Air Flow Meter/Sensor: Description and Operation

The mass air flow (MAF) sensor measures the amount of air which passes through the throttle body. The PCM uses this information to determine the operating condition of the engine, in order to control fuel delivery. A large quantity of air indicates acceleration, while a small quantity indicates deceleration or idle.

The scan tool displays the MAF value in grams per second (g/s). At idle, MAF should read between 4 gm/s - 7 gm/s on a fully warmed up engine. Values should change rather quickly on acceleration, but should remain fairly stable at any given RPM. A MAF sensor malfunction or MAF signal circuit problem should set DTC P0101, DTC P0102, or DTC P0103.