DTC Troubleshooting

DTC Troubleshooting: P0116

DTC P0116: ECT Sensor 1 Circuit Range/Performance Problem

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

Is about 176 °F (80 °C) or more, or 0.78 V or less indicated?
YES - Go to step 6.

NO - Go to step 3.


3. Note the value of ECT SENSOR 1 in the DATA LIST with the HDS.

4. Start the engine. Hold the engine speed at 3,000 rpm without load (in neutral) until the radiator fan comes on, then let it idle.

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

Does ECT SENSOR 1 change 18 °F (10 °C) or more?
YES - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1 and the ECM.

NO - Go to step 11.


6. Note the value of ECT SENSOR 1 in the DATA LIST with the HDS.

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

8. Open the hood, and let the engine cool for 3 hours.

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

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

Does ECT SENSOR 1 change 18 °F (10 °C) or more?
YES - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1 and the ECM.

NO - Go to step 11.


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

12. Replace ECT sensor 1. ECT Sensor 1 Replacement

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

14. Reset the ECM with the HDS.

15. Do the ECM idle learn procedure. ECM Idle Learn Procedure

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

Is DTC P0116 indicated?
YES - Check for poor connections or loose terminals at ECT sensor 1 and the ECM, 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.