Infiniti FX35, FX50 (S51). Manual - part 1772

DIAGNOSIS AND REPAIR WORKFLOW

STC-29

< BASIC INSPECTION >

[WITH REAR ACTIVE STEER]

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• When multiple DTCs are detected, refer to 

STC-102, "DTC Inspection Priority Chart"

 to determine the

sequence of performing a self-diagnosis.

• When DTC is not detected, refer to Freeze frame data.

Is any DTC detected?

YES

>> GO TO 6.

NO

>> Check harness and connector, based on information obtained from the interview with the cus-

tomer. Refer to 

GI-36, "Intermittent Incident"

.

6.

REPAIR AND REPLACE PART

1.

Repair or replace malfunctioning part.

CAUTION:

Securely connect the removed parts and connectors.

2.

Erase the memory of self-diagnosis results (history) of “4WAS(MAIN)/RAS/HICAS”. 

>> GO TO 7.

7.

RECHECK SYMPTOM

With CONSULT-III

Perform “DTC CONFIRMATION PROCEDURE” for each malfunction.
NOTE:
• When multiple DTCs are detected, refer to 

STC-102, "DTC Inspection Priority Chart"

 to determine the

sequence of performing a self-diagnosis.

• When DTC is not detected, refer to Freeze frame data.
Is any DTC detected?

YES

>> GO TO 6.

NO

>> GO TO 9. 

8.

DIAGNOSIS BY SYMPTOM

Estimate and check malfunctioning parts, based on the symptoms obtained from the diagnosis by symptom. 

Is a malfunctioning part identified?

YES

>> GO TO 9.

NO

>> Check harness and connector, based on information obtained from the interview with the cus-

tomer. Refer to 

GI-36, "Intermittent Incident"

.

9.

FINAL CHECK

With CONSULT-III

1.

Check the input-output reference values of RAS control unit.

2.

Recheck the symptom under the same conditions as those for the successfully reproduced malfunction
symptom.

Is a malfunction symptom reproduced?

OK

>> GO TO 4.

NO

>> INSPECTION END

Question sheet

INFOID:0000000005566496

DESCRIPTION

There are many operating conditions that may cause a malfunction of the transmission parts. By understand-
ing those conditions properly, a quick and exact diagnosis can be achieved.
In general, customers have their own criteria for a problem. Therefore, it is important to understand the symp-
tom and status well enough by asking the customer about the concerns carefully. In order to systemize all the
information for the diagnosis, prepare the question sheet referring to the question points.

STC-30

< BASIC INSPECTION >

[WITH REAR ACTIVE STEER]

DIAGNOSIS AND REPAIR WORKFLOW

WORKSHEET SAMPLE

Question Sheet

Customer name       MR/MS

Engine #

Manuf. Date

Incident Date

VIN

Model & Year

In Service Date

Trans.

Mileage

km / Mile

Symptoms

†

 steering wheel position (center) is in the wrong position 

†

 Warning lamp turn ON

†

 Noise 

†

 Vibration

†

 Others

Frequency

†

 All the time

†

 Under certain conditions

†

 Sometimes (         times a day)

Weather conditions

†

 Not affected

Weather

†

 Fine

†

 Clouding

†

 Raining

†

 Snowing

†

 Other (                                  )

Temp.

†

 Hot

†

 Warm

†

 Cool

†

 Cold

†

 Temp. [Approx.       

°

C (     

°

F)]

Humidity

†

 High

†

 Middle

†

 Low

Road conditions

†

 Not affected

†

 In town

†

 In suburbs

†

 Freeway

†

 Off road (Up / Down)

Driving conditions

†

 Not affected

†

 At starting

†

 While idling

†

 While engine racing

†

 At racing

†

 While cruis-

ing

†

 While accelerating

†

 While decelerating

†

 While turning (Right / Left)

†

 Vehicle speed [                        km/h (                 MPH)]

Other conditions

RAS SYSTEM

STC-31

< SYSTEM DESCRIPTION >

[WITH REAR ACTIVE STEER]

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SYSTEM DESCRIPTION

RAS SYSTEM

System Diagram

INFOID:0000000005235356

CONTROL DIAGRAM

 CROSS-SECTIONAL VIEW

RAS Actuator

System Description

INFOID:0000000005235357

DESCRIPTION

• RAS control unit controls the rear active steer.
• RAS system consists of RAS control unit and RAS actuator components.
• RAS control unit controls the RAS actuator assembly according to the steering angle and vehicle speed.
• Self-diagnosis can be performed with CONSULT-III at each control unit to another RAS control unit.

JSGIA0787GB

SGIA1577E

1.

Rod

2.

Offset shaft

3.

Gear housing assembly

4.

RAS motor

5.

Motor shaft

6.

Rear wheel steering angle sensor

7.

HRH gear

STC-32

< SYSTEM DESCRIPTION >

[WITH REAR ACTIVE STEER]

RAS SYSTEM

• It transmits/receives each signal from the following control unit via CAN communication line.

Model Following Control

• Situation :

The rear wheels turn to the opposite phase of front wheels for a
moment so as to improve the start-up of yaw rate (steering angle
speed).

• Situation :

The rear wheels turn to the same phase of front wheels after
securing the necessary yaw rate (steering angle speed) to corner-
ing.

OPERATION DESCRIPTION

The rear wheel angle changes as per the following:

During high-speed driving

• The rear wheels turn to the same phase of front wheels regardless

of the operation speed of steering wheel.

During middle- low-speed driving

• When turning the steering wheel rapidly, the rear wheels turn to the

opposite phase of front wheels for a moment just after starting the
steering wheel operation. And then, they turn to the same phase.

Component parts

Function

Steering angle sensor

It mainly transmits the following signals to RAS control unit via CAN communication.
• Steering angle sensor signal

ABS actuator and electronic unit (con-
trol unit)

It mainly transmits the following signals to RAS control unit via CAN communication.
• Vehicle speed signal
• VDC malfunction signal

ECM

It mainly transmits the following signals to RAS control unit via CAN communication.
• Engine speed signal

Unified meter and A/C amp.

It mainly transmits the following signals from RAS control unit via CAN communication. 
• RAS warning lamp signal

SGIA1439E

SGIA1440E

SGIA1441E