Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC P0111: IAT Sensor Circuit Range/ Performance Problem
- 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.
- Remove the IAT sensor (see MAP SENSOR REPLACEMENT ).
- Allow the IAT sensor to cool to ambient temperature.
- Note the ambient temperature.
- Connect IAT sensor to its 2P connector, but do not install it on the intake air duct.
- Turn the ignition switch to ON (II).
- Note the value of the IAT SENSOR quickly in the DATA LIST with the HDS.
- 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.
- Disconnect the IAT sensor from its 2P connector.
- 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.
- Connect the IAT sensor to its 2P connector, but do not install it on the intake air duct.
- 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.
- Turn the ignition switch to LOCK (0).
- Replace the IAT sensor (see MAP SENSOR REPLACEMENT ).
- Turn the ignition switch to ON (II).
- Reset the ECM with the HDS.
- Do the ECM idle learn procedure (see ECM IDLE LEARN PROCEDURE ).
- 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.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.