Coolant Temperature Sensor / Switch HVAC: Testing and Inspection

INSPECTION

1. Ignition "ON".
2. Using the multi-tester, Measure resistance between terminal "1" and "2" of water temperature sensor.




Specification





3. If the measured resistance is not specification, substitute with a known-good water temperature sensor and check for proper operation.
4. If the problem is corrected, replace the water temperature sensor.

NOTE:
Negative type thermistor that resistance will rise with lower temperature, and reduce with higher temperature.