Checking The Intake Air Temperature (IAT) Sensor

Purpose:
The Intake Air Temperature (IAT) sensor element extends into the incoming air stream to measure the temperature of the air passing through the intake manifold.

Operation:
The Powertrain Control Module (PCM) sends out a reference voltage of approximately five (5) volts to the IAT sensor. As air temperature changes, the internal resistance of the sensor will change, causing a varying voltage drop across the sensor. The PCM reads the voltage drop across the sensor as charge air temperature.

The PCM uses this information to calculate the proper injector pulse width and spark advance.

Using an Ohmmeter, measure the resistance between each terminal.

As always, check the service manual for the proper procedures and specifications for your particular vehicle.