE SENSOR NEU-

TRAL POSITION : Description"

.

>> END

ABS actuator and electric unit (control unit)

Condition

Voltage

Connector

Terminal

E41

30

Brake pedal is depressed

Battery voltage

Brake pedal is released

Approx. 0 V

Condition

PRESS SENSOR

(DATA MONITOR)

With ignition switch turned ON and brake pedal released.

Approx. 0 bar

With ignition switch turned ON and brake pedal depressed.

−

 40 to 300 bar

C1143, C1144 STEERING ANGLE SENSOR

BRC-59

< COMPONENT DIAGNOSIS >

[VDC/TCS/ABS]

C

D

E

G

H

I

J

K

L

M

A

B

BRC

N

O

P

C1143, C1144 STEERING ANGLE SENSOR

Description

INFOID:0000000001635100

The steering angle sensor detects the rotation amount, angular velocity and direction of the steering wheel,
and transmits the data to the ABS actuator and electric unit (control unit) via CAN communication.

DTC Logic

INFOID:0000000001635101

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

CHECK SELF-DIAGNOSIS RESULTS

Check the self-diagnosis results.

Is above displayed on the self-diagnosis display?

YES

>> Proceed to diagnosis procedure. Refer to 

BRC-59, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000001635102

1.

VEHICLE INSPECTION

Check that the vehicle equips 4WAS.

Does the vehicle equips 4WAS?

YES

>> Check 4WAS system. Refer to 

STC-39, "CONSULT-III Function [4WAS(FRONT)]"

 (4WAS

FRONT CONTROL UNIT), 

STC-43, "CONSULT-III Function [4WAS(MAIN)/RAS/HICAS]"

 (4WAS

MAIN CONTROL UNIT).

NO

>> GO TO 2.

2.

CHECK CONNECTOR

1.

Turn ignition switch OFF.

2.

Disconnect ABS actuator and electric unit (control unit) connector.

3.

Disconnect steering angle sensor connector.

4.

Check terminal for deformation, disconnection, looseness, and so on. If any malfunction is found, repair or
replace terminal.

5.

Reconnect connectors and then perform the self-diagnosis.

Is any item indicated on the self-diagnosis display?

YES

>> GO TO 3.

NO

>> Poor connection of connector terminal. Repair or replace connector.

3.

CHECK STEERING ANGLE SENSOR HARNESS

1.

Turn ignition switch OFF.

2.

Disconnect steering angle sensor connector.

3.

Check continuity between steering angle sensor harness connector terminal and ground.

DTC

Display item

Malfunction detected condition

Possible cause

C1143

ST ANG SEN CIRCUIT

Steering angle sensor is malfunctioning.

• Harness or connector
• Steering angle sensor
• 4WAS control unit (4WAS 

models)

• ABS actuator and electric unit 

(control unit)

C1144

ST ANG SEN SIGNAL

Neutral position of steering angle sensor is not finished.

Self-diagnosis results

ST ANG SEN CIRCUIT

ST ANG SEN SIGNAL

BRC-60

< COMPONENT DIAGNOSIS >

[VDC/TCS/ABS]

C1143, C1144 STEERING ANGLE SENSOR

4.

Turn ignition switch ON.

5.

Check voltage between steering angle sensor harness connector terminal and ground.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Replace steering angle sensor and adjust neutral position of steering angle sensor.

4.

CHECK DATA MONITOR

1.

Connect the steering angle sensor connector and ABS actuator and electric unit (control unit) connector.

2.

Select “STR ANGLE SIG” in “DATA MONITOR” and check steering angle sensor signal.

Is the inspection result normal?

YES

>> Replace ABS actuator and electric unit (control unit).

NO

>> Replace steering angle sensor and adjust neutral position of steering angle sensor.

Component Inspection

INFOID:0000000001635103

1.

CHECK DATA MONITOR

Select “STR ANGLE SIG” in “DATA MONITOR” and check steering angle sensor signal.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Go to diagnosis procedure. Refer to 

BRC-59, "Diagnosis Procedure"

.

