Air Flow Meter/Sensor: Description and Operation

The MAF sensor is attached to the front (air inlet side) of the throttle body.

The Mass Air Flow (MAF) sensor measures the amount of air which passes through it. The PCM uses this information to determine the operating condition of the engine, to control fuel delivery.

A large quantity of air indicates acceleration, while a small quantity indicates deceleration or idle.

The scan tool reads the MAF value and displays it in grams per second (gm/s). At idle, it should read between 4gm/s to 6gm/s on a fully warmed up engine. Values should change rather quickly on acceleration, but values should remain fairly stable at any given RPM. A failure in the MAF sensor or circuit should set DTC P0101 Mass Air Flow (MAF) Sensor Performance, DTC P0102 Mass Air Flow (MAF) Sensor Circuit Low Frequency, or DTC P0103 Mass Air Flow (MAF) Sensor Circuit High Frequency.