the lines in the assistance graphic
(Ypage 214) appear in green. Active Lane
Keeping Assist is ready for use.
XTo deactivate: press button;.
Indicator lamp :goes out. The Active Lane
Keeping Assist is deactivated. The Lane
Keeping Assist Offmessage appears on
the multifunction display.
Selecting Standard or Adaptive setting
XIn the DriveAssistmenu on the on-board
computer, select the Active Lane Keep‐
ing Assistfunction (Ypage 216).
XSelect settingStandardorAdaptive.
When Standardis selected, no warning vibra-
tion occurs if:
Ryou switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
Ra driving safety system intervenes, such as
ABS, BAS or ESP®.
When Adaptive
is selected, no warning vibra-
tion occurs if:
Ryou switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
Ra driving safety system intervenes, e.g.
ABS, BAS or ESP®.
Ryou accelerate hard, e.g. kickdown.
Ryou brake hard.
Ryou steer actively, e.g. swerve to avoid an
obstacle or change lanes quickly.
Ryou cut the corner on a sharp bend.
In order that you are warned only when neces-
sary and in good time if you cross the lane mark-
ing, the system recognizes certain conditions
and warns you accordingly.
The warning vibration occurs earlier if:
Ryou approach the outer lane marking on a
bend.
Rthe road has very wide lanes, e.g. a highway.
Rthe system detects solid lane markings.
The warning vibration occurs later if:
Rthe road has narrow lanes.
Ryou cut the corner on a bend.
Towing a trailer
When you attach a trailer, make sure you have
correctly established the electrical connection. This can be accomplished by checking the trailer
lighting.
Towing a trailer
Important safety notes
GWARNING
Installing an unsuitable ball coupling may
result in overloading of the trailer tow hitch
and the rear axle. This applies especially if the ball coupling in question is longer or angled
differently. This could seriously impair the
driving characteristics and the trailer can
come loose. There is a risk of an accident.
You should only ever install a ball coupling
that has the permissible dimensions and that
is designed to meet your trailer-towing
requirements. Do not modify the ball coupling
or the trailer tow hitch.
You will find the values approved by the manu-
facturer on the vehicle identification plates and
those for the towing vehicle under "Technical
data" (
Ypage 365).
GWARNING
When the vehicle/trailer combination begins
to lurch, you could lose control of it. The vehi- cle/trailer combination could even rollover.
There is a risk of an accident.
On no account should you attempt to
straighten up the vehicle/trailer combination
by increasing the speed. Reduce vehicle
speed and do not countersteer. Apply the
brake as necessary.
!If you have a trailer tow hitch retrofitted,
changes to the engine cooling system may be
necessary, depending on the vehicle type.
If you have a trailer tow hitch retrofitted,
observe the anchorage points on the chassis
frame.
The installation of a trailer tow hitch is only per-
missible if a towing weight is specified in your
vehicle documents. If this is not the case, then
the vehicle is not approved for the towing of a
trailer.
Towing a trailer197
Driving an d parking
Z
which the maximum permissible speed for vehi-
cle/trailer combinations is above 60 mph
(100 km/h).
When towing a trailer, your vehicle's handling
characteristics will be different in comparison towhen driving without a trailer and it will con-
sume more fuel.
Shift to a lower gear on long and steep downhill
gradients.
This also applies to:
Ractivated DISTRONIC PLUS
Ractivated cruise control
This will use the braking effect of the engine, so that less braking will be required to maintain the
speed. This relieves the load on the brake sys-
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 could come loose while driving and endanger other road users. There is a risk
of an accident and injury.
Install and secure the ball coupling as descri-
bed in the ball coupling manufacturer's instal- lation instructions. Make sure that the ball
coupling is correctly installed and secured
before every journey.
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.
XObserve the manufacturer's installation
instructions.
Observe the loading guidelines (
Ypage 273)
and the safety notes regarding stowage
spaces (
Ypage 273).
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.
XApply the vehicle's electric parking brake
manually.
XStart the engine.
XShift the transmission to position j.
XVehicles with AIR BODY CONTROL: select
the Comfort drive program.
Towing a trailer199
Driving and parking
Z
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 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
Vehicles with AIR BODY CONTROL: if you couple
up a trailer, the vehicle always remains at high-
way level. Observe the following note when cou-
pling up a trailer:
RUnless highway level has been set manually,
the vehicle is automatically lowered to high-
way level. If a speed of 5 mph (8 km/h) has
been reached, this may be the case.
These restrictions apply to accessories that are
supplied with power via the trailer socket in your
vehicle, e.g. a rear bicycle rack.
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 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 feature applies the
trailer brakes.
Towing a trailer
There are several legal requirements for towing
a trailer, e.g. the maximum permissible speed.
