Instrument Panel Cluster (IPC) Description and Operation: Speedometer: Diesel
WARNING: This page is about a different car, the 2002 GMC Savana Special, 2002 GMC Savana Camper Special, 2002 GMC Savana, and 2002 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
The IPC displays the vehicle speed based on the information from the vehicle speed sensor buffer. The vehicle speed sensor buffer converts the analog signal from the VSS into a 4000 pulses/mile signal. The IPC uses the vehicle speed signal circuit from the vehicle speed sensor buffer in order to calculate the vehicle speed.