
In order to maintain the appropriatedistance
to the vehicle in front and thus prevent a
collision, you must apply the brakes yourself.
Due to the nature of the system, particularly
complicated driving conditionsmay cause
unnecessarywarningsortheunnecessary
intervention of PRE-SAFE®Brake.
Followingdamagetothe front end of the
vehicle, have the configurationand operation
of the radarsensorschecked ataqualified
specialist workshop. This also applies to
collisions at low speeds where thereisno
visible damage to the frontofthe vehicle.
Function
XTo activate/deactivate:activate or
deactivate PRE-SAFE®Brake in the on-
board computer (Ypage 228).
If the PRE-SAFE®Brake is not activated, the
 symbol appears in the multifunction
display.
If you approachavehicle in front very quickly,
this function warns you fromaspeed of
approximately4mph (7 km/h). An
intermittent warning tone sounds and the
 distance warning signal lamp in the
instrumentcluster lightsup.
XBrake immediately to defuse the situation.
or
XTake evasiveaction provided it is safe to do
so.
Fromaspeed of approximately4mph
(7 km/h), if the driver and frontpassenger
have fastened their seat belts, PRE-SAFE®
Brakecan brake the vehicle automatically at
speeds up to approximately 124 mph
(200 km/h).
You can preventthe intervention of the PRE-
SAFE®Brakeatany time by:
Rdepressingthe accelerator pedal further.
Ractivating kickdown.
Rreleasing the brake pedal.
The brakingaction of PRE-SAFE®Brakeis
ended automatically if:
Ryou maneuver to avoid the obstacle.
Rthereisnolonger any danger ofarear-end
collision.
Rthereisnolonger an obstacle detected in
frontofyour vehicle.
If you approach an obstacle and PRE-SAFE®
Brakedetectsarisk ofacollision, the system
will alert you both visually and acoustically. If
you do not brake or takeevasive action,the
system will warn you by automatically braking
the vehicle gently. If thereisanincreased risk
of collision, preventative passenger
protection measures (PRE-SAFE®)are
activated (Ypage 54). Ifarisk of collision
remains at speeds of over 20 mph
(30 km/h) and you do not brake, takeevasive
action or significantly accelerate, automatic
brakingmay be performed up to and including
emergency braking. Automatic emergency
brakingisnot performed until immediately
prior to an accidentthat can no longer be
avoided.
Theftdeterrent locking system
Immobilizer
The immobilizer prevents your vehicle from
being started without the correct SmartKey.
XTo activate with the SmartKey:remove
the SmartKey from the ignition lock.
XTo activate with KEYLESS-GO:switchthe
ignition off and open the driver'sdoor.
XTo deactivate:switchonthe ignition.
When leaving the vehicle, always takethe
SmartKey with you and lock the vehicle.
Anyone can start the engineifavalid
SmartKey has been left inside the vehicle.
iThe immobilizer is always deactivated
when you start the engine.
In the event that the enginecannot be
started when the starter battery is fully
charged, the immobilizer may be faulty.
Theft deterrent locking system73
Safety
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Asaresult, DISTRONICPLUSmay neither give
warningsnor interveneinsuchsituations.
There isariskofanaccident.
Alwayspaycarefulattentiontothe traffic
situationand be ready to brake.
GWARNING
DISTRONIC PLUScannotalwaysclearly
identify otherroad users and complex traffic
situations.
In such cases, DISTRONIC PLUS may:
Rgive an unnecessary warning and then
brake the vehicle
Rneither giveawarning nor intervene
Raccelerate unexpectedly
There isarisk of an accident.
Continue to drive carefully and be ready to
brake, in particular when warned to do so by
DISTRONIC PLUS.
GWARNING
DISTRONIC PLUS brakes your vehicle with up
to 40% of the maximum braking force. If this
braking force is insufficient,DISTRONIC PLUS
warns you visually and audibly. There isarisk
of an accident.
In such cases, apply the brakes yourself and
try to take evasive action.
