Infiniti EX35. Manual - part 1395

STC-6

< COMPONENT DIAGNOSIS >

[EPS]

POWER SUPPLY AND GROUND CIRCUIT

COMPONENT DIAGNOSIS

POWER SUPPLY AND GROUND CIRCUIT

Description

INFOID:0000000003552473

Power supply to EPS system

Diagnosis Procedure

INFOID:0000000003552474

1.

CHECK POWER SUPPLY

1.

Turn the ignition switch OFF.

2.

Disconnect power steering control unit harness connector.

3.

Check voltage between power steering control unit harness connector and ground.

4.

Turn the ignition switch ON.

CAUTION:

Never start the engine.

5.

Check voltage between power steering control unit harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>>

Check the following. If any items are damaged, repair or replace damaged parts.

• 10A fuses (#45) open
- Harness for short or open between ignition switch and power steering control unit harness con-

nector No. 3 terminal.

- Ignition switch. Refer to 

PCS-131, "Removal and Installation"

.

2.

CHECK GROUND CIRCUIT

1.

Turn the ignition switch OFF.

2.

Check continuity between power steering control unit harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair open circuit or short to power in harness or connectors.

3.

CHECK TERMINALS AND HARNESS CONNECTORS

Check power steering control unit pin terminals for damage or loose connection with harness connector.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Repair or replace damaged parts.

Power steering control unit

—

Voltage

Connector

Terminal

M108

3 Ground

0 

V

Power steering control unit

—

Voltage

Connector

Terminal

M108

3 Ground

Battery 

voltage

Power steering control unit

—

Continuity

Connector

Terminal

M108

6 Ground

Existed

POWER STEERING SOLENOID VALVE

STC-7

< COMPONENT DIAGNOSIS >

[EPS]

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POWER STEERING SOLENOID VALVE

Description

INFOID:0000000003552475

Power steering solenoid valve controls the power steering oil pressure in the gear housing assembly.

Diagnosis Procedure

INFOID:0000000003552476

1.

CHECK POWER STEERING SOLENOID VALVE SIGNAL

1.

Turn the ignition switch OFF.

2.

Check voltage between power steering control unit harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> GO TO 4.

2.

CHECK HARNESS BETWEEN POWER STEERING SOLENOID VALVE AND POWER STEERING CON-

TROL UNIT

1.

Turn the ignition switch OFF.

2.

Disconnect power steering solenoid valve harness connector.

3.

Disconnect power steering control unit harness connector.

4.

Check the continuity between power steering solenoid valve harness connector and the power steering
control unit harness connector.

5.

Check continuity between power steering control unit harness connector and ground.

Is the inspection result normal?

 YES

>> GO TO 3.

 NO

>> Repair or replace damaged parts.

3.

CHECK POWER STEERING SOLENOID VALVE

Check power steering solenoid valve. Refer to 

STC-8, "Component Inspection"

. 

Is the inspection result normal?

 YES

>> GO TO 4.

 NO

>> Replace gear-sub assembly. Refer to 

ST-25, "2WD : Exploded View"

 (2WD models), 

ST-34,

"AWD : Exploded View"

 (AWD models).

4.

CHECK TERMINALS AND HARNESS CONNECTORS

• Check power steering control unit pin terminals for damage or loose connection with harness connector.
• Check power steering solenoid valve pin terminals for damage or loose connection with harness connector.

Is the inspection result normal?

Power steering control unit

—

Condition

Voltage (Approx.)

Connector

Terminal

M108

 1 

Ground

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

Power steering solenoid valve

Power steering control unit

Continuity

Connector

Terminal

Connector

Terminal

F45

1

M108

1

Existed

2

5

Existed

Power steering control unit

—

Continuity

Connector

Terminal

M108

1

Ground

Not existed

5

STC-8

< COMPONENT DIAGNOSIS >

[EPS]

POWER STEERING SOLENOID VALVE

YES

>> INSPECTION END

NO

>> Repair or replace damaged parts.

Component Inspection

INFOID:0000000003552477

1.

CHECK POWER STEERING SOLENOID VALVE

1.

Turn the ignition switch OFF.

2.

Disconnect power steering solenoid valve harness connector.

3.

Check resistance between power steering solenoid valve connector terminals.

4.

Check power steering solenoid valve by listening for its operation sound while applying battery voltage to
power steering solenoid valve connector F45 terminals 1 (positive) and 2 (negative).

Is the inspection result normal?

 YES

>> INSPECTION END

 NO

>> Replace gear-sub assembly. Refer to 

ST-25, "2WD : Exploded View"

 (2WD models), 

ST-34,

"AWD : Exploded View"

 (AWD models).

Power steering solenoid valve

Resistance (Approx.)

Connector

Terminal

F45

1 2

4 

– 

6 

Ω

ENGINE SPEED SIGNAL CIRCUIT

STC-9

< COMPONENT DIAGNOSIS >

[EPS]

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ENGINE SPEED SIGNAL CIRCUIT

Description

INFOID:0000000003552478

ECM sends engine speed signal to power steering control unit.

Diagnosis Procedure

INFOID:0000000003552479

1.

PERFORM ECM SELF-DIAGNOSIS

With CONSULT-III

1.

Turn the ignition switch ON.

Perform ECM self-diagnosis. Refer to 

EC-113, "CONSULT-III Function"

.

Is any DTC detected?

YES

>> Check the DTC.

NO

>> GO TO 2.

2.

CHECK HARNESS BETWEEN ECM AND POWER STEERING CONTROL UNIT

1.

Turn the ignition switch OFF.

2.

Disconnect ECM harness connectors.

3.

Disconnect power steering control unit harness connector.

4.

Check continuity between ECM harness connector and power steering control unit harness connector.

5.

Check continuity between power steering control unit harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace damaged parts.

3.

CHECK ENGINE SPEED SIGNAL (1)

1.

Connect ECM harness connectors.

2.

Check signal between ECM harness connector and ground with oscilloscope.

ECM

Power steering control unit

Continuity

Connector

Terminal

Connector

Terminal

M107

110

M108

10

Existed

Power steering control unit

—

Continuity

Connector

Terminal

M108

10

Ground

Not existed