Speedometer Malfunctioning But Tachometer Operates Properly

Diagnose Vehicle Speed Sensor (VSS). See ELECTRONIC CONTROLS article in TRANSMISSION SERVICING article. Repair as necessary. If speedometer is still malfunctioning, go to next step.
Using scan tool, verify speedometer input is active. If speedometer input is active, replace instrument cluster. See INSTRUMENT PANEL article. If speedometer input is not active, check for short to ground in Dark Green/White wire between PCM and instrument cluster. Repair as necessary.