Mass Airflow (MAF) Sensor (9-3 With Trionic T-7 & 9-5)

The MAF sensor is located between the air cleaner and throttle body. Sensor contains 2 PTC resistors which are heated electrically to 428°F (220°C). When airflow increases, heating element requires higher voltage to maintain temperature. The voltage required is converted into ground pulses, which increase in frequency as air flow increases. ECM uses ground pulse frequency to calculate mass air flow.