
tem 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:
XDo not accelerate.
XDo not counter-steer.
XBrake if necessary.
RMaintain a greater distance from the vehicle
in front than when driving without a trailer.
RAvoid braking abruptly. If possible, brake gen-tly at first to allow the trailer to run on. Then,
increase the braking force rapidly.
RThe values given for gradient-climbing capa-
bilities from a standstill refer to sea level.
When driving in mountainous areas, note that
the power output of the engine and, conse-
quently, the vehicle's gradient-climbing capa-
bility, decreases with increasing altitude.
Installing the ball coupling
GWARNING
If the ball coupling is not correctly installed
and secured, it can come loose during the
journey and endanger other road users. There is a risk of an accident and injury.
Always install and secure the ball coupling as
described. Before every journey, ensure that
the ball coupling is secured with the bolt and
the corresponding spring cotter.
GWARNING
If the ball coupling is not installed correctly or not secured with the bolt provided and the
corresponding spring cotter, the trailer may
come loose. There is a risk of an accident.
Always install and secure the ball coupling as
described. Before every journey, ensure that
the ball coupling is secured with the bolt and
the corresponding spring cotter.
GWARNING
If the ball coupling is not installed and secured
correctly the trailer may come loose. There is
a risk of an accident.
Install and secure the ball coupling as descri-
bed in the ball coupling installation instruc-
tions. Make sure that the ball coupling is
installed and secured correctly before every
journey.
XPull protective cap :in the direction of the
arrow, out of the ball coupling recess.
XStow protective cap :so that it cannot be
thrown around.
Observe the loading guidelines (
Ypage 329)
and the safety notes regarding stowage
spaces (
Ypage 330).
258Towing a trailer
Driving an d parking

XInsert the ball coupling horizontally into ball
coupling recess;in the direction of the
arrow until the holes in ball coupling =are in
line with the holes in ball coupling recess ?.
XSlide boltAinto the hole in the ball coupling
recess and the ball coupling to the stop.
XSecure the bolt using spring cotter B.
XCheck the ball coupling, bolt and spring cotter
for correct installation.
If the ball coupling cannot be correctly mounted,
remove the ball coupling. Under these circum-
stances, the ball coupling must not be used for
trailer towing.
Have the entire trailer tow hitch checked at a
qualified specialist workshop.
Coupling up a trailer
!
Do not connect the trailer's brake system (if
featured) to the hydraulic brake system of the
towing vehicle, as the latter is equipped with
an anti-lock brake system. Doing so will result
in a loss of function of the brake systems of
both the vehicle and the trailer.
XShift the transmission to position P.
XApply the vehicle's electric parking brake.
XStart the engine.
XVehicles with AIRMATIC package: select
normal level and the Comfortdrive program.
XSwitch off the engine.
XClose the doors and tailgate.
XCouple up the trailer.
Towing a trailer259
Driving and parking
Z

XEstablish the electrical connection between
the vehicle and the trailer.
XCheck that the trailer lighting system is work-
ing.
XPush the combination switch upwards/down-wards and check whether the corresponding
turn signal on the trailer flashes.
A trailer that is connected is recognized only
when the electrical connection is established
correctly and when the lighting system is work-
ing properly. The function of other systems also
depends on this, for example:
RESP®
RPARKTRONIC
RActive Parking Assist
RActive Blind Spot Assist
RActive Lane Keeping Assist
iVehicles with the AIRMATIC package: if you
couple up a trailer, the vehicle always remains
at normal level. When coupling up a trailer,
please observe the following:
RIf the normal level has not been set man-
ually, the vehicle is automatically lowered
to normal level. This is the case if a speed of
5 mph (8 km/h) is reached.
RThe Sport drive program is not available.
These restrictions apply to all accessories
powered through a connection to the trailer
power socket of your vehicle, e.g. a bicycle
carrier.
Observe the maximum permissible trailer
dimensions (width and leng
th).
