Circuit Description

The vehicle speed sensor has a magnet rotated by the transmission output shaft. Attached to the sensor is a hall effect circuit the interacts with the magnetic field treated by the rotating magnet. A 12V operating supply for the speed sensor hall circuit is supplied from the meter fuse. The VSS pulses to ground the 9V signal sent from the PCM on the reference circuit. The PCM interprets vehicle speed by the number of pulses to ground per second on the reference circuit.