Disconnect negative battery cable. Drain cooling system. Disconnect ECT sensor harness connector and remove sensor from engine. Using an ohmmeter, measure resistance of ECT sensor while immersed in container of water. Heat or cool water and compare with values of the ENGINE COOLANT TEMPERATURE (ECT) SENSOR RESISTANCE
table. Replace ECT sensor if resistance is not as specified. If ECT sensor tests okay, go to next step.ENGINE COOLANT TEMPERATURE (ECT) SENSOR RESISTANCE
| Temperature °F (°C) |
Ohms |
| 32 (0) |
5740 |
| 68 (20) |
2280-2610 |
| 104 (40) |
1150 |
| 140 (60) |
584 |
| 176 (80) |
303-326 |