Tachometer Inaccurate
WARNING: This page is about a different car, the 1998 Cadillac Seville. However, it is still accessible from the selected car via links, so may be relevant.
Turn ignition switch to ON position. Connect scan tool to Data Link Connector (DLC). See COMPONENT LOCATIONS . Select IPC DATA MENU on scan tool display. Start engine. If scan tool indicates engine RPM to be same as RPM on tachometer, repair as necessary. See procedures in TESTS W/CODES article in ENGINE PERFORMANCE section. If scan tool does not indicate engine RPM to be same as RPM on tachometer, replace IPC. See INSTRUMENT PANEL CLUSTER under REMOVAL & INSTALLATION. Recheck system operation.