Code P0113, IAT Sensor Circuit High Temperature Indicated: Notes

Intake Air Temperature (IAT) sensor is a thermistor. PCM applies and monitors a 5-volt reference signal to sensor. When air is cold, sensor resistance is high and PCM will measure a high signal voltage. If air is warm, sensor resistance is low causing PCM to measure low voltage.

Code P0113 will set when the following conditions are present.

• Signal voltage indicates an intake air temperature greater than 284°F (140°C).
• Vehicle speed is greater than 35 MPH.
• Conditions are met for at least for 5 seconds.
  NOTE: Test numbers refer to numbers on diagnostic chart.

1. Scan tester may be used to diagnose this fault since PCM transmits actual values when fault is present. A grounded circuit will cause tester to display a temperature of about 147°C.
2. If scan tester displays about -40°C with IAT sensor disconnected, PCM and wiring are okay. Replace IAT sensor.