Engine Speed Signal Circuit

ENGINE SPEED SIGNAL CIRCUIT

Description

ECM sends engine speed signal to power steering control unit.


Diagnosis Procedure


1. PERFORM ECM SELF-DIAGNOSIS

With CONSULT
Perform ECM self-diagnosis.
Is any error system detected?
YES- Check the error system.
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 the continuity between ECM harness connector and power steering control unit harness connector.





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 ENGINE SPEED SIGNAL (1)

1.Turn the ignition switch OFF.
2.Connect ECM harness connectors.
3.Check the signal between ECM harness connector and ground with oscilloscope.





Also check harness for short to ground and short to power.
Is the inspection result normal?
YES- GO TO 4.
NO- Replace ECM. (VQ-37VHR), Description (VQ-25HR for USA and Canada), {LINK_TO_MANY:0000000007742347}{LINK_TO_MANY:0000000007742348}, "ADDITIONAL SERVICE
WHEN REPLACING CONTROL UNIT : Description" (VQ-25HR for Mexico).

4. CHECK ENGINE SPEED SIGNAL (2)

1.Turn the ignition switch OFF.
2.Connect power steering control unit harness connector.
3.Check the signal between power steering control unit harness connector 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. Exploded View.

5. CHECK TERMINALS AND HARNESS CONNECTORS

- Check the power steering control unit pin terminals for damage or loose connection with harness connector.
- Check ECM pin terminals for damage or loose connection with harness connector.
Is the inspection result normal?
YES- INSPECTION END
NO- Repair or replace damaged parts.