Coolant Temperature Sensor / Switch HVAC: Testing and Inspection
ENGINE COOLANT TEMPERATURE (ECT) SWITCHINSPECTION
1. DRAIN ENGINE COOLANT FROM
2. INSPECT NO.1 ECT SWITCH CONTINUITY
a. Using an ohmmeter, check that there is no continuity between the terminals when the coolant temperature is above 98 °C (208 °F).
If there is continuity, replace the switch.
b. Using an ohmmeter, check that there is continuity between the terminals when the coolant temperature is below 88 °C (190 °F).
If there is no continuity, replace the switch.
3. INSPECT NO.2 ECT SWITCH CONTINUITY
a. Using an ohmmeter, check that there is continuity between terminal and switch body when the coolant temperature is above 93 °C (199 °F).
b. Using an ohmmeter, check that there is no continuity between terminal and switch body when the coolant temperature is below 83 °C (181 °F).
If continuity is not as specified, replace the switch.
4. INSTALL ECT SWITCH
a. Install the new O-ring to the switch.
b. Install the switch.
5. FILL WITH ENGINE COOLANT