Vehicle Speed Sensor: Description and Operation

Vehicle Speed Sensor (VSS)
The vehicle speed sensor, located on the transmission, generates a signal in proportion to the vehicle speed (Signal (1)). Receiving this signal, the speedometer uses it for operation of its indicator and also converts it into the ON/OFF signal by doubling the cycle (Signal (2)). This signal is sent to ECM where it is used as one of the signals to control various devices.