
125 mph (200 km/h) range. If ATTEN-
TION ASSIST detects typical indicators of fati-
gue or increasing lapses in concentration on
the part of the driver, it suggests taking a
break.
Important safety notes
ATTENTION ASSIST is only an aid to the
driver. It might not always recognize fatigue
or increasing inattentiveness in time or fail to
recognize them at all. The system is not a
substitute for a well-rested and attentive
driver.
The functionality of ATTENTION ASSIST is
restricted and warnings may be delayed or
not occur at all:
Rif the length of the journey is less than
approximately 30 minutes
Rif the road condition is poor, e.g. if the sur-face is uneven or if there are potholes
Rif there is a strong side wind
Rif you have adopted a sporty driving style
with high cornering speeds or high rates of
acceleration
Rif you are predominantly driving slower
than 37 mph (60 km/h) or faster than
125 mph (200 km/h)
Rif you are driving with the active Steer
Assist of DISTRONIC PLUS
Rif the time has been set incorrectly
Rin active driving situations, such as when
you change lanes or change your speed
The ATTENTION ASSIST tiredness assess-
ment is deleted and restarted when continu-
ing the journey, if:
Ryou switch off the engine
Ryou take off your seat belt and open the
driver's door, e.g. for a change of drivers or
to take a break
Displaying the attention level
You can have current status information dis-
played in the assistance menu (
Ypage 252)
of the on-board computer.
XSelect the Assistance display for Attention
Assist using the on-board computer
(
Ypage 251).
The following information is displayed:
Rlength of the journey since the last break.
Rthe attention level determined by ATTEN-
TION ASSIST ( Attention Level
), dis-
played in a bar display in five levels from
high to low.
RIf ATTENTION ASSIST is unable to calculate
the attention level and cannot issue a warn-
ing, the System Suspended
message
appears. The bar display then changes the
display, e.g. if you are driving at a speed
below 37 mph (60 km/h) or above 124 mph
(200 km/h).
Activating ATTENTION ASSIST
XActivate ATTENTION ASSIST using the on-
board computer (
Ypage 253).
The system determines the attention level
of the driver depending on the setting
selected:
Selection Standard
: the sensitivity with
which the system determines the attention
level is set to normal.
Selection Sensitive
: the sensitivity is set
higher. The attention level detected by Atten-
tion Assist is adapted accordingly and the
driver is warned earlier.
Driving systems215
Driving and parking
Z

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

cle occupants from suffering acid burns
should the battery be damaged in the event of
an accident.
In order for the battery to achieve the maxi-
mum possible service life, it must always be
sufficiently charged.
The vehicle battery, like other batteries, can
discharge over time if you do not use the
vehicle. In this case, have the battery discon-
nected at a qualified specialist workshop. You
can also charge the battery with a charger
recommended by Mercedes-Benz. Contact a
qualified specialist workshop for further infor-
mation.
Have the battery condition of charge checked
more frequently if you use the vehicle mainly
for short trips or if you leave it standing idle
for a lengthy period. Consult a qualified spe-
cialist workshop if you wish to leave your
vehicle parked for a long period of time.
Remove the SmartKey if you park the vehicle and do not require any electrical consumers.
The vehicle will then use very little energy,
thus conserving battery power.
Charging the 12 V battery
Vehicles with a lithium-ion battery:
!Only use battery chargers with a maxi-
mum charging voltage of 14.4 V.
Al lot her vehicles:
GWARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery.
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with plenty of clean water and seek medical atten-
tion.
GWARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing the vehicle or charging the battery, gases can escape from the battery. There is a risk of
an explosion.
Allow the frozen battery to thaw out before
charging it or jump-starting.
!Only use battery chargers with a maxi-
mum charging voltage of 14.8 V.
Al lve hicles:
!Only charge the battery using the jump-
starting connection point.
The jump-starting connection point is in the
engine compartment (
Ypage 365).
XOpen the hood.
XConnect the battery charger to the positive
terminal and ground point in the same
order as when connecting the donor bat-
tery in the jump-starting procedure
(
Ypage 365).
Keep away from fire and open flames. Do not
lean over a battery. Never charge the battery if it is still installed in the vehicle, unless you
use a battery charger which has been tested
and approved by Mercedes-Benz. A battery
charger unit specially adapted for Mercedes-
Benz vehicles and tested and approved by
Mercedes-Benz is available as an accessory.
It permits the charging of the battery in its
installed position. Contact an authorized
Mercedes-Benz Center for further informa-
tion and availability. Read the battery charg-
er's operating instructions before charging
the battery.
All vehicles except vehicles with a lith-
ium-ion battery: if the indicator/warning
lamps in the instrument cluster do not light up at low temperatures, it is very likely that the
Battery (vehicle)363
Breakdown assistance
Z

