P0112
DTC P0112: IAT Sensor Circuit Low Voltage1. Turn the ignition switch ON (II).
2. Check the IAT with a scan tool or the HDS.
Is 302 °F (150 °C) or higher or 0 V indicated?
YES - Go to step 3.
NO - Go to step 8.
3. Disconnect the IAT sensor 2P connector.
4. Check the IAT with a scan tool or the HDS.
Is 302 °F ( 150 °C) or higher or 0 V indicated?
YES - Go to step 5.
NO - Replace the IAT sensor.
5. Turn the ignition switch OFF.
6. Disconnect the ECM connector C (31P).
7. Check the continuity between IAT sensor 2P connector terminal No. 2 and body ground.
Is there continuity?
YES - Repair short in the wire between the ECM (C25) and the IAT sensor.
NO - Substitute a known-good ECM and recheck. If normal IAT is indicated, replace the original ECM.
8. Check the temperature reading on 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.
NO - Replace the IAT sensor.