Auxiliary heating (auxiliary heating and ventilation)
Description and important information The auxiliary heating (auxiliary heating and ventilation) heats or
supplies the interior of the vehicle with fresh air independent of the
engine.
Auxiliary heating (parking heating)
The auxiliary heater (parking heater) functions in connection with the air-condi-
tioning system or Climatronic.
It can be used when stationary, when engine is switched off for preheating of the
vehicle as well as while driving (e.g. during the heating phase of the engine).
The engine is also preheated when the vehicle is stationary and the engine is
switched off, if the auxiliary heating is switched on.
The auxiliary heating (parking heating) warms up the coolant during the combus-
tion of fuel from the vehicle tank. The coolant warms up the air, which (if the
blower speed is not set to zero) flows into the occupant compartment.
Auxiliary ventilation
The auxiliary ventilation enables fresh air to flow into the vehicle interior by
switching off the engine, whereby the interior temperature is effectively de-
creased (e.g. with the vehicle parked in the sun). WARNING
● The auxiliary heating must never be operated in closed rooms - risk of poi-
soning!
● The auxiliary heating must not be running during refueling - risk of fire.
● The exhaust pipe of the auxiliary heating is located on the underside of
the vehicle. Therefore do not place the vehicle, if you wish to operate the aux-
iliary heating, in such a way that the exhaust gases of the auxiliary heating
can come easily into contact with inflammable materials (e.g. dry grass) or
easily inflammable substances (e.g. fuel run out). Note
If the auxiliary heating runs, the fuel consumption comes from the vehicle tank.
The auxiliary heating automatically controls the filling level in the fuel tank. If only
a low quantity of fuel is present in the fuel tank, the function of the auxiliary heat-
ing is blocked.
● The exhaust pipe of the auxiliary heating, which is located on the underside of
the vehicle, must not be clogged and the exhaust flow must not be blocked.
● If the auxiliary heating and ventilation is running, the vehicle battery discharg-
es. If the auxiliary heating and ventilation has been operated several times over a
longer period, the vehicle must be driven a few kilometers in order to recharge the
vehicle battery.
● The auxiliary heating only switches the blower on, if it has achieved a coolant
temperature of approx. 50 °C.
● At low outside temperatures, this can result in a formation of water vapour in
the area of the engine compartment. This is quite normal and is not an operating
problem.
● After switching off the auxiliary heating, the coolant pump runs for a short pe-
riod.
● The auxiliary heating and ventilation does not switch on or comes on, if the
vehicle battery indicates a low loading state ⇒
page 190, Automatic consumer
shut-off.
● The auxiliary heating (parking heating) does not switch on, if the following was
shown in the information display or before switching off the ignition: Please re-
fuel!
● The air inlet in front of the windscreen must be free of ice, snow or leaves in
order to ensure that the auxiliary heating operates properly.
● So that warm air can flow into the vehicle interior after switching on the auxili-
ary heating, you must maintain the comfort temperature normally selected by you
and leave the air outlet vents in an open position. It is recommended to put the air
flow in the position or . 94
Heating and air conditioning system
