ECPS Indicator Comes on While Driving the Vehicle (But the ECPS Indicator Goes Off After the Engine Is Restarted)

Electronically Controlled Power Steering System (ECPS) Symptom Troubleshooting - ECPS indicator comes on while driving the vehicle (but the ECPS indicator goes off after the engine is restarted)

ECPS indicator comes on while driving the vehicle (but the ECPS indicator goes off after the engine is restarted)

NOTE: High engine speed (1,700 rpm or more) when the vehicle is not moving may cause the ECPS indicator to come on.

1. Start the engine.

2. Check the ECPS indicator.

Does the indicator come on with the engine running?

YES -

Go to symptom troubleshooting ECPS Indicator Does Not Go Off After the Engine Is Started.

NO -

Go to step 3.

3. Test-drive under these conditions:

- Drive the vehicle at 6 mph (10 km/h) or more for 3 minutes
- Engine speed about 2,100 rpm or more

Does the indicator come on?

YES -

Go to step 4.

NO -

Intermittent failure, the system is OK at this time.

4. Turn the ignition switch to LOCK (0).

5. Disconnect the ECPS control unit 12P connector.

6. Short the SCS line with the HDS.

7. Disconnect PCM connector A (49P).

8. Measure the resistance between ECPS control unit 12P connector terminal No. 1 and body ground.





Is there 1 MOhms or more?

YES -

Go to step 9.

NO -

Repair a short to body ground in the wire between the ECPS control unit and PCM.

9. Check for continuity between ECPS control unit 12P connector terminal No. 1 and PCM connector A (49P) terminal No. 30.





Is there continuity?

YES -

Go to step 10.

NO -

Repair an open in the wire between the ECPS control unit and the PCM.

10. Substitute a known-good ECPS control unit Service and Repair.

11. Reconnect all disconnected connectors.

12. Test drive the vehicle under these conditions:

- Drive the vehicle at 6 mph (10 km/h) or more for 3 minutes
- Engine speed about 2,100 rpm or more

Does the indicator come on?

YES -

Update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM, then go to step 1 and recheck. If the PCM was updated and DTCs are not indicated, troubleshooting is complete. If the PCM was substituted and DTCs and not indicated, replace the original PCM Service and Repair.

NO -

Replace the original ECPS control unit Service and Repair.