Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection

1. Remove sensor from engine and allow to stabilize for approximately 10 minutes.
2. Place a thermometer in a pyrex beaker or equivalent filled with water, then place sensor in beaker and measure resistance of sensor across terminals as follows:
a. With water temperature at 68 °F, resistance should be 283-297 ohms.
b. Raise water temperature to 177 °F and measure resistance of sensor. Resistance should be 383-397 ohms.
c. Raise water temperature to 194 °F and measure resistance of sensor. Resistance should be 403-417 ohms.
3. If resistance values are not as specified, replace sensor.