Description & Operation: Speedometer
WARNING: This page is about a different car, the 1997 Buick LeSabre. However, it is still accessible from the selected car via links, so may be relevant.
Operated electronically by Powertrain Control Module (PCM). Speedometer is driven by a signal generated from Vehicle Speed Sensor (VSS). This AC voltage is proportional to vehicle speed and goes to PCM. Signal from PCM goes to a solid state unit on instrument panel which drives pointer of speedometer.