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. In this event, Blind Spot Assist is deac- tivated. The warning lamp lights up yellow in the
exterior mirrors and the Blind Spot Assist Blind Spot Assist
Not Available When Towing a Trailer Not Available When Towing a Trailer
See Operator's Manual See Operator's Manual message appears in
the multifunction display.
i You can deactivate the warning lamps in the
exterior mirrors.
To do so, switch off Blind Spot Assist when:
R the SmartKey is in position 0048in the igni-
tion lock
R the engine is not running
Lane Keeping Assist General notes
0043
Lane Keeping Assist camera
Lane Keeping Assist monitors the area in front of
your vehicle with camera 0043, which is mounted
at the top of the windshield. Lane Keeping Assist
detects lane markings on the road and can warn
you before you leave your lane unintentionally.
This function is available in the range between
40 mph and 120 mph (60 km/h and 200 km/h).
A warning may be given if a front wheel passes
over a lane marking. It will warn you by means of intermittent vibration in the steering wheel for
up to 1.5 second s.
Im portant safety notes G
WARNING
Lane Keeping Assist cannot always clearly
detect lane markings. In such cases, Lane Keeping Assist can:
R give an unnecessary warning
R not give a warning
There is a risk of an accident.
Always pay particular attention to the traffic
situation and keep within the lane, especially
if Lane Keeping Assist alerts you. G
WARNING
The Lane Keeping Assist warning does not
return the vehicle to the original lane. There is a risk of an accident.
You should always steer, brake or accelerate
yourself, in particular if warned by Lane Keep-ing Assist.
If you fail to adapt your driving style, Lane Keep- ing Assist can neither reduce the risk of an acci-
dent nor override the laws of physics. Lane
Keeping Assist cannot take into account the
road, traffic and weather conditions. Lane Keep- ing Assist is merely an aid. You are responsible
for the distance to the vehicle in front, for vehi-
cle speed, for braking in good time and for stay-
ing in your lane.
The Lane Keeping Assist does not keep the vehi- cle in the lane.
The system may be impaired or may not function if:
R there is poor visibility, e.g. due to insufficient
illumination of the road, or due to snow, rain,fog or heavy spray
R there is glare, e.g. from oncoming traffic, the
sun or reflection from other vehicles (e.g. if
the road surface is wet)
R the windshield is dirty, fogged up, damaged or
covered, for instance by a sticker, in the vicin-
ity of the camera
R there are no or several unclear lane markings
for one lane, e.g. roadworks
R the lane markings are worn away, dark or cov-
ered up, e.g. by dirt or snow
R the distance to the vehicle in front is too short
and thus the lane markings cannot be detec-
ted
R the lane markings change quickly, e.g. lanes
branch off, cross one another or merge Driving systems
193Driving and parking Z
R
the road is narrow and winding
R there are highly variable shade conditions on
the roadway
Switching on Lane Keeping Assist
X Switch on Active Lane Keeping Assist using
the on-board computer; to do so, select
Standard
Standard orAdaptive Adaptive (Ypage 217).
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected,
the lines in the assistance graphic are shown
in green (Y page 216). Lane Keeping Assist is
ready for use.
Standard If Standard
Standard is selected, no warning vibration
occurs if:
R you switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
R a driving safety system intervenes, e.g. ABS,
BAS or ESP ®
.
Adaptive When Adaptive
Adaptive is selected, no warning vibra-
tion occurs if:
R you have switched on the turn signal; in this
event, the warnings are suppressed for a cer-
tain period of time.
R a driving safety system intervenes, e.g. ABS,
BAS or ESP ®
.
R you accelerate hard, e.g. kickdown.
R you brake hard.
R you steer actively, e.g. swerve to avoid an
obstacle or change lanes quickly.
R you cut the corner on a sharp bend.
To ensure that you are warned only when nec-
essary and in good time if you cross the lane
markings, the system detects certain conditions
and warns you accordingly.
The warning vibration occurs earlier if:
R you approach the outer lane marking on a
bend
R the road has very wide lanes, e.g. a freeway
R the system detects solid lane markings
The warning vibration occurs later if:
R the road has narrow lanes
R you cut the corner on a bend Driving Assistance Plus package
General notes The Driving Assistance Plus Package consists of
Active Distance Assist DISTRONI C(Ypage 157),
Active Blind Spot Assist (Y page 194) and
Active Lane Keeping Assist (Y page 197).
