FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

Vehicle Speed Sensor: Description and Operation

PURPOSE
The ECM determines the vehicle speed based on signals from the vehicle speed sensor.

OPERATION



When vehicle speed sensor detects the rotation speed of the transmission output shaft and sends signals to the Engine Control Module (ECM). The ECM determines the vehicle speed based on these signals. An AC voltage is generated in the vehicle speed sensor coil as the rotor mounted on the output shaft rotates, and this voltage is sent to the ECM.