P1658

DTC P1658: Electronic Throttle Control System (ETCS) Control Relay ON Malfunction

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

1. Turn the ignition switch ON (II).
2. Do the ETCS TEST in the INSPECTION MENU with the HDS.

Is the RELAY circuit OK?

YES - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the ETCS control relay (F) and the ECM.

NO - Go to step 3.

3. Turn the ignition switch OFF.




4. Remove the ETCS control relay (F) from the under-hood fuse/relay box.
5. Test the ETCS control relay (F).

Is the ETCS control relay (F) OK?

YES - Go to step 6.

NO - Replace the ETCS control relay (F), then go to step 13.

6. Jump the SCS line with the HDS.
7. Disconnect ECM connector A (44P).




8. Check for continuity between ECM connector terminal A20 and body ground.

Is there continuity?

YES - Repair short in the wire between the ECM (A20) and the ETCS control relay (F), then go to step 13.

NO - Go to step 9.

9. Disconnect ECM connector C (44P).
10. Turn the ignition switch ON (II).




11. Measure voltage between ECM connector terminal C1 and body ground.

Is there battery voltage?

YES - Repair short to power in the wire between the ECM (C1) and the ETCS control relay (F), then go to step 12.

NO - Go to step 18.

12. Turn the ignition switch OFF.
13. Reconnect all connectors.
14. Turn the ignition switch ON (II).
15. Reset the ECM with the HDS.
16. Do the ECM idle learn procedure.
17. Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES - If DTC P1658 is indicated, check for poor connections or loose terminals at the ETCS control relay (F) and the ECM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

NO - Troubleshooting is complete.

18. Update the ECM if it does not have the latest software, or substitute a known-good ECM.
19. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P1658 indicated?

YES - Check for poor connections or loose terminals at the ETCS control relay (F) and the ECM. If the ECM was updated, substitute a known-good ECM, then recheck. If the ECM was substituted, go to step 1.

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