Vehicle Speed Sensor: Description and Operation

Vehicle Speed Sensor (VSS):

The Vehicle Speed Sensor (VSS) is a pulse counter type input that informs the PCM how fast the vehicle is being driven. The VSS system uses an inductive sensor mounted to the differential housing and a toothed reluctor wheel attached to the ring gear. 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 various components.