Pinpoint Test M - Speedometer Erratic

Remove instrument cluster, leaving connectors attached. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Connect AC voltmeter to speedometer SP+ and SP- terminals on back of speedometer. Drive vehicle at speeds specified in SPEEDOMETER INPUT SPECIFICATIONS table in PINPOINT TEST L. If voltages are not approximately as specified, Test vehicle speed sensor. See appropriate TESTS W/CODES article in ENGINE PERFORMANCE section. Repair as necessary. If voltages are approximately as specified, replace speedometer.