Vehicle Speed Sensor: Description and Operation

Vehicle Speed Sensor:

Vehicle Speed Sensor (VSS):

PURPOSE
Provides vehicle speed information to the Engine Control Module (ECM).

OPERATION
The vehicle speed sensor, located in the speedometer drive gear, is a magnetic reed switch that rotates in conjunction with the transmission output shaft. It sends the ECM on/off pulse signals. The ECM interprets the speed at which the on/off pulse signals occur into vehicle speed.