Active Blind Spot Assist General notes
Active Blind Spot Assist monitors the areas on
either side of the vehicle that are not directly
visible to the driver with two lateral, rear-facing radar sensors. A warning lamp lights up in the
exterior mirrors and draws your attention to
vehicles detected in the monitored area. If you
then switch on the corresponding turn signal to
change lanes, you will also receive a visual and
audible collision warning. If a risk of lateral col-
lision is detected, corrective braking may help
you avoid a collision. Before a course-correcting
brake application, Active Blind Spot Assist eval- uates the space in the direction of travel and at
the sides of the vehicle. For this, Active Blind
Spot Assist uses the forward-facing radar sen-
sors.
Active Blind Spot Assist supports you from a
speed of approximately 20 mph (30 km/ h).
Important safety notes Active Blind Spot Assist is only an aid and is not
a substitute for attentive driving. G
WARNING
Active Blind Spot Assist does not react to:
R vehicles overtaken too closely on the side,
placing them in the blind spot area
R vehicles which approach with a large speed
differential and overtake your vehicle
As a result, Active Blind Spot Assist may nei-
ther give warnings nor intervene in such sit-
uations. There is a risk of an accident.
Always observe the traffic conditions care-
fully, and maintain a safe lateral distance.
i USA only: This device has been approved by
the FCC as a "Vehicular Radar System". The
radar sensor is intended for use in an auto-
motive radar system only. Removal, tamper-
ing, or altering of the device will void any war- 194
Driving systemsDriving and pa
rking
Warning lamp
0043
Warning lamp
Active Blind Spot Assist is not operational at
speeds below approximately 20 mph (30 km/h). Vehicles in the monitoring range are then not
indicated.
If Active Blind Spot Assist is activated, warning
lamp 0043in the exterior mirrors lights up yellow
at speeds of up to 20 mph (30 km/h). At speeds
above 20 mph (30 km/h), the warning lamp
goes out and Active Blind Spot Assist is opera-
tional.
If a vehicle is detected within the monitoring
range at speeds above approximately 20 mph
(30 km/h), warning lamp 0043on the correspond-
ing side lights up red. This warning lamp always lights up 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, Active Blind Spot Assist is not operational.
The brightness of the warning lamps is auto-
matically adapted to the brightness of the sur-
roundings.
Visual and acoustic collision warning
If you switch on the turn signals to change lanes
and a vehicle is detected in the side monitoring range, you receive a visual and acoustic collision
warning. You then hear a double warning tone
and red warning lamp 0043flashes. If the turn sig-
nal remains on, detected vehicles are indicated
by the flashing of red warning lamp 0043. There are
no further warning tones. Course-correcting brake application
If Active Blind Spot Assist detects a risk of a lat-
eral collision in the monitoring range, a course-
correcting brake application is carried out. This
is meant to assist you in avoiding a collision. G
WARNING
A course-correcting brake application cannot always prevent a collision. There is a risk of an
accident.
Always steer, brake or accelerate yourself,
especially if Active Blind Spot Assist warns
you or makes a course-correcting brake appli-
cation. Always maintain a safe distance at the sides.
If a course-correcting brake application occurs, red warning lamp 0043flashes in the exterior mir-
ror and a double warning tone sounds. In addi-
tion, a display underlining the danger of a side
collision appears in the multifunction display.
In very rare cases, the system may make an
inappropriate brake application. A course-cor-
recting brake application may be interrupted at
any time by countersteering slightly or acceler-
ating.
The course-correcting brake application is avail-
able in the speed range between 20 mph
(30 km/h) and 120 mph (200 km/h).
Either no braking application, or a course-cor-
recting brake application adapted to the driving situation occurs if:
R there are vehicles or obstacles, e.g. crash
barriers, located on both sides of your vehicle.
R a vehicle approaches you too closely at the
side.
R you have adopted a sporty driving style with
high cornering speeds.
R you clearly brake or accelerate.
R a driving safety system intervenes, e.g. ESP ®
or PRE-SAFE ®
Brake.
