Page 225 of 389

On long and steep downhill gradients, espe-
cially if the vehicle is laden or towing a trailer,
you must select shift range
1,2or 3.
i This also applies if you have activated
cruise control, SPEEDTRONIC or DIS-
TRONIC PLUS.
This will use the braking effect of the engine,
so less braking will be required to prevent the
vehicle from gaining speed. This relieves the
load on the brake system and prevents the
brakes from overheating and wearing too
quickly. If you need additional braking,
depress the brake pedal repeatedly rather
than continuously.
Driving tips If the trailer swings from side to side:
X
Do not accelerate.
X Do not countersteer.
X Brake if necessary.
R Maintain a greater distance from the vehi-
cle in front than when driving without a
trailer.
R Avoid braking abruptly. If possible, brake
gently at first to allowt he trailer to run on.
Then, increase the braking force rapidly.
R The values given for gradient-climbing
capabilities from a standstill refer to sea
level. When driving in mountainous areas,
note that the power output of the engine,
and consequently the vehicle's gradient-
climbing capability, decrease with increas-
ing altitude. Folding out the ball coupling
G
WARNING
If the ball coupling is not correctly engaged,
the trailer can detach. There is a risk of an
accident.
Always engage the ball coupling as described. G
WARNING
If you release the ball coupling or it does not
engage correctly when folding in, it will swing
out. Within pivoting range of the ball coupling,
there is an increased risk of an accident and
injury.
Only release the ball coupling if the pivoting
range is unobstructed. Always make sure that
the ball coupling engages when folding in. Before you can tow a trailer with your vehicle,
you must fold out the ball coupling.
The release wheel is located behind the left-
hand side trim panel in the boot.
To open the cover:
X
Turn handle :anti-clockwise and fold
down cover ;. To release and fold out the ball coupling:
X Pull out release wheel ?.
X Turn release wheel ?anti-clockwise until
the ball coupling releases and folds out
from under the rear bumper. Indicator lamp
= flashes. 222
Towing
atrailerDriving an d parking
Page 226 of 389

X
Pull the ball coupling in the direction of the
arrow until it engages in a vertical position.
Indicator lamp =goes out. The power
socket folds down automatically.
The multifunction display shows the
Trailer hitch Check lock mech. dis-
play message until the ball coupling is
engaged.
X Remove the protective covering from the
ball coupling and store it in a safe place.
X Make sure that the ball of the ball coupling
is clean and greased. Coupling up a trailer
G
WARNING
If you uncouple a trailer with an engaged over-
run brake, you could trap your hand between
the vehicle and the trailer drawbar. This poses
a risk of injury.
Do not uncouple a trailer with an engaged
overrun brake.
X Make sure that the transmission is in posi-
tion P.
X Apply the parking brake.
X Position the trailer level behind the vehicle.
X Couple up the trailer.
X Establish the electrical connection
between the vehicle and the trailer.
X Check that the trailer lighting system is
working. Uncoupling
atrailer G
WARNING
If you uncouple a trailer with an engaged over-
ru nb rake, you could trap yourh and between
the vehicle and the trailer drawbar .This poses
a risk of injury.
Do not uncouple a trailer with an engaged
overrun brake. G
WARNING
Vehicles with level control:
If you disconnectt he trailer cable, the vehicle
is lowered. This can cause you or others to
become trapped between the vehicle body
and tyres, or underneath the vehicle. This
poses a risk of injury.
Make sure that no-one is in the immediate
vicinity of the wheel arch or underneath the
vehicle when disconnecting the trailer cable.
! Do not disconnect a trailer with an
engaged overrun brake. Otherwise, your
vehicle could be damaged by the rebound-
ing of the overrun brake.
X Make sure that the transmission is in posi-
tion P.
X Apply the parking brake.
X Secure the trailer against rolling away.
X Remove the trailer cable and decouple the
trailer. Folding in the ball coupling
G
WARNING
If you release the ball coupling or it does not
engage correctly when folding in, it will swing
out. Within pivoting range of the ball coupling,
there is an increased risk of an accident and
injury.
Only release the ball coupling if the pivoting
range is unobstructed. Always make sure that
the ball coupling engages when folding in. Towing
atrailer
223Driving an d parking Z
Page 227 of 389

