(Y page 197) availability is limited or not avail-
able at all.
i The height of the ball coupling changes
with the load of the vehicle. If necessary,
use a trailer with a height-adjustable draw-
bar.
Driving tips
i Observe the notes on ESP ®
trailer stabi-
lisation ( Y page 70).
The maximum permissible speed for vehicle/
trailer combinations depends on the type of
trailer. Before beginning the journey, check
the trailer's documents to see what the max-
imum permitted speed is. Observe the legally
prescribed maximum speed in the relevant
country.
For certain Mercedes-Benz vehicles, the max-
imum permissible rear axle load is increased
when towing a trailer. Refer to the "Technical
data" section to find out whether this applies
to your vehicle. If you utilise any of the added
maximum rear axle load when towing a trailer,
the vehicle/trailer combination may not
exceed a maximum speed of 100 km/h for
reasons concerning the operating permit.
This also applies in countries in which the
permissible maximum speed for vehicle/
trailer combinations is above 100 km/h.
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
to when driving without a trailer and it will
consume more fuel.
Change into a lower gear in good time on long
and steep downhill gradients. For vehicles
with automatic transmission, you need to
have selected manual drive program
M (Y page 156).
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 maintain
vehicle 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.
i Briefly depressing the accelerator pedal
on downhill gradients while the manual
drive program M is temporarily activated
(vehicles with automatic transmission): the
automatic transmission may switch back to
the last active automatic drive program E
or S. The automatic transmission may shift
to a higher gear. This can reduce the
engine's braking effect.
Driving tips
If the trailer swings from side to side:
XDo not accelerate.XDo not countersteer.XBrake 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 allow the 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
GWARNING
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 a trailer203Driving and parkingZProCarManuals.com
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.XTo open the cover: turn handle : anti-
clockwise and fold down cover ; and
remove it.XPull out release wheel =.XTurn release wheel = anti-clockwise as far
as it will go.
The ball coupling disengages and folds out
behind the rear bumper. Indicator
lamp ? flashes.GWARNING
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.
XPull 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
Check trailer hitch lock display mes-
sage until the ball coupling is engaged.XRemove the protective covering from the
ball coupling and store it in a safe place.XMake sure that the ball of the ball coupling
is clean and that it is either greased or dry
(grease free), depending on the instruc-
tions for the trailer.
Coupling up a trailer
XMake sure that the transmission is in posi-
tion P.XApply the electric parking brake.XPosition the trailer level behind the vehicle.XCouple up the trailer.XEstablish the electric connection between
the vehicle and the trailer.XCheck that the trailer lighting system is
working.
A trailer that is connected is recognised
only when the electrical connection is
established correctly and when the lighting
system is working properly. The function of
other systems, such as ESP ®
or PARK-
TRONIC also depends on this.
Uncoupling a trailer
GWARNING
If you uncouple a trailer with an engaged over-
run brake, you could trap your hand between
204Towing a trailerDriving and parking
ProCarManuals.com
the vehicle and the trailer drawbar. This poses
a risk of injury.
Do not uncouple a trailer with an engaged
overrun brake.
! Do not disconnect a trailer with an
engaged overrun brake. Otherwise, your
vehicle could be damaged by the rebound-
ing of the overrun brake.
! Remove the installed adapter cable
before folding in the ball coupling. Other-
wise, damage may occur to the rear
bumper and the adapter cable.XMake sure that the transmission is in posi-
tion P.XApply the electric parking brake.XSecure the trailer against rolling away.XRemove the trailer cable and decouple the
trailer.
Folding in the ball coupling
GWARNING
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.
XFold the ball coupling back in if you are not
using the trailer tow hitch.XPlace the protective covering on the ball
coupling.
The release wheel is located behind the left-
hand side trim panel in the boot.
XTo open the cover: turn handle : anti-
clockwise and fold down cover ; and
remove it.XPull out release wheel =.XTurn release wheel = anti-clockwise as far
as it will go.
The ball coupling disengages and folds out
behind the rear bumper. Indicator
lamp ? flashes.Towing a trailer205Driving and parkingZProCarManuals.com
XPress 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.
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.
XTo switch the connected power supply
on or off: turn the key in the ignition lock
to position 2 or 0 respectively.
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 permanent power 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 electrics at a qualified 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
the current has fallen below the minimum
of 50 mA.
To ensure reliable operation of the 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.
! Remove the installed adapter cable
before folding in the ball coupling. Other-
wise, damage may occur to the rear
bumper and the adapter cable.
XOpen the socket cover.XInsert connector with lug : into
groove ; of the socket. Turn the connec-
tor clockwise to the stop.XLet the cover engage.XIf you are using an adapter cable, secure
the cable to the trailer with cable ties.206Towing a trailerDriving and parking
ProCarManuals.com
XPress the = or ; button on the steer-
ing wheel to select the Trip menu.XPress the 9 or : button to select the
function that you wish to reset.XPress the a button.XPress the : button to select Yes and
press a to confirm.
i
If you reset the values in the ECO display,
the values in the "From start" trip computer
are also reset. If you reset the values in the
"From start" trip computer, the values in
the ECO display are also reset.
