Auxiliary Cabin Heater Overheat Sensor / Switch: Service and Repair

Overheat protection thermostat / flame sensor / engine coolant temperature sensor, replacing

The information below applies to cars manufactured up to week 38 2001 inclusive.

Information for cars manufactured from week 39 2001 inclusive. See Replacing the overheat protection thermostat, the flame sensor and the engine coolant temperature sensor Service and Repair

Removal

Preparations
Remove the heater. See Engine coolant heater, replacing Engine Coolant Heater, Replacing.

Removing components
For the overheat protection thermostat and coolant temperature sensor:





Remove:
- Remove the nut (tightened to 2 Nm) and cover
- Remove the coolant temperature sensor and the overheat protection thermostat.




For the flame sensor:

Remove:
- the fan shroud. See Fuel injection nozzle / fan motor / pressure equalizer, replacing Fuel Injection Nozzle / Fan Motor / Pressure Equalizer, Replacing.




Remove the flame sensor.

Cutting and splicing wiring
Cut the wiring and splice. See Splicing the cables Splicing the Cables

Installation

Bleeding the fuel system
Connect the fuel line to a vacuum pump. Suck carefully until fuel comes out. Connect the cables and hoses.

Installing components
Reinstall the components.
Reinstall the heater in reverse order.

Note! Always check that there is clearance between the fuel line and water hose.

Final check

Note! Start the engine and let it idle for a few seconds before starting the heater.

Test run the heater. Check the function of the heater. See Engine coolant heater, test running Engine Coolant Heater, Test Running
Check both the coolant hoses and the fuel lines for leakage.
Top up the coolant if necessary.
Check that no diagnostic trouble codes (DTC) have been stored during the repair work.