Air Temperature Sensor ( Ambient / Intake ): Description and Operation
DESCRIPTIONThe Intake Air Temperature (IAT) sensor is mounted in the air cleaner assembly. This sensor measures the temperature of the air entering the intake manifold and provides this information to the ECM for use in calculating air density. The ECM uses IAT, MAP and engine speed to calculate the quantity of air flowing into the engine.
OPERATION
The IAT sensor is a thermistor (a resistor whose resistance changes as a function of temperature). When the temperature is low, the resistance is high. The resistance decreases as temperature increases. The IAT sensor is a "two-wire" sensor with a reference or signal voltage and a ground coming from the ECM.
SENSOR CIRCUIT FAILURE
A failure in the IAT sensor circuit should set a DTC 24 Intake Air Temperature Sensor Circuit.