Air Flow Meter/Sensor: Description and Operation

DESCRIPTION
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. A small quantity of air indicates deceleration or idle.

The scan tool reads the MAF value and displays it in grams per second (gm/Sec). At idle, it should read between 6 gm/Sec - 9 gm/Sec on a fully warmed up engine. Values should change rather quickly on acceleration, but values should remain fairly stable at any given RPM. When the PCM detects a malfunction in the MAF sensor circuit, the following DTCs will set:
^ DTC P0100 circuit malfunction.
^ DTC P0101 system performance.
^ DTC P0102 frequency low.
^ DTC P0103 frequency high.