Operation CHARM: Car repair manuals for everyone.

Engine Speed Signal Circuit


ENGINE SPEED SIGNAL CIRCUIT





Diagnosis Procedure
1.PERFORM ECM SELF-DIAGNOSIS
With CONSULT-III
Perform "ENGINE" self-diagnosis.
Is any DTC detected?
YES - Check the DTC. Testing and Inspection.
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 (ECM)
1. Connect ECM harness connectors.
2. Check the signal between ECM harness connector and ground with oscilloscope.






Is the inspection result normal?
YES - GO TO 4.
NO - Replace ECM. Description.
4.CHECK ENGINE SPEED SIGNAL (POWER STEERING CONTROL UNIT)
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. 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.