Air Flow Meter/Sensor: Description and Operation

Mass Air Flow (MAF) Sensor

The Mass Air Flow (MAF) sensor measures the amount of air which passes through it. The ECM 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 Tech 1 reads the MAF value and displays it in grams per second. It should read between 4-7 on a fully warmed up idling 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 a Code 34.