Infiniti G35 (V35) Sedan. Manual - part 1315

STC-150

< ECU DIAGNOSIS >

[WITH 4WAS]

4WAS FRONT CONTROL UNIT

JCGWA0008GB

4WAS FRONT CONTROL UNIT

STC-151

< ECU DIAGNOSIS >

[WITH 4WAS]

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

Fail Safe

INFOID:0000000000958918

4WAS system (front)

• 4WAS system enters in the fail-safe mode (4WAS system stopped), and 4WAS warning lamp turns ON if an

error is detected in 4WAS system (4WAS front control unit and 4WAS main control unit) component part. 

• 4WAS system enters in the protection function mode (4WAS system temporarily stopped) if 4WAS system

continues the heavy load condition and the overheat condition.4WAS system reactivates automatically if the

JCGWA0009GB

STC-152

< ECU DIAGNOSIS >

[WITH 4WAS]

4WAS FRONT CONTROL UNIT

heavy load condition and the overheat condition are resolved.4WAS warning lamp continues turning OFF in
the protection function mode.

*: Communication line between 4WAS front control unit and 4WAS main control unit.

DTC Inspection Priority Chart

INFOID:0000000000958919

Function

Warn-

ing 

lamp

DTC No.

Detected area (Error area)

Error area and root cause

Protec-

tion 

function

Turn-

OFF

—

4WAS front control unit

4WAS front control unit overheat condition

Protec-

tion 

function

Turn-

OFF

—

4WAS front actuator

4WAS front actuator overheat condition

Protec-

tion 

function

Turn-

OFF

—

4WAS front control unit

4WAS front control unit heavy load condition

Fail-safe 

mode

Turn-

ON

C1621
C1622

4WAS front actuator

4WAS front control unit or 4WAS front motor error is detected.

Fail-safe 

mode

Turn-

ON

C1627

4WAS front actuator

4WAS front actuator error

Fail-safe 

mode

Turn-

ON

C1628

Front wheel steering angle 
sensor

Front wheel steering angle sensor error

Fail-safe 

mode

Turn-

ON

C1631
C1632

4WAS front control unit

4WAS front control unit or 4WAS front control unit power supply er-
ror is detected.

Fail-safe 

mode

Turn-

OFF

C1633

4WAS front control unit

4WAS front control unit error

Fail-safe 

mode

Turn-

ON

C1651

4WAS front control unit

4WAS front control unit or the ignition power supply error is detect-
ed.

Fail-safe 

mode

Turn-

ON

C1652

4WAS front control unit

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

Fail-safe 

mode

Turn-

ON

C1654

4WAS front control unit

The main relay power supply inside 4WAS front control unit error is 
detected.

Fail-safe 

mode

Turn-

ON

C1655

4WAS front control unit

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

Fail-safe 

mode

Turn-

ON

C1661

4WAS front lock solenoid 
valve (lock structure)

4WAS front control unit or 4WAS front lock solenoid valve error is 
detected.

Fail-safe 

mode

Turn-

ON

C1667

4WAS front actuator

The inside 4WAS front actuator error is detected.

Fail-safe 

mode

Turn-

ON

C1668

4WAS front actuator

The inside 4WAS front actuator error is detected.

Fail-safe 

mode

Turn-

ON

C1669

4WAS front actuator

The power steering oil pressure or the inside 4WAS front actuator 
error is detected.

Fail-safe 

mode

Turn-

ON

C1671

4WAS front actuator

4WAS front actuator adjustment is not performed.

Fail-safe 

mode

Turn-

ON

C1672

4WAS main actuator

4WAS front actuator adjustment is incomplete.

Fail-safe 

mode

Turn-

ON

C1684
C1685
U1000
U1002
U1010

4WAS communication line*/
4WAS main control unit/4WAS 
front control unit

4WAS communication line*/4WAS main control unit/4WAS front 
control unit error

Fail-safe 

mode

Turn-

ON

C1686

4WAS main control unit

4WAS main control unit fail-safe mode

4WAS FRONT CONTROL UNIT

STC-153

< ECU DIAGNOSIS >

[WITH 4WAS]

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.

*: 4WAS communication line

DTC Index

INFOID:0000000000958920

Priority

Detected items (DTC)

1

• U1000 CANCOMM CIRCUIT*
• U1002 SYSTEM COMM(CAN)*
• U1010 CONTROL UNIT(CAN)*

2

• C1671 ACT ADJ NOT PRFRM
• C1672 INCOMP ACTUATR ADJ

3

• C1631 CONTROL UNIT
• C1632 CONTROL UNIT

4

• C1651 IGN POWER SUPPLY
• C1652 MOTOR POWER SUPPLY
• C1654 ACTUATOR RELAY
• C1655 PRE-DRIVER

5

• C1621 ACTUATOR
• C1622 ACTUATOR
• C1627 ACTUATOR
• C1628 ACTUATOR
• C1661 LOCK SOLENOID
• C1667 LOCK INSERTION
• C1668 LOCK HLD GAP DETCT
• C1669 INCOMP LOCK RELEAS

6

• C1684 4WAS MAIN ECU COMM
• C1685 4WAS MAIN ECU COMM
• C1686 4WAS MAIN ECU

7

• C1633 CONTROL UNIT

DTC

Items 

(CONSULT-III screen terms)

Reference

C1621

ACTUATOR

STC-47, "Description"

C1622

ACTUATOR

STC-47, "Description"

C1627

ACTUATOR

STC-50, "Description"

C1628

ACTUATOR

STC-52, "Description"

C1631

CONTROL UNIT

STC-55, "Description"

C1632

CONTROL UNIT

STC-55, "Description"

C1633

CONTROL UNIT

STC-58, "Description"

C1651

IGN POWER SUPPLY

STC-60, "Description"

C1652

MOTOR POWER SUPPLY

STC-62, "Description"

C1654

ACTUATOR RELAY

STC-64, "Description"

C1655

PRE-DRIVER

STC-66, "Description"

C1661

LOCK SOLENOID

STC-68, "Description"

C1667

LOCK INSERTION

STC-70, "Description"

C1668

LOCK HLD GAP DETCT

STC-72, "Description"

C1669

INCOMP LOCK RELEAS

STC-73, "Description"

C1671

ACT ADJ NOT PRFRM

STC-74, "Description"

C1672

INCOMP ACTUATR ADJ

STC-76, "Description"

C1684

4WAS MAIN ECU COMM

STC-77, "Description"

C1685

4WAS MAIN ECU COMM

STC-77, "Description"