R
a driving safety system intervenes, e.g. ESP ®
or PRE-SAFE ®
Brake.R
ESP ®
is switched off.R
the offroad program is activated (vehicles
without the Offroad Engineering package). R
the Offroad or Offroad Plus drive program is
activated (vehicles with the Off-Road Engi-
neering package). R
the LOW RANGE offroad gear is activated
(vehicles with the Offroad Engineering pack-
age). R
a loss of tire pressure or a defective tire is
detected.
Switching on Active Blind Spot Assist X
Make sure that Active Blind Spot Assist is
activated in the on-board computer
( Y
page 272). X
Turn the SmartKey to position 2 in the ignition
lock.
Warning lamps C 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 a
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 C 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 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
to the vehicle R
not 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.Driving systems 233
Driving and parking Z
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 D .R
on vehicles with a trailer tow hitch, the elec-
trical connection to the trailer has been cor-
rectly established. R
the offroad program is activated (vehicles
without the Offroad Engineering package). R
the Offroad or Offroad Plus drive program is
activated (vehicles with the Off-Road Engi-
neering package). R
the LOW RANGE offroad gear is activated
(vehicles with the Offroad Engineering pack-
age). 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 AssistR
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 or Adaptive ( Y
page 272).
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected,
the lines in the assistance graphics display
( Y
page 271) are shown in green. Active Lane
Keeping Assist is ready for use.
If 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
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.
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 forDriving systems 235
Driving and parking Z
the distance to the vehicle in front, for vehicle
speed, for braking in good time and for staying in
your lane.
! Never tow the vehicle with one axle raised.
This may damage the transfer case. Damage
of this sort is not covered by the Mercedes-
Benz Limited Warranty. All wheels must
remain either on the ground or be fully raised.
Observe the instructions for towing the vehi-
cle with all wheels in full contact with the
ground.
! A function or performance test should only
be carried out on a two-axle dynamometer.
Before you operate the vehicle on such a
dynamometer, please consult a qualified
workshop. You could otherwise damage the
drive train or the brake system.
i In wintry driving conditions, the maximum
effect of 4MATIC can only be achieved if you
use winter tires (M+S tires), with snow chains
if necessary.
Further information about "Driving off-road"
( Y
page 186).
DSR (Downhill Speed Regulation)
General notes DSR is an aid to assist you when driving down-
hill. It keeps the speed of travel at the speed
selected on the on-board computer. The steeper
the downhill gradient, the greater the DSR brak-
ing effect on the vehicle. When driving on flat
stretches of road or on an uphill gradient, the
DSR braking effect is minimal or nonexistent.
DSR controls the vehicle’s speed when it is acti-
vated and the transmission is in position D , R or
N . You can drive at a higher or a lower speed
than that set on the on-board computer at any
time by accelerating or braking.
Important safety notes
G WARNING
If the speed driven and the set speed deviate
and you activate DSR on a slippery road sur-
face, the wheels may lose traction. There is an
increased danger of skidding and accidents.
Before switching DSR on, please take into
consideration the road surface and the differ-
ence between driving speed and the set
speed. If you fail to adapt your driving style, DSR can
neither reduce the risk of accident nor override
the laws of physics. DSR cannot take account of
road, weather and traffic conditions. DSR is only
an aid. You are responsible for the distance to
the vehicle in front, for vehicle speed, for brak-
ing in good time and for staying in your lane.
You are always responsible for keeping control
of the vehicle and for assessing whether the
downhill gradient can be managed. DSR may not
always be able to keep to the set speed, depend-
ing on road surface and tire conditions. Select a
set speed suitable for the prevailing conditions
and when necessary, apply the brakes manually.
Activating DSR
X
Press button C .
Indicator lamp D lights up.
The