
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 272).
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected,
the lines in the assistance graphics display
(
Ypage 271) 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 193), Active Blind
Spot Assist (Ypage 230 )and Active Lane Keep-
ing Assist (Ypage 233).
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
230Driving 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 veh icle isdetected inthe side monitoring
range, you receive a visual and acoustic collisio n
warning. You then hear a double
war
ning tone
and red warning lamp :flashes. Ifthe turn sig-
nal remains on, detected veh icles 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).
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.
232Driving systems
Driving and parking

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.
Rthe offroad program is activated (vehicles
without the Offroad Engineering package).
Rthe Offroad or Offroad Plus drive program is
activated (vehicles with the Off-Road Engi-
neering package).
Rthe LOW RANGE offroad gear is activated
(vehicles with the Offroad Engineering pack-
age).
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 Keeping Assist
XSwitch on Active Lane Keeping Assist using
the on-board computer; to do so, select
Standard
or Adaptive(Ypage 272).
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected,
the lines in the assistance graphics display
(
Ypage 271) 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.
Off-road driving systems
4MATIC (permanent four-wheel drive)
4MATIC ensures that all four wheels are perma-
nently driven. Together with ESP®and 4ETS, it
improves the traction of your vehicle whenever
a drive wheel spins due to insufficient grip.
If you fail to adapt your driving style, 4MATIC can
neither reduce the risk of accident nor override
the laws of physics. 4MATIC cannot take
account of road, weather and traffic conditions.
4MATIC is only an aid. You are responsible for
Driving systems235
Driving and parking
Z

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 leng
th).
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 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.
260Towing a trailer
Driving an d parking

Display messagesPossible causes/consequences andMSolutions
XVisitaqualified specialist workshop immediately.
Fo rfurther information about th eOccupant Classification System, see
(
Ypage 52).
Lights
i
Vehicles wit hLE Dbulbs in th eligh tclusters :
The display message for th ecorrespondin glamp only appear swhen all of th eLEDs in th elamp
hav efailed.
Display messagesPossible causes/consequences and MSolutions
b
Check LeftCorner ‐ing LightorCheckRight CorneringLight
The lef tor right-hand cornering ligh tis defective.
XVisit aqualified specialist workshop .
b
CheckLeftLowBeamorCheck Right LowBea m
The lef tor right-hand low-beam headlamp is defective.
XHalogen headlamp :replace th ebulb (Ypage 119).
XLED headlamps: consultaqualified specialist workshop .
b
CheckTrailerRightTailLam p
The lef tand/o rright-hand trailer tai llamp is faulty.
XConsult th emanufacturer' soperating instructions.
b
Check Traile rLef tTurnSignalor
CheckTraile rRightTurnSignal
The lef tor right-hand trailer tur nsignal lamp is defective.
XConsult th emanufacturer' soperating instructions.
b
CheckTraile rBrakeLamp
The trailer brak elamp is defective.
XConsult th emanufacturer' soperating instructions.
b
Check Rea rLef tTurnSignalor
Check Rea rRight
Tur nSignal
The rear left-han dor rear right-hand tur nsignal is defective.
XVisit aqualified specialist workshop .
292Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
b
Check Front LeftTurnSignalor
Check Front Right
Tur nSignal
The fron tleft-han dor fron tright-hand tur nsignal is defective.
XHalogen headlamp :replace th ebulb (Ypage 119).
XLED headlamps: consultaqualified specialist workshop .
b
Check LeftMirrorTur nSignalor
Check Right Mirror
Tur nSignal
The tur nsignal in th eleft-han dor right-hand exterio rmirror is defec -
tive.
XVisit aqualified specialist workshop .
b
Check Center BrakeLamp
The high-mounte dbrak elamp is faulty.
XVisit aqualified specialist workshop .
b
Check LeftBrakeLam porCheck RightBrake Lam p
The leftor right-hand brak elamp is defective.
XVisit aqualified specialist workshop .
b
CheckLeftTailandBrake Lampsor
Check Right Tai l
and Brake Lamps
The leftor right-hand tai llamp/brake lamp is defective.
XVisit aqualified specialist workshop .
b
Check LeftHig hBeamorCheck RightHig hBea m
The lef tor right-hand high beam is defective.
XHalogen headlamp :replace th ebulb (Ypage 119).
XLED headlamps: consultaqualified specialist workshop .
b
LicensePlate Lam p
The leftor right-hand license plat elamp is faulty.
XVisit aqualified specialist workshop .
b
RearFog Lam p
The rear fog lamp is faulty.
XVisitaqualified specialist workshop .
b
Check Front LeftParkingLam por
Check Front Right
Parkin gLam p
The fron tlef tor fron tright parking or standing lamp is defective.
XVisit aqualified specialist workshop .
b
Backup Light
The backup lamp is defective.
XVisitaqualified specialist workshop .
Display messages293
On-board computer and displays
Z

