Instrument Cluster: Gauges: Speedometer
WARNING: This page is about a different car, the 2005 Ford Pickup, 2005 Ford F550 Super Duty, 2005 Ford F450 Super Duty, and 2005 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The instrument cluster receives the vehicle speed sensor (VSS) signal from the PCM through the communication network. The instrument cluster monitors the VSS input from the PCM and commands a corresponding movement of the speedometer pointer.