Operation CHARM: Car repair manuals for everyone.

Speedometer

The vehicle speed sensor (VSS) is a gear driven permanent magnet generator housed in the transaxle. The sensor generates a sine wave output with a frequency proportional to the vehicle speed. The PCM converts the signal to an output that switches to ground at a frequency of 4000 pulses per mile. The signal CKT drives the speedometer and the odometer and is used by various vehicle components.