Infiniti FX35, FX50 (S51). Manual - part 545

C1203 ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)

DLN-15

< DTC/CIRCUIT DIAGNOSIS >

[TRANSFER: ETX13C]

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C1203 ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)

Description

INFOID:0000000005249041

Transmits the following signals via CAN communication to AWD control unit.
• Vehicle speed signal
• Stop lamp switch signal (brake signal)

DTC Logic

INFOID:0000000005249042

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

DTC REPRODUCTION PROCEDURE

With CONSULT-III

1.

Start the engine and drive at 30 km/h (19 MPH) or more for approximately 1 minute.

2.

Perform self-diagnosis for “ALL MODE AWD/4WD”.

Is DTC “C1203” detected?

YES

>> Proceed to diagnosis procedure. Refer to 

DLN-15, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005249043

1.

PERFORM ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) SELF-DIAGNOSIS

With CONSULT-III

Perform self-diagnosis for “ABS”.

Is any DTC detected?

YES

>> Check the DTC.

NO

>> GO TO 2.

2.

PERFORM SELF-DIAGNOSIS

With CONSULT-III

1.

Erase results for “ALL MODE AWD/4WD”.

2.

Start the engine and drive vehicle at 30 km/h (19 MPH) or more for approximately 1 minute.

3.

Make sure that ABS warning lamp turns OFF.

4.

Perform self-diagnosis for “ALL MODE AWD/4WD”.

Is DTC “C1203” detected?

YES

>>  Replace AWD control unit. Refer to 

DLN-58, "Exploded View"

. 

NO

>> Check AWD control unit pin terminals for damage or loose connection with harness connector. If

any items are damaged, repair or replace error-detected parts.

DTC

Display items

Malfunction detected condition

Possible cause

C1203

ABS SYSTEM

Malfunction related to wheel sensor has 
been detected by ABS actuator and 
electric unit (control unit).

ABS malfunction
• Vehicle speed signal error

DLN-16

< DTC/CIRCUIT DIAGNOSIS >

[TRANSFER: ETX13C]

C1204 AWD SOLENOID

C1204 AWD SOLENOID

Description

INFOID:0000000005249044

Controls electric controlled coupling by command current from AWD control unit.

DTC Logic

INFOID:0000000005249045

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

DTC REPRODUCTION PROCEDURE

With CONSULT-III

1.

Turn the ignition switch OFF to ON.

2.

Perform self-diagnosis for “ALL MODE AWD/4WD”.

Is DTC “C1204” detected?

YES

>> Proceed to diagnosis procedure. Refer to 

DLN-16, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005249046

1.

CHECK AWD SOLENOID POWER SUPPLY

1.

Turn the ignition switch OFF.

2.

Disconnect AWD control unit harness connector.

3.

Check the voltage between AWD control unit harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Perform the trouble diagnosis for power supply circuit. Refer to 

DLN-27, "Diagnosis Procedure"

.

2.

CHECK AWD CONTROL UNIT GROUND

Check the continuity between AWD control unit harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace error-detected parts.

3.

CHECK AWD SOLENOID CIRCUIT 

1.

Disconnect AWD solenoid harness connector.

2.

Check the continuity between AWD control unit harness connector and AWD solenoid harness connector.

DTC

Display items

Malfunction detected condition

Possible cause

C1204

4WD SOLENOID

Malfunction related to AWD solenoid has 
been detected.

Internal malfunction of electronic con-
trolled coupling

AWD control unit

—

Voltage

Connector

Terminal

M105

9

Ground

Battery voltage

AWD control unit

—

Continuity

Connector

Terminal

M105

10

Ground

Existed

11

C1204 AWD SOLENOID

DLN-17

< DTC/CIRCUIT DIAGNOSIS >

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3.

Check the continuity between AWD control unit harness connector and the ground.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair or replace error-detected parts.

4.

CHECK AWD SOLENOID

Check the resistance between AWD solenoid harness connector terminals. Refer to 

DLN-17, "Component

Inspection"

.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> AWD solenoid is malfunctioning. Replace electric controlled coupling. Refer to 

DLN-88, "VQ35HR

: Exploded View"

 (VQ35HR), 

DLN-92, "VK50VE : Exploded View"

 (VK50VE).

5.

CHECK TERMINALS AND HARNESS CONNECTORS

1.

Check AWD control unit pin terminals for damage or loose connection with harness connector.

2.

Check AWD solenoid pin terminals for damage or loose connection with harness connector.

Is the inspection result normal?

YES

>> Replace AWD control unit. Refer to 

DLN-58, "Exploded View"

.

NO

>> Repair or replace error-detected parts.

Component Inspection

INFOID:0000000005249047

1.

CHECK AWD SOLENOID

1.

Turn the ignition switch OFF.

2.

Disconnect AWD solenoid harness connector.

3.

Check the resistance between AWD solenoid connector terminals.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> AWD solenoid is malfunctioning. Replace electric controlled coupling. Refer to 

DLN-88, "VQ35HR

: Exploded View"

 (VQ35HR), 

DLN-92, "VK50VE : Exploded View"

 (VK50VE).

AWD control unit

AWD solenoid

Continuity

Connector

Terminal

Connector

Terminal

M105

1

F57

1

Existed

2

2

AWD control unit

—

Continuity

Connector

Terminal

M105

1

Ground

Not existed

2

AWD solenoid

 Resistance (Approx.)

Terminal

1

2

2.45 

Ω

DLN-18

< DTC/CIRCUIT DIAGNOSIS >

[TRANSFER: ETX13C]

C1205 AWD ACTUATOR RELAY

C1205 AWD ACTUATOR RELAY

Description

INFOID:0000000005249048

AWD solenoid is supplied with voltage by the internal circuit of AWD control unit. 

DTC Logic

INFOID:0000000005249049

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

DTC REPRODUCTION PROCEDURE

With CONSULT-III

1.

Turn the ignition switch OFF to ON.

2.

Perform self-diagnosis for “ALL MODE AWD/4WD”.

Is DTC “C1205” detected?

YES

>> Proceed to diagnosis procedure. Refer to 

DLN-18, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005249050

1.

PERFORM SELF-DIAGNOSIS

With CONSULT-III

1.

Erase self-diagnostic results for “ALL MODE AWD/4WD”.

2.

Turn ignition switch OFF, and wait 10 seconds or more.

3.

Perform self-diagnosis for “ALL MODE AWD/4WD”.

Is DTC “C1205” detected?

YES

>> Replace AWD control unit. Refer to 

DLN-58, "Exploded View"

. 

NO

>> Check AWD control unit pin terminals for damage or loose connection with harness connector. If

any items are damaged, repair or replace error-detected parts.

DTC

Display item

Malfunction detected condition

Possible cause

C1205

4WD ACTUATOR RLY

Malfunction has been detected from 
AWD actuator relay integrated with AWD 
control unit, or malfunction related to 
AWD solenoid has been detected.

Internal malfunction of AWD control unit