Vehicle Speed Sensor: Description and Operation

Circuit Description
The vehicle speed sensor, located on the speedometer driven gear in the transaxle, generates pulse signals that indicate the vehicle's speed and provides signals to the control modules to calculate the vehicle speed.

The vehicle speed sensor (VSS) intermittently grounds the circuits. The number of pulses per minute increase/decrease with the speed of the car.

The vehicle speed sensor is a reed switch that is built into the speedometer. The sensor converts the transaxle gear revolutions into a pulse signal which is sent to the ECM.