F 250 4WD Super Duty V10-6.8L VIN S (2001)
Thermistor-type sensors are considered passive sensors. A passive sensor is connected to a voltage divider network so that varying the resistance of
the passive sensor causes a variation in total current flow.
Voltage that is dropped across a fixed resistor in a series with the sensor resistor determines the voltage signal at the PCM. This voltage signal is equal
to the reference voltage minus the voltage drop across the fixed resistor.
The IAT provides air temperature information to the PCM. The PCM uses the air temperature information as a correction factor in the calculation of
fuel spark and MAF.
The IAT sensor provides a quicker temperature change response time than the ECT or CHT sensor.
Supercharged 5.4L Lightning vehicles use (2) AT sensors. Both sensors operate as above. However, one is located before the supercharger at the air
cleaner for standard OBD II/cold weather input, while a second sensor Second Intake Air Temperature (IAT2) is located after the supercharger in the
intake manifold. The IAT2 sensor located after the supercharger provides air temperature information to the PCM to control border-line spark and to
help determine intercooler efficiency.
