Vehicle Speed Sensor (VSS)

The Vehicle Speed Sensor (VSS) is mounted to the transmission assembly and produces an AC signal. The frequency of this signal is proportional to the speed at which the transmission assembly output shaft rotates, which in turn is proportional to the speed of the vehicle.

The AC signal produced by the VSS is amplified and converted by the VSS buffer assembly. The signal is supplied to the ECM, cruise control module and speedometer by the VSS buffer. The VSS buffer produces the signal by opening and closing internal solid state switches to ground.

The signal to the ECM cruise control module, and speedometer assembly is at a rate of 4000 pulses per mile. The ECM, cruise control module and speedometer assembly internally converts the number of pulses per mile per second to determine vehicle speed.