Rthere are no, several or unclear lane markings
for a lane, e.g. in areas with road construction
work
Rthe lane markings are worn away, dark or cov-
ered up, e.g. by dirt or snow
Rthe distance to the vehicle in front is too small
and the lane markings thus cannot be detec-
ted
Rthe lane markings change quickly, e.g. lanes
branch off, cross one another or merge
Rthe road is narrow and winding
Rthere are strong shadows cast on the road
Switching on Lane Keeping Assist
XSwitch on Active Lane Keeping Assist using
the on-board computer; to do so, select
Standard
orAdaptive(Ypage 228).
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected,
the lines in the assistance graphics display
(
Ypage 227) are shown in green. Lane Keep-
ing Assist is ready for use.
Standard
If Standardis selected, no warning vibration
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®.
Adaptive
When Adaptiveis 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 recognizes solid lane markings.
The warning vibration occurs later if:
Rthe road has narrow lanes.
Ryou cut the corner on a bend.
Active Driving Assistance package
General notes
The Active Driving Assistance package consists
of DISTRONIC PLUS (Ypage 170), Active Blind
Spot Assist (Ypage 206 )and Active Lane Keep-
ing Assist (Ypage 209).
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.
GWARNING
Active Blind Spot Assist does not react to:
Rvehicles overtaken too closely on the side,
placing them in the blind spot area
Rvehicles which approach with a large speed
differential and overtake your vehicle
206Driving systems
Driving an d parking
Indicator and warning display
:Yellow indicator lamp/red warning lamp
Active BlindSpo t Assist isnot active at speeds
below approximately 20 mph (30 km/h). Vehi-
cles inthe monitoring range are then not ind i-
cated.
When Active BlindSpo t Assist isactivated, ind i-
cator lamp :inthe exterior mirrors lights up
yellow at speeds of up to 20 mph (30 km /h). At
speeds above 20 mph (30 km/h), the indicator
lamp goes out and Active BlindSpo t Assist is
operational.
If a veh icle is detected within the monitoring
range at speeds aboveapproximately 20 mph
(30 km/h), warning lamp :on the correspond-
ing side lights up red. This warning lamp always
lights up when a veh icleenters the blind spot
monitoring range from behind or from the side.
When you overtake a veh icle with adifference in
speed of less than 7 mph (12 km /h), a delayed
warning occurs.
The yellow indicator lamp goes out ifreverse
gear isengaged. Active BlindSpo t Assist isnot
operational.
The brightness of the indicator/warning lamps
is adjusted automatical lyaccording to the
brig htness of the surroundin gs.
Visual and acoustic collision warning
Ifyou switch on the turn signals to change lanes
and a vehicle is detected inthe side monitoring
range, you receive a visual and acoustic collision
warning. You then hear a double war
ning tone
and red warning lamp :flashes. If the turn sig-
nal remains on, detected vehicles are indicated
by the flashing of red warning lamp :. 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 inavoiding a collision.
GWARNING
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 :flashes in the exterior mir-
ror and a dual warning tone sounds. In addition,
disp lay;underlining the danger of a sidecol-
lisio n appears in the multifunction display.
In very rare cases, the system may make an
inappropriate brake application. A course-cor-
recting brake application may beinterrupted at
any time if you steer slightly in the opposite
dire ction or accelerate.
The course-correcting brake application is avail-
able in the speed range between 20 mph
(30 km/h) and 120 mph (200 km/h).
208Driving systems
Driving and parking
Either no braking application, or a course-cor-
recting brake application adapted to the driving
situation occurs if:
Rthere are vehicles or obstacles, e.g. crash
barriers, close to both sides of your vehicle.
Ra vehicle approaches you too closely at the
side.
Ryou have adopted a sporty driving style with
high cornering speeds.
Ryou brake or accelerate significantly.
Ra driving safety system intervenes, e.g. ESP®
or PRE-SAFE®Brake.
RESP®is switched off.
Ra loss of tire pressure or a defective tire is
detected.
Switching on Active Blind Spot Assist
XMake sure that Active Blind Spot Assist is
activated in the on-board computer
(
Ypage 228).
XTurn the SmartKey to position2in the ignition
lock.
Warning lamps :in 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
Asst. Not Available When Towing aTrailer See Operator's Manualmessage
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 :at 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. Active
Lane 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 Ke
eping Assist cannot continuously
keep your vehicle in its lane.
GWARNING
Active Lane Keeping Assist cannot always
clearly detect lane markings.
Driving system s209
Driving an d parking
Z
In such cases, Active Lane Keeping Assist
can:
Rgive an unnecessary warning and then
make a course-correcting brake application
to the vehicle
Rnot give a warning or 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:
Rthere is poor visibility, e.g. due to insufficient
illumination of the road, or due to snow, rain,
fog or spray
Rthere is glare, e.g. from oncoming traffic, the
sun or reflections (e.g. when the road surface
is wet)
Rthe windshield is dirty, fogged up, damaged or
covered, for instance by a sticker, in the vicin-
ity of the camera
Rthere are no, several or unclear lane markings
for a lane, e.g. in areas with road construction
work
Rthe lane markings are worn away, dark or cov-
ered up, e.g. by dirt or snow
Rthe distance to the vehicle in front is too small
and the lane markings thus cannot be detec-
ted
Rthe lane markings change quickly, e.g. lanes
branch off, cross one another or merge
Rthe road is narrow and winding
Rthere are highly variable shade conditions on the roadway
Rno vehicle is detected in the adjacent lane andthere 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 seconds.
