Infiniti G35 (V35) Sedan. Manual - part 1297

STC-78

< COMPONENT DIAGNOSIS >

[WITH 4WAS]

C1684, C1685 4WAS MAIN CONTROL UNIT COMMUNICATION

Check the continuity between ABS actuator and electric unit (control unit) harness connector and the ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace the harnesses and connectors. Refer to 

STC-176, "Precautions for Harness

Repair"

.

3.

CHECK COMMUNICATION LINE (3)

Check the continuity between ABS actuator and electric unit (control unit) harness connector.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair or replace the harnesses and connectors. Refer to 

STC-176, "Precautions for Harness

Repair"

.

4.

CHECK ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)

Check the continuity between ABS actuator and electric unit (control unit) connector. Refer to 

STC-84, "Com-

ponent Inspection [ABS Actuator and Electric Unit (Control Unit)]"

.

Is the inspection result normal?

YES

>> GO TO 5.

NO

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

BRC-102, "Exploded View"

.

5.

CHECK YAW RATE/SIDE G SENSOR

Check the continuity between yaw rate/side G sensor connector. Refer to 

STC-84, "Component Inspection

(Yaw Rate/Side G Sensor)"

.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Replace yaw rate/side G sensor. Refer to 

BRC-104, "Exploded View"

.

6.

CHECK CAN DIAGNOSIS SUPPORT MONITOR (4WAS FRONT CONTROL UNIT)

 With CONSULT-III

1.

Connect ABS actuator and electric unit (control unit) harness connector.

2.

Connect yaw rate/side G sensor harness connector.

3.

Connect 4WAS front control unit harness connector.

4.

Connect 4WAS main control unit harness connector.

5.

Start the engine.

CAUTION:

Stop the vehicle.

6.

Perform CAN diagnosis support monitor of 4WAS front control unit.

7.

Replace 4WAS main control unit error history. Refer to 

STC-39, "CONSULT-III Function

[4WAS(FRONT)]"

.

What is the indicated item?

All items are “OK”>>GO TO 7.
“TRANSMIT DIAG” is other than “OK”>>GO TO 7.
“4WAS(MAIN)” is other than “OK”>>GO TO 8.

7.

CHECK 4WAS FRONT CONTROL UNIT CIRCUIT

1.

Turn the ignition switch OFF.

2.

Disconnect 4WAS front control unit harness connector.

ABS actuator and electric unit (control unit)

Continuity

Connector

Terminal

E41

25 – Ground

Not existed

45 – Ground

ABS actuator and electric unit (control unit)

Continuity

Connector

Terminal

E41

25 – 45

Not existed

C1684, C1685 4WAS MAIN CONTROL UNIT COMMUNICATION

STC-79

< COMPONENT DIAGNOSIS >

[WITH 4WAS]

C

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STC

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3.

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

4.

Check the continuity between 4WAS front control unit harness connector and ABS actuator and electric
unit (control unit) harness connector.

5.

Check that 4WAS front control unit connector No. 14 terminal and No. 25 are connected properly and not
deformed.

Is the inspection result normal?

YES

>> Replace 4WAS front control unit. Refer to 

STC-177, "Exploded View"

.

NO

>> Repair or replace the harnesses and connectors. Refer to 

STC-176, "Precautions for Harness

Repair"

.

8.

CHECK 4WAS MAIN CONTROL UNIT CIRCUIT

1.

Turn the ignition switch OFF.

2.

Disconnect 4WAS main control unit harness connector.

3.

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

4.

Check the continuity between 4WAS main control unit harness connector and ABS actuator and electric
unit (control unit) harness connector.

5.

Check that 4WAS main control unit connector No. 31 terminal and No. 32 are connected properly and not
deformed.

Is the inspection result normal?

YES

>> Replace 4WAS main control unit. Refer to 

STC-178, "Exploded View"

.

NO

>> Repair or replace the harnesses and connectors. Refer to 

STC-176, "Precautions for Harness

Repair"

.

Component Inspection [ABS Actuator and Electric Unit (Control Unit)]

INFOID:0000000000958810

1.

CHECK ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)

1.

Turn the ignition switch OFF.

2.

Remove ABS actuator and electric unit (control unit). Refer to 

BRC-102, "Exploded View"

.

3.

Check the resistance between ABS actuator and electric unit (control unit) connector terminals.

Is the inspection result normal?

YES

>> INSPECTION END

NO

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

Component Inspection (Yaw Rate/Side G Sensor)

INFOID:0000000000958811

1.

CHECK YAW RATE/SIDE G SENSOR

1.

Turn the ignition switch OFF.

2.

Remove yaw rate/side G sensor. Refer to 

BRC-104, "Exploded View"

.

4WAS front control unit

ABS actuator and electric 

unit (control unit)

Continuity

Connector

Terminal

Connector

Terminal

M204

14

E41

25

Existed

25

45

4WAS main control unit

ABS actuator and electric 

unit (control unit)

Continuity

Connector

Terminal

Connector

Terminal

B54

31

E41

45

Existed

32

25

ABS actuator and electric unit (control unit)

Resistance (Approx.)

Connector

Terminal

E41

25 – 45

60 

Ω

STC-80

< COMPONENT DIAGNOSIS >

[WITH 4WAS]

C1684, C1685 4WAS MAIN CONTROL UNIT COMMUNICATION

3.

Check the resistance between yaw rate/side G sensor connector terminals.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace yaw rate/side G sensor.

Special Repair Requirement

INFOID:0000000000958812

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).

BEFORE REPLACING 4WAS MAIN ACTUATOR

• Record the self-diagnosis results (history).

CAUTION:

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

main 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)"

.

Yaw rate/side G sensor

Resistance (Approx.)

Connector

Terminal

M143

2 – 3

60 

Ω

C1686 4WAS MAIN CONTROL UNIT

STC-81

< COMPONENT DIAGNOSIS >

[WITH 4WAS]

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STC

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C1686 4WAS MAIN CONTROL UNIT

Description

INFOID:0000000000958813

• It transmits the value calculated by 4WAS main control unit to 4WAS front control unit with 4WAS communi-

cation line (line for 4WAS system). 4WAS front control unit controls 4WAS front actuator according to the
received command value.

DTC Logic

INFOID:0000000000958814

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 “C1686” detected?

YES

>> Proceed to diagnosis procedure. Refer to 

STC-81, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000000958815

1.

PERFORM SELF-DIAGNOSIS (4WAS FRONT CONTROL UNIT)

 With CONSULT-III

Perform 4WAS front control unit self-diagnosis.

Is any DTC other than “C1686” detected?

YES

>> Check the error system.

NO

>> Perform 4WAS main control unit self-diagnosis.

DTC

Items

(CONSULT-III screen terms)

Diagnostic item is detected when...

Possible cause

C1686

4WAS MAIN ECU

An error is detected on 4WAS main control unit side.
(4WAS main control unit fail-safe mode)

4WAS main control unit 
fail-safe mode