Caprice V8-265 4.3L VIN W MFI (1995)
Air Flow Meter/Sensor: Description and Operation
The Mass Air Flow (MAF) sensor measures the amount of air that is ingested by a vehicles' engine. This information is required by the engine's
Powertrain Control Module (PCM) to schedule fuel and maintain the desired air/fuel ratio.
The MAF sensor used on this vehicle is a hot wire type and is used to measure air flow rate. The Mass Air Flow (MAF) output frequency is a function of
the power required to keep the air flow sensing elements (hot wires) at a fixed temperature above ambient temperature. As air flows through the MAF
sensor the "hot wires" are cooled. The amount of cooling is proportional to the rate of air flow. As air flow increases a greater amount of current is
required to maintain the "hot wires" at a constant temperature. The MAF sensor converts the changes in current draw to a frequency signal read by the
PCM. The PCM calculates air flow (grams per second) based on this signal. A failure in the MAF circuit should set a Diagnostic Trouble Code (DTC)
48.
