Prizm L4-1600cc 1.6L DOHC VIN 6 (1990)
Vehicle Speed Sensor: Description and Operation
Vehicle Speed Sensor (VSS)
The Vehicle Speed Sensor (VSS) consists of the lead switch and magnet that is built into the speedometer. As the magnet turns with the speedometer
cable, its magnetic force causes the lead switch to turn "ON" and "OFF." Such "ON/OFF" frequency increases or decreases in proportion with the car
speed and is sent to the ECM as pulse signals.