In order 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:
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
Lane-correcting brake application
GWARNING
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.
GWARNING
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.
210Driving systems
Driving and parking
If a lane-correcting brake application occurs,
display:appears in the multifunction display.
A lane-correcting brake application can be made after driving over a lane marking recognized as
being solid or broken. 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 be recog-
nized.
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.
iA further lane-correcting brake application
can only occur after your vehicle has returned
to the original lane.
No lane-correcting brake application occurs if:
Ryou clearly and actively steer, brake or accel-
erate.
Ryou cut the corner on a sharp bend.
Ryou have switched on the turn signal.
Ra driving safety system intervenes, e.g. ESP®,
PRE-SAFE®Brake or Active Blind Spot Assist.
Ryou have adopted a sporty driving style with
high cornering speeds or high rates of accel-
eration.
RESP®is switched off.
Rthe transmission is not in position D.
Ron vehicles with a trailer tow hitch, the elec-
trical connection to the trailer has been cor-
rectly established.
Ran obstacle has been detected in the lane in
which you are driving.
Rwhen 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:
Rsteer slightly in the opposite direction
Rswitch on the turn signal
Rclearly brake or accelerate A lane-correcting brake application is interrup-
ted automatically if:
Ra driving safety system intervenes, e.g. ESP®,
PRE-SAFE®Brake or Active Blind Spot Assist
Rlane markings are no longer detected
Switching on Active Lane K eeping Assist
XSwitch on Active Lane Keeping Assist using
the on-board computer; to do so, select
Standard
orAdaptive(Ypage 228).
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected,
the lines in the assistance graphics display
(
Ypage 227) are shown in green. Active Lane
Keeping Assist is ready for use.
If Standard
is selected, no warning vibration
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.
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.
Driving systems211
Driving and parking
Z
XSecure the bolt using spring cotterB.
XCheck the ball coupling, bolt and spring cotter
for correct installation.
If the ball coupling cannot be correctly mounted,
remove the ball coupling. Under these circum-
stances, the ball coupling must not be used for
trailer towing.
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 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.
XShift the transmission to position P.
XApply the vehicle's electric parking brake.
XStart the engine.
XVehicles with AIRMATIC package: select
normal level and the Comfortdrive 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 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
iVehicles 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:
RIf 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.
RThe 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:
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 switch applies the
trailer brakes.
Towing a trailer215
Driving and parking
Z
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:
Rin your place of residence
Rin the location to which you are driving
The police and local authorities can provide reli- able information.
Observe the following when towing a trailer:
RTo 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
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 regular
intervals that the load is firmly secured. If the
tra
iler 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 driving
without one. Avoid sudden steering move-
ments.
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 moderately 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 gra-
dients, 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 toutilize the engine's braking effect.
Avoid continuous brake application as this
may overheat the vehicle brakes and, if instal-
led, the trailer brakes.
RIf the coolant temperature increases dramat-
ically while the air-conditioning system is
switched on, switch off the air-conditioning
system.
Coolant heat can also be dissipated by open-
ing the windows and switching the ventilation blower and the interior temperature 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 com-
bination, you require additional 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.
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-
216Towing a trailer
Driving an d parking
Useful information
i
This Operator's Manual describes all models
and all standard and optional equipment of
your vehicle available at the time of publica-
tion of the Operator's Manual. Country-spe-
cific differences are possible. Please note
that your vehicle may not be equipped with all
features described. This also applies to
safety-related systems and functions.
iRead the information on qualified specialist
workshops (Ypage 26).
Important safety notes
GWARNING
If you operate information systems and com-
munication equipment integrated in the vehi-
cle while driving, you will be distracted from
traffic conditions. You could also lose control
of the vehicle. There is a risk of an accident.
Only operate the equipment when the traffic
situation permits. If you are not sure that this
is possible, park the vehicle paying attention
to traffic conditions and operate the equip-
ment when the vehicle is stationary.
You must observe the legal requirements for the
country in which you are currently driving when
operating the on-board computer.
GWARNING
If the instrument cluster has failed or mal-
functioned, you may not recognize function
restrictions in systems relevant to safety. The
operating safety of your vehicle may be
impaired. There is a risk of an accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop immedi-
ately.
If the operating safety of your vehicle is
impaired, pull over as soon as it is safe to do so.
Contact a qualified specialist workshop.
The on-board computer only shows messages or
warnings from certain systems in the multifunc-
tion display. You should therefore make sure
your vehicle is operating safely at all times. For an overview, see the instrument panel illus-
tration (
Ypage 31).
Displays and operation
Instrument cluster lighting
The lighting in the instrument cluster, in the dis-
plays and the controls in the vehicle interior can
be adjusted using the brightness control knob.
The brightness control knob is located on the
bottom left of the instrument cluster
(
Ypage 31).
XTurn the brightness control knob clockwise or
counter-clockwise.
If you turn the light switch to Ã,Tor
L, the brightness is dependent upon the
brightness of the ambient light.
iThe light sensor in the instrument cluster
automatically controls the brightness of the
multifunction display.
In daylight, the displays in the instrument
cluster are not illuminated.
Speedometer with segments
The speedometer is divided into segments only
on vehicles with DISTRONIC PLUS.
The segments in the speedometer indicate
which speed range is available.
RDISTRONIC PLUS activated (Ypage 170):
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 vehi- cle 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.
Displays and operation219
On-board computer and displays
Z