DTC Troubleshooting: P0112 (10-1)

DTC P0112 (10-1):  IAT Sensor Circuit Low Voltage

1.Turn the ignition switch ON (II).

2.Check the IAT with the HDS or the scan tool.

Is 150°C (302°F) or higher, or about 0 V indicated?


YES - Go to 3.


NO - Go to 8.


3.Disconnect the IAT sensor 2P connector.

4.Check the IAT with the HDS or the scan tool.

Is 150°C (302°F) or higher, or about 0 V indicated?


YES - Go to 5.


NO - Replace the  IAT sensor.n


5.Turn the ignition switch OFF.

6.Disconnect ECM/PCM connector B (24P).

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

 

Is there continuity?


YES - Repair short in the wire between the ECM/PCM (B17) and the IAT sensor.n


NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original  ECM/ PCM.n

8.Check the temperature reading on the HDS or the scan tool.
Be aware that if the engine is warm, the reading will be higher than ambient temperature. If the engine is cold, the IAT and ECT will have the same value.

Is the correct ambient temperature indicated?


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


NO - Replace the  IAT sensor.n