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

Intake Air Temperature Sensor:

The intake air temperature sensor is located on the intake air tube leading to the throttle body. Through holes in the sensor, the intake air flows in and past an NTC (Negative Temperature Coefficient) resistor which acts as the sensitive element. When the temperature of the intake air rises the resistance decreases and, with a voltage applied across the resistor, the voltage drop also decreases. At extremely low temperatures the ECM accordingly receives a high signal voltage from the IAT sensor while a high temperature results in a low signal voltage.

On the basis of the actual air temperature and details of the pressure in the intake manifold, the air mass can be determined instantaneously by the ECM.