R ESP ®
is switched off.
R a loss of tire pressure or a defective tire is
detected.
Switching on Active Blind Spot Assist 196
Driving systemsDriving and parking
X
Make sure that Active Blind Spot Assist
(Y page 217) is activated in the on-board
computer.
X Turn the SmartKey to position 0048in the igni-
tion lock.
Warning lamps 0043in the exterior mirrors light
up red for approximately 1.5 seconds and
then turn yellow.
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. Active Blind Spot Assist is then deacti-
vated. The indicator lamp lights up yellow in the
exterior mirrors and the Active Blind Spot
Active Blind Spot
Asst. Not Available When Towing a Asst. Not Available When Towing a
Trailer See Operator's Manual
Trailer See Operator's Manual message
appears in the multifunction display.
Active Lane Keeping Assist General notes
Active Lane Keeping Assist monitors the area in
front of your vehicle by means of multifunction
camera 0043at the top of the windshield. Various
different areas to the front, rear and side of your vehicle are also monitored with the aid of the
radar sensor system. Active Lane Keeping
Assist detects lane markings on the road and
can warn you before you leave your lane unin-
tentionally. If you do not react to the warning, a
lane-correcting application of the brakes can
bring the vehicle back into the original lane.
This function is available in a speed range
between 40 mph and 120 mph (60 km/h and
200 km/h).
For Active Lane Keeping Assist to assist you
when driving, the radar sensor system must be
operational. Important safety notes
If you fail to adapt your driving style, Active Lane Keeping Assist can neither reduce the risk of
accident nor override the laws of physics. ActiveLane Keeping Assist cannot take into account
road, weather or traffic conditions. Active Lane
Keeping Assist is only an aid. You are responsi-
ble for the distance to the vehicle in front, for
vehicle speed, for braking in good time and for
staying in your lane.
Active Lane Keeping Assist cannot continuously
keep your vehicle in its lane. G
WARNING
Active Lane Keeping Assist cannot always
clearly detect lane markings.
In such cases, Active Lane Keeping Assist
can:
R give an unnecessary warning and then
make a course-correcting brake application
R neither give a warning nor intervene
There is a risk of an accident.
Always pay particular attention to the traffic
situation and keep within the lane, especially
if Active Lane Keeping Assist alerts you. Ter-
minate the intervention in a non-critical driv-
ing situation.
The system may be impaired or may not function if:
R there is poor visibility, e.g. due to insufficient
illumination of the road, or due to snow, rain,fog or heavy spray
R there is glare, e.g. from oncoming traffic, the
sun or reflection from other vehicles (e.g. if
the road surface is wet)
R the windshield is dirty, fogged up, damaged or
covered, for instance by a sticker, in the vicin- ity of the camera
R there are no or several unclear lane markings
for one lane, e.g. roadworks
R the lane markings are worn away, dark or cov-
ered up, e.g. by dirt or snow
R the distance to the vehicle in front is too short
and thus the lane markings cannot be detec-
ted
R the lane markings change quickly, e.g. lanes
branch off, cross one another or merge
R the road is narrow and winding Driving systems
197Driving and parking Z
R
there are highly variable shade conditions on
the roadway
R no vehicle is detected in the adjacent lane and
there are broken lane markings
Warning vibration in the steering wheel
A warning may be given if a front wheel passes
over a lane marking. It will warn you by means of intermittent vibration in the steering wheel for
up to 1.5 second s.
In orde r that you are warned only when neces-
sary and in good time if you cross the lane mark-
ing, the system detects certain conditions and
warns you accordingly.
The warning vibration occurs earlier if:
R you approach the outer lane marking on a
bend
R the road has very wide lanes, e.g. a freeway
R the system detects solid lane markings
The warning vibration occurs later if:
R the road has narrow lanes
R you cut the corner on a bend
Lane-correcting brake application G
WARNING
A lane-correcting brake application cannot
always bring the vehicle back into the original lane. There is a risk of an accident.
Always steer, brake or accelerate yourself,
especially if Active Lane Keeping Assist warns
you or makes a lane-correcting brake appli-
cation. G
WARNING
Active Lane Keeping Assist does not detect
traffic conditions or road users. In very rare
cases, the system may make an inappropriate brake application, e.g. after intentionally driv-
ing over a solid lane marking. There is a risk of an accident.
