Infiniti FX35, FX50 (S51). Manual - part 1778

C1911, C1912 RAS MOTOR POWER SUPPLY

STC-53

< DTC/CIRCUIT DIAGNOSIS >

[WITH REAR ACTIVE STEER]

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

• Open between the ignition switch and RAS control unit harness connector No. 27 terminal
• Ignition switch

2.

CHECK RAS MOTOR POWER SUPPLY CIRCUIT (1)

1.

Turn the ignition switch OFF.

2.

Remove RAS motor relay.

3.

Check the continuity between RAS motor relay harness connector and ground.

4.

Check the continuity between RAS motor relay harness connector and RAS control unit harness connec-
tor.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace the harnesses and connectors.

3.

CHECK RAS MOTOR POWER SUPPLY CIRCUIT (2)

Check the voltage between RAS motor relay harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>>

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

• 20A fuse (#37) open
- Short among 20A fuse (#37) connector, RAS motor relay harness connector No. 3 terminal and

the ground

• Open between the battery and RAS motor relay harness connector No. 3 terminal

4.

CHECK RAS MOTOR POWER SUPPLY CIRCUIT (3)

1.

Connect RAS control unit harness connector.

2.

Turn the ignition switch ON.

CAUTION:

Never start the engine.

3.

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

4.

Turn the ignition switch OFF.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Replace RAS control unit. Refer to 

STC-109, "Removal and Installation"

.

5.

CHECK RAS MOTOR RELAY

Check the RAS motor relay. Refer to 

STC-54, "Component Inspection"

.

RAS motor relay

—

Continuity

Connector

Terminal

B36

2 

Ground

Existed

1 Not 

existed

RAS motor relay

RAS control unit

Continuity

Connector

Terminal

Connector

Terminal

B36

1

B37

25

Existed

RAS motor relay

—

Voltage (Approx.)

Connector

Terminal

B36

3

Ground

Battery voltage

RAS control unit

—

Voltage (Approx.)

Connector

Terminal

B37

25

Ground

Battery voltage

STC-54

< DTC/CIRCUIT DIAGNOSIS >

[WITH REAR ACTIVE STEER]

C1911, C1912 RAS MOTOR POWER SUPPLY

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Replace RAS motor relay.

6.

CHECK RAS MOTOR POWER SUPPLY

1.

Install RAS rear motor relay.

2.

Turn the ignition switch ON.

CAUTION:

Never start the engine.

3.

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

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> Replace RAS control unit. Refer to 

STC-109, "Removal and Installation"

.

7.

PERFORM SELF-DIAGNOSIS (RAS CONTROL UNIT)

With CONSULT-III

1.

Turn the ignition switch from OFF to ON.

2.

Perform “4WAS(MAIN)/RAS/HICAS” self-diagnosis.

Without CONSULT-III

1.

Start the engine.

2.

Perform the self-diagnosis. Refer to 

STC-38, "Diagnosis Description"

.

Is DTC “C1911”, “C1912” or “RAS warning lamp flickering pattern:12” detected?

YES

>> Proceed to diagnosis procedure. Refer to 

STC-52, "Diagnosis Procedure"

.

NO

>> GO TO 8.

8.

CHECK INFORMATION

With CONSULT-III

1.

Select “DATA MONITOR” of “4WAS(MAIN)/RAS/HICAS”.

2.

Check the “DATA MONITOR” value of each DTC detected with the self-diagnosis function. Refer to 

STC-

89, "Reference Value"

.

Is each data the standard value?

YES

>> Check each harness connector pin terminal for disconnection.

NO

>> Replace RAS control unit. Refer to 

STC-109, "Removal and Installation"

.

Component Inspection

INFOID:0000000005549681

1.

CHECK RAS MOTOR RELAY

1.

Turn the ignition switch OFF.

2.

Disconnect RAS motor relay harness connector.

3.

Apply 12 V to RAS motor relay connector No. 1 terminal and No. 2 terminal.

CAUTION:

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

4.

Check the continuity between RAS motor relay connector.

5.

Check the resistance between RAS motor relay connector.

RAS control unit

—

Voltage (Approx.)

Connector

Terminal

B37

37

Ground

Battery voltage

RAS motor relay

Continuity

Terminal

Condition

3

5

Apply the voltage between No. 1 
terminal and No. 2 terminal.

Existed

Do not apply the voltage between 
No. 1 terminal and No. 2 terminal.

Not existed

C1911, C1912 RAS MOTOR POWER SUPPLY

STC-55

< DTC/CIRCUIT DIAGNOSIS >

[WITH REAR ACTIVE STEER]

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace RAS motor relay.

Special Repair Requirement

INFOID:0000000005549683

BEFORE REPLACING RAS CONTROL UNIT

• Record the self-diagnosis results (history).

CAUTION:

• Never erase the memory (history) of self-diagnosis results when replacing RAS 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”.

RAS motor relay

Resistance (Approx.)

Terminal

1

2

50 

Ω

STC-56

< DTC/CIRCUIT DIAGNOSIS >

[WITH REAR ACTIVE STEER]

C1914 REAR WHEEL STEERING ANGLE SENSOR

C1914 REAR WHEEL STEERING ANGLE SENSOR

Description

INFOID:0000000005549684

• It detects the steering angle condition of rear wheel.
• 2 systems (main and sub sensor) are equipped.

DTC Logic

INFOID:0000000005549685

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

DTC REPRODUCTION PROCEDURE

With CONSULT-III

1.

Turn the ignition switch from OFF to ON.

2.

Perform “4WAS(MAIN)/RAS/HICAS” self-diagnosis.

Without CONSULT-III

1.

Start the engine.

2.

Perform the self-diagnosis. Refer to 

STC-38, "Diagnosis Description"

.

Is DTC “C1914” or “RAS warning lamp flickering pattern:24” detected?

YES

>> Proceed to diagnosis procedure. Refer to 

STC-56, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005549686

1.

CHECK REAR WHEEL STEERING ANGLE SENSOR POWER SUPPLY

1.

Turn the ignition switch OFF.

2.

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

3.

Turn the ignition switch ON.

CAUTION:

Never start the engine.

4.

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

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Replace RAS control unit. Refer to 

STC-109, "Removal and Installation"

.

2.

CHECK REAR WHEEL STEERING ANGLE SENSOR

Check the rear wheel steering angle sensor. Refer to 

STC-57, "Component Inspection"

.

Is the inspection result normal?

DTC

Display items

Malfunction detected condition

Possible cause

C1914

RR ST ANGLE SENSOR
[ABNORML VOL]

The rear wheel angle sensor (main) or (sub) power 
supply value is malfunction.

• RAS actuator assembly 

(Rear wheel angle sen-
sor)

• Harness or connector
• RAS control unit

RAS control unit

—

Voltage (Approx.)

Connector

Terminal

B37

5

Ground

0 V

RAS control unit

—

Value (Approx.)

Connector

Terminal

B37

5

Ground

5 V