Mass Airflow (MAF) Sensor

MAF sensor measures flow of air entering engine. This measurement of airflow is a reflection of engine load (throttle opening). Sensing element (hot wire) is a thin platinum wire wound on a ceramic bobbin and coated with glass.

Hot wire is maintained at 392°F (200°C) above cold wire (ambient) temperature. Cold wire is located downstream of hot wire. As air passes through airflow sensor, air temperature is measured as air passes over cold wire sensor. PCM uses this information to control fuel delivery.