Nissan Altima (L32) 2007-2012 Service Manual: Vehicle speed signal circuit

Description

• Combination meter sends vehicle speed signal to power steering control unit.

Diagnosis Procedure

1.PERFORM COMBINATION METER SELF-DIAGNOSIS

Perform combination meter self-diagnosis.

Is any error system detected? YES >> Check the error system.

NO >> GO TO 2.

2.CHECK HARNESS BETWEEN COMBINATION METER AND POWER STEERING CONTROL UNIT

1. Turn the ignition switch OFF.

2. Disconnect combination meter harness connector.

3. Disconnect power steering control unit harness connector.

4. Check continuity between combination meter harness connector M24 (A) terminal 30 and power steering control unit harness connector M59 (B) terminal 8.

Also check harness for short to ground and short to power.

Is the inspection result normal? YES >> GO TO 3.

NO >> Repair or replace damaged parts.

3.CHECK VEHICLE SPEED SIGNAL (COMBINATION METER SIDE)

1. Turn the ignition switch OFF.

2. Connect combination meter harness connector.

3. Check combination meter input/output standard values. Refer to MWI-59, "Reference Value".

Is the inspection result normal? YES >> GO TO 4.

NO >> Replace combination meter. Refer to MWI-176, "Removal and Installation".

4.CHECK VEHICLE SPEED SIGNAL (POWER STEERING CONTROL UNIT SIDE)

1. Turn the ignition switch OFF.

2. Connect power steering control unit harness connector.

3. Check signal between power steering control unit harness connector M59 terminal 8 and ground with oscilloscope.

Also check harness for short to ground and short to power.

Is the inspection result normal? YES >> GO TO 5.

NO >> Replace power steering control unit.

5.CHECK TERMINALS AND HARNESS CONNECTORS

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

• Check combination meter pin terminals for damage or loose connection with harness connector.

Is the inspection result normal? YES >> Inspection End

NO >> Repair or replace damaged parts.