Circuit Description
WARNING: This page is about a different car, the 2008 Isuzu Ascender, 2008 GMC Envoy, and 2008 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
The vehicle speed signal (VSS) circuit from the instrument cluster to the navigation radio provides vehicle speed information to the radio for the purpose of updating the vehicle position indicator on the navigation screen.