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

The Engine Coolant Temperature Sensor (ECTS) can be tested in water.

The temperature of the component should be measured with an accurately calibrated thermometer, make sure that the temperature of the component has stabilized. Using a DMM set to ohms measure the resistance across the connector blades.

Temperature Chart:

Compare the reading obtained to chart; the resistance should be within the band.

If the reading falls outside the band, recheck temperature and resistance measurement. Check each pin to the component case, the resistance should be very high (infinity).

Reject components which fall outside of the tolerance.