Air Flow Meter/Sensor: Description and Operation

MASS AIR FLOW SENSOR

Typical Mass Air Flow (MAF) Sensor:

Mass Air Flow (MAF) Sensor (E-Series):

The mass air flow (MAF) sensor provides an analog voltage signal to the PCM proportional to the intake air mass. The MAF sensor utilizes a hot wire sensing element to measure the amount of air entering the engine. The hot wire is maintained at 200°C (392°F) above ambient temperature. Air passing over the hot wire cools the wire. The current required to maintain the temperature of the hot wire is proportional to the air mass flow. The MAF signal is used to calculate exhaust gas recirculation (EGR) and for fault detection.