Vehicle Speed Signal

42LE - Automatic Transmission
VEHICLE SPEED SIGNAL
The vehicle speed signal is calculated from the Output Speed Sensor. The PCM converts the OSS signal into a roughly 8000 pulse per mile vehicle speed signal (using pinion factor information programmed into its memory), and sends it to the PCM.

The PCM, in turn, sends the vehicle speed message across the PCI bus to the Instrument Cluster to display vehicle speed to the driver.