General Information

A Vehicles Speed Sensor (VSS) signal is supplied by the Powertrain Control Module (PCM) via discrete inputs to the IPC. The VSS discrete signal is pulled up to ignition voltage in the IPC. This vehicle speed pulse train is expressed as 4000 pulses per mile. The IPC uses the VSS data received from the PCM and a software program to determine the proper vehicle speed to display. The ENG/MET button is used in order to change the displayed vehicle speed between english and metric units.