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
Removing fuse cover
–
Move the circlips A ⇒
fig. 177 as far as the stop, the symbol appears behind
the circlip and remove the cover.
Installing fuse cover
– Position the fuse cover on the fuse box and push the circlips A as far as the
stop - the symbol is visible behind the circlip. CAUTION
● When unlocking and locking the fuse cover, it must be pressed on the sides to
the box, otherwise damage can occur to the locking mechanism.
● Carefully position the fuse cover in the engine compartment. If the cover was
not correctly positioned, water can get into the fuses and this results in a damage
to the vehicle!
Fuse assignment in engine compartment Fig. 178 Schematic representation of
fuse carrier in engine compartment
Certain electrical components are only standard on certain vehicle model versions
or only available as optional equipment for certain models. No. Power consumer
F1 Not assigned
F2 Control unit for automatic gearbox DQ 200
F3 Measuring circuit
F4 Valves for ABS
F5 Control unit for automatic gearbox
F6 Instrument cluster, windshield wiper lever and turn signal light lever
F7 Power supply terminal 15, Starter No. Power consumer
F8 Radio
F9 Not assigned
F10 Engine control unit, Main relay
F11 Control unit for auxiliary heating
F12 Control unit for CAN databus
F13 Engine control unit
F14 Ignition
F15 Lambda probe
glow plug system relay
F16 Central control unit, right main headlight, right rear light unit
F17 Horn
F18 Amplifier for digital sound processor
F19 Front window wiper
F20 Water pump
valve for fuel dosing
F21 Lambda probe
F22 Clutch pedal switch, brake pedal switch
F23 Secondary air pump
Air mass meter
Fuel high pressure pump
F24 Activated charcoal filter, exhaust gas recirculation valve
F25 Pump for ABS
F26 Central control unit, left main headlight, left rear light unit
F27 Secondary air pump
Glow plug system
F28 Not assigned
F29 Power supply terminal 30
F30 Terminal X
a) a)
In order not to drain the battery unnecessarily when starting the engine, the electrical components
of this terminal are automatically switched off. 212
Fuses and light bulbs
