Engine Speed Signal Circuit

ENGINE SPEED SIGNAL CIRCUIT


Description

ECM sends engine speed signal to power steering control unit.




ENGINE SPEED SIGNAL CIRCUIT


Diagnosis Procedure

1.PERFORM ECM SELF-DIAGNOSIS
With CONSULT-III
1. Turn the ignition switch ON.
2. Perform ECM self-diagnosis. Refer to CONSULT-III Function (VQ35HR)
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.






Is the inspection result normal?
YES - GO TO 4.
NO - Replace ECM. Refer to Description (VQ engine),
4.CHECK ENGINE SPEED SIGNAL (2)
1. Turn the ignition switch OFF.
2. Connect power steering control unit harness connector.
3. Check 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 Exploded View.
5.CHECK TERMINALS AND HARNESS CONNECTORS
- Check 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.