Vehicle Speed Sensor: Description and Operation

Vehicle Speed Sensor:

The Vehicle Speed Sensor (VSS) sends a pulsing voltage signal to the ECM/PCM, which the ECM/PCM converts to miles per hour. The BCM receives an input signal from the VSS to control the operation of the Torque Converter Clutch (TCC) system. There are several different types of vehicle speed sensors. The ECM/PCM parameter ED12 reading should closely match the speedometer reading with drive wheels turning.