Mass Air Flow (MAF) Sensor

Mass Air Flow (MAF) Sensor





The mass air flow (MAF) sensor measures the difference between the volume and the quantity of air that enters the engine. Volume means the size of the space to be filled. Quantity means the number of air molecules that will fit into the space. This information is important to the PCM because heavier, denser air will hold more fuel than lighter, thinner air. The PCM adjusts the air/fuel ratio as needed depending on the MAF value.

The scan tool reads the MAF value and displays it in terms of grams per second (gm/s). At idle, the scan tool should read between 4-7 gm/s on a fully warmed up engine. Values should change quickly on acceleration. Values should remain stable at any given RPM. A failure in the MAF sensor or circuit will set a DTC.