Test B: Coolant Temperature Gauge Inoperative Or Inaccurate
- Turn ignition switch to START position. With engine running, check operation of Engine Coolant Temperature (ECT) gauge. If ECT gauge is inoperative, go to next step. If ECT gauge is operating correctly, check for intermittent condition. See appropriate BODY CONTROL MODULES article.
- Turn ignition switch to LOCK position. Disconnect ECT sending unit 3-pin harness connector. ECT is located on rear of left cylinder head. Using Pin-Out Box (J-33431-C), connect red lead to ECT sending unit and other lead to ground. Using Pin-Out Box (J-33431-C), test operation of gauge. Gauge should indicate as specified in table. See TEMPERATURE GAUGE POSITION
table. If gauge position is not as specified, go to next step. If gauge position is as specified, replace ECT sending unit and retest system.TEMPERATURE GAUGE POSITION
Temperature Gauge Position Ohms Cold 138 Midpoint Between Cold & Hot 52 Hot 10 - Remove instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Disconnect instrument cluster 13-pin harness connector C3. Check continuity between ground and ECT sending unit harness connector terminal No. 2 (Yellow/White wire). If continuity does not exist, go to next step. If continuity exists, repair short to ground in Yellow/White wire between ECT sending unit and instrument cluster. See WIRING DIAGRAMS .
- Measure resistance in Yellow/White wire between instrument cluster harness connector C3 terminal No. 4 and ECT sending unit harness connector terminal No. 2. If resistance is 2 ohms or more, go to next step. If resistance is less than 2 ohms, go to step 6 .
- Repair open in Yellow/White wire between instrument cluster and ECT sending unit and retest system.
- Inspect for damage or loose connections in instrument cluster printed circuit. If printed circuit is damaged, go to next step. If printed circuit is not damaged, go to step 8 .
- Replace instrument cluster printed circuit and retest system.
- Replace ECT gauge and retest system.