P1658

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

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, system is OK at this time. Check for poor connections or loose terminals at the electronic throttle control system (ETCS) control relay and the PCM.

NO - Go to step 3.

3. Turn the ignition switch OFF.




4. Remove the electronic throttle control system (ETCS) control relay (A).
5. Test the electronic throttle control system (ETCS) control relay.

Is the electronic throttle control system (ETCS) control relay OK?

YES - Go to step 8.

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

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




8. Check the continuity between PCM connector terminal A20 and body ground.

Is there continuity?

YES - Repair short in the wire between the PCM (A20) and electronic throttle control system (ETCS) control relay, then go to step 13.

NO - Go to step 9.

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




11. Measure voltage between PCM connector terminal C4 and body ground.

Is there battery voltage?

YES - Repair short in the wire between the PCM (C4) and electronic throttle control system (ETCS) control relay, 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 PCM with the HDS.
16. Do the PCM 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 electronic throttle control system (ETCS) control relay and PCM, 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 PCM if it does not have the latest software, or substitute a known-good PCM.
19. 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 electronic throttle control system (ETCS) control relay and PCM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

NO - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM.