Vehicle Speed Sensor: Description and Operation
DescriptionVehicle speed information is provided to the Powertrain Control Module (PCM) by the Vehicle Speed Sensor (VSS). The VSS is a permanent magnet generator that is mounted in the transmission and produces a pulsing voltage whenever vehicle speed is greater than 3 mph (5 km/h). The AC voltage level and the number of pulses increases with vehicle speed. The PCM then supplies the signal to the instrument panel for speedometer and odometer.