Heater Core Temperature Sensor / Switch: Service and Repair

COLD ENGINE LOCK OUT (CELO) SWITCH






The cold engine lock out (CELO) switch is threaded and screws into a fitting in the heater core inlet tube in the engine compartment (illustration).

REMOVAL AND INSTALLATION
1. Disconnect two-wire connector from CELO switch.
2. Partially drain coolant from radiator.
3. Remove threaded switch by turning out of fitting in heater tube.
4. Apply Sealer ESG-M4G194-A or equivalent to switch threads and install into fitting. Tighten to 11-19Nm(8-14lbft).
5. Attach electrical connector to top of switch.
6. Refill radiator.