Vehicle Speed Sensor

Vehicle Speed Sensor (VSS) is mounted in transmission. VSS produces an AC signal with a frequency proportional to speed at which transmission output shaft rotates, which is also proportional to vehicle speed. This signal is then sent to VCM, which converts signal to a rate of 4000 pulses per mile. The VCM then sends signal to speedometer and cruise control module, where number of pulses per mile is converted to pulses per second to determine speed of vehicle.