P0118

DTC P0118: ECT Sensor 1 Circuit High Voltage

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. Check ECT SENSOR 1 in the DATA LIST with the HDS.

Is about -40 degree F (-40 degree C) or less, or 4.90 V or more indicated?

YES - Go to step 3.

NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1 and the PCM.

3. Turn the ignition switch OFF.
4. Disconnect ECT sensor 1 2P connector.




5. Connect ECT sensor 1 2P connector terminals No. 1 and No. 2 with a jumper wire.
6. Turn the ignition switch ON (II).
7. Check ECT SENSOR 1 in the DATA LIST with the HDS.

Is about -40 degree F (-40 degree C) or less, or 4.90 V or more indicated?

YES - Go to step 8.

NO - Go to step 18.

8. Turn the ignition switch OFF.
9. Remove the jumper wire from ECT sensor 1 2P connector.
10. Turn the ignition switch ON (II).




11. Measure voltage between ECT sensor 1 2P connector terminal No. 1 and body ground.

Is there about 5 V?

YES - Go to step 12.

NO - Go to step 17.

12. Turn the ignition switch OFF.
13. Jump the SCS line with the HDS.
14. Disconnect PCM connector C (22P).




15. Connect ECT sensor 1 2P connector terminal No. 2 to body ground with a jumper wire.




16. Check for continuity between PCM connector terminal C12 and body ground.

Is there continuity?

YES - Go to step 25.

NO - Repair open in the wire between the PCM (C12) and ECT sensor 1, then go to step 20.




17. Measure voltage between PCM connector terminal A14 and body ground.

Is there about 5 V?

YES - Repair open in the wire between the PCM (A14) and ECT sensor 1, then go to step 20.

NO - Go to step 25.

18. Turn the ignition switch OFF.
19. Replace ECT sensor 1.
20. Reconnect all connectors.
21. Turn the ignition switch ON (II).
22. Reset the PCM with the HDS.
23. Do the PCM idle learn procedure.
24. Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES - If DTC P0118 is indicated, check for poor connections or loose terminals at ECT sensor 1 and the 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.

25. Update the PCM if it does not have the latest software, or substitute a known-good PCM.
26. Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES - If DTC P0118 is indicated, check for poor connections or loose terminals at ECT sensor 1 and the 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.