Vehicle Speed Sensor (VSS)

Vehicle Speed Sensor:

This device contains a permanent magnet surrounded by a coil of wire producing a magnetic field which is interrupted by rotor teeth pressed on an output shaft. As the rotor interrupts the magnetic field, an AC voltage is generated in the circuit. This device is used to provide an output shaft speed signal to the Powertrain Control Module (PCM). The control module uses the vehicle speed sensor signal input to:

^ Calculate vehicle speed, transmission output speed, Torque Converter Clutch (TCC) slip speed.
^ Control shift quality.
^ The VSS is attached to the output shaft housing.

For further information and diagnostic procedures refer to Computers and Control Systems / Vehicle Speed Sensor.