Test F: Incorrect Temperature Gauge Indication
WARNING: This page is about a different car, the 2000 Ford Mustang and 1999 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.
Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition switch to RUN position. Using NGS tester, select instrument cluster active command ENGCOOLNT. Trigger, monitor and scroll ENGCOOLNT at 0%, 50% and 100%. Temperature gauge should indicate cold at 0%, half at 50% and hot at 100%. If temperature gauge responds as specified, repair engine coolant temperature sensor circuit. See SELF-DIAGNOSTICS - EEC-V (GASOLINE) article. If temperature gauge does not respond as specified, replace instrument cluster.