The intake air temperature (IAT) sensor is a thermistor that varies resistance according to changes in air induction temperature. The powertrain control module (PCM) supplies a 5-volt reference through a pull-up resistor to the sensor, which is connected to ground. When the sensor is cold, it has high resistance (high signal voltage at PCM). As the sensor temperature increases, its resistance decreases (lower signal voltage at PCM). The PCM uses the signal voltage to determine air induction temperature. DTC P0113 sets when the IAT sensor signal voltage at the PCM is above the calibrated voltage value (below the calibrated temperature value).
DTC Parameters
DTC P0113 will set if IAT sensor temperature is less than -30°C (-22°F) when:
| • | The condition exists for longer than 20 seconds. |
| • | The engine coolant temperature (ECT) is greater than 60°C (140°F). |
| • | The vehicle speed is less than 24 km/h (15 mph). |
| • | The calculated air flow is less than 16 gm/s. |
| • | No ECT or vehicle speed DTCs has been set. |
DTC P0113 diagnostic runs continuously once the above conditions have been met.
DTC P0113 is a type A DTC.
Diagnostic Aids
To locate an intermittent problem, use scan tool to monitor IAT temperature with ignition ON, engine OFF. Wiggling the wires while watching for a change in IAT temperature may locate the area where an open or short to voltage in the wiring could lie.
Notice: A short to B+ on signal circuit 472 may damage the IAT sensor. Check for correct resistance vs. temperature of the sensor after repair has been made.
Refer to Engine Controls Component Descriptions for a Temperature versus Resistance chart.
