Infiniti FX35, FX50 (S51). Manual - part 1773

RAS SYSTEM

STC-33

< SYSTEM DESCRIPTION >

[WITH REAR ACTIVE STEER]

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

• The rear wheels turn to the same phase of front wheels when turn-

ing the steering wheel slowly.

During extremely slow-speed driving and at straight-ahead driving 

• The rear wheels do not turn during extremely slow-speed driving regardless of the operation speed of steer-

ing wheel.

• The rear wheels do not turn at straight-ahead driving regardless of the vehicle speed.

OPERATION FEATURE

RAS ACTUATOR

• It is driven by RAS motor.
• The irreversible efficiency performance hypoid gear secures the toe-stiffness of rear wheels against the road

external force and keep the steering angle when system is malfunction.

• The power from the pinion gear (motor side) is transmitted, but the pinion gear does not rotate as caused by

the gear mechanical characteristics (teeth angle) even though the ring gear (tire side) starts to rotate.

Component Parts Location

INFOID:0000000005235358

SGIA1442E

1.

RAS control unit

2.

RAS motor relay

3.

RAS warning lamp

4.

RAS rear motor

5.

RAS rear actuator

6.

Rear wheel steering angle sensor

A.

Inside the rear wheel house finisher 
(left)

B.

Inside combination meter

C.

RAS rear actuator assembly

JSGIA0770ZZ

STC-34

< SYSTEM DESCRIPTION >

[WITH REAR ACTIVE STEER]

RAS SYSTEM

Component Description

INFOID:0000000005235359

Component parts

Reference/Function

Steering angle sensor

STC-67, "Description"

RAS control unit

STC-50, "Description"

RAS actuator

The rear wheel steering angle is activated.

Rear wheel steering angle sensor

STC-56, "Description"

RAS motor

STC-44, "Description"

ABS actuator and electronic unit (con-
trol unit)

STC-65, "Description"

ECM

STC-69, "Description"

Power steering solenoid valve

STC-83, "Description"

RAS warning lamp

STC-85, "Description"

Stop lamp switch

This switch is used for self-diagnosis without CONSULT-III.

EPS SYSTEM

STC-35

< SYSTEM DESCRIPTION >

[WITH REAR ACTIVE STEER]

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

EPS SYSTEM

System Diagram

INFOID:0000000005235360

CONTROL DIAGRAM

CROSS-SECTIONAL VIEW

System Description

INFOID:0000000005235361

• The EPS system controls the power steering solenoid valve through the RAS control unit.

JSGIA0416GB

1.

Unified meter and A/C amp.

2.

RAS control unit

3.

Power steering solenoid valve

4.

Steering gear assembly

5.

Gear housing assembly

6.

Gear sub-assembly

7.

Pinion

8.

Power steering oil pump

9.

Reservoir tank

JSGIA0376ZZ

STC-36

< SYSTEM DESCRIPTION >

[WITH REAR ACTIVE STEER]

EPS SYSTEM

• The valve driving voltage to control the power steering solenoid

valve varies according to the vehicle speed.

OPERATION PRINCIPLE

During Parking (When Turning The Steering Wheel To The Right.)

1.

Power steering solenoid valve is closed while a vehicle is stopped.

2.

Pinion “1R”, “2R” and “3R” are closed depending on steering torque of steering wheel.

3.

Oil pressure “P” in the gear housing assembly is the sum of oil pressures occurred in “2R” and “3R”. This
results in a light steering force because of high pressure.

During High-speed Operation

1.

Power steering solenoid valve is opened during high-speed operation.

2.

Pinion “1R”, “2R” and “3R” are closed depending on steering torque of steering wheel.

3.

Oil pressure “2R” does not occur because the power steering solenoid valve is on full throttle.

4.

Oil pressure “P” in the gear housing assembly includes only oil pressure occurred in “3R” and results in a
heavy steering force.

JSGIA0451GB

SGIA1583E

SGIA1584E