DTC Troubleshooting

DTC P0112: IAT Sensor Circuit Low Voltage

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.

1. Turn the ignition switch ON (II).
2. Check the IAT SENSOR in the DATA LIST with the HDS.

Is about 356 °F (180 °C) or more, or 0.08 V or less indicated?

YES - Go to step 3.

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the IAT sensor and the ECM/PCM.

3. Turn the ignition switch OFF.
4. Disconnect the IAT sensor 2P connector.
5. Turn the ignition switch ON (II).
6. Check the IAT SENSOR in the DATA LIST with the HDS.

Is about 356 °F (180 °C) or more, or 0.08 V or less indicated?

YES - Go to step 7.

NO - Go to step 11.

7. Turn the ignition switch OFF.
8. Jump the SCS line with the HDS.
9. Disconnect ECM/PCM connector A (31P).




10. Check for continuity between IAT sensor 2P connector terminal No. 1 and body ground.

Is there continuity?

YES - Repair short in the wire between the IAT sensor and the ECM/PCM (A5), then go to step 13.

NO - Go to step 18.

11. Turn the ignition switch OFF.
12. Replace the IAT sensor.
13. Reconnect all connectors.
14. Turn the ignition switch ON (II).
15. Reset the ECM/PCM with the HDS.
16. Do the ECM/PCM idle learn procedure.
17. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0112 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.

18. Reconnect all connectors.
19. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.
20. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0112 indicated?

YES - Check for poor connections or loose terminals at the IAT sensor and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM, then recheck. If the ECM/PCM was substituted, go to step 1.

NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.