Special Repair Requirement

INFOID:0000000001635104

1.

ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION

Always perform the neutral position adjustment for the steering angle sensor, when replacing the steering
angle sensor or the ABS actuator and electric unit (control unit). Refer to 

BRC-8, "ADJUSTMENT OF STEER-

ING ANGLE SENSOR NEUTRAL POSITION : Description"

.

>> END

Steering angle sensor

—

Continuity

Connector

Terminal

M37

7

Ground

Existed

Steering angle sensor

—

Voltage

Connector

Terminal

M37

8

Ground

Battery voltage

Steering condition

STR ANGLE SIG (DATA MONITOR)

Straight-ahead

±

2.5 

°

Turn 90 

°

 to right

Approx. +90 

°

Turn 90 

°

 to left

Approx. 

−

90 

°

Steering condition

STR ANGLE SIG (DATA MONITOR)

Straight-ahead

±

2.5 

°

Turn 90 

°

 to right

Approx. +90 

°

Turn 90 

°

 to left

Approx. 

−

90 

°

C1145, C1146 YAW RATE/SIDE G SENSOR

BRC-61

< COMPONENT DIAGNOSIS >

[VDC/TCS/ABS]

C

D

E

G

H

I

J

K

L

M

A

B

BRC

N

O

P

C1145, C1146 YAW RATE/SIDE G SENSOR

Description

INFOID:0000000001635105

The yaw rate/side G sensor detects the yaw rate/side G affecting the vehicle, and transmits the data to the
ABS actuator and electric unit (control unit) as an analog voltage signal.

DTC Logic

INFOID:0000000001635106

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

CHECK SELF-DIAGNOSIS RESULTS

Check the self-diagnosis results.

Is above displayed on the self-diagnosis display?

YES

>> Proceed to diagnosis procedure. Refer to 

BRC-61, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000001635107

CAUTION:

• Sudden turns (such as spin turns, acceleration turns), drifting, etc., when VDC function is off (VDC

OFF switch “ON”) may cause yaw rate/side G sensor system to indicate a malfunction. However, this
is not a malfunction, if normal operation can be resumed after restarting engine. Then erase memory
of self-diagnosis.

• If vehicle is on turn-table at entrance to parking garage, or on other moving surface, VDC OFF indica-

tor lamp may illuminate and CONSULT-III self-diagnosis may indicate yaw rate sensor system mal-
function. However, in this case there is no malfunction in yaw rate sensor system. Take vehicle off of
turn-table or other moving surface, and start engine. Results will return to normal. And after doing
spin turns or acceleration turns with VDC function is being off (VDC OFF switch “ON”), too, the
results will return to a normal condition by re-starting vehicle.

INSPECTION PROCEDURE

1.

CHECK CONNECTOR

1.

Turn ignition switch OFF.

2.

Disconnect ABS actuator and electric unit (control unit) connector.

3.

Disconnect yaw rate/side G sensor connector.

4.

Check terminal for deformation, disconnection, looseness, and so on. If any malfunction is found, repair or
replace terminal.

5.

Reconnect connectors and then perform the self-diagnosis.

Is any item indicated on the self-diagnosis display?

YES

>> GO TO 2.

NO

>> Poor connection of connector terminal. Repair or replace connector.

2.

CHECK YAW RATE/SIDE G SENSOR POWER SUPPLY CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect yaw rate/side G sensor connector.

DTC

Display item

Malfunction detected condition

Possible cause

C1145

YAW RATE SENSOR

Yaw rate sensor is malfunctioning, or the yaw rate sensor 
signal line is open or shorted.

• Harness or connector
• ABS actuator and electric unit 

(control unit)

• Yaw rate/side G sensor

C1146

SIDE G-SEN CIRCUIT

Side G sensor is malfunctioning, or circuit of side G sen-
sor is open or shorted.

Self-diagnosis results

YAW RATE SENSOR

SIDE G-SEN CIRCUIT