Vehicle Speed Sensor (VSS)

VSS is mounted in transmission. VSS produces an AC signal with a frequency proportional to speed at which transmission assembly output shaft rotates, which is also proportional to vehicle speed. The AC signal is sent to cruise control module assembly and speedometer by Powertrain Control Module (PCM). The signal is sent at a rate of 4000 pulses per mile, and the PCM converts number of pulses per mile per second to determine speed of vehicle.