Supply air temperature (IAT) sensor

Supply air temperature sensor (IAT) is a thermistor with a negative temperature coefficient of resistance.

The sensor resistance is 4,500 ohms at 40°C, and 70 ohms at 130°C.

The engine control unit (ECM) applies 5 volts to the IAT sensor through a resistor in the ECM and measures the voltage drop to determine the supply air temperature.

The task of the IAT sensor is also to control ignition distribution at low manifold air temperatures.

A failure in the IAT sensor circuit causes DTC P0112 or P0113 to be set.