Programming
Programming buttons
Pay attention to the "Important safety notes"
(Ypage 352).
Garage door remote controlAis not included
with the integrated garage door opener.
XTurn the SmartKey to position 2in the ignition
lock (Ypage 145).
XSelect one of buttons ;to? to use to con-
trol the garage door drive.
XTo start programming mode: press and
hold one of buttons ;to? on the integrated
garage door opener.
The garage door opener is now in program-
ming mode. After a short time, indicator
lamp :lights up yellow.
Indicator lamp :lights up yellow as soon as
button ;,=or? is programmed for the
first time. If the selected button has already
been programmed, indicator lamp :will only
light up yellow after ten seconds have
elapsed.
XRelease button ;,=or?. Indicator
lamp :flashes yellow.
XTo program the remote control: point
garage door remote control Atowards but-
tons ;to? on the rear-view mirror at a dis-
tance of 2 to 8 in (5 to 20 cm).
XPress and hold button Bon remote control
A until indicator lamp :lights up green.
When indicator lamp :lights up green: pro-
gramming is finished.
When indicator lamp :flashes green: pro-
gramming was successful. The next step is to synchronize the rolling code (
Ypage 353).
XRelease button Bon remote control Afor
the garage door drive system.
If indicator lamp :lights up red: repeat the
programing procedure for the corresponding button on the rear-view mirror. When doing
so, vary the distance between remote control
A
and the rear-view mirror.
The required distance between remote con-
trol Aand the integrated garage door opener
depends on the garage door drive system.
Several attempts might be necessary. You
should test every position for at least
25 seconds before trying another position.
Synchronizing the rolling code
Pay attention to the "Important safety notes"
(Ypage 352).
If the garage door system uses a rolling code,
you will also have to synchronize the garage
door system with the integrated garage door
opener in the rear-view mirror. To do this you will
need to use the programming button on the door
drive control panel. The programming button
may be positioned in different places depending
on the manufact
urer. It is usually located on the
door drive unit on the garage ceiling.
Familiarize yourself with the garage door drive
operating instructions, e.g. under "Program-
ming of additional remote controls", before car-
rying out the following steps.
Your vehicle must be within reach of the garage
door or gate opener drive. Make sure that nei-
ther your vehicle nor any persons/objects are
present within the sweep of the door or gate.
XTurn the SmartKey to position 2in the ignition
lock (Ypage 145).
XGet out of the vehicle.
XPress the programming button on the door
drive unit.
Usually, you now have 30 seconds to initiate
the next step.
XGet into the vehicle.
XPress previously programmed button ;,=
or ? on the integrated garage door opener
multiple times until the door closes.
The rolling code synchronization is then com- plete.
Notes on programming the remote con-
trol
Canadian radio frequency laws require a "break"
(or interruption) of the transmission signals
after broadcasting for a few seconds. Therefore,
these signals may not last long enough for the
integrated garage door opener. The signal is not
recognized during programming. Comparable
Features353
Stowage and features
Z

with Canadian law, some U.S. garage door open-
ers also feature a "break".
Proceed as follows:
Rif you live in Canada
Rif you have difficulties programming the
garage door opener (regardless of where you
live) when using the programming steps
XPress and hold one of buttons;to? on the
integrated garage door opener.
After a short time, indicator lamp :lights up
yellow.
XRelease the button.
Indicator lamp :flashes yellow.
XPress button Bof garage door remote con-
trol Afor two seconds, then release it for two
seconds.
XPress button Bagain for two seconds.
XRepeat this sequence on button Bof remote
control Auntil indicator lamp :lights up
green.
When indicator lamp :lights up green: pro-
gramming is finished.
When indicator lamp :flashes green: pro-
gramming was successful. The next step is to
synchronize the rolling code.
XRelease button Bof remote control Aof the
garage door drive.
If indicator lamp :lights up red: repeat the
programming process for the corresponding
button on the rear-view mirror. When doing
so, vary the distance between remote control
A and the rear-view mirror.
The required distance between remote con-
trol Aand the integrated garage door opener
depends on the garage door drive system.
Several attempts might be necessary. You
should test every position for at least
25 seconds before trying another position.
Problems when programming
If you are experiencing problems programing
th e integrated garage door opener on the rear-
view mirror, take note of the following instruc-
tions:
RCheck the transmitter frequency used by
garage door drive remote control Aand
whether it is supported. The transmitter fre-
quency can usually be found on the back of
the garage door drive remote control.
The integrated garage door opener is com-
patible with devices that have units which operate in the frequency range of 280 to
433 MHz.
RReplace the batteries in garage door remote
control
A. This increases the likelihood that
garage door remote control Awill transmit a
strong and precise signal to the integrated
garage door opener.
RWhen programming, hold remote control A
at varying distances and angles from the but-
ton which you are programming. Try various
angles at a distance between 2and 12 inches
(5to 30 cm) or at the same angle but at varying
distances.
RIf another remote control is available for the
same garage door drive, repeat the same pro-
gramming steps with this remote control.
Before performing these steps, make sure
that new batteries have been installed in
garage door drive remote control A.
RNote that some remote controls only transmit
for a limited amount of time (the indicator
lamp on the remote control goes out). Press
buttonBon remote control Aagain before
transmission ends.
RAlign the antenna cable of the garage door
open er unit. This can improve signal recep-
tion/transmission.
Opening/closing the garage door
After it has been programmed, the integrated
garage door opener performs the function of the
garage door system remote control. Please also
read the operating instructions for the garage
door system.
XTurn the SmartKey to position 2in the ignition
lock (Ypage 145).
XPress button ;,=or? which you have
programmed to operate the garage door.
Garage door system with a fixed code: indi-
cator lamp :lights up green.
Garage door system with a rolling code: indi-
cator lamp :flashes green.
The transmitter will transmit a signal as long
as the button is pressed. The transmission is
halted after a maximum of ten seconds and
indicator lamp :lights up yellow.
XPress button ;,=or? again if necessary.
354Features
Stowage and features