DTC Troubleshooting

DTC Troubleshooting: P0111

DTC P0111: IAT Sensor 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. Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the IAT sensor.

Are the connections and terminals OK?
YES - Go to step 2.

NO - Repair the connections or terminals, then go to step 15.


2. Remove the IAT sensor. Service and Repair

3. Allow the IAT sensor to cool to ambient temperature.

4. Note the ambient temperature.

5. Connect IAT sensor to its 2P connector, but do not install it on the intake air duct.

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

7. Note the value of the IAT SENSOR quickly in the DATA LIST with the HDS.

8. Compare the value of the IAT SENSOR and the ambient temperature.

Does the value of the IAT SENSOR differ 5.4 °F (3 °C) or more from the ambient temperature?
YES - Go to step 13.

NO - Go to step 9.


9. Disconnect the IAT sensor from its 2P connector.

10. Using a heat gun, blow hot air on the IAT sensor for a few seconds. Do not apply the heat longer than a few seconds or you will damage the sensor.

11. Connect the IAT sensor to its 2P connector, but do not install it on the intake air duct.

12. Check the IAT SENSOR in the DATA LIST with the HDS.

Does the IAT SENSOR change 58 °F (32 °C) or more from the ambient temperature?
YES - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the IAT sensor and the ECM.

NO - Go to step 13.


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

14. Replace the IAT sensor. Service and Repair

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

16. Reset the ECM with the HDS.

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

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

Is DTC P0111 indicated?
YES - Check for poor connections or loose terminals at the IAT sensor 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.