Most U.S. states and all Canadian provinces
require by law:
RSafety chains between the towing vehicle and
the trailer. The chains should be cross-wound
under the trailer drawbar. They must be fas-
tened to the vehicle's trailer coupling, not to
the bumper or the axle.
Leave enough play in the chains to make tight
cornering possible.
RA separate brake system for certain types of
trailer.
RSafety switch for braked trailers. Check the
specific legal requirements applicable to your
state.
If the trailer becomes detached from the tow-
ing vehicle, the safety switch applies the
trailer brakes.
Towing a trailer
There are numerous legal requirements con-
cerning the towing of a trailer, e.g. speed restric- tions. Make sure that your car/trailer combina-
tion complies with the local regulations:
Rin your place of residence
Rin the location to which you are driving
The police and local authorities can provide reli- able information.
Observe the following when towing a trailer:
RTo gain driving experience and to become
accustomed to the new handling characteris-
tics, you should practice the following in a
traffic-free location:
-cornering
-stopping
-backing up
RBefore driving, check:
-trailer tow hitch
-safety switch for braked trailers
-safety chains
-electrical connections
-lights
-wheels
RAdjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer.
RIf the trailer has electronically controlled
brakes, pull away carefully. Brake manually
using the brake controller and check whether
the brakes function correctly.
RSecure any objects on the trailer to prevent
the cargo from slipping when the vehicle is in
motion.
RWhen you couple up a trailer, check at regular
intervals that the load is firmly secured. If the
tra
iler is equipped with trailer lights and
brakes, check the trailer to ensure that these
are working.
RBear in mind that the handling will be less
stable when towing a trailer than when driving
without one. Avoid sudden steering move-
ments.
RThe vehicle/trailer combination is heavier,
accelerates more slowly, has a decreased
gradient climbing capability and a longer
braking distance.
It is more susceptible to side winds and
requires more careful steering.
260Towing a trailer
Driving an d parking

RIf possible, do not brake suddenly, but insteaddepress the brake pedal moderately at first so
that the trailer can activate its brakes. Then
increase the pressure on the brake pedal.
RIf the automatic transmission repeatedly
shifts between gears on uphill or downhill gra-
dients, shift to a lower gear using the left-hand
steering wheel paddle shifter.
A lower gear and lower speed reduce the risk
of engine failure.
RWhen driving downhill, shift to a lower gear toutilize the engine's braking effect.
Avoid continuous brake application as this
may overheat the vehicle brakes and, if instal-
led, the trailer brakes.
RIf the coolant temperature increases dramat-
ically while the air-conditioning system is
switched on, switch off the air-conditioning
system.
Coolant heat can also be dissipated by open-
ing the windows and switching the ventilation blower and the interior temperature to the
highest level.
RWhen overtaking, pay particular attention to
the extended length of your vehicle/trailer
combination.
Due to the length of the vehicle/trailer com-
bination, you require additional road space in
relation to the vehicle you are overtaking
before you can change back to the original
lane.
Decoupling a trailer
GWARNING
If you uncouple a trailer with the overrun
brake engaged, you could trap your hand
between the vehicle and the trailer drawbar.
There is a risk of injury.
Do not uncouple a trailer if the overrun brake
is engaged.
GWARNING
Vehicles with level control:
The vehicle is lowered as soon as you discon-
nect the trailer cable. This could result in your
limbs or those of other people that are
between the vehicle body and tires or under-
neath the vehicle being trapped. There is a
risk of injury.
Make sure that nobody is in the immediate
vicinity of the wheel housings or under the
vehicle when you disconnect the trailer cable.
!Do not disconnect a trailer with an engaged
overrun brake. Otherwise, your vehicle could
be damaged by the rebounding of the overrun brake.
XShift the transmission to position P.
XApply the vehicle's electric parking brake.
XStart the engine.
XClose the doors and tailgate.
XApply the trailer's parking brake.
XDetach the trailer cable and decouple the
trailer.
XSwitch off the engine.
Permissible trailer loads and drawbar
loads
Weight specifications
Maximum allowable gross mass
The gross vehicle weight of the trailer is calcu-
lated by adding the weight of the trailer to the
weight of the load and equipment on the trailer. You will find installing dimensions and loads
under "Technical data" (
Ypage 444).
