Problem
Possible causes/consequences and MM Solutions
The low-voltage protection system integrated in the control unit
switches off the auxiliary heating because the on-board voltage is
less than 10 V.
X
Have the alternator and battery checked.
or
The fuse is blown.
X
Replace the fuse; see the "Fuse allocation" supplement.
X
Have the cause of the blown fuse determined at a qualified spe-
cialist workshop.
or
A malfunction has occurred.
X
Switch the ignition on and off twice.
If the auxiliary heating still cannot be switched on, the heating
device is faulty.
X
Have the auxiliary heating checked at a qualified specialist
workshop.
The auxiliary heating is
overheated.
The coolant level is too low.
X
Check the coolant level and add more coolant if necessary
(Y page 253).
Operating the cargo compartment air
vents
If your vehicle is equipped with a roof venti-
lator, you can ventilate and extract air from
the cargo compartment.
X
Turn the key to position 2 in the ignition
lock.
X
To activate and extract air: press the
upper section of the ´ switch.
The roof ventilator removes used air from
the cargo compartment.
X
To activate and ventilate: press the lower
section of the · switch.
The roof ventilator feeds fresh air into the
cargo compartment.
X
To switch off: set the switch to the middle
position.
Operating the cargo compartment air vents
133
Climate control
Z