Nissan Murano Z51. Manual - part 1406

POWER STEERING CONTROL UNIT

STC-15

< ECU DIAGNOSIS INFORMATION >

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STC

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JCGWM0269GB

STC-16

< ECU DIAGNOSIS INFORMATION >

POWER STEERING CONTROL UNIT

Fail-Safe

INFOID:0000000005515255

EPS system

JCGWM0270GB

POWER STEERING CONTROL UNIT

STC-17

< ECU DIAGNOSIS INFORMATION >

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• EPS system enters the fail-safe mode (that allows the steering

force to be controlled without impairing the drivability) if any of the
input/output values to/from EPS system (power steering control
unit) deviate from the standard range.
NOTE:
The system enters the fail-safe mode if the engine speed remains
at 1,500 rpm or more for over 10 seconds while the vehicle is
stopped. This is normal.

• The fail-safe function is canceled when a vehicle speed signal of 2

km/h (1.2 MPH) or more is inputted or the ignition switch is turned
OFF

→

ON. EPS system restores the normal operation at that time.

JSGIA0368GB

Mode

Warn-

ing lamp

DTC

Detection point (malfunction part)

Error area and root cause

Fail-safe 

function

—

—

Vehicle speed signal input

• Engine speed is 1,500 rpm or more and there is no vehicle 

speed signal input for over 10 seconds during vehicle travel.

• Vehicle speed signal has abruptly dropped from 30 km/h (19 

MPH) or more to 2 km/h (1.2 MPH) or less within 1.4 sec-
onds.

STC-18

< SYMPTOM DIAGNOSIS >

UNBALANCE STEERING WHEEL TURNING FORCE (TORQUE VARIATION)

SYMPTOM DIAGNOSIS

UNBALANCE STEERING WHEEL TURNING FORCE (TORQUE VARIA-
TION)

Description

INFOID:0000000005515256

• Hard steering when fully turning the steering wheel.
• Light steering when driving at a high speed.

Diagnosis Procedure

INFOID:0000000005515257

1.

CHECK SYSTEM FOR POWER SUPPLY AND GROUND

Perform trouble diagnosis for power supply and ground. Refer to 

STC-6, "Diagnosis Procedure"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace damaged parts.

2.

CHECK SYSTEM FOR VEHICLE SPEED SIGNAL

Perform trouble diagnosis for vehicle speed signal. Refer to 

STC-11, "Diagnosis Procedure"

.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace damaged parts.

3.

CHECK SYSTEM FOR ENGINE SPEED SIGNAL

Perform trouble diagnosis for engine speed signal. Refer to 

STC-9, "Diagnosis Procedure"

.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair or replace damaged parts.

4.

CHECK SYSTEM FOR POWER STEERING SOLENOID VALVE

Perform trouble diagnosis for power steering solenoid valve. Refer to 

STC-7, "Diagnosis Procedure"

.

Is the inspection result normal?

YES

>> Perform the symptom diagnosis for the steering system. Refer to 

ST-3, "NVH Troubleshooting

Chart"

.

NO

>> Repair or replace damaged parts.