Make sure that your car/trailer combination
complies with the local regulations:
Rin your place of residence
Rat your destination
The police and local authorities can provide reli- able information.
To accumulate driving experience and accustom
yourself to the new handling characteristics,
practice the following at a location where there
is no traffic:
RCornering
RStopping
RBacking up
Check the following before the journey:
RTrailer tow hitch
RSafety switch for braked trailers
RSafety chains
RElectrical connections
RLighting system
RWheels and tires
RLoad securing
Adjust the exterior mirrors so that you have a
clear view of the rear section of the trailer.
If the trailer is equipped with electronically con-
trolled brakes, pull away carefully in the car/
trailer combination. Brake manually using the
brake controller and check whether the brakes
function correctly.
Regularly check that the load is secure.
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
with when driving without a trailer.
The vehicle/trailer combination:
Ris heavier
Ris restricted in its acceleration and gradient-
climbing capability
Rhas an increased braking distance
Ris affected more by strong crosswinds
Rdemands more sensitive steering
Rhas a larger turning circle
Avoid sudden steering movements.
Avoid braking abruptly. If possible, brake gently
at first to allow the trailer to run on. Then,
increase the braking force rapidly.
200Towing a trailer
Driving and parking
When overtaking, pay particular attention to the
extended length of your vehicle/trailer combi-
nation.
Due to the length of the vehicle/trailer combi-
nation, you require additional road space when
overtaking before you can change back to the
original lane.
If the automatic transmission repeatedly shifts
between gears on uphill or downhill gradients,
shift to a lower gear.
Driving in a lower gear and at a reduced speed
decreases the risk of engine damage.
If the coolant temperature increases signifi-
cantly when climate control is switched on,
switch climate control off.
Coolant heat can also be dissipated by opening
the windows and switching the ventilation
blower and the interior temperature to the high-
est level.
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.
XApply the vehicle's parking brake manually.
XShift the transmission to position j.
XClose all doors and the tailgate.
XSwitch off the engine.
XSecure the vehicle and trailer against rolling
away.
XRemove the trailer cable.
XRemove the safety chains, if there are any.
XUncouple the trailer.
Removing the ball coupling
XObserve the manufacturer's installation
instructions.
XPress the protective cap into the ball coupling
recess.
XMake sure that the protective cap is firmly in
place.
Observe the loading guidelines (
Ypage 273)
and the safety notes regarding stowage spaces
(
Ypage 273).
Information on cleaning and care of the trailer
tow hitch (
Ypage 310).
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.
Permissible trailer loads and trailer
drawbar noseweights
Weight specifications
The gross trailer weight is calculated as the
weight of the trailer plus the weight of the load
and the trailer's equipment.
Towing a trailer201
Driving and parking
Z
Display messagesPossible causes/consequences andMSolutions
T!
÷
Inoperative SeeOperator'sManual
EB D(electronic brak eforce distribution), AB Sand ES P®are malfunc -
tioning .
Other drivin gsystems and drivin gsafet ysystems may also malfunc -
tion .
In addition ,th e÷ and! warning lamp sligh tup in th einstru-
men tcluste rand awarning tone sounds.
GWARNIN G
The brak esystem continues to function normally, but without th e
function slisted above. The fron tand rear wheels could therefor eloc k
if you brak ehard, for example.
The steerabilit yand braking characteristics may be severely affected.
The braking distanc ein an emergenc ybraking situation can increase.
If ES P
®is no toperational, ES P®is unable to stabiliz eth evehicle.
There is an increased ris kof skiddin gand an accident.
XDrive on carefully.
XVisit aqualified specialist workshop immediately.
F(USA
only)
!( Canada
only)
Tur nOn the Igni‐
tio ntoReleas etheParkingBrake
The red F(USAonly) or !(Canada only) indicator lamp lights
up.
You attempte dto release th eelectric parking brak ewhile th eignition
was switched off .
XSwitchon th eignition .
F(USA
only)
!( Canada
only)
Please
Releas ePark‐ing Brake
The red F(USAonly) or !(Canada only) indicator lamp flashes
and awarning tone sounds. Acondition for automatic release of th e
electric parking brak eis no tfulfilled (
Ypage 151).
You are drivin gwit hth eelectric parking brak eapplied.
XReleas eth eelectric parking brak emanually.
The red F(USAonly) or !(Canada only) indicator lamp flashes
and awarning tone sounds.
You are usin gth eelectric parking brak efor emergenc ybraking
(
Ypage 152).
F(USA
only)
!( Canada
only)
Parkin gBrake See
Operator' sManual
The yellow !warning lamp lights up.
The electric parking brak eis malfunctioning .
To apply :
XSwitchth eignition off .
XPress theelectric parking brak ehandle for at least te nseconds.
XShift th etransmission to position j.
XConsultaqualified specialist workshop .
Display messages225
On-board computer and displays
Z
Display messagesPossible causes/consequences andMSolutions
The yellow!warning lamp lights up. The red F(USAonly)
or ! (Canada only) indicator lamp flashes for about te nseconds
after th eelectric parking brak ehas been applie dor released. It then
goe sout or remain slit .
The electric parking brak eis malfunctioning .
XSwitchoff th eignition and tur nit bac kon .
XApply th eelectric parking brake.
If it is no tpossibl eto engage th eelectric parking brake:
XShift th etransmission to position j.
XVisitaqualified specialist workshop .
If it is no tpossibl eto release th eelectric parking brak emanually:
XReleas eth eelectric parking brak eautomatically (Ypage 151).
If th eelectric parking brak estill canno tbe released:
XConsult aqualified specialist workshop .
The yellow!warning lamp lights up. If you manually apply or
release th eelectric parking brake, th ered F (USAonly) or !
(Canada only) indicator lamp flashes .
The electric parking brak eis malfunctioning .It is no tpossibl eto apply
th eelectric parking brak emanually.
XShift th etransmission to position j,as th eelectric parking brak e
is no tapplie dautomatically.
XVisit aqualified specialist workshop .
If it is no tpossibl eto release th eelectric parking brak emanually:
XReleas eth eelectric parking brak eautomatically (Ypage 151).
F(USA
only)
!( Canada
only)
Parkin gBrake Inop‐
erativ e
The yellow !warning lamp lights up. The red F(USAonly)
or ! (Canada only) indicator lamp flashes for about te nseconds
after th eelectric parking brak ehas been applie dor released. It then
goe sout or remain slit .
The electric parking brak eis malfunctioning ,e.g. because of over-
voltag eor undervoltage.
XRemove th ecaus efor th eovervoltage or undervoltage, e.g. by
charging th ebattery or restarting th eengine.
XEngage or release th eelectric parking brake.
If it remain simpossible to apply or release th eelectric parking brake:
XSwitc hoff th eignition and tur nit bac kon .
XEngage or release th eelectric parking brake.
If th eelectric parking brak estill canno tbe released:
XConsult aqualified specialist workshop .
If th eelectric parking brak estill canno tbe applied:
XVisit aqualified specialist workshop .
Display messages227
On-board computer and displays
Z
Display messagesPossible causes/consequences andMSolutions
The yellow!warning lamp lights up and th ered F (USAonly)
or ! (Canada only) indicator lamp flashes .
It is no tpossibl eto apply th eelectric parking brak emanually.
XShift th etransmission to position j.
XVisitaqualified specialist workshop .
$(USA
only)
J( Canada
only)
Check Brake Fluid
Level
There is no tenough brak efluid in th ebrak efluid reservoir .
In addition ,th e$ (USAonly) or J(Canada only) warning lamp
lights up in th einstrumen tcluste rand awarning tone sounds.
GWARNIN G
The braking effec 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 tcontinu edrivin g
under any circumstances.
XSecur eth evehicl eagainst rollin gaway (Ypage 149).
XConsult aqualified specialist workshop .
XDo notadd brak efluid .This does no tcorrec tth emalfunction .
#
CheckBrakePadWear
The brak epads/linings hav ereached their wear limit.
US Aonly: th e$ red brak esystem warning lamp is lit while th e
engin eis running.
XVisit aqualified specialist workshop .
G
Inoperative
Oneor mor emain features of th embrace system are malfunctioning .
XVisitaqualified specialist workshop .
Collision Preven‐tionAssist Plu sCurrently Unavaila‐ble See Operator' sManual
COLLISION PREVENTION ASSIST PLU Sis temporarily no toperational.
Possibl ecauses are:
Rth eradar sensor system is temporarily inoperative, e.g. due to elec -
tromagneti cradiation emitted by nearby TV or radi ostation sor
other source sof electromagneti cradiation
Rth esystem is outside th eoperating temperature range
Rth eon-boar dvoltag eis to olow
Whe nth ecauses state dabov eno longer apply, th edisplay message
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 149).
XRestart th eengine.
228Display messages
On-board computer and displays
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
F!NF (USA only), !(Canada only): the red indicator lamp for the electric
parking brake flashes or is lit and/or the yellow warning lamp for the electric
parking brake is lit.
XObserve the additional display messages in the multifunction display.
6N The red restraint system warning lamp is lit while the engine is running.
The restraint system is malfunctioning.
GWARNING
The air bags or Emergency Tensioning Devices may either be triggered uninten-
tionally or, in the event of an accident, may not be triggered.
There is an increased risk of injury.
XObserve the additional display messages in the multifunction display.
XDrive on carefully.
XContact a qualified specialist workshop and have the restraint system checked.
For further information about the restraint system, see (
Ypage 42).
Warning and indicator lamps in the instrument cluster257
On-board computer and displays
Z