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

Schematic:

The Intake Air Temperature (IAT) sensor (2) is an integral part of the Mass Air Flow (MAF) sensor and is mounted in the air cleaner assembly. The IAT sensor measures the temperature of the air entering the intake manifold. The AT sensor provides temperature information to the circuitry of the MAF sensor and the PCM.

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 the temperature increases. The IAT sensor is a 2-wire circuit with a reference or signal voltage and a ground coming from the PCM.