Intake Air Temperature (IAT) Sensor

Air Cleaner Housing With Intake Air Temperature Sensor:

The IAT sensor is a thermistor (a resistor which changes value based on temperature) mounted inside of the air cleaner and measures the air temperature entering the engine. At cold air temperatures, the IAT sensor resistance is high and at hot air temperatures the resistance of the sensor is low. The PCM supplies a 5 volt reference signal and a ground to the sensor and measures the voltage signal as it is changed by the sensor. The voltage is close to 5 volts at cold temperatures and close to zero volt at hot temperatures.