Infiniti Q45. Manual - part 889

TROUBLE DIAGNOSIS FOR SYSTEM

STC-59

[WITH REAR ACTIVE STEER]

C

D

E

F

H

I

J

K

L

M

A

B

STC

3. 

CHECK RAS MOTOR

1.

Turn ignition switch “OFF”.

2.

Disconnect RAS motor harness connector.

3.

Remove RAS motor. Refer to 

STC-92, "COMPONENTS"

 .

4.

Check operation by supply 6 V (B) voltage to RAS motor con-
nector (A) terminals 1 and 2.

CAUTION:

●

Never supply 12 V voltage (battery, etc.) to the RAS
motor.

●

Never operate RAS motor for more than 1 second.

●

Be careful not to overheat the harness.

5.

Check continuity between RAS motor connector (A) terminals 1
and 2.

OK or NG

OK

>> GO TO 4.

NG

>> Replace RAS motor.

4. 

CHECK RAS CONTROL UNIT

Check RAS control unit input/output signal. Refer to 

STC-47, "RAS Control Unit Input/Output Signal Refer-

ence Values"

 .

OK or NG

OK

>> GO TO 5.

NG

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

any items are damaged, repair or replace damaged parts.

5. 

CHECK DTC

Perform the self-diagnosis, after driving a vehicle for a while.

OK or NG

OK

>> INSPECTION END

NG

>> Replace RAS control unit. Refer to 

STC-90, "Removal and Installation"

 .

Terminal

Actuator motor

1 (Positive) - 2 (Negative)

Clockwise rotate

2 (Positive) - 1 (Negative)

Counterclockwise rotate

SGIA1473E

1 – 2

: Approx. 0.45 

Ω

SGIA1474E

STC-60

[WITH REAR ACTIVE STEER]

TROUBLE DIAGNOSIS FOR SYSTEM

DTC C1909 CONTROL UNIT

NGS0006X

●

Check the following if “CONTROL UNIT [ABNORMAL6] [C1909]” is detected in self-diagnosis results with
CONSULT-II or “flickering pattern for 11” is detected in self-diagnosis results without CONSULT-II.

CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE

Data are reference value.

RAS CONTROL UNIT TERMINALS AND REFERENCE VALUE

Data are reference value and are measured between each terminal and ground.

CAUTION:

When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.

DIAGNOSTIC PROCEDURE

1. 

INSPECTION START

Is CONSULT-II available?

YES or NO

YES

>> GO TO 2.

NO

>> GO TO 3.

2. 

CHECK POWER SUPPLY SIGNAL

 With CONSULT-II

1.

Start engine.

2.

Select “DATA MONITOR” mode for “RAS/HICAS” with CONSULT-II.

3.

Read out the value of “C/U VOLTAGE”.

OK or NG

OK >> GO 

TO 

5.

NG

>> GO TO 3.

Monitored item

Content

Condition

Display value

C/U VOLTAGE [V]

Power supply voltage for 
RAS control unit

Ignition switch: ON

Battery voltage

Ignition switch: OFF

—

Terminal

Wire 

color

Item

Condition

Data (Approx.)

27

GY

Ignition switch

Ignition switch: ON

Battery voltage

Ignition switch: OFF

0 V

34

B

Ground

Always

0 V

Monitored item

Condition

Display value

C/U VOLTAGE

Ignition switch: ON

Battery voltage

SGIA1468E

TROUBLE DIAGNOSIS FOR SYSTEM

STC-61

[WITH REAR ACTIVE STEER]

C

D

E

F

H

I

J

K

L

M

A

B

STC

3. 

CHECK POWER SUPPLY

1.

Turn ignition switch “OFF”.

2.

Disconnect RAS control unit harness connector.

3.

Check voltage between RAS control unit harness connector (A)
terminal and ground.

4.

Turn ignition switch “ON”. (Do not start engine.)

5.

Check voltage between RAS control unit harness connector (A)
terminal and ground.

OK or NG

OK

>> GO TO 4.

NG

>> Check the following. If any items are damaged, repair or 

replace damaged parts.

●

10 A fuse [No. 7 located in the fuse block (J/B) No.1].
Refer to 

PG-2, "POWER SUPPLY ROUTING"

 .

●

Harness for short or open between ignition switch and RAS control unit harness connector B39
terminal 27.

●

Ignition switch. Refer to 

PG-2, "POWER SUPPLY ROUTING"

 .

4. 

CHECK GROUND CIRCUIT

1.

Turn ignition switch “OFF”.

2.

Disconnect RAS control unit harness connector.

3.

Check continuity between RAS control unit harness connector
(A) B39 terminal 34 and ground.

Also check harness for short to power.

OK or NG

OK

>> GO TO 5.

NG

>> Repair open circuit or short to power in harness or con-

nectors.

5. 

CHECK RAS CONTROL UNIT

Check RAS control unit input/output signal. Refer to 

STC-47, "RAS Control Unit Input/Output Signal Refer-

ence Values"

 .

OK or NG

OK

>> GO TO 6.

NG

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

any items are damaged, repair or replace damaged parts.

Connector

Terminal

Voltage (Approx.)

B39

27 - Ground

0 V

SGIA1461E

Connector

Terminal

Voltage (Approx.)

B39

27 - Ground

Battery voltage

SGIA1462E

Continuity should exist.

SGIA1463E

STC-62

[WITH REAR ACTIVE STEER]

TROUBLE DIAGNOSIS FOR SYSTEM

6. 

CHECK DTC

Perform the self-diagnosis, after driving a vehicle for a while.

OK or NG

OK

>> INSPECTION END

NG

>> Replace RAS control unit. Refer to 

STC-90, "Removal and Installation"

 .

DTC C1911, C1912 MOTOR VOLTAGE

NGS0008J

●

Check the following if “MOTOR VOLTAGE [LOW VOLTEGE] [C1911]” or “MOTOR VOLTAGE [BAD
OBSTRCT] [C1912]” is detected in self-diagnosis results with CONSULT-II or “flickering pattern for 12” is
detected in self-diagnosis results without CONSULT-II.

CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE

Data are reference value.

RAS CONTROL UNIT TERMINALS AND REFERENCE VALUE

Data are reference value and are measured between each terminal and ground.

CAUTION:

When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.

DIAGNOSTIC PROCEDURE

1. 

INSPECTION START

Is CONSULT-II available?

YES or NO

YES

>> GO TO 2.

NO

>> GO TO 3.

Monitored item

Content

Condition

Display value

C/U VOLTAGE [V]

Power supply voltage for 
RAS control unit

Ignition switch: ON

Battery voltage

Ignition switch: OFF

—

MOTOR VOLTAGE [V]

Monitored value of voltage 
at RAS motor

Ignition switch: ON

Battery voltage

Ignition switch: OFF

0 V

HICAS RELAY [ON/OFF]

RAS motor relay condition

Ignition switch: ON

ON

Ignition switch: OFF

OFF

Terminal

Wire 

color

Item

Condition

Data (Approx.)

25

L/W

RAS motor relay

Ignition switch: ON

Battery voltage

Ignition switch: OFF

0 V

27

GY

Ignition switch

Ignition switch: ON

Battery voltage

Ignition switch: OFF

0 V

37

L/Y

Power supply
(RAS motor)

Ignition switch: ON

Battery voltage

Ignition switch: OFF

0 V