Permissible noseweight
You will find installing dimensions and loads
under "Technical data" (Ypage 444).
Loading a trailer
RWhen loading the trailer, make sure that nei-
ther the permissible gross weight of the trailer
nor the gross vehicle weight are exceeded.
The permissible gross vehicle weight is indi-
cated on the identification plate located on
the B-pillar on the driver's side of the vehicle.
You can find the maximum permissible values
on the type plates of your vehicle and the
trailer. When calculating how much weight
Towing a trailer261
Driving and parking
Z

the vehicle and trailer may carry, pay atten-
tion to the respective lowest values.
RThe trailer drawbar load on the ball coupling
must be added to the rear axle load to avoid
exceeding the permissible gross axle weight.
The permissible gross vehicle weight is indi-
cated on the identification plate located on
the B-pillar on the driver's side of the vehicle.
iMercedes-Benz recommends a trailer load
where the trailer drawbar noseweight
accounts for 8 % to 15 % of the trailer's per-
missible gross weight.
iThe weight of additional accessories, pas-
sengers, and cargo reduces the permissible
trailer load and drawbar load for your vehicle.
Checking the vehicle and trailer weight
RTo check that the weights of the towing vehi-
cle and the trailer comply with the maximum
permissible values, have the vehicle/trailer
combination (including the driver, passen-
gers, and cargo with a fully laden trailer)
weighed on a calibrated weighbridge.
RCheck the gross axle weight rating of the front and rear axles, the gross weight of the trailer
and the trailer drawbar noseweight.
Removing the ball coupling
XRemove the spring cotter.
XRemove the bolt from the ball coupling
recess.
XRemove the ball coupling from the ball cou-
pling recess.
XClean the ball coupling if it is dirty.
XStow the ball coupling so that it cannot be
thrown around.
Observe the loading guidelines (
Ypage 329)
and the safety notes regarding stowage spaces
(
Ypage 330).
Information on cleaning and care of the trailer
tow hitch (
Ypage 366).
Trailer power supply
!
Accessories with a maximum power con-
sumption of 180 W can be connected to the
permanent power supply. You must not charge a trailer battery using the
power supply.
The trailer socket of your vehicle is equipped at
the factory with a permanent power supply.
The permanent power supply is supplied via
trailer socket pin 4.
The trailer's permanent power supply is
switched off in the event of low vehicle supply
voltage and after six hours at the latest.
A qualified specialist workshop can provide
more information about installing the trailer
electrics.
262Towing a trailer
Driving an d parking

Display messagesPossible causes/consequences andMSolutions
OnlyE-MODE Availa ‐ble Power Limite dRefuel Immediately
PLUG-INHYBRID vehicles:
The fuel tan khas been run dry and th ecombustion engin ehas been
switched off .
A warning tone also sounds.
The vehicl ewill be powered by electrical energ yonly. Performance is
restricted and th evehicl emay accelerate mor eslowly than normal.
XRefue lat th eneares tgas station without fail .
In th e"Total range and electric range" menu, you can display th e
approximat erange of th evehicl e (
Ypage 250).
Withou tstartingengine again, con ‐sultworkshop
You canno tstart th eengin eagain due to amalfunction .
A warning tone also sounds.
If th eengin eis running:
XVisit aqualified specialist workshop .
If you switch off th eengine:
XSecur eth evehicl eagainst rollin gaway (Ypage 178).
XNotify aqualified specialist workshop or breakdown service.
á
Towing Not Permit ‐ted See Operator'sManual
The hybrid drive system is faulty.
XHaveth evehicl etransporte don atransporte ror trailer to th enear-
est qualified specialist workshop .
Û
Malfunction VisitWorkshop
The hybrid drive system is faulty.
XVisitaqualified specialist workshop .
Û
Malfunction
The hybrid drive system is faulty.
XHaveth evehicl etowed away by aprofessional recovery compan yto
th eneares tqualified specialist workshop .
d
Malfunction
The drive system is malfunctioning .
