Test J: Incorrect Tachometer Indication

NOTE: Perform all voltage and resistance tests using a Digital Volt-Ohm Meter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use ohmmeter to isolate wiring harness shorts or opens.

Turn ignition switch to LOCK position. Connect Worldwide Diagnostic System (WDS) tester or New Generation Star (NGS) tester to Data Link Connector (DLC). See Figure. DLC is located under instrument panel between steering column and the radio. See Figure. Turn ignition switch to RUN position. Using WDS or NGS tester, select instrument cluster active command TCHOMETER. Trigger, monitor and scroll TCHOMETER at 0%, 50% and 100%. Tachometer should indicate 0 RPM at 0%, middle RPM at 50% and maximum RPM at 100%. If tachometer does not respond as specified, go to next step. If tachometer responds as specified, repair engine speed input from PCM (retrieve codes from PCM). See SELF-DIAGNOSTICS - EEC-V - GASOLINE & NGV article in ENGINE PERFORMANCE. After repair, test system for normal operation.
Disconnect all instrument cluster harness connectors. It may be necessary to remove instrument cluster for access to instrument cluster harness connectors. See INSTRUMENT CLUSTER MODULE under REMOVAL & INSTALLATION. Inspect all instrument cluster harness connectors for loose, damaged or corroded terminals. If terminals are damaged, repair or replace as necessary. If terminals are not damaged, reconnect all instrument cluster harness connectors. Ensure instrument cluster harness connectors are seated properly. If problem still exists, replace instrument cluster module. After repair, clear DTCs, repeat self-test and check system for normal operation.