Air Temperature Sensor ( Ambient / Intake ): Description and Operation
INTAKE AIR TEMPERATURE (IAT) SENSORSThe intake air temperature (IAT) sensor 1 is located in the inlet air duct between the air cleaner and the throttle body. The intake air temperature (IAT) sensor 2 is mounted in the front of the intake manifold just behind the throttle body. The IAT sensors measure the temperature of the air at their respective locations in the intake system. The IAT sensors provide useful air temperature information to the powertrain control module (PCM).
Each 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.