Infiniti G35 (V35) Sedan. Manual - part 1291

STC-54

< COMPONENT DIAGNOSIS >

[WITH 4WAS]

C1628 4WAS FRONT ACTUATOR

1.

Start the engine.

CAUTION:

Stop the vehicle.

2.

Steer to the straight-ahead position. Then turn the ignition switch OFF.

3.

Disconnect 4WAS front actuator harness connector.

4.

Apply 12 V current between 4WAS front actuator harness connector No. 10 terminal (positive) and NO. 3
terminal (negative).(Release the lock structure.)

CAUTION:

• Never make the terminals short.
• Connect the fuse between the terminals when applying the voltage.

5.

Slowly steer rightward and leftward alternately. Check the resistance between 4WAS front actuator har-
ness connectors.

CAUTION:

The steering angle must be within 10

°

 rightward and leftward.

6.

Connect 4WAS front actuator harness connector.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace 4WAS front actuator. Refer to 

ST-21, "WITH 4WAS : Exploded View"

.

Special Repair Requirement

INFOID:0000000000958757

AFTER REPLACING 4WAS FRONT ACTUATOR

• Perform 4WAS front actuator adjustment after replacing 4WAS front actuator. Refer to 

STC-28, "4WAS

FRONT ACTUATOR NEUTRAL POSITION ADJUSTMENT : Special Repair Requirement (Pattern 2)"

.

BEFORE REPLACING 4WAS FRONT CONTROL UNIT

• Record the self-diagnosis results (history).

CAUTION:

• Replace it without erasing the memory (history) of self-diagnosis results when replacing 4WAS

front control unit after diagnosis.

• Erase the memory of the self-diagnosis results (record) after printing out or recording all the val-

ues of “DATA MONITOR” when erasing the memory of the self-diagnosis results (record).

AFTER REPLACING 4WAS FRONT CONTROL UNIT

• Perform 4WAS front actuator adjustment after replacing 4WAS front control unit. Refer to 

STC-28, "4WAS

FRONT ACTUATOR NEUTRAL POSITION ADJUSTMENT : Special Repair Requirement (Pattern 3)"

.

4WAS front actuator

Resistance (Ap-

prox.)

Connector

Terminal

Connector

Terminal

M351

2

M351

7

1 k – 100 k

Ω

4

7

8

7

C1631, C1632 4WAS FRONT CONTROL UNIT

STC-55

< COMPONENT DIAGNOSIS >

[WITH 4WAS]

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

C1631, C1632 4WAS FRONT CONTROL UNIT

Description

INFOID:0000000000958758

• Each sensor signal controls 4WAS front actuator.
• The fail-safe functions stops the rear wheel angle (the front wheel is the steering wheel cutting angle) when

the electric components and the mechanical components are malfunctioning.

• The protection function mode stops 4WAS system intermittently when 4WAS system continues high loaded

condition and overheat condition or the input signal does not transmit to 4WAS front control unit.

• 4WAS front control unit and 4WAS main control unit control the best control of 4WAS system by 4WAS com-

munication line.

DTC Logic

INFOID:0000000000958759

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

RECHECK DTC

 With CONSULT-III

1.

Turn the ignition switch OFF to ON.

2.

Perform 4WAS front control unit self-diagnosis.

Is DTC “C1631” or “C1632” detected?

YES

>> Proceed to diagnosis procedure. Refer to 

STC-55, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000000958760

1.

CHECK 4WAS FRONT CONTROL UNIT POWER SUPPLY

1.

Turn the ignition switch OFF.

2.

Disconnect 4WAS front control unit harness connector.

3.

Check the voltage between 4WAS front control unit harness connector terminal and ground.

4.

Turn the ignition switch ON.

CAUTION:

Never start the engine.

5.

Check the voltage between 4WAS front control unit harness connector terminal and ground.

DTC

Items

(CONSULT-III screen terms)

Diagnostic item is detected when...

Possible cause

C1631

CONTROL UNIT

An error is detected inside 4WAS front control unit.

4WAS front control unit or 
4WAS front control unit 
power supply error is de-
tected.

C1632

CONTROL UNIT

An error is detected inside 4WAS front control unit.

4WAS front control unit or 
4WAS front control unit 
power supply error is de-
tected.

4WAS front control unit

Voltage (Approx.)

Connector

Terminal

M203

11 – Ground

Battery voltage

M204

15 – Ground

0 V

STC-56

< COMPONENT DIAGNOSIS >

[WITH 4WAS]

C1631, C1632 4WAS FRONT CONTROL UNIT

Is the inspection result normal?

YES

>> GO TO 2.

NO

>>

Check the following items. Repair or replace the malfunctioning parts.

• 40A fusible link (#I) open
- Short among 40A fusible link (#I) connector, 4WAS front control unit harness connector No. 11

terminal and the ground

• Open between the battery and 4WAS front control unit harness connector No. 11 terminal
• 10A fuse (#3) open
- Short among 10A fuse (#3) connector, 4WAS front control unit harness connector No. 15 termi-

nal and the ground

- Short among 10A fuse (#3) connector, unified meter and A/C amp harness connector No. 53

terminal and the ground

• Open between the ignition switch and 4WAS front control unit harness connector No. 15 termi-

nal

• Battery or ignition switch

2.

CHECK 4WAS FRONT CONTROL UNIT GROUND

Check the continuity between 4WAS front control unit harness connector terminal and the ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace the harnesses and connectors.

3.

CHECK TERMINAL

Check 4WAS front control unit harness connector pin terminal and connection for disconnection.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair or replace the specific malfunctioning part.

4.

CHECK INFORMATION

• Check that any item below is applicable when the malfunctions occur.
- The engine stall occurs while driving or stopping the vehicle.
- When detecting the charging system error
Is the item applicable?

YES

>>

Check the error system.

• Perform ECM symptom diagnosis. Refer to 

EC-531, "Symptom Table"

.

• Perform the symptom diagnosis for the charging system. Refer to 

CHG-18, "Symptom Table"

.

NO

>> Replace 4WAS front control unit. Refer to 

STC-177, "Exploded View"

.

Special Repair Requirement

INFOID:0000000000958761

BEFORE REPLACING 4WAS FRONT CONTROL UNIT

• Record the self-diagnosis results (history).

CAUTION:

• Replace it without erasing the memory (history) of self-diagnosis results when replacing 4WAS

front control unit after diagnosis.

4WAS front control unit

Voltage (Approx.)

Connector

Terminal

M203

11 – Ground

Battery voltage

M204

15 – Ground

4WAS front control unit

Continuity

Connector

Terminal

M204

12 – Ground

Existed

18 – Ground

34 – Ground

C1631, C1632 4WAS FRONT CONTROL UNIT

STC-57

< COMPONENT DIAGNOSIS >

[WITH 4WAS]

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

• Erase the memory of the self-diagnosis results (record) after printing out or recording all the val-

ues of “DATA MONITOR” when erasing the memory of the self-diagnosis results (record).

AFTER REPLACING 4WAS FRONT CONTROL UNIT

• Perform 4WAS front actuator adjustment after replacing 4WAS front control unit. Refer to 

STC-28, "4WAS

FRONT ACTUATOR NEUTRAL POSITION ADJUSTMENT : Special Repair Requirement (Pattern 3)"

.