!If DISTRONIC PLUS or the HOLD function
is activated, the vehicle brakes
automatically in certain situations. To
prevent damage to the vehicle, deactivate
DISTRONIC PLUS and the HOLD function in
the following or other similar situations:
Rwhen towing the vehicle
Rin the car wash
If you fail to adapt your driving style,
DISTRONIC PLUS can neither reduce the risk
of accident nor override the laws of physics.
DISTRONIC PLUS cannot take into account
the road, traffic and weather conditions.
DISTRONIC PLUS is only an aid. You are
responsible for the distance to the vehicle in
front,for vehicle speed, for braking in good
time and for staying in your lane.
Do not use DISTRONIC PLUS:
Rin road and traffic conditions which do not
allow you to maintainaconstant speed e.g.
in heavy traffic or on winding roads
Ron slippery road surfaces. Brakingor
accelerating could cause the drive wheels
to lose traction and the vehicle could then
skid
Rwhen there is poor visibility, e.g. due to fog,
heavy rain or snow
DISTRONIC PLUS may not detect narrow
vehicles driving in front,e.g. motorcycles, or
vehicles driving onadifferent line.
In particular, the detection of obstacles can
be impaired if:
Rdirt on the sensors or anything else
coveringthe sensors
Rsnow or heavy rain
Rinterference by other radar sources
Rstrongradar reflections, for example, in
parking garages
If DISTRONIC PLUS no longer detectsa
vehicle in front,DISTRONIC PLUS may
unexpectedly accelerate the vehicle to the
stored speed.
This speed may:
Rbe too high if you are driving inafilter lane
or an exit lane
Rbe so high in the right lane that you pass
vehicles driving on the left (left-handdrive
countries)
Rbe so high in the left lane that you pass
vehicles driving on the right (right-hand
drive countries)
If there isachange of drivers, advise the new
driver of the speed stored.
General notes
DISTRONIC PLUS regulates the speed and
automatically helps you maintain the
distance to the vehicle detected in front.
Vehicles are detected with the aid of the radar
178Driving systems
Driving and parking 

sensor system. DISTRONIC PLUS brakes
automaticallysothat the set speed is not
exceeded.
Change intoalower gear in good time on long
and steep downhill gradients. This is
especially important if the vehicle is laden. By
doing so, you will make use of the braking
effect of the engine. This relieves the load on
the brake system and prevents the brakes
from overheating and wearing too quickly.
If DISTRONIC PLUS detects that there isarisk
ofacollision, you will be warned visually and
acoustically.DISTRONIC PLUS cannot
preventacollision without your intervention.
An intermittent warning tone will then sound
and the distance warning lamp will light up in
the instrument cluster. Brake immediately in
order to increase the distance to the vehicle
in front or take evasive action provided it is
safe to do so.
For DISTRONIC PLUS to assist you, the radar
sensor system must be operational.
If there is no vehicle in front,DISTRONIC
PLUS operates in the same way as cruise
control in the speed range between 20 mph
(Canada: 30 km/h) and 120 mph (Canada:
200 km/h). Ifavehicle is driving in front of
you, it operates in the speed range between
0mph (0 km/h) and 120 mph (Canada:
200 km/h).
Do not use DISTRONIC PLUS while driving on
roads with steep gradients.
As DISTRONIC PLUS transmits radar waves,
it can resemble the radar detectors of the
responsible authorities. You can refer to the
relevant chapter in the Operator's Manual if
questions are asked aboutthis.
iUSA only: This device has been approved
by the FCC asa"VehicularRadar System".
The radar sensor is intended for use in an
automotive radar system only. Removal,
tampering,oralteringofthedevice will void
any warranties, and is notpermitted by the
FCC. Do not tamper with, alter, or use in
any non-approved way.
Anyunauthorized modification to this
device could void the user's authorityto
operate the equipment.
iCanada only: This device complies with
RSS-210 of Industry Canada. Operation is
subject to the following two conditions:
1. This device may not cause harmful
interference, and
2. this device must accept any interference
received, including interference that may
cause undesired operation of the device.
