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

Regarding Wiring Diagram information, refer to Electrical Diagrams.
1.PERFORM ECM SELF-DIAGNOSIS
With CONSULT-III
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 connector E10 (QR25DE except California), E31 (QR25DE California) or E32 (VQ35DE).
3. Disconnect power steering control unit harness connector.
4. Check continuity between ECM harness connector E10 (QR25DE except California), E31 (QR25DE California) or E32 (VQ35DE) (A) terminal 94 and power steering control unit harness connector M59 (B) terminal 10.










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 (ECM SIDE)





1. Turn the ignition switch OFF.
2. Connect ECM harness connector.
3. Check signal between ECM harness connector E10 (QR25DE except California), E31 (QR25DE California) or E32 (VQ35DE) terminal 94 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. Refer to (QR25DE for California), (QR25DE except for California), Engine Control System (VQ35DE).
4.CHECK ENGINE 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 10 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. Refer to Service and Repair.
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.