X
Place the protective covering on the ball
coupling. The release wheel is located behind the left-
hand side trim panel in the boot.
To open the cover:
X
Turn handle :anti-clockwise and fold
down cover ;. To release and lower the ball coupling:
X Pull out release wheel ?.
X Turn release wheel ?anti-clockwise.
The ball coupling unlocks and lowers. Indi-
cator lamp =flashes. X
Press the ball coupling in the direction of
the arrow until it engages behind the
bumper.
Indicator lamp =goes out and the mes-
sage in the multifunction display disap-
pears.
i Fold the ball coupling back in if you are
not using the trailer tow hitch. Trailer power supply
! You can connect accessories with a
power rating of up to 240 W to the perma-
nent power supply and with a power rating
of up to 180 W to the power supply that is
switched on via the ignition lock.
The trailer battery may not be charged from
the power supply.
X To switch the connected power supply
on or off: turn the key in the ignition lock
to position 2or 0respectively
(Y page 159).
When it leaves the factory, your vehicle's
trailer socket is equipped with a permanent
power supply and a power supply that is
switched on via the ignition lock.
The permanen tpower supply is supplied via
trailer socket pin 9.
The power supply that is switched on via the
ignition lock is supplied via trailer socket pin
10.
The trailer's permanent power supply is
switched off in the event of low vehicle supply
voltage and after six hours at the latest.
You can find more information about instal-
ling the trailer electric sataqualified special-
ist workshop. Bulb failure indicator for LED lamps
i If LED lamps are fitted in the trailer, an
error message may appear in the multi-
function display even if there is no fault. The
reason for the error message could be that 224
Towing
atrailerDriving an d parking
Page 228 of 389
the current has fallen below the minimum
of 50 mA.
To ensure reliable operatio nofthe bulb failure
indicator, each LED chain in the trailer lighting
must be guaranteed a minimum current of
50 mA. Trailer with 7-pin connector
General notes Trailers with 7-pin connector:
you can
make a connection to the 13-pin connector
on the ball coupling using an adapter plug or,
if necessary, an adapter cable. Both can be
obtained in a qualified specialist workshop.
Fitting the adapter !
Make sure that there is sufficient cable
play so that the cable cannot become
detached when cornering. X
Open the socket cover.
X Insert connector with lug :into
groove ;of the socket. Turn the connec-
tor clockwise to the stop.
X Let the cover engage.
X If you are using an adapter cable, secure
the cable to the trailer with cable ties. Towing
atrailer
225Driving an d parking Z
Page 229 of 389
Page 230 of 389
Useful information
............................228
Important safety notes ....................228
Displays and operation ....................229
Menus and submenus ......................233
Display messages ............................. 249
Warning and indicator lamps in the
instrument cluster ............................275 227On-board computer and displays
Page 231 of 389

Useful information
i This Owner's Manual describes all mod-
els, series and optional equipment for your
vehicle that were available at the time of
going to press. National variations are pos-
sible. Note that your vehicle may not be
equipped with all of the functions descri-
bed. This is also the case for systems and
functions relevant to safety.
i Read the information on qualified special-
ist workshops: (Y page 23). Important safety notes
G
WARNING
Only use the on-board computer when road
and traffic conditions permit .You would oth-
erwise be distracted and unable to concen-
trate properly on driving, and could cause an
accident. G
WARNING
No messages will be displayed if either the
instrument cluster or the multifunction dis-
play is inoperative.
As a result, you will not be able to see infor-
mation about your driving conditions, such as
speed, outside temperature, warning and indi-
cator lamps, display messages or system fail-
ures. Driving characteristics may be impaired.
Adjust your driving style and vehicle speed
accordingly.
Contact a qualified specialist workshop
immediately. G
WARNING
The on-board computer only records and dis-
plays malfunctions and warnings from certain
systems. For this reason, you should always
make sure that your vehicle is safe to use. You
could otherwise cause an accident by driving
an unsafe vehicle. G
WARNING
The operating safety of your vehicle could be
impaired if maintenance work is carried out
incorrectly. This could cause you to lose con-
trol of your vehicle and cause an accident.
Moreover, the safety systems may no longer
be able to protect you or others as they are
designed to do.
Always have service work carried out at a
qualified specialist workshop.
For an illustration of the instrument cluster,
see (Y page 30). 228
Important safety notesOn-board computer and displays
Page 232 of 389
Displays and operation
Instrument cluster
Instrument cluster: kilometres
:
Fuel gauge
; Time
= Speedometer with segments (Y page 231)
? Multifunction display (Y page 232)
A Rev counter (Y page 231)
B Coolant temperature ( Ypage 230)
C Instrumen tcluster lighting (Y page 230) Displays and operation
229On-board computer and displays Z