LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Acura >> 2009 >> CSX Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> PGM-FI System >> DTC Troubleshooting >> DTC P0111: IAT Sensor Circuit Range/Performance Problem
April 5, 2026: LEMON Manuals is launched! Read the announcement.

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 (see GENERAL TROUBLESHOOTING INFORMATION ).
  1. Check for poor connections or loose terminals at the ECT sensor 1/2 and the IAT sensor.

    Are the connections and terminals OK? 

    YES  -Go to step 2.

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

  2. Remove the MAF sensor/IAT sensor (see MAF SENSOR/IAT SENSOR REPLACEMENT  ).
  3. Allow IAT sensor to cool to ambient temperature.
  4. Note the ambient temperature.
  5. Connect the MAF sensor/IAT sensor to the 5P connector, but do not install the sensor onto the air cleaner.
  6. Turn the ignition switch ON (II).
  7. Note the value of the IAT SENSOR quickly in the DATA LIST with the HDS.
  8. Compare the value of IAT SENSOR and the ambient temperature.

    Does the value of IAT SENSOR differ 3°C (5.4°F) or more? 

    YES  -Go to step  13.

    NO  -Go to step 9.

  9. Disconnect the MAF sensor/IAT sensor from the 5P connector.
  10. 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.
  11. Connect the MAF sensor/IAT sensor to the 5P connector, but do not install the sensor onto the air cleaner.
  12. Check the IAT SENSOR in the DATA LIST with the HDS.

    Does the IAT SENSOR change 33°C (59°F) or more? 

    YES  -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the IAT sensor and the ECM/PCM.

    NO  -Go to step 13.

  13. Turn the ignition switch OFF.
  14. Replace the MAF sensor/IAT sensor (see MAF SENSOR/IAT SENSOR REPLACEMENT  ).
  15. Turn the ignition switch ON (II).
  16. Reset the ECM/PCM with the HDS.
  17. Do the ECM/PCM idle learn procedure (see ECM/PCM 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/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 .

scientia non olet · About LEMON Manuals