F 150 2WD V8-4.6L VIN W (2007)
Intake Air Temperature Sensor: Description and Operation
INTAKE AIR TEMPERATURE (IAT) SENSOR
Typical Stand-Alone/Non-Integrated Intake Air Temperature (IAT) Sensors
Typical Integrated Intake Air Temperature (IAT) Sensor Incorporated Into A Drop-in Or Flange-type MAF Sensor
The IAT sensor is a thermistor device in which resistance changes with temperature. The electrical resistance of a thermistor decreases as the
temperature increases, and the resistance increases as the temperature decreases. The varying resistance affects the voltage drop across the sensor
terminals and provides electrical signals to the PCM corresponding to temperature.
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 air flow.
