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 permissible speed is. Observe the
legally prescribed maximum speed in the rel-
evant 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 utilize any of the added maximum rear
axle load when towing a trailer, the vehicle/
trailer combination may not exceed a maxi-
mum speed of 60 mph (100 km/h) for rea-
sons concerning the operating permit. This
also applies in countries in which the permis-
sible maximum speed for vehicle/trailer com-
binations is above 60 mph (100 km/h).
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
with when driving without a trailer.
Use the left-hand steering wheel paddle
shifter to shift into a lower gear in good time
on long and steep downhill gradients.
iThis also applies if you have activated
cruise control.
This will use the braking effect of the engine,
so that less braking will be required to main-
tain the 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
RMaintain a greater distance from the vehi-
cle in front than when driving without a
trailer.
RAvoid braking abruptly. If possible, brake
gently at first to allow the trailer to run on.
Then, increase the braking force rapidly.
RThe 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, decreases with
increasing altitude.
If the trailer swings from side to side:
XDo not accelerate.
XDo not counter-steer.
XBrake if necessary.
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.
230Towing a trailer
Driving and parking
cleaned, remove the ball coupling. The trailer
tow hitch must then not be used to tow a
trailer, as safe operation cannot be guaran-
teed.
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 equip-
ped 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 AIR BODY CONTROL:
selectComfort driving program or Trailer
off-road program.
XSwitch off the engine.
XClose the doors and tailgate.
XCouple up the trailer.
XEstablish the electrical connection
between the vehicle and the trailer.
XCheck that the trailer lighting system is
working.
XPush the combination switch upwards/
downwards and check whether the corre-
sponding 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
working properly. The function of other sys-
tems also depends on this, for example:
RESP®
RPARKTRONIC
RActive Parking Assist
RActive Blind Spot Assist
RActive Lane Keeping Assist
iVehicles with AIR BODY CONTROL: if you
couple up a trailer, the vehicle always
remains at highway level. When coupling up
a trailer, please observe the following:
RUnless highway level has been set man-
ually, the vehicle is automatically low-
ered to highway level. This is the case if a
speed of 5 mph (8 km/h) is reached.
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 length).
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 fastened to the vehicle's trailer cou-
pling, 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
towing 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
restrictions. Make sure that your car/trailer
combination complies with the local regula-
tions:
Rin your place of residence
Rin the location to which you are driving
The police and local authorities can provide
reliable information.
232Towing a trailer
Driving and parking
Observe the following when towing a trailer:
RTo gain driving experience and to become
accustomed to the new handling charac-
teristics, 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 reg-
ular intervals that the load is firmly secured.
If the trailer 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 driv-
ing without one. Avoid sudden steering
movements.
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.
RIf possible, do not brake suddenly, but
instead depress the brake pedal moder-
ately 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
gradients, 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
to utilize the engine's braking effect.
Avoid continuous brake application as this
may overheat the vehicle brakes and, if
installed, the trailer brakes.
RIf the coolant temperature increases dra-
matically while the air-conditioning system is switched on, switch off the air-condition-
ing system.
Coolant heat can also be dissipated by
opening the windows and switching the
ventilation blower and the interior temper-
ature 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
combination, you require addi
tional 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.
!Do not disconnect a trailer with an
engaged overrun brake. Otherwise, your
vehicle could be damaged by the rebound-
ing of the overrun brake.
Towing a trailer233
Driving and parking
Z
Display messagesPossible causes/consequences andMSolutions
F(USA
only)
!(Canada
only)
Parkin g
BrakeInop‐
erative
The yello w! warnin glamp lights up. The red F(USAonly)
or ! (Canada only) indicato rlamp flashes fo rabout te nsec -
onds after th eelectric parkin gbrak ehas been applied or released.
It then goe sout or remain slit .
The electric parkin gbrak eis malfunctioning, e.g. because of over-
voltag eor undervoltage.
XRemove th ecaus efo rth eovervoltage or undervoltage, e.g. by
chargin gth ebattery or restarting th eengine.
XEngage or release th eelectric parkin gbrake.
If it remain simpossible to apply or release th eelectric parkin g
brake:
XSwitc hof fth eignition and tur nit bac kon .
XEngage or release th eelectric parkin gbrake.
If th eelectric parkin gbrak estill canno tbe released:
XConsult aqualified specialist workshop .
If th eelectric parkin gbrak estill canno tbe applied:
XVisit aqualified specialist workshop .
The yellow! warnin glamp lights up and th ered F (USA
only) or !(Canada only) indicato rlamp flashes .
It is no tpossibl eto apply th eelectric parkin gbrak emanually.
XShift th etransmissio nto position P.
XVisit aqualified specialist workshop .
$(USA
only)
J(Canada
only)
Check Brake Fluid
Level
There is no tenough brak eflui din th ebrak eflui dreservoir .
In addition ,th e$ (USAonly) or J(Canada only) warnin g
lamp lights up in th einstrumen tcluster and awarnin gtone
sounds.
GWARNIN G
The brakin geffec tmay be impaired.
There is aris kof an accident.
XPull ove rand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions. Do no tcontinue drivin g
under any circumstances.
XSecur eth evehicl eagainst rollin gaway (Ypage 172).
XConsult aqualified specialist workshop .
XDo notadd brak efluid. This does no tcorrec tth emalfunction .
264Display messages
On-board computer and displays
Display messagesPossible causes/consequences andMSolutions
#
Check Brake Pad
Wear
The brak epads/lining shav ereached their wear limit.
US Aonly: th e$ red brak esystem warnin glamp is lit while th e
engin eis running .
XVisitaqualified specialist workshop .
G
Inoperative
Oneor mor emain features of th embrace system are malfunc -
tioning.
