Airflow Meter

Nissan uses two types of airflow meters. The first type uses a swinging door that measures all air flow through it. The amount of door movement is detected by a potentiometer. The second type measures airflow by detecting the electrical current relationship to the amount of heat that is dissipated from a hot wire (located in path of incoming air). The more incoming air entering through the airflow meter, the more heat removed from the hot wire. The more heat removed from hot wire the less the resistance of the hot wire. The ECU evaluates the air flow rate through this change in resistance of the hot wire.