
In order to maintain an appropriate distance
from the vehicle in front and thus prevent a
collision, you must apply the brakes yourself.
At speeds up to approximately
40 mph (70 km/h), PRE-SAFE ®
 Brake may
also detect stationary obstacles, for example
stopped or parked vehicles.GWarning!
If you do not receive visual or acoustic
warning signals, the PRE-SAFE ®
 Brake may
R not have recognized the collision risk
R have been deactivated
R be malfunctioning
Apply the brakes yourself to avoid a collision.
XTo activate/deactivate:  activate or
deactivate PRE-SAFE ®
 Brake in the on-
board computer ( Y page 376).
After activation, the  Ä symbol is
displayed on the left in the instrument
cluster.
For PRE-SAFE ®
 Brake to assist you when
driving, the radar sensor system must be
switched on and operational.
PRE-SAFE ®
 Brake does not always detect
complex traffic situations properly. You can
terminate the braking action of PRE-SAFE ®
Brake in a non-critical driving situation at any
time if:
R an acoustic and visual warning occurs.
R the vehicle brakes.
To stop the braking action, you can either
depress the accelerator pedal further,
activate kickdown or release the brake pedal.
The braking action of PRE-SAFE ®
 Brake is
ended automatically if:
R you maneuver to avoid the obstacle.
R your speed drops below approximately
9 mph (15 km/h).
R there is no longer an obstacle detected in
front of your vehicle.
R there is no longer any danger of a collision.
Following a collision or collision-related
damage to the front end of the vehicle, have
the configuration and operation of the radar
sensors checked. Choose a qualified
specialist workshop which has the necessary
specialist knowledge and tools for the work
required. Mercedes-Benz recommends that
you use an authorized Mercedes-Benz Center
for this purpose.
Anti-theft systems
Immobilizer
The immobilizer prevents your vehicle from
being started without the correct key.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. The
engine can be started by anyone with a valid
key that is left inside the vehicle.
XTo activate with the SmartKey:  remove
the SmartKey from the ignition lock.XTo activate with KEYLESS-GO:  switch the
ignition off and open the driver's door.XTo deactivate:  switch on the ignition.
i
The immobilizer is always deactivated
when you start the engine.
ATA (Anti-Theft Alarm system)
A visual and audible alarm is triggered if the
alarm system is armed and you open:
R a door
R the vehicle with the mechanical key
R the trunk lid
R the hood
The alarm is not switched off, even if you
close the open door that has triggered it, for
example.
Anti-theft systems73SafetyZ 

Instructions included in your vehicle literature
portfolio. You may otherwise not receive all
necessary safety information and warning for
the operation of your vehicle.GWarning!
The DISTRONIC PLUS requires familiarity with
its operational characteristics. We strongly
recommend that you review the following
information carefully before operating the
system.
GWarning
When DISTRONIC brakes, the brake pedal is
pulled back (i.e. operated automatically). The
area around the pedal must not be blocked by
obstacles:
R do not place any objects in the footwell.
R ensure that floormats and carpets are fixed
securely. In particular, do not place several
floormats on top of one another.
R do not place your foot under the brake
pedal, as it could become trapped.
Non-compliance could lead you to cause an
accident in which you and/or others could be
seriously injured.
GWarning!
The DISTRONIC PLUS is a convenience
system. Its speed adjustment reduction
capability is intended to make cruise control
more effective and usable when traffic speeds
vary. It is not however, intended to, nor does
it, replace the need for extreme care.
The responsibility for the vehicle's speed,
distance to the preceding vehicle and, most
importantly, brake operation to ensure a safe
stopping distance, always remains with the
driver.
The DISTRONIC PLUS cannot take street and
traffic conditions into account.
Complex driving situations are not always
fully recognized by the DISTRONIC PLUS. This
could result in wrong or missing distance
warnings.
If you want DISTRONIC PLUS to assist you,
the radar sensor system must be activated
( Y  page 378) and 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). If there is a
vehicle in front, DISTRONIC PLUS is
operational in the speed range between
0 mph (Canada: 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 emits radar waves, it can
simulate radar detectors used by police
authorities. You can refer to the applicable
chapter in the Operator's Manual if there is
any question concerning this.
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 automotive
radar system only. Removal, tampering, or
altering of 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.GWarning!
The DISTRONIC PLUS adaptive cruise control
is not a substitute for active driving
involvement. It does not react to pedestrians
or on stationary objects, nor does it recognize
or predict the curvature and lane layout or the
movement of preceding vehicles. The
DISTRONIC PLUS can only apply a maximum
of 40% of the vehicle's braking power.
The DISTRONIC PLUS may not detect narrow
vehicles possibly driving in front of you, such
as motorcycles and vehicles driving in an
offset formation.
326Driving systemsDriving and parking 

Deactivating DISTRONIC PLUS
There are several ways to deactivate
DISTRONIC PLUS:
XBriefly press the cruise control lever
forwards :.
or
XBrake, unless the vehicle is stationary.
iThe last speed stored remains stored until
you switch off the engine.
iDISTRONIC PLUS is not deactivated if you
depress the accelerator pedal. If you
accelerate to overtake, DISTRONIC PLUS
adjusts the vehicle's speed to the last
speed stored after you have finished
overtaking.
DISTRONIC PLUS is automatically
deactivated if:
Ryou engage the electric parking brake or if
the vehicle is automatically secured with
the electric parking brake.
Ryou are driving slower than
15 mph (25 km/h) and there is no vehicle
in front, or if the vehicle in front is no longer
detected.
RESP® intervenes or you deactivate ESP®.
Rthe transmission is in the P, R or N position.
Ryou switch off the radar sensor system
(Y page 378).
Ryou pull the cruise control lever towards
you in order to pull away and the front-
passenger door or one of the rear doors is
open.
Rthe vehicle has skidded.
If DISTRONIC PLUS is deactivated, you will
hear a warning tone. You will see the
DISTRONIC PLUS off message in the
multifunction display for approximately five
seconds.
Tips for driving with DISTRONIC PLUS
Important safety guidelines
The following contains descriptions of certain
road and traffic conditions in which you must
be particularly attentive. In such situations,
brake if necessary. DISTRONIC PLUS is then
deactivated.
GWarning!
The DISTRONIC PLUS works to maintain the
speed selected by the driver unless a moving
obstacle proceeding directly ahead of it in the
same travel direction is detected (e.g.
following another vehicle ahead of you at your
set distance).
This means that:
RYour vehicle can pass another vehicle after
you have changed lanes.
RWhile in a sharp