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

Intake Air Temperature (IAT) Sensor:

PURPOSE AND OPERATION
The Intake Air Temperature (IAT) sensor is threaded into the intake air passage with a sensing element extending into the air chamber.
The IAT sensor is a negative temperature coefficient sensor, meaning that as the temperature of the sensor increases, the resistance will decrease. As the resistance value changes, the signal sensed by the Powertrain Control Module (PCM) will also change. The PCM reads the varying sensor resistance and determines the air charge temperature, using this information to optimize the air/fuel mixture.
The IAT sensor will also set a fault code when the PCM determines the output signal to be out of the normal operating range.