Vehicle Speed Sensor (VSS)

The vehicle speed sensor (VSS) produces an AC voltage of different amplitude and frequency depending on the velocity of the output shaft. The VSS produces the signal from 16 evenly spaced machined notches on the transaxle differential carrier. The vehicle speed sensor produces a readable AC voltage signal when vehicle speed is above 5 km/h (3 mph). This VSS signal is sent to the PCM, which is used to determine the velocity of the output shaft.
The PCM uses the VSS to monitor the speed of the output shaft. In conjunction with the transaxle ISS, the PCM can determine the slip across the commanded gear clutch pack. The PCM can use this information to determine the actual gear ratio, gear slippage or lack of main line hydraulic pressure.