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

Fig. 11 Intake Air Temperature Sensor And MAP Sensor:

PURPOSE
The sensor supplies one of the inputs the PCM uses to determine injector pulse-width.

OPERATION
The intake air temperature sensor (IAT) is located in the intake manifold where it measures the temperature of the air that is about to enter the combustion chambers.

The IAT is a negative temperature coefficient (NTC) thermistor-type sensor (resistance varies inversely with temperature).
- This means at cold temperatures its resistance is high so the voltage signal will be high.
- At high temperatures, resistance decreases and the voltage will decrease.

This allows the sensor to provide an analog voltage signal to cavity 37 of the PCM connector.

The IAT sensor threads into the intake manifold Fig. 11.