Navigation menu
Displaying navigation instructions
XSwitch on Audio 20 with Becker ®
MAP
PILOT or COMAND Online (see the sepa-
rate operating instructions).XPress the = or ; button on the steer-
ing wheel to select the Navi menu.
In the Navi menu, the multifunction display
shows navigation instructions. For more
information, see the separate operating
instructions.
Route guidance not active
:Direction of travel;Current streetActivating route guidance
No change of direction announced
:Distance to the destination;Distance to the next change of direction=Current street?Symbol indicating "follow the road's
course"
Change of direction announced without a
lane recommendation
:Road to which the change of direction
leads;Distance to change of direction and visual
distance display=Change-of-direction icon
When a change of direction is announced, you
will see symbol = for the change of direction
and distance graphic ;. This shortens
towards the top of the display as you
approach the point of the announced change
of direction.
Menus and submenus213On-board computer and displaysZProCarManuals.com
Display messagesPossible causes/consequences and M SolutionsThe red ! indicator lamp flashes and the yellow ! warning
lamp is lit.
The electric parking brake is malfunctioning.
To release:XSwitch off the ignition and turn it back on.XRelease the electric parking brake manually.
To apply:
XSwitch off the ignition and turn it back on.XApply the electric parking brake manually.
If the red ! indicator lamp continues to flash:
XDo not drive on.XSecure the vehicle against rolling away ( Y page 326).XMove the transmission selector lever to P.XTurn the front wheels towards the kerb.XConsult a qualified specialist workshop.The yellow ! warning lamp lights up. The red ! indicator
lamp flashes for about ten seconds after the electric parking brake
has been applied or released. It then goes out or remains lit.
The electric parking brake is malfunctioning.XSwitch off the ignition and turn it back on.XApply the electric parking brake.
If it is not possible to apply the electric parking brake:
XMove the transmission selector lever to P.XVisit a qualified specialist workshop.
If it is not possible to release the electric parking brake:
XRelease the electric parking brake automatically ( Y page 163).
If the electric parking brake still cannot be released:
XConsult a qualified specialist workshop.The yellow ! warning lamp lights up. If you manually apply or
release the electric parking brake, the red ! indicator lamp
flashes.
The electric parking brake is malfunctioning. It is not possible to
apply the electric parking brake manually.XMove the transmission selector lever to P.XVisit a qualified specialist workshop.Display messages231On-board computer and displaysZProCarManuals.com
Display messagesPossible causes/consequences and M Solutionsb
Reversing lightThe reversing lamp is faulty.XCheck whether you are permitted to replace the bulb yourself
( Y page 114).
or
XVisit a qualified specialist workshop.b
Left tail lamp or
Right tail lamp The left or right-hand tail lamp is faulty.XCheck whether you are permitted to replace the bulb yourself
( Y page 114).
or
XVisit a qualified specialist workshop.b
Left daytime driv‐
ing lamp or Right
daytime driving
lampThe left-hand or right-hand daytime driving lamp is faulty.XCheck whether you are permitted to replace the bulb yourself
( Y page 114).
or
XVisit a qualified specialist workshop.b
Intell. Light Sys‐
tem inoperativeThe Intelligent Light System is faulty. The lights remain available
without the Intelligent Light System.XVisit a qualified specialist workshop.b
Malfunction See
Owner's ManualThe exterior lighting is faulty.XVisit a qualified specialist workshop.Vehicles with trailer tow hitch: a fuse may have blown.XCheck the fuses ( Y page 312).XIf necessary, replace the blown fuse. Observe the warning notes
as you do so.
If the display message continues to be displayed:
XVisit a qualified specialist workshop.b
AUTO lights inoper‐
ativeThe light sensor is faulty.XVisit a qualified specialist workshop.b
Switch off lightsThe lights are still switched on when you leave the vehicle. A
warning tone also sounds.XTurn the light switch to Ã.Display messages239On-board computer and displaysZProCarManuals.com
Display messagesPossible causes/consequences and M SolutionsLane Keeping
Assist currently
unavailable See
Owner's ManualLane Keeping Assist is deactivated and temporarily inoperative.
Possible causes:
R the windscreen is dirty in the camera's field of vision.
R visibility is impaired due to heavy rain, snow or fog.
R there are no lane markings for a longer period.
R the lane markings are worn, dark or covered, e.g. by dirt or snow.
Once the causes listed above no longer apply, the display message
goes out.
Lane Keeping Assist is operational again.
If the display message does not disappear:XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XSecure the vehicle against rolling away ( Y page 162).XClean the windscreen.Lane Keeping
Assist inoperativeLane Keeping Assist is faulty.XVisit a qualified specialist workshop.Blind Spot Assist
currently unavail‐
able See Owner's
ManualBlind Spot Assist is temporarily inoperative.
You have established the electrical connection between the trailer
and your vehicle.XPress a on the steering wheel to confirm the display mes-
sage.
Blind Spot Assist is deactivated while towing a trailer.
244Display messagesOn-board computer and displays
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