Intake Air Temperature Sensor

WARNING: This page is about a different car, the 2003 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.

The 2-wire Intake Manifold Air Temperature (IAT) sensor is installed in the intake manifold with the sensor element extending into the air stream. The IAT sensor is a Negative Thermal Coefficient (NTC) sensor. Meaning, as intake manifold temperature increases, resistance in the sensor decreases. As temperature decreases, resistance in the sensor increases. The IAT sensor provides an input voltage to the Powertrain Control Module (PCM) indicating the density of the air entering the intake manifold based upon intake manifold temperature. At key-on, a 5-volt power circuit is supplied to the sensor from the PCM. The sensor is grounded at the PCM through a low-noise, sensor-return circuit. The PCM uses this input to calculate Injector pulse-width and adjustment of spark timing to help prevent spark knock with high intake manifold air-charge temperatures. The resistance values of the IAT sensor is the same as for the Engine Coolant Temperature sensor.