Coolant Temperature Sensor / Switch HVAC: Testing and Inspection

INSPECT ECT SWITCH
a. Using an ohmmeter, check that no continuity exists between the terminals when the coolant temperature is above 100°C (212 °F).
If continuity exists, replace the switch.

b. Using an ohmmeter, check that continuity exists between the terminals when the coolant temperature is below 91°C (196°F).
If there no continuity exists, replace the switch.