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

REMOVING AND INSTALLING CHECKING TEMPERATURE SENSOR FOR COOLANT





- The temperature sensor measures the engine temperature and sends this information to the control unit as a resistance value.
- The resistance value drops with rising temperature (NTC).
1 = Plug connection
2 = Housing
3 = NTC resistor

Removing and Installing





- Pull off plug (1).
- Unscrew temperature sensor.


Installation Note:





- Check code number (1).
- Replace seal (2).
FD = Manufacturing date
- Fill and bleed cooling system.

Checking:





- Connect Jetronic test lead 61 1 440.
- Check nominal value with an ohmmeter.
- To check the entire temperature range, remove temperature sensor, place it in a water bath heated to testing temperature and check resistance with an ohmmeter.

-. Resistance should be as follows:

70000 - 11,600 ohms at 14°F,
2100 - 2900 ohms at 68°F,
270 - 400 ohms at 176°F.

-. If resistance is not within specifications, sensor is defective.