Inlet Air Temperature Sensor
WARNING: This page is about a different car, the 2003 Dodge SX and 2003 Dodge Neon. However, it is still accessible from the selected car via links, so may be relevant.
The Inlet Air Temperature (IAT) sensor attaches to the clean air duct. See Fig 1. The IAT Sensor is a Negative Temperature Coefficient (NTC) sensor that provides information to the Powertrain Control Module (PCM) regarding the temperature of the air entering the intake manifold. The IAT sensor value is used by the PCM to determine air density. The PCM uses this information to calculate injector pulse width and adjustment of ignition timing (to prevent spark knock at high intake air temperatures).