XVisit aqualified specialist workshop .
Collision Preven‐
tionAssist Plu s
Currently Unavail‐
ableSee Opera‐
tor's Manual
COLLISION PREVENTION ASSIST PLU Sis temporarily no topera-
tional.
Possibl ecauses are:
Rth erada rsensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radi osta-
tion sor other source sof electromagnetic radiation .
Rthesystem is outside th eoperating temperature range.
Rth eon-boar dvoltag eis to olow.
Whe nth ecauses state dabov eno longer apply, th edisplay mes -
sage disappears.
COLLISION PREVENTION ASSIST PLU Sis operational again .
If th edisplay message does no tdisappear :
XPull overand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 172).
XRestart th eengine.
Collision Preven ‐
tionAssist Plu s
Inoperative
COLLISION PREVENTION ASSIST PLU Sis temporarily inoperative
due to amalfunction .Adaptive Brake Assis tmay also hav efailed.
XVisit aqualified specialist workshop immediately.
PRE-SAFE Inopera‐
tiv eSee Opera‐
tor's Manual
Importan tfunction sof PRE-SAF E®havefailed. Al lother occupant
safet ysystems ,e.g. air bags ,remain available.
XVisit aqualified specialist workshop immediately.
Display messages26 5
On-board computer and displays
Z
Engine
Display messagesPossible causes/consequences andMSolutions
+
Check Coolant
Level See Opera‐
tor's Manual
The coolant level is too low.
!Avoid making long journeys with too little coolant in the engine
cooling system. The engine will otherwise be damaged.
XAdd coolant, observing the warning notes before doing so
(
Ypage 341).
If you have to add coolant frequently:
XContact a qualified specialist workshop and have the engine
cooling system checked.
?The fan motor is faulty.
XAt coolant temperatures below 248 ‡ (120 †), drive to the
nearest qualified specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in
mountainous terrain and stop-start traffic.
?
Coolant Too Hot
Stop Vehicle Turn
Engine Off
The coolant is too hot.
A warning tone also sounds.
GWARNING
Do not drive when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catch fire.
Steam from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There is a risk of injury.
XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 172).
XWait until the engine has cooled down.
XMake sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
XDo not start the engine again until the display message goes out
and the coolant temperature is below 248 ‡ (120 †). Other-
wise, the engine could be damaged.
XPay attention to the coolant temperature display.
If the temperature increases again:
XVisit a qualified specialist workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 248 ‡ (120†) .
276Displa y messages
On-board computer and displays
Display messagesPossible causes/consequences andMSolutions
4
Check Engine Oil
At NextRefueling
The engin eoil level has dropped to th eminimum level.
A warnin gtone also sounds.
!Avoid lon gjourneys wit hto olittl eengin eoil. The engin ewill
otherwise be damaged.
XChec kth eoil level when next refueling, at th elatest
(
Ypage 339).
XIf necessary, add engin eoil (Ypage 340).
If th eengin eoil need stopping up more often:
XContac t aqualified specialist workshop and hav eth eengin e
checked.
Information on approve dengin eoils can be obtained from aquali-
fie dspecialist workshop or on th eInternet at http:/ /
bevo.mercedes-benz.co m.
8
Fuel Level Low
The fuel level has dropped into the reserve range.
XRefuel at the nearest gas station.
CThere is only a very small amount of fuel in the fuel tank.
XRefuel at the nearest gas station without fail.
8
Gas Cap Loose
The fuel system pressure is too low. The fuel filler cap is not closed
correctly or the fuel system is leaking.
XCheck that the fuel filler cap is correctly closed.
If the fuel filler cap is not correctly closed:
XClose the fuel filler cap.
If the fuel filler cap is correctly closed:
XVisit a qualified specialist workshop.
278Display messages
On-board computer and displays
Display messagesPossible causes/consequences andMSolutions
ParkAssistInoper ‐
ative
PARKTRONI Cis malfunctionin gor faulty.
XFollow th einstruction sand helpful hints in th e"Problems wit h
PARKTRONIC" section (
Ypage 201).
If th emultifunction display still shows th edisplay message :
XVisitaqualified specialist workshop .
Active Parking Assistis unavailable or faulty.
XSwitc hof fth eignition and restar tth eengine.
If Active Parking Assis tcontinues to be unavailable (the jsymbol
does no tappea rin th emultifunction display):
XVisit aqualified specialist workshop .
ParkAssist
Switched Off
The vehicl eis parked. Awarnin gtone also sounds.
The display message disappear sautomatically.
Ã
Inoperative
DS R(Downhill Speed Regulation )is deactivated due to amalfunc -
tion .
XHaveDS Rchecke dat aqualified specialist workshop .
TrafficSig n
Assist Currently
Unavailable See
Operator' sManual
Traffic Sig nAssis tis temporarily inoperative.
Possibl ecauses are:
Rth ewindshield in th ecamera' sfield of vision is dirty.
Rvisibility is impaire ddue to heav yrain ,snow or fog.
XClean th ewindshield.
If th esystem detects that th ecamera is full yoperational, th edis-
play message disappears.
Traffic Sig nAssis tis operational again .
TrafficSig n
Assist Inoperative
Traffic Sig nAssis tis faulty.
XVisit aqualified specialist workshop .
ë
Off
The HOLD function is deactivated. The vehicl eis skidding.
A warnin gtone also sounds.
XReactivat eth eHOLD function later (Ypage 194).
The HOLD function is deactivated. Whe nth ebrak epedal is firmly
depressed, an activation condition is no tfulfilled .
A warnin gtone also sounds.
XChec kth eactivation condition sfo rth eHOLD function
(
Ypage 194).
282Display messages
On-board computer and displays