Air Temperature Sensor ( Ambient / Intake ): Description and Operation

Air Cleaner Housing With Intake Air Temperature Sensor:

DESCRIPTION
The Intake Air Temperature (IAT) sensor is a thermistor (a resistor which changes value based on temperature) mounted inside of the air cleaner housing and measures the air temperature entering the engine.

OPERATION
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.