The ECO start/sto pfunction may be malfunctioning .
The drive powe ris restricted.
XVisit aqualified specialist workshop .
ï
ChargerCable Con ‐nected
PLUG-INHYBRID vehicles:
The charging cable connecto ris connecte dto th evehicl esocket.
You canno tdrive off as lon gas th echarging cable connecto ris still
connected.
Befor eyou drive off :
XRemove thecharging cable connecto rfrom th evehicl esocke t
(Ypage 174).
300Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
Blind SpotAssistNot Available Whe nTowingaTraile rSee Operator' sMan ‐ualorAct. BlindSpo tAssist NotAvailable Whe nTow ‐ing aTraile rSeeOperator' sManual
Blind Spot Assis tor Active Blind Spot Assis tis deactivated while tow-
ing atrailer .
You hav eestablished th eelectrical connection between th etrailer and
your vehicle.
XPress aon thesteering whee lto confirm th edisplay message .
Blind SpotAssistInoperativeorActiveBlind Spo tAssistInoperative
Blind Spot Assis tor Active Blind Spot Assis tis defective.
The yellow 9indicator lamp salso ligh tup in th eexterio rmirrors.
XVisit aqualified specialist workshop .
ParkAssistCanceledThe driver's door is open .
XRepeat theparking gap measuremen tand parking process wit hth e
driver's door closed .
You haveinadvertentl ytouched th emultifunction steering whee lwhile
steering intervention was active .
XWhilesteering intervention is active ,mak esur ethat th emultifunc-
tion steering whee lis no ttouched unintentionally.
The vehicl ehas started to skid and ES P®has intervened.
XUse Active Parking Assistagain later (Ypage 213).
ParkAssist Inoper ‐ativePARKTRONICis malfunctioning or faulty.
XFollow th einstruction sand helpful hints in th e"Problem swit h
PARKTRONIC" section (Ypage 213).
If th emultifunction display still shows th edisplay message :
XVisitaqualified specialist workshop .
Active Parking Assistis unavailable or faulty.
XSwitc hoff th eignition and restar tth eengine.
If Active Parking Assis tcontinues to be unavailable (the jsymbol
does no tappear in th emultifunction display):
XVisit aqualified specialist workshop .
ParkAssistFinishedThe vehicl eis parked. Awarning tone also sounds.
The display message disappear sautomatically.
DISTRONIC PLU SOffDISTRONI CPLU Shas been deactivated.
If awarning tone also sounds, DISTRONI CPLU Shas switched itself off .
(
Ypage 193)
DISTRONIC PLU SNowAvailableDISTRONI CPLU Sis operational again after having been temporarily
unavailable .You can no wreactivat eDISTRONI CPLU S (Ypage 193).
306Display messages
On-board computer and displays

Stowage spaces
Important safety notes
GWARNING
If objects in the passenger compartment are
stowed incorrectly, they can slide or be
thrown around and hit vehicle occupants.
There is a risk of injury, particularly in the
event of sudden braking or a sudden change
in direction.
RAlways stow objects so that they cannot be
thrown around in such situations.
RAlways make sure that objects do not pro-
trude from stowage spaces, parcel nets or
stowage nets.
RClose the lockable stowage spaces while
driving.
RStow and secure objects that are heavy,
hard, pointy, sharp-edged, fragile or too
large in the cargo compartment.
Observe the loading guidelines (
Ypage 329).
Glove box
XTo open: pull handle :and open glove box
flap ;.
XTo close: fold glove box flap ;upwards until
it engages.
iThe glove box can be cooled (Ypage 142).
1Glove box unlocked
2Glove box locked
The glove box can be locked and unlocked using the mechanical key.
Partition :for stowing flat objects is located in
the upper section of the glove box. It can be
removed to increase the stowage space in the
glove box.
XTo remove: pull out partition :
XTo install:insert partition :and push it back
until it engages.
Stowage compartment under the arm-
rest
330Stowage areas
Stowage and features