Removal, tampering, or altering of the
device will void any warranties, and is not
permitted. Do not tamper with, alter, or use
in any non-approved way.
Anyunauthorized modification to this
device could void the user's authorityto
operate the equipment.
Cruise control lever
 To storethe currentspeed orahigher
speed
 To storethe currentspeed oralower
speed
 $To deactivate DISTRONIC PLUS
 !To storethe currentspeed or call up the
last stored speed
 To set the specified minimum distance
Driving systems179
Driving and parking
Z 

Load compensation
The vehicle can compensatedifferences in
thevehicle level by raisingorlowering the
rear axle. This is the case, for example, if
people get out or if luggage is being loaded.
Load compensation takes place if:
Radoor or the trunk lid/tailgate is opened
Rthe parked vehicle is unlocked
For larger level changes, the engine must be
running.
4MATIC (permanent four-wheel drive)
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 the distance to the vehicle in
front,for vehicle speed, for braking in good
time and for staying in your lane.
Ifadrive wheel spins due to insufficientgrip:
ROnly depress the accelerator pedalasfar
as necessary when pulling away.
RAccelerate less when driving.
!Never tow the vehiclewith one axle
raised. This may damage the transfer case.
Damageofthis sort is not covered by the
Mercedes-Benz Limited Warranty. All
wheels must remaineitheronthe ground
or be fully raised. Observe the instructions
for towing the vehicle with all wheels in full
contact with the ground.
iIn 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.
4MATIC ensures that allfour wheels are
permanently driven. Together with ESP®,it
improves the traction of yourvehicle
wheneveradrive wheel spins due to
insufficient grip.
PARKTRONIC
Important safetynotes
PARKTRONIC is an electronic parkingaid with
ultrasonic sensors. It indicates visually and
audibly the distancebetween your vehicle
and an object.
PARKTRONIC is only an aid. It is not a
replacementfor your attention to your
immediate surroundings. You are always
responsible for safe maneuvering, parking
and exitingaparkingspace. When
maneuvering, parkingorpulling out of a
parkingspace, make sure that thereare no
persons, animals or objects in the area in
which you are maneuvering.
!When parking, pay particular attention to
objects above or below the sensors, such
as flower pots or trailer drawbars.
PARKTRONIC does not detectsuch objects
when they are in theimmediatevicinity of
thevehicle. You could damagethe vehicle
or the objects.
The sensors may not detect snow and other
objectsthat absorb ultrasonic waves.
Ultrasonic sources such as an automatic
car wash, the compressed-air brakes on a
truck orapneumatic drill could cause
PARKTRONIC to malfunction.
PARKTRONIC may not function correctly on
uneven terrain.
PARKTRONIC is activated automatically when
you:
Rswitch on the ignition
Rshift the transmission to positionD,RorN
Rrelease the parking brake
PARKTRONIC is deactivated at speeds above
11 mph (18 km/h). It is reactivated at lower
speeds.
PARKTRONIC monitors the area around your
vehicle using six sensors in the front bumper
and four sensors in the rear bumper.
Driving systems193
Driving and parking
Z 

Active Driving Assistance package
Generalnotes
The Active DrivingAssistance package
consistsofDISTRONICPLUS(Ypage 177),
Active Blind Spot Assist(Ypage 211) and
Active LaneKeepingAssist(Ypage 214).
Active Blind Spot Assist
Generalnotes
Active Blind Spot Assistusesaradar sensor
system, pointed toward the rear of the
vehicle, to monitor the area to the sides of the
vehicle which the driver is unable to see. A
warning displayinthe exterior mirrors draws
your attention to vehicles detected in the
monitored area. If you then switch on the
corresponding turn signal to change lane, you
will also receive an optical and audible
warning. Ifarisk of lateral collision is
detected, corrective braking may help you
avoidacollision. Beforeacourse-correcting
brake application, Active Blind Spot Assist
evaluates the space in the direction of travel
and at the sides of the vehicle. For this, Active
Blind Spot Assist uses radar sensors which
are pointed in the direction of travel.
