Vehicle Speed Signal

The vehicle speed signal is generated by the Vehicle Speed Sensor (VSS), and translated by the vehicle control module (VCM).

The VSS mounts to the automatic transmission assembly and produces an AC signal. The frequency of this signal is proportional to transmission output shaft speed.

The VCM receives a signal from the VSS (permanent magnet generator) indicating the speed of the vehicle.

The AC signal produced by the VSS is amplified and converted to a digital signal by the VCM.

This signal is supplied to the cruise control module and speedometer. The VCM produces the signal by opening and closing internal solid-state switches to ground.

The signal to the cruise control module and speedometer assembly pulses at a rate of 4,000 times per mile. The cruise control module and speedometer assembly internally convert the number of pulses per mile per second to determine vehicle speed.