Express 1/2 Ton Van V8-5.7L VIN R (1999)
Mass Air Flow (MAF) Sensor: Description and Operation
Component Location
The Mass Air Flow (MAF) sensor measures the amount of air entering the engine. The VCM uses this information to determine the operating condition
of the engine in order to control the fuel delivery. A large quantity of air indicates an acceleration. A small quantity of air indicates a deceleration or an
idle. The scan tool reads the MAF value and displays the MAF value in grams per second (gm/Sec). At idle, the MAF value should read between 5
gm/sec - 7 gm/sec on a fully warmed up engine. The values should change rather quickly on acceleration, but values should remain fairly stable at any
given RPM. When the VCM detects a malfunction in the MAF sensor circuit, the following DTCs will set:
^
DTC P0101 system performance
^
DTC P0102 frequency low
^
DTC P0103 frequency high