An inappropriate brake application may be
interrupted at any time if you steer slightly in
the opposite direction. Always make sure that
there is sufficient distance on the side for
other traffic or obstacles. If you leave your lane, under certain circumstan-
ces the vehicle will brake briefly on one side.
This is meant to assist you in bringing the vehicle
back to the original lane.
If a lane-correcting brake application occurs,
display 0043appears in the multifunction display.
A lane-correcting brake application can be made
after driving over a solid or broken lane marking.
Before this, a warning must be given by means of
intermittent vibration in the steering wheel. In
addition, a lane with lane markings on both sides must have been detected.
In the case of a broken lane marking being
detected, a lane-correcting brake application
can only be made if a vehicle has been detected
in the adjacent lane. The following vehicles can
have an influence on brake application: oncom- ing traffic, vehicles that are overtaking and vehi-cles that are driving parallel to your vehicle.
i A further lane-correcting brake application
can only occur after your vehicle has returned
to the original lane.
No lane-correcting brake application occurs if:
R you clearly and actively steer, brake or accel-
erate
R you cut the corner on a sharp bend
R you have switched on the turn signal
R a driving safety system intervenes, e.g. ESP ®
,
PRE-SAFE ®
Brake or Active Blind Spot Assist
R you have adopted a sporty driving style with
high cornering speeds or high rates of accel-
eration
R ESP ®
is switched off
R the transmission is not in position 005B
R on vehicles with a trailer tow hitch, the elec-
trical connection to the trailer has been cor-
rectly established 198
Driving systemsDriving and parking
R
an obstacle has been detected in the lane in
which you are driving
R when a loss of tire pressure or a defective tire
has been detected and displayed
There is a possibility that the Active Lane Keep- ing Assist could misjudge the given traffic sit-
uation. An inappropriate brake application may
be interrupted at any time if you:
R steer slightly in the opposite direction
R switch on the turn signal
R clearly brake or accelerate
A lane-correcting brake application is interrup-
ted automatically if:
R a driving safety system intervenes, e.g. ESP ®
,
PRE-SAFE ®
Brake or Active Blind Spot Assist
R lane markings are no longer detected
Switching on Active Lane Keeping Assist X Switch on Active Lane Keeping Assist using
the on-board computer; to do so, select
Standard
Standard orAdaptive Adaptive (Ypage 217).
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected,
the lines in the assistance graphic are shown in green (Y page 216). Active Lane Keeping
Assist is ready for use.
If Standard Standard is selected, no warning vibration
occurs if:
R you switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
R a driving safety system intervenes, such as
ABS, BAS or ESP ®
.
When Adaptive
Adaptive is selected, no warning vibra-
tion occurs if:
R you switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
R a driving safety system intervenes, e.g.
ABS, BAS or ESP ®
.
R you accelerate hard, e.g. kickdown.
R you brake hard.
R you steer actively, e.g. swerve to avoid an
obstacle or change lanes quickly.
R you cut the corner on a sharp 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. Lane-correcting brake application does
not take place when towing a trailer. Active Lane
Keeping Assist is not activated and the lines in
the assistance graphic are gray. Towing a trailer
Important safety notes
G
WARNING
Installing an unsuitable ball coupling may
overload the trailer tow hitch and the rear
axle. This is particularly likely in the case of
longer or differently angled ball couplings.
Consequently, the driving characteristics may
be significantly impaired and the trailer may
detach. This presents the risk of an accident
or even fatal injuries!
Install only a ball coupling that adheres to the permissible dimensions and is designed for
your intended purpose for towing a trailer. Do
not make any changes to 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" (Y page 367). G
WARNING
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. G
WARNING
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 Towing a trailer
199Driving and parking
Z
X
Establish the electrical connection between
the vehicle and the trailer.
X Check that the trailer lighting system is work-
ing.
X Push 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:
R ESP ®
R Parking Assist PARKTRONIC
R Active Parking Assist
R Parking Package with rear view camera
R Active Blind Spot Assist
R Active Lane Keeping Assist
i Vehicles 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:
R If 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.
