Diagnostic Aids
WARNING: This page is about a different car, the 2003 Ford Pickup, 2003 Ford F550 Super Duty, 2003 Ford F450 Super Duty, 2003 Ford Excursion, and 2003 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The Intake Air Temperature (IAT2) sensor is a thermistor-type sensor with a variable resistance that changes when exposed to different temperatures. When interfaced with the Powertrain Control Module (PCM), it produces a 0-5 volt analog signal that will measure temperature. The primary function of the IAT2 sensor is to provide feedback signal to the PCM indicating manifold air temperature. The PCM monitors the IAT2 signal to determine if the temperature is satisfactory.
The PCM continuously monitors the IAT2 sensor. If the PCM detects the signal voltage is higher or lower than expected, a DTC will be set.