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 sensors 1 and 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 2.
- Remove the MAF sensor/IAT sensor (see MAP SENSOR REPLACEMENT ).
- Allow IAT sensor to cool to ambient temperature.
- Note the ambient temperature.
- Connect the MAF sensor/IAT sensor to its 5P connector, but do not install it.
- 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 MAF sensor/IAT sensor from its 5P connector.
- Using a heat gun, blow hot air on the MAF sensor/IAT sensor for a few seconds. Do not apply the heat longer than a few seconds or you will damage the sensor.
- Connect the MAF sensor/IAT sensor to its 5P connector, but do not install it.
- Check the IAT SENSOR in the DATA LIST with the HDS.
Does the IAT SENSOR change 63°F (35°C) or more?
YES -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM.
NO -Go to step 13.
- Turn the ignition switch to LOCK (0).
- Replace the MAF sensor/IAT sensor (see MAP SENSOR REPLACEMENT ).
- Turn the ignition switch to ON (II).
- Reset the PCM with the HDS.
- Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
- Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0111 indicated?
YES -Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM, then go to step 1.
NO -Troubleshooting is complete. If any other Pending or Confirmed 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.