Infiniti G35 (V35) Sedan. Manual - part 1292

STC-58

< COMPONENT DIAGNOSIS >

[WITH 4WAS]

C1633 4WAS FRONT CONTROL UNIT

C1633 4WAS FRONT CONTROL UNIT

Description

INFOID:0000000000958762

• 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:0000000000958763

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 “C1633” detected?

YES

>> Proceed to diagnosis procedure. Refer to 

STC-58, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000000958764

1.

CHECK 4WAS FRONT CONTROL UNIT (1)

 With CONSULT-III

1.

Start the engine.

CAUTION:

Stop the vehicle.

2.

Check “THERM TEMP” on DATA MONITOR of 4WAS front control unit.

3.

Steer the steering wheel 360

°

 leftward slowly and then steer 360

°

 rightward. Return the steering wheel to

the straight-ahead position. Repeat the same service for 3 minutes.

4.

Check “THERM TEMP” on DATA MONITOR of 4WAS front control unit.

Is DATA MONITOR value difference between before and after the service 3

°

 or less?

YES

>> Replace 4WAS front control unit. Refer to 

STC-177, "Exploded View"

.

NO

>> GO TO 2.

2.

CHECK 4WAS FRONT CONTROL UNIT (2)

 With CONSULT-III

1.

Start the engine.

CAUTION:

Stop the vehicle.

2.

Check “THERM TEMP” item on “DATA MONITOR” of 4WAS front control unit.

3.

Steer the steering wheel 360

°

 leftward slowly and then steer 360

°

 rightward. Return the steering wheel to

the straight-ahead position. Repeat the same service for 3 minutes.

4.

Check “THERM TEMP” item on “DATA MONITOR” of 4WAS front control unit.

DTC

Items

(CONSULT-III screen terms)

Diagnostic item is detected when...

Possible cause

C1633

CONTROL UNIT

An error is detected inside 4WAS front control unit.

4WAS front control unit 
error

C1633 4WAS FRONT CONTROL UNIT

STC-59

< COMPONENT DIAGNOSIS >

[WITH 4WAS]

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Replace 4WAS front control unit. Refer to 

STC-177, "Exploded View"

.

3.

CHECK INFORMATION

• Check that any item below is applicable when malfunction occurs.
- Entering and exiting the garage (Frequent steering)
- When steering the steering wheel for a long time
Is the item applicable?

YES

>> 4WAS system protection function mode (overheat protection)(4WAS system temporary stop)

NO

>> Replace 4WAS front control unit. Refer to 

STC-177, "Exploded View"

.

Special Repair Requirement

INFOID:0000000000958765

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)"

.

Monitor item

Condition

Display value

THERM TEMP

Engine running (idling)

−

40 – 100

°

C

STC-60

< COMPONENT DIAGNOSIS >

[WITH 4WAS]

C1651 IGNITION POWER SUPPLY

C1651 IGNITION POWER SUPPLY

Description

INFOID:0000000000958766

• 4WAS system function is controlled by transmitting the ignition switch signal to 4WAS front control unit.

DTC Logic

INFOID:0000000000958767

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 “C1651” detected?

YES

>> Proceed to diagnosis procedure. Refer to 

STC-60, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000000958768

1.

CHECK 4WAS FRONT CONTROL UNIT GROUND

1.

Turn the ignition switch OFF.

2.

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

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace the harnesses and connectors.

2.

CHECK 4WAS FRONT CONTROL UNIT POWER SUPPLY

1.

Start the engine.

CAUTION:

Stop the vehicle.

2.

Check the voltage between 4WAS front control unit harness connectors.

Is the measurement value “9 V” or less?

YES

>>

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

• 4WAS front control unit harness connector pin terminal and connection
• 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 No. 53 terminal and the

ground

DTC

Items

(CONSULT-III screen terms)

Diagnostic item is detected when...

Possible cause

C1651

IGN POWER SUPPLY

The ignition voltage signal error is detected.

4WAS front control unit or 
the ignition power supply 
error is detected.

4WAS front control unit

Continuity

Connector

Terminal

M204

18 – Ground

Existed

4WAS front control unit

Voltage (Approx.)

Connector

Terminal

M204

15 – 18

Battery voltage

C1651 IGNITION POWER SUPPLY

STC-61

< COMPONENT DIAGNOSIS >

[WITH 4WAS]

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

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

nal

• Ignition switch

NO

>> GO TO 3.

3.

CHECK 4WAS FRONT CONTROL UNIT SIGNAL

 With CONSULT-III

1.

Start the engine.

CAUTION:

Stop the vehicle.

2.

Check “IGN VOLT” item on “DATA MONITOR” of 4WAS front control unit.

Does the item on “DATA MONITOR” indicate “16 V” or more?

YES

>> 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:0000000000958769

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)"

.