Coolant Temperature Sensor Test
- Warm engine to operating temperature and run at idle speed. Remove rubber boot from coolant temperature sensor connector. See Figure . Turn ignition on. Verify voltage between Blue/Red terminal and ground is 0.5 volt. If voltage is not 0.5 volt, check wiring harness for an open or short circuit.
- If wiring harness is okay, remove coolant temperature sensor and place in water with a thermometer. Heat water gradually. Verify resistance of sensor is to specifications. See COOLANT TEMPERATURE SENSOR RESISTANCE table.
COOLANT TEMPERATURE SENSOR RESISTANCE
| Temperature °F (°C) | Ohms |
|---|---|
| -4 (-20) | 14,600-17,800 |
| 68 (20) | 2200-2700 |
| 176 (80) | 290-350 |