Vehicle Speed Sensor: Description and Operation

Vehicle Speed Sensor:

PURPOSE
The Vehicle Speed Sensor (VSS) produces an Alternating Current (AC) signal and sends this signal to the Powertrain Control Module (PCM). The PCM converts this signal to a vehicle speed value.
The PCM uses this value to aid in controlling torque converter lock-up, vehicle speed control, air/fuel ratio, and igniting timing.

CONSTRUCTION
The VSS is a magnetic pulse generator driven by the transmission speedometer gear.