Infiniti G37 Coupe. Manual - part 1276

4WAS MAIN CONTROL UNIT

STC-155

< ECU DIAGNOSIS >

[WITH 4WAS]

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

4WAS MAIN CONTROL UNIT

Reference Value

INFOID:0000000001666483

VALUES ON THE DIAGNOSIS TOOL

CONSULT-III MONITOR ITEM

Monitor item

Condition

Value/Status

VHCL SPEED SE

Vehicle stopped

0 km/h (0 MPH)

Start the engine. Wait a minute. Drive the vehicle.

CAUTION:

Check air pressure of tire under standard conditions.

Approximately equal to the indi-
cation on speedometer (Inside 
of 

±

10%)

STEERING ANG

Steering wheel turned right

Approx. 0 – R550

°

Straight-ahead

Approx. 0

°

Steering wheel turned left

Approx. 0 – L550

°

ENGINE SPEED

Engine stopped

0 rpm

Engine running
(Engine speed: 400 rpm or more)

Approximately equal to the indi-
cation on tachometer

STR ANGL SPD

The steering wheel is not steered.

0 deg/s

The steering wheel is steering.

1 – 3,000 deg/s

POWER STR SOL

Vehicle speed: 0 km/h (0 MPH)
(Engine is running)

Approx. 1.10 A

Vehicle speed: 100 km/h (62 MPH)

Approx. 0.42 A

RR ST ANG-MAI

4WAS rear actuator turns right completely

Approx. 4.4 V

4WAS rear actuator is neutral

Approx. 2.4 V

4WAS rear actuator turns left completely

Approx. 0.4 V

RR ST ANG-SUB

4WAS rear actuator turns right completely

Approx. 4.4 V

4WAS rear actuator is neutral

Approx. 2.6 V

4WAS rear actuator turns left completely

Approx. 0.4 V

RR ST ANG-VOL

Ignition switch: ON

Approx. 5 V

C/U VOLTAGE

Ignition switch: ON

Battery voltage

MOTOR VOLTAGE

Ignition switch: ON

Battery voltage

MOTOR CURRENT

4WAS rear motor running

0 – 20 A

MTR CRNT OPE

4WAS rear actuator neutral condition and vehicle straight-ahead 
position.

Approx. 

−

2 – 2 A

4WAS rear motor running

Approx. 

−

20 – 20 A

RR ANGLE OPE

4WAS rear actuator turned right

Approx. 0 – 1 deg

4WAS rear actuator is neutral

Approx. 0 deg

4WAS rear actuator turned left

Approx. 0 – 

−

1 deg

FR ANGLE OPE

Steering wheel turned to the right (with vehicle stopped).

Approx. 0 – R60

°

Straight-ahead

Approx. 0

°

 

Steering wheel turned to the left (with vehicle stopped).

Approx. 0 – L60

°

STOP LAMP SW

Brake pedal: Depressed

On

Brake pedal: Released

Off

HICAS RELAY

Ignition switch: ON

On

FAIL SAFE

Fail-safe condition

On

Normal

Off

WARNING LAMP

4WAS warning lamp: ON

On

4WAS warning lamp: OFF

Off

STC-156

< ECU DIAGNOSIS >

[WITH 4WAS]

4WAS MAIN CONTROL UNIT

TERMINAL LAYOUT

PHYSICAL VALUES

FRONT ECU FAIL

4WAS front control unit fail-safe mode

On

Normal

Off

FRONT ECU EX

4WAS front control unit enters in the protection function mode

On

Normal

Off

Monitor item

Condition

Value/Status

SGIA1449E

Terminal No.

Wire 

color

Description

Condition

Value (Approx.)

+

-

Signal name

Input/

Output

1

—

L

CAN-H

—

—

—

4

Ground

BR

Rear wheel steering 
angle sensor (main) 
output voltage

Output

4WAS rear actuator assembly turns 
right completely.

4.4 V

4WAS rear actuator assembly is neu-
tral

2.4 V

4WAS rear actuator assembly turns 
left completely.

0.4 V

5

Ground

W

Rear wheel steering 
angle sensor power 
supply

Output

Ignition switch: ON

5 V

Ignition switch: OFF

0 V

7

Ground

R

Rear wheel steering 
angle sensor (sub) 
output voltage

Output

4WAS rear actuator assembly turns 
right completely.

4.4 V

4WAS rear actuator assembly is neu-
tral

2.6 V

4WAS rear actuator assembly turns 
left completely.

0.4 V

8

—

P

CAN-L

—

—

—

15

Ground

G

Rear wheel steering 
angle sensor 
ground

—

Always

0  V

22

Ground

GR

Stop lamp switch

Input

Brake pedal: Depressed

Battery voltage

Brake pedal: Released

0 V

25

Ground

SB

4WAS rear motor 
relay

Input

Ignition switch: ON

Battery voltage

Ignition switch: OFF

0 V

27

Ground

V

Ignition switch

Input

Ignition switch: ON

Battery voltage

Ignition switch: OFF

0 V

31

—

BR

4WAS communica-
tion-H

—

—

—

32

—

Y

4WAS communica-
tion-L

—

—

—

4WAS MAIN CONTROL UNIT

STC-157

< ECU DIAGNOSIS >

[WITH 4WAS]

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

CAUTION:

When using circuit tester to measure voltage for inspection, never forcibly extend any connector terminals.

Wiring Diagram - 4WAS SYSTEM -

INFOID:0000000001666484

Click here to view the eWD.

34

Ground

B

Ground

—

Always

0 V

36

Ground

LG

Power steering so-
lenoid valve

Output

Vehicle speed: 0 km/h (0 MPH)
(Engine is running)

4.4 – 6.6 V

Vehicle speed: 100 km/h (62 MPH)

2.4 – 3.6 V

37

Ground

P

4WAS rear motor 
power supply

Input

Ignition switch: ON

Battery voltage

Ignition switch: OFF

0 V

38

Ground

W

4WAS rear motor 
output voltage
(right)

Output

While 4WAS rear motor activates 
rightward

Battery voltage

While 4WAS rear motor activates left-
ward

0 V

39

Ground

B

4WAS rear motor 
output voltage
(left)

Output

While 4WAS rear motor activates 
rightward

0 V

While 4WAS rear motor activates left-
ward

Battery voltage

40

Ground

B

4WAS rear motor 
ground

—

Always

0  V

Terminal No.

Wire 

color

Description

Condition

Value (Approx.)

+

-

Signal name

Input/

Output

STC-158

< ECU DIAGNOSIS >

[WITH 4WAS]

4WAS MAIN CONTROL UNIT

JCGWA0049GB