Coolant Temperature Sensor / Switch HVAC: Testing and Inspection
1. INSPECT No. 1 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.
2. INSPECT No. 2 SWITCH CONTINUITY
a. Using an ohmmeter, check that there is no continuity between the terminal and switch body when the coolant temperature is above 93 °C (199 °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 83 °C (181 °F).
If there is no continuity, replace the switch.
3. INSTALL ECT SWITCH
4. FILL WITH ENGINE COOLANT TO RADIATOR