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
1.Turn the ignition switch ON.

CAUTION:
Never start the engine
2.Perform "ENGINE" self-diagnosis. Refer to "CONSULT Function" CONSULT 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 the continuity between ECM harness connector and power steering control unit harness connector.





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





Is the inspection result normal?
YES- GO TO 3.
NO- Repair or replace error-detected parts.

3. CHECK ENGINE SPEED SIGNAL (1)

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





Is the inspection result normal?
YES- GO TO 4.
NO- Replace ECM. Refer to "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT (ECM) : Description" Description.

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.





Is the inspection result normal?
YES- GO TO 5.
NO- Replace power steering control unit. Refer to "Removal and Installation" Service and Repair.

5. CHECK TERMINALS AND HARNESS CONNECTORS

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