Problem
Possible causes/consequences and
M
Solutions
The auxiliary heating sys-
tem switches off auto-
matically and/or cannot
be switched on.
The low-voltage protection system integrated in the control unit
switches off the auxiliary heating because the on-board voltage is
below 10 V.
X
Have the alternator and starter battery checked.
The auxiliary heating sys-
tem switches off auto-
matically and/or cannot
be switched on.
The fuse is malfunctioning.
X
Replace the fuse; see the "Fuse allocation" supplement.
X
Have the cause of the blown fuse determined at a qualified spe-
cialist workshop.
The auxiliary heating sys-
tem switches off auto-
matically and/or cannot
be switched on.
A malfunction has occurred.
X
Switch the ignition on and off twice.
If the auxiliary heating system still cannot be switched on, the heating
unit is faulty.
X
Have the auxiliary heating checked at a qualified specialist work-
shop.
The auxiliary heating is
overheated.
The air ducts are blocked.
X
Make sure that the flow of hot air behind and next to the left front
seat is not blocked.
X
Have the auxiliary heating checked at a qualified specialist work-
shop.
Adjusting the air vents
Important safety notes
G
WARNING
Very hot or very cold air can flow from the air
vents. This could result in burns or frostbite in
the immediate vicinity of the air vents. There
is a risk of injury.
Make sure that all vehicle occupants always
maintain a sufficient distance to the air out-
lets. If necessary, redirect the airflow to
another area of the vehicle interior.
The centre and side air vents are adjustable.
The air vents can also be adjusted on vehicles
with rear compartment air conditioning.
In order to ensure the direct flow of fresh air
through the air vents into the vehicle interior,
please observe the following notes:
R
keep the air inlet between the windscreen and
the bonnet free of blockages, such as ice,
snow or leaves.
R
never cover the vents or the ventilation grilles
in the vehicle interior.
156
Adjusting the air vents
Climate control
