DTC Troubleshooting
DTC P0118: ECT Sensor/ECT Sensor 1 Circuit High VoltageNOTE: 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 (Din the DATA LIST with the HDS.
Is about - 40 °F (- 40 °C) or less, or 4.90 V or more indicated?
YES - Go to step 3.
NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the ECT sensor/ECT sensor 1 and the ECM/PCM.
3. Turn the ignition switch OFF.
4. Disconnect the ECT sensor/ECT sensor 12P connector.
5. Connect ECT sensor/ECT sensor 1 2P connector terminals No. 1 and No. 2 with a jumper wire.
6. Turn the ignition switch ON (II).
7. Check the ECT SENSOR (1) in the DATA LIST with the HDS.
Is about - 40 °F (- 40 °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 the ECT sensor/ECT sensor 1 2P connector.
10. Turn the ignition switch ON (II).
11. Measure voltage between ECT sensor/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 ECM/PCM connector D (17P).
15. Connect ECT sensor/ECT sensor 1 2P connector terminal No. 2 to body ground with a jumper wire.
16. Check for continuity between ECM/PCM connector terminal D10 and body ground.
Is there continuity?
YES - Go to step 26.
NO - Repair open in the wire between the ECM/PCM (D10) and the ECT sensor/ECT sensor 1, then go to step 20.
17. Measure voltage between ECM/PCM connector terminal D17 and body ground.
Is there about 5 V?
YES - Repair open in the wire between the ECM/PCM (D17) and the ECT sensor/ECT sensor 1,then go to step 20.
NO - Go to step 25.
18. Turn the ignition switch OFF.
19. Replace the ECT sensor/ECT sensor 1.
20. Reconnect all connectors.
21. Turn the ignition switch ON (II).
22. Reset the ECM/PCM with the HDS.
23. Do the ECM/PCM idle learn procedure. Programming and Relearning
24. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0118 indicated?
YES - Check for poor connections or loose terminals at the ECT sensor/ECT sensor 1 and the ECM/PCM, then go to step 1.
NO - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.
25. Turn the ignition switch OFF.
26. Reconnect all connectors.
27. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.
28. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0118 indicated?
YES - Check for poor connections or loose terminals at the ECT sensor/ECT sensor 1 and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM, then recheck. If the ECM/PCM was substituted, go to step 1.
NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.