Coolant Temperature Sensor / Switch HVAC: Testing and Inspection

INSPECTION







1. DRAIN ENGINE COOLANT FROM
2. REMOVE ENGINE UNDER COVER
3. REMOVE ECT SWITCH




4. 5S-FE engine:
INSPECT ECT SWITCH CONTINUITY
a. Using an ohmmeter, check that there is no continuity between the terminals when the engine 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 engine coolant temperature is below 83 °C (181 °F).
If there is no continuity, replace the switch.




5. 1MZ-FE engine:
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.




6. 1MZ-FE engine:
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.

7. INSTALL ECT SWITCH
a. Install the new O-ring to the switch.
b. Install the switch.

8. 5S-FE engine only:
INSTALL ENGINE UNDER COVER
9. FILL WITH ENGINE COOLANT