Caprice V8-265 4.3L VIN W MFI (1995)
Vehicle Speed Sensor: Description and Operation
General Description
Vehicle Speed Sensor (2WD)
The Vehicle Speed Sensor (VSS) is a pulse counter type input that informs the Powertrain Control Module (PCM) how fast the vehicle is being driven.
The VSS system uses an inductive sensor mounted in the tail housing of the transmission and a toothed reluctor wheel on the tail shaft. As the reluctor
rotates, the teeth alternately interfere with the magnetic field of the sensor creating an induced voltage pulse.
The VSS produces an AC voltage signal that increases with vehicle speed. The PCM processes this signal and sends it to the instrument panel, EVO
module, chime module and cruise control module on CKT 817. A malfunction in the VSS system could set Diagnostic Trouble Code (DTC) 24 or DTC
72.
