Air Flow Meter/Sensor: Testing and Inspection

Following is a short description of how the Mass Air Flow (MAF) (1) sensor can be diagnosed by using a scan tool. The scan tool can also be used to compare the values for a normal running engine with the engine you are diagnosing.

DESCRIPTION
The Mass Air Flow (MAF) (1) 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.

DIAGNOSIS
The scan tool reads the MAF value and displays it in grams per second (gm/s). At idle, it should read between 4gm/s-7gm/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, DTC P0102, or DTC P0103. Refer to System DIagnosis / Diagnostic Tables / Diagnostic Trouble Code Tables. Testing and Inspection