Grand Prix V6-3.8L SC VIN 1 (1997)
Mass Air Flow (MAF) Sensor: Description and Operation
DESCRIPTION
The Mass Air Flow (MAF) sensor is located in the MAF sensor housing between the air snorkel and the throttle body. It senses the amount of air
entering the intake manifold. This information is required by the PCM to control fuel and emissions.
The MAF sensor used on this vehicle is a hot wire type and is used to measure air flow rate (mass/unit time). The MAF sensor output is a variable
frequency square wave based on air mass traveling through the sensor. A low frequency output signal from the MAF sensor indicates low air flow
and high frequency indicates high air flow. The MAF sensor has two wires crossing the air stream through it. One senses ambient temperature and
the other, the hot wire, is kept at a fixed temperature above the ambient temperature. The MAF sensor senses air flow by measuring the power
necessary to keep the hot wire hot, which is proportional to air flow, and converts it to a frequency modulate output signal.
The scan tool reads the MAF value and displays it in grams per second (gm/s). At idle, it should read between 4 gm/s-7 gm/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.
