Operation CHARM: Car repair manuals for everyone.

Vehicle Speed Signal

The Vehicle Speed Sensor (VSS) mounts onto the automatic transaxle. The VSS provides a low voltage Alternating Current (AC) signal to the powertrain control module (PCM). The PCM converts the AC signal to a pulse width modulated direct current (DC) signal. The PCM sends the DC signal to the cruise control module at a rate of 4,000 pulses per mile.