Coolant Temperature Sensor

The coolant temperature sensor is located on the front side of the cylinder head. To test the sensor, disconnect the harness connector as shown in Fig. 7-6 and measure resistance across the sensor terminals. The proper resistance value depends on coolant temperature. A graph of resistance vs. temperature is shown in Fig. 7-7. If the resistance of the sensor is incorrect, the sensor is faulty and should be replaced. Replacing the sensor will require draining and replacing some of the engine coolant. See COOLING SYSTEM.

Fig. 7-6.

Harness connector shown disconnected from coolant temperature sensor (arrow) on models up to 1989 (top) and later (bottom).

Fig. 7-7.

Graph showing coolant temperature sensor resistance vs. temperature. Example: At 68°F (20°C), resistance should be 2200 to 2800 ohms.