Oil gas vent line heater fault

Mercedes-Benz C200 CDI 

To reduce the presence of oil in engine components such as the air intake manifold, intercooler, turbo, etc., vehicle manufacturers are working to make improvements in this area, and have introduced the "Oil gas vent line heater” into the engine's oil vapour recovery system.

Mercedes-Benz C200 CDI fuse box

This "Heater" is simply a heating element and its purpose is to reduce the density of the oil vapours to make it more difficult or prevent its condensation in the aforementioned components. This reduction in the condensation of oil vapours is achieved by the heater converting the oil from a liquid to gaseous state.

The heater is usually located in the turbo intake pipe or engine oil vapour recovery circuit lines. This component is controlled by the Engine Control Unit, which takes the engine working temperature into consideration.



AFFECTED VEHICLES:


Mercedes-Benz C200 CDI (203.004) (OM 611.962) 2148 Cm3, 116 Cv, 85 Kw


SYMPTOM:

Vehicle in low power or emergency mode.


Fuse F54 of 7.5 A blows in the engine compartment fuse and relay box, left side (SAM).


CAUSE:

Short-circuit in the heater element (R39/1) for engine oil vapours.


REMEDY:

Repair procedure:

- Check the condition of fuse F54 in the engine compartment fuse and relay box, left side (SAM).
- Replace fuse F54.

- Replace the engine oil vapour heater element R39/1.