Jump-starting
For the jump-starting procedure, use only the jump-starting connection point in the engine
compartment, consisting of a positive terminal and a ground point.
All vehicles except vehicles with a lithium-ion battery:
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do not inhale any battery gases. Do not lean over the
battery. Keep children away from batteries. Wash away battery acid immediately with plenty of
clean water and seek medical attention.
GWARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open flames, creating sparks and smoking. Ensure there is sufficient ven-
tilation while charging and jump-starting. Do not lean over a battery.
GWARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or sparks
are created, the hydrogen gas can ignite. There is a risk of an explosion.
RMake sure that the positive terminal of a connected battery does not come into contact with
vehicle parts.
RNever place metal objects or tools on a battery.
RIt is important that you observe the described order of the battery terminals when connecting
and disconnecting a battery.
RWhen jump-starting, make sure that the battery poles with identical polarity are connected.
RIt is particularly important to observe the described order when connecting and disconnecting
the jumper cables.
RNever connect or disconnect the battery terminals while the engine is running.
GWARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting the
vehicle or charging the battery, gases can escape from the battery. There is a risk of an explosion. Allow the frozen battery to thaw out before charging it or jump-starting.
!Avoid repeated and lengthy starting attempts. Otherwise, the catalytic converter could be
damaged by the non-combusted fuel.
If, at low temperatures, the indicator lamps/warning lamps in the instrument cluster do not
light up, it is highly likely that the discharged battery has frozen. In this case, you may neither
charge the battery nor jump-start the vehicle. The service life of a thawed-out battery may be
shorter. The starting characteristics can be impaired, particularly at low temperatures. Have
the thawed-out battery checked at a qualified specialist workshop.
All vehicles:
Jump-starting365
Breakdown assistance
Z

Vehicle data
General notes
Please note that for the specified vehicle
data:
Rthe heights specified may vary as a result
of:
-tires
-load
-condition of the suspension
-optional equipment
Roptional equipment reduces the maximum
payload.
Observe the information relating to level con-
trol:
RAIR BODY CONTROL (Ypage 196)
Dimensions and weights
Model:
Opening height
;
Maximum
headroom
All models83.2 in
(2114 mm)77.8 in
(1977 mm)
All models
Vehicle length183.3 in (4656 mm)
Vehicle width
including exterior
mirrors82.5 in (2096 mm)
All models
Vehicle height65.5 in (1663 mm)
Wheelbase113.1 in (2873 mm)
Turning radius38.7 ft (11.80 m)
Maximum roof load165 lb (75 kg)
Maximum trunk
load220 lb (100 kg)
Trailer tow hitch
Mounting dimensions
!
If you have a trailer tow hitch retrofitted,
changes to the cooling system and drive
train may be necessary, depending on the
vehicle type.
If you have a trailer tow hitch retrofitted,
observe the anchorage points on the chas-
sis frame.
:Anchorage points for the trailer tow hitch
;Rear axle center line
Trailer tow hitch415
Technical data
Z