Active Blind Spot Assist supports you from a
speed of approximately 20 mph (30 km/h).
For Active Blind Spot Assist to assist you
when driving, the radar sensor system must
be:
Ractivated(Ypage 232)
Roperational
Important safety notes
Active Blind Spot Assist is only an aid and is
notasubstitute 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 withalarge speed
differential and overtakeyour vehicle
Asaresult, Active Blind Spot Assist may
neither give warnings nor intervene in such
situations. There isarisk of an accident.
Always observe the traffic conditions
carefully, and maintainasafe lateral distance.
iUSA only:
This device has been approved by the FCC
asa"Vehicular RadarSystem". The radar
sensor is intended foruse in an automotive
radar system only. Removing, tampering
with, or altering the device will void any
warranties, and is not permitted by the
FCC. Do not tamper with, alter, or use in
any non-approved way.
Any unauthorized modification to this
device could void the user’s authority to
operate the equipment.
iCanada only: This device complies with
RSS-210ofIndustry Canada.Operation is
subject to the following two conditions:
1. This device may not cause harmful
interference, and
2. this device must accept any interference
received, including interference that may
cause undesired operation of the device.
Removal, tampering, or altering of the
device will void any warranties, and is not
permitted. Do not tamper with, alter, or use
in any non-approved way.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
Radarsensors
The Active Blind Spot Assist radar sensors are
integrated into the front and rear bumpers
and behindacover in the radiator grill. Make
sure that the bumpers and the cover in the
radiator grill are free of dirt, ice or slush. The
rear sensors must not be covered, for
example by cycle racks or overhanging cargo.
Followingasevere impact or in the event of
damage to the bumpers, have the function of
the radar sensors checked ataqualified
Driving systems211
Driving and parking
Z 

The brightness of the indicator/warning
lamps is adjusted automatically accordingto
the ambient light.
Visual and acoustic collision warning
If you switch on the turn signals to change
lanes andavehicle is detected in the side
monitoring range, you receiveavisual and
acoustic collision warning. You then hear a
double warning toneand red warning
lamp flashes. If the turn signal remains on,
detected vehicles are indicated by the
flashing of red warning lamp .There are no
further warning tones.
Course-correcting brake application
GWARNING
Acourse-correctingbrake application cannot
alwayspreventacollision. There isarisk of
an accident.
Always steer, brake or accelerate yourself,
especially if Active Blind Spot Assist warns
you or makesacourse-correcting brake
application. Always maintainasafe distance
at the sides.
If Active Blind Spot Assist detectsarisk of a
lateral collision in the monitoring range, a
course-correcting brake application is carried
out. This is meant to assist you in avoiding a
collision.
Ifacourse-correcting brake application
occurs, red warning lamp flashes in the
exterior mirror andadual warning tone
sounds. In addition, the display shown in the
lower image appears in the multifunction
display.
In very rare cases, the system may make an
inappropriate brake application. An
inappropriate course-correcting brake
application may be interrupted at any time if
you steer slightly in the opposite direction or
accelerate, for example.
The course-correcting brake application is
available in the speed range between
20 mph (30 km/h) and 120 mph (200 km/h).
Either no braking application, oracourse-
correcting brake application adapted to the
driving situation occurs if:
Rthere are vehicles or obstacles, e.g. crash
barriers, located on both sides of your
vehicle.
Ravehicle approaches you too closely at the
side.
Ryou have adoptedasporty driving style with
high cornering speeds.
Ryou clearly brake or accelerate.
Radriving safety system intervenes, e.g.
ESP®or PRE-SAFE®Brake.
RESP®is switched off.
Raloss of tire pressure oradefectivetire is
detected.
Switching on Active Blind Spot Assist
XMake sure that the radar sensor system
(Ypage 232) and Active Blind Spot Assist
(Ypage 228) are activated in the on-board
computer.
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.
Driving systems213
Driving and parking
Z