R The 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 length).
Most U.S. states and all Canadian provinces
require by law: R Safety chains between the towing vehicle and
the trailer. The chains should be cross-woundunder 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.
R A separate brake system for certain types of
trailer.
R Safety 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 triggers 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:
R in your place of residence
R in the location to which you are driving
The police and local authorities can provide reli- able information.
Observe the following when towing a trailer:
R To 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
R Before driving, check:
- trailer tow hitch
- safety switch for braked trailers
- safety chains
- electrical connections
- lights
- wheels
R Adjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer.
R If the trailer has electronically controlled
brakes, pull away carefully. Brake manually
using the brake controller and check whether
the brakes function correctly.
R Secure any objects on the trailer to prevent
the cargo from slipping when the vehicle is in
motion.
R When you couple up a trailer, check at regular
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.
R Bear in mind that the handling will be less
stable when towing a trailer than when driving
without one. Avoid sudden steering move-
ments.
R The 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. Towing a trailer
203Driving and parking Z
deactivate Active Brake Assist with cross-traffic
function.
X Press the 0059or0065 button on the steering
wheel to select the DriveAssist
DriveAssist menu.
X Press the 0063or0064 button to select
Brake Assist
Brake Assist .
X Press 0076to confirm.
The current selection appears.
X To activate/deactivate: press the0076but-
ton again.
When Active Brake Assist or Active Brake
Assist with cross-traffic function is deactiva-
ted, the 00D4symbol appears in the multi-
function display in the assistance graphic dis-
play.
Further information on Active Brake Assist
(Y page 65) and Active Brake Assist with cross-
traffic function (Y page 70).
Activating/deactivating ATTENTION
ASSIST X
Press the 0059or0065 button on the steering
wheel to select the DriveAssist
DriveAssist menu.
X Press the 0063or0064 button to select
Attention Assist
Attention Assist .
X Press the 0076button.
The current selection appears.
X Press 0076to confirm.
X Press the 0064or0063 button to set Off Off,
Standard
Standard orSensitive
Sensitive.
X Press the 0076button to save the setting.
When ATTENTION ASSIST is deactivated, the
00D7 symbol appears in the multifunction dis-
play in the assistance graphics display.
For further information about ATTENTION
ASSIST, see (Y page 189).
Activating/deactivating Blind Spot
Assist X
Press the 0059or0065 button on the steering
wheel to select the DriveAssist DriveAssistmenu.
X Press the 0063or0064 button to select
Blind Spot Assist
Blind Spot Assist .
X Confirm by pressing 0076on the steering
wheel.
The current selection appears.
X To activate/deactivate: press the0076but-
ton again. For further information about Blind Spot Assist,
see (Y page 191).
For further information about Active Blind Spot
Assist, see (Y page 194).
Activating/deactivating Lane Keeping
Assist X
Press the 0059or0065 button on the steering
wheel to select the DriveAssist DriveAssistmenu.
X Press the 0063or0064 button to select
Lane Keeping Assist
Lane Keeping Assist .
X Press 0076to confirm.
The current selection appears.
X Press 0076to confirm.
X Press the 0064or0063 button to set Off
Off,
Standard
Standard orAdaptive
Adaptive.
When Lane Keeping Assist or Active Lane
Keeping Assist is activated, the multifunction display shows the lane markings as bright
lines in the assistance graphic.
X Press the 0076button to save the setting.
For further information about Lane Keeping
Assist, see (Y page 193).
For further information about Active Lane Keep- ing Assist, see (Y page 197). Service menu
Depending on the equipment installed in the
vehicle, you have the following options in the
Serv. Serv. menu:
R calling up display messages in message mem-
ory (Y page 223)
R restarting the tire pressure loss warning sys-
tem (Y page 334) or checking the tire pres-
sure electronically (Y page 336)
R calling up the service due date (Y page 300). Settings menu
Introduction Depending on the equipment installed in the
vehicle, In the
Sett. Sett.menu you have the follow-
ing options:
R Changing the instrument cluster settings
(Y page 218)
R Changing the light settings (Y page 218)
R Changing the vehicle settings (Y page 219) Menus and submenus
217On-board computer and displays Z