DTC Troubleshooting

DTC Troubleshooting: P1659

DTC P1659: ETCS Control Relay OFF Malfunction

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information. Initial Inspection and Diagnostic Overview

1. Turn the ignition switch to ON (II).

2. Clear the DTC with the HDS.

3. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P1659 indicated?
YES - Go to step 4.

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the under-hood fuse/relay box (ETCS control relay) and the PCM.


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

5. Check the No. 10 THROTTLE ACTUATOR CONTROL (DBW+) (15 A) fuse in the under-hood fuse/relay box.

Is the fuse OK?
YES - Go to step 6.

NO - Go to step 14.


6. Test the ETCS control relay in the under-hood fuse/relay box. Power Relay Test

Is the ETCS control relay OK?
YES - Go to step 7.

NO - Replace the relay control module (under-hood fuse/relay box), Under-Hood Fuse/Relay Box Removal and Installation then go to step 22.


7. Jump the SCS line with the HDS.

8. Disconnect PCM connector C (49P).

9. Disconnect the under-hood fuse/relay box connector H (9P).

10. Check for continuity between under-hood fuse/relay box connector H (9P) terminal No. 7 and PCM connector terminal C4.

Is there continuity?
YES - Go to step 11.

NO - Repair open in the wire between the PCM (C4) and the under-hood fuse/relay box, then go to step 22.






11. Disconnect PCM connector A (49P).

12. Disconnect under-hood fuse/relay box connector E (14P).

13. Check for continuity between under-hood fuse/relay box connector E (14P) terminal No. 14 and PCM connector terminal A29.

Is there continuity?
YES - Go to step 27.

NO - Repair open in the wire between the PCM (A29) and the under-hood fuse/relay box, then go to step 22.






14. Jump the SCS line with the HDS.

15. Disconnect PCM connector C (49P).

16. Disconnect the under-hood fuse/relay box connector H (9P).

17. Check for continuity between PCM connector terminal C4 and body ground.

Is there continuity?
YES - Repair short in the wire between the PCM (C4) and the under-hood fuse/relay box, then go to step 22.

NO - Go to step 18.






18. Install the under-hood fuse/relay box connector H (9P), and replace the No. 10 THROTTLE ACTUATOR CONTROL (DBW+) fuse in the under-hood fuse/relay box.

19. Turn the ignition switch to ON (II).

20. Measure the voltage between PCM connector terminal C4 and body ground.

Is there battery voltage?
YES - Go to step 27.

NO - Replace the right side engine compartment wire harness. Also replace the No. 10 THROTTLE ACTUATOR CONTROL (DBW+) fuse in the under-hood fuse/relay box, then go to step 21.






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

22. Reconnect all connectors.

23. Turn the ignition switch to ON (II).

24. Reset the PCM with the HDS.

25. Do the PCM idle learn procedure. PCM Idle Learn Procedure

26. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P1659 indicated?
YES - Check for poor connections or loose terminals at the under-hood fuse/relay box and the PCM, then go to step 1.

NO - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


27. Reconnect all connectors.

28. Update the PCM if it does not have the latest software, PCM Update or substitute a known-good PCM. Initial Inspection and Diagnostic Overview

29. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P1659 indicated?
YES - Check for poor connections or loose terminals at the under-hood fuse/relay box and the PCM. If the PCM was updated, substitute a known-good PCM, Initial Inspection and Diagnostic Overview then recheck. If the PCM was substituted, go to step 1.

NO - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. Service and Repair If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.