Mass Airflow Sensor

The Mass Air Flow (MAF) sensor measures difference between volume and quantity of air that enters engine. Volume means size of space to be filled. Quantity means number of air molecules that will fit into the space. MAF information is important to the PCM because heavier, denser air will hold more fuel than lighter, thinner air. PCM adjusts air/fuel ratio as needed depending on MAF value. Scan tool reads MAF value and displays it in terms of grams per second (grams/sec.). At idle, scan tool should read between 4-7 grams/sec. 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 DTC P0101, DTC P0102, or DTC P0103.