Coolant Temperature Gauge Needle Moves Past Hot Mark
- Remove PCM. See POWERTRAIN CONTROL MODULE (PCM) under REMOVAL & INSTALLATION. Disconnect Powertrain Control Module (PCM) 32-pin connector "A". See Figure. Turn ignition on and observe coolant temperature gauge for about 30 seconds. If coolant temperature gauge needle moves, go to next step. If coolant temperature gauge needle does not move, substitute a known-good PCM and recheck. See SUBSTITUTING PCM under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS - INTRODUCTION article. If problem goes away, replace original PCM.
- Turn ignition off and on. Watch coolant temperature gauge. If coolant temperature gauge needle immediately moves past hot mark, replace fuel and temperature gauge. If coolant temperature gauge needle travel past hot mark took about 30 seconds or more, go to next step.
- Turn ignition switch to OFF position. Remove instrument cluster and disconnect instrument cluster 18-pin connector "B". See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Check for continuity in Yellow/Green wire between PCM 32-pin harness connector "A" terminal No. 31 and instrument cluster 18-pin harness connector "B" terminal No. 3. If continuity exists, check for short in Yellow/Green wire between PCM 32-pin harness connector "A" and instrument cluster 18-pin connector "B". If continuity does not exist, replace fuel and temperature gauge.