Air Temperature Sensor ( Ambient / Intake ): Description and Operation

The Intake Air Temperature (IAT) sensor is located in the side of air cleaner.

The IAT sensor is a thermistor (a resistor whose resistance changes as a function of temperature). The ECT is a two wire sensor with a referance voltage and a ground provided by the ECM. Low air temperature produces a high resistance and high temperatures result in a low resistance.

The ECM supplies a five-volt signal to the sensor through a resistor in the ECM and measures the signal voltage. The voltage will be high when the air is cold and low when the air is hot.

The IAT sensor provides air temperature information to the ECM for calculating air density. The ECM uses IAT, MAP and engine speed to calculate the amount of air flowing into the engine.

A failure in the IAT sensor circuit should set a Diagnostic Trouble Code (DTC) 24.