Grand AM L4-138 2.3L DOHC VIN D MFI (1994)
Vehicle Speed Sensor: Description and Operation
Vehicle Speed Sensor (VSS)
PURPOSE
The Vehicle Speed Sensor (VSS) provides information to the PCM for control of transmission Torque Converter Clutch (TCC), speedometer,
odometer and cruise control.
LOCATION
Transaxle
OPERATION
The VSS is a Permanent Magnet (PM) generator that produces a pulsing Alternating Current (A.C.) voltage whenever vehicle speed exceeds about 3
mph (5 kph). The A.C. voltage level and the number of pulses increases with vehicle speed and is converted by the PCM to MPH (KPH). A VSS
buffer is incorporated into the PCM for operating the instrument panel speedometer and odometer.
