Infiniti G37 Coupe. Manual - part 1279

4WAS MAIN CONTROL UNIT

STC-167

< ECU DIAGNOSIS >

[WITH 4WAS]

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

C1925

AD CONVERTER

STC-92, "DTC Logic"

C1926

STEERING ANGLE SEN

STC-123, "DTC Logic"

C1927

CONTROL UNIT
[ABNORMAL5]

STC-87, "DTC Logic"

C1928

CONTROL UNIT
[ABNORMAL9]

STC-92, "DTC Logic"

C1930

4WAS FRONT ECU

STC-126, "DTC Logic"

C1931

4WAS FRONT ECU COMM

STC-127, "DTC Logic"

C1932

STEERING ANGLE SEN

STC-123, "DTC Logic"

C1933

CONTROL UNIT

STC-87, "DTC Logic"

U1000

CAN COMM

STC-131, "DTC Logic"

U1010

CONTROL UNIT (CAN)

STC-132, "DTC Logic"

DTC

Items 

(CONSULT-III screen terms)

Reference

STC-168

< SYMPTOM DIAGNOSIS >

[WITH 4WAS]

4WAS SYMPTOMS

SYMPTOM DIAGNOSIS

4WAS SYMPTOMS

Symptom Table

INFOID:0000000001666488

If 4WAS warning lamp turns ON, perform self-diagnosis

Symptom

Condition

Check item

Reference

4WAS warning lamp does not turn on.
(4WAS warning lamp does not turn ON 
when turning ignition switch ON from OFF)

Ignition switch: ON

4WAS system power supply and ground

STC-169, "De-

scription"

Unified meter and A/C amp.

CAN communication line

Combination meter

4WAS main control unit

4WAS warning lamp does not turn off.

Engine running

4WAS main control unit self-diagnosis

STC-170, "De-

scription"

4WAS front control unit self-diagnosis

Steering wheel miss alignment
(The steering wheel position (center) is in 
the wrong position at driving)

Driving

Return to 4WAS front actuator initial po-
sition

STC-171, "De-

scription"

4WAS system condition

Steering system

Wheel alignment

4WAS front actuator adjustment

4WAS system ignition power supply

4WAS system 4WAS front motor power 
supply

4WAS system incomplete lock release

4WAS system history inspection

Steering system vibration and noise
(Vibration or noise occurs in the steering 
wheel while driving the vehicle.)

Driving

4WAS system protection function mode

STC-173, "De-

scription"

4WAS front actuator control stopped

Unbalance steering wheel turning force
(torque variation)

Driving

Vehicle speed signal

STC-174, "De-

scription"

Steering system

Power steering solenoid valve

4WAS WARNING LAMP DOES NOT TURN ON

STC-169

< SYMPTOM DIAGNOSIS >

[WITH 4WAS]

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

4WAS WARNING LAMP DOES NOT TURN ON

Description

INFOID:0000000001666489

• 4WAS warning lamp does not turn ON when turning ignition switch ON from OFF.

Diagnosis Procedure

INFOID:0000000001666490

1.

CHECK 4WAS SYSTEM POWER SUPPLY AND GROUND CIRCUIT

With CONSULT-III

Perform the trouble diagnosis of the power supply and ground circuit.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace the specific malfunctioning part.

2.

CHECK 4WAS WARNING LAMP

With CONSULT-III

Perform the trouble diagnosis of 4WAS warning lamp. Refer to 

STC-140, "Diagnosis Procedure"

.

Is the inspection result normal?

YES

>> Check that there is no malfunction in each harness connector pin terminal or disconnection.

NO

>> Repair or replace the specific malfunctioning part.

STC-170

< SYMPTOM DIAGNOSIS >

[WITH 4WAS]

4WAS WARNING LAMP DOES NOT TURN OFF

4WAS WARNING LAMP DOES NOT TURN OFF

Description

INFOID:0000000001666491

• 4WAS system stops (error) when turning 4WAS warning lamp ON.

Diagnosis Procedure

INFOID:0000000001666492

1.

PERFORM SELF-DIAGNOSIS (4WAS MAIN CONTROL UNIT)

With CONSULT-III

Perform 4WAS main control unit self-diagnosis.

Is any DTC detected other than “C1930” or “C1931”?

YES

>> GO TO 2.

NO

>> GO TO 3.

2.

PERFORM TROUBLE DIAGNOSIS (4WAS MAIN CONTROL UNIT)

With CONSULT-III

1.

Check the error system detected from the self-diagnosis.

2.

Perform 4WAS main control unit self-diagnosis again after the inspection.

Is any error system detected?

YES

>> Check the error system.

NO

>> GO TO 3.

3.

PERFORM SELF-DIAGNOSIS (4WAS FRONT CONTROL UNIT)

With CONSULT-III

Perform 4WAS front control unit self-diagnosis.

Is any error system detected?

YES

>> Check the error system.

NO

>> GO TO 4.

4.

PERFORM SELF-DIAGNOSIS (4WAS MAIN CONTROL UNIT)

With CONSULT-III

Perform 4WAS main control unit self-diagnosis.
Is any error system detected?

YES

>> Check the error system.

NO

>> Check that there is no malfunction in each harness connector pin terminal or disconnection.