
When ATTENTION ASSIST is deactivated, the
ésymbol appears in the multifunction
display in the assistance graphic display.
When ATTENTION ASSIST has been deactiva-
ted, it is automatically reactivated after the
engine has been stopped. The sensitivity
selected corresponds to the last selection
activated (standard/sensitive).
Warning in the multifunction display
If fatigue or increasing lapses in concentra-
tion are detected, a warning appears in the
multifunction display: ATTENTION ASSIST
Take a Break!.
In addition to the message shown in the mul-
tifunction display, you will then hear a warn-
ing tone.
XIf necessary, take a break.
XConfirm the message by pressing the a
button on the steering wheel.
On long journeys, take regular breaks in good
time to allow yourself to rest properly. If you
do not take a break and ATTENTION ASSIST
still detects increasing lapses in concentra-
tion, you will be warned again after
15 minutes at the earliest. This will only hap-
pen if ATTENTION ASSIST still detects typical
indicators of fatigue or increasing lapses in
concentration.
If a warning is output in the multifunction dis-
play, a service station search is performed in
COMAND. You can select a service station
and navigation to this service station will then
begin. This function can be activated and
deactivated in COMAND.
Traffic Sign Assist
General notes
Traffic Sign Assist displays the maximum
speed permitted to the driver in the instru-
ment cluster. The data and general traffic reg-
ulations stored in the navigation system are
used to determine the current speed limit. Traffic Sign Assist is a map-based system,
and thus, traffic signs put up temporarily (e.g.
near roadworks) are not detected.
If a traffic sign that is relevant to your vehicle
is passed, the display of the speed limits is
updated.
Traffic signs with a restriction indicated by an
additional sign (e.g. in wet conditions) are
also shown.
The traffic signs are only displayed with the
restrictions if:
Rthe regulation must be observed with the
restriction, or
RTraffic Sign Assist is unable to determine
whether the restriction applies
If Traffic Sign Assist is unable to determine a
maximum permitted speed from any of the
available sources, no speed limit is displayed
in the instrument cluster either.
Traffic Sign Assist is not available in all coun-
tries. In this case, symbol :is shown in the
assistance graphic display (
Ypage 251).
Important safety notes
Traffic Sign Assist is only an aid and is not
always able to correctly display speed limits.
Traffic signs always have priority over the
Traffic Sign Assist display.
The system may be either functionally
impaired or temporarily unavailable if the
information in the digital street map of the
navigation system is incorrect or out of date.
216Driving systems
Driving and parking

Blind Spot Assist monitors the area up to 10 ft
(3 m) behind your vehicle and directly next to
your vehicle, as shown in the diagram.
If the lanes are narrow, vehicles driving in the
lane beyond the lane next to your vehicle may
be indicated, especially if the vehicles are not
driving in the middle of their lane. This may be
the case if there are vehicles driving at the
inner edge of their lanes.
Due to the nature of the system:
Rwarnings may be issued in error when driv-
ing close to crash barriers or similar solid
lane borders.
Rthe warning is canceled when driving for an
extended period next to long vehicles, such
as trucks.
Warning display
:Warning display Blind Spot Assist is not active at speeds below
approximately 20 mph (30 km/h). Vehicles in
the monitoring range are then not indicated.
If a vehicle is detected within the blind spot
monitoring range at speeds above 20 mph
(30 km/h), warning lamp
:on the corre-
sponding side lights up red. This warning is
always emitted when a vehicle enters the
blind spot monitoring range from behind or
from the side. When you overtake a vehicle,
the warning only occurs if the difference in
speed is less than 7 mph (12 km/h).
If you select the reverse gear, Blind Spot
Assist is not operational.
The brightness of the warning lamps is auto-
matically adapted to the brightness of the
surroundings.
Collision warning
If a vehicle is detected in the monitoring range
of Blind Spot Assist and you switch on the
corresponding turn signal, a double warning
tone sounds. Red warning lamp :flashes. If
the turn signal remains on, vehicles detected
are indicated by the flashing of red warning
lamp :. There are no further warning tones.
Switching on Blind Spot Assist
XMake sure that Blind Spot Assist is activa-
ted in the on-board computer
(
Ypage 253).
XTurn the SmartKey to position 2in the igni-
tion lock.
Warning lamps :in the exterior mirrors
light up red until the engine is started.
Driving systems219
Driving and parking
Z

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

The segments in the speedometer indicate
which speed range is available.
RCruise control activated (Ypage 181):
The segments light up from the stored
speed to the type-tested maximum speed.
RDISTRONIC PLUS activated (Ypage 183):
One or two segments in the set speed
range light up.
RDISTRONIC PLUS detects a vehicle in front
that is driving at a slower speed than the
stored speed:
The segments between the speed of the
vehicle in front and the stored speed light
up.
Tachometer
!
Do not drive in the overrevving range, as
this could damage the engine.
The red band in the tachometer indicates the engine's overrevving range.
The fuel supply is interrupted to protect the
engine when the red band is reached.
Outside temperature display
You should pay special attention to road con-
ditions when temperatures are around freez-
ing point.
Bear in mind that the outside temperature
display indicates the temperature measured
and does not record the road temperature.
The outside temperature display is in the mul-
tifunction display (
Ypage 241).
Changes in the outside temperature are dis-
played after a short delay.
Coolant temperature display
GWARNING
Opening the hood when the engine is over-
heated or when there is a fire in the engine
compartment could expose you to hot gases
or other service products. There is a risk of
injury.
Let an overheated engine cool down before
opening the hood. If there is a fire in the
engine compartment, keep the hood closed
and contact the fire department.
!A display message is shown if the coolant
temperature is too high.
If the coolant temperature is over 248 ‡
(120 †), do not continue driving. The
engine will otherwise be damaged.
The coolant temperature display is in the
lower section of the tachometer (
Ypage 33).
Under normal operating conditions and with
the specified coolant level, the coolant tem-
perature may rise to 248 ‡ (120 †).
Operating the on-board computer
:Multifunction display
;Right control panel
=Left control panel
XTo activate the on-board computer: turn
the SmartKey to position 1in the ignition
lock.
You can control the multifunction display and
the settings in the on-board computer using
Displays and operation239
On-board computer and displays
Z

Trip menu
Standard display
XPress and hold the %button on the
steering wheel until the Trip
menu with
trip odometer :and odometer ;
appears.
Displaying the range and current fuel
consumption
XPress the òbutton on the steering
wheel to open the menu list.
XPress :or9 on the steering wheel
to select the Trip
menu.
XPress9or: to select the display
with approximate range :and current fuel
consumption ;.
Approximate range :that can be covered
is calculated according to your current driv-
ing style and the amount of fuel in the tank.
If there is only a small amount of fuel left in
the fuel tank, a vehicle being refueled C
appears instead of approximate range :.Recuperation display
=shows you if
energy has been recuperated from the
kinetic energy in overrun mode and saved
in the battery. Recuperation display =
depends on the engine installed and is
therefore not available in all vehicles.
ECO display
XPress òon the steering wheel to open
the menu list.
XPress the :or9 button on the steer-
ing wheel to select the Trip
menu.
XConfirm by pressingaon the steering
wheel.
XPress the :or9 button to select
ECO display.
If the ignition remains switched off for longer
than four hours, the ECO display will be auto- matically reset.
For more information on the ECO display, see
(
Ypage 177).
244Menus and submenus
On-board computer and displays

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