ECPS Indicator Does Not Go Off After the Engine Is Started
Electronically Controlled Power Steering System (ECPS) Symptom Troubleshooting - ECPS indicator does not go off after the engine is started
ECPS indicator does not go off after the engine is started
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 step 3.
NO -
Intermittent failure, the system is OK at this time.�
3. Turn the ignition switch to LOCK (0).
4. Check the No. 21 (10 A) fuse in the driver's under-dash fuse/relay box.
Is the fuse blown?
YES -
Replace the fuse. Turn the ignition switch to ON (II), then turn the ignition switch to LOCK (0). If the fuse blows again, repair the short to ground on the No. 21 (10 A) fuse circuit.�
NO -
Reinstall the checked fuse, then go to step 5.
5. Disconnect the ECPS control unit 12P connector.
6. Turn the ignition switch to ON (II).
7. Measure the voltage between body ECPS control unit 12P connector terminal No. 7 and body ground.
Is there battery voltage?
YES -
Go to step 8.
NO -
Repair an open in the wire between the ECPS control unit 12P connector and No. 21 fuse in the driver's under-dash fuse/relay box.�
8. Turn the ignition switch to LOCK (0).
9. Check for continuity between the ECPS control unit 12P connector terminal No. 9 and body ground.
Is there continuity?
YES -
Go to step 10.
NO -
Repair an open in the wire between the ECPS control unit and body ground (G203).�
10. Start the engine.
11. Measure the voltage between ECPS control unit 12P connector terminal No. 4 and body ground.
Is the voltage between 2.1 and 10.6 V?
YES -
Go to step 20.
NO -
Go to step 12.
12. Turn the ignition switch to LOCK (0).
13. Measure the resistance between the ECPS control unit 12P connector terminal No. 4 and body ground.
Is there 1 MOhms or more?
YES -
Go to step 14.
NO -
Go to step 17.
14. Short the SCS line with the HDS.
15. Disconnect PCM connector A (49P).
16. Check for continuity between ECPS control unit 12P connector terminal No. 4 and PCM connector A (49P) terminal No. 33.
Is there continuity?
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 -
Repair an open in the wire between the ECPS control unit and PCM.�
17. Short the SCS line with the HDS.
18. Disconnect PCM connector A (49P).
19. Measure the resistance between the ECPS control unit 12P connector terminal No. 4 and body ground.
Is there 1 MOhms or more?
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 -
Repair a short to body ground in the wire between the ECPS control unit and PCM.�
20. Measure the resistance between ECPS control unit 12P connector terminals No. 2 and No. 5, No. 6, No. 11, and No. 12 individually.
Is the resistance between 19.8 to 24.2 Ohms at 68 °F (20 °C)?
YES -
Go to step 21.
NO -
Go to step 22.
21. Measure the resistance between ECPS control unit 12P connector terminal No. 2 and body ground.
Is there 1 MOhms or more?
YES -
Go to step 26.
NO -
Go to step 24.
22. Disconnect the ECPS valve motor 6P connector.
23. On the motor side, measure the resistance between ECPS valve motor 6P connector terminals No. 4 and No. 1, No. 2, No. 5, and No. 6 individually.
Is the resistance between 19.8 Ohms to 24.2 Ohms at 68 °F (20 °C)?
YES -
Repair an open in the wire between the ECPS control unit and ECPS valve motor.�
NO -
Replace the valve body unit Overhaul.�
24. Disconnect the ECPS valve motor 6P connector.
25. On the motor side, measure the resistance between ECPS valve motor 6P connector terminal No. 4 and body ground.
Is there 1 MOhms or more?
YES -
Repair a short to body ground in the wire between the ECPS control unit and ECPS valve motor.�
NO -
Replace the valve body unit Overhaul.�
26. Turn the ignition switch to ON (II).
27. Measure the voltage between ECPS control unit 12P connector terminal No. 8 and body ground.
Is there about 4.5 V or more?
YES -
Go to step 28.
NO -
Go to step 29.
28. Connect ECPS control unit 12P connector terminal No. 8 and body ground with a jumper wire.
Does the ECPS indicator go off?
YES -
Replace the ECPS control unit Service and Repair.�
NO -
Do the troubleshooting for the gauge control module Initial Inspection and Diagnostic Overview.�
29. Turn the ignition switch to LOCK (0).
30. Disconnect gauge control module connector B (28P).
31. Check for continuity between ECPS control unit 12P connector terminal No. 8 and gauge control module connector B (28P) terminal No. 21.
Is there continuity?
YES -
Do the troubleshooting for the gauge control module Initial Inspection and Diagnostic Overview.�
NO -
Repair an open in the wire between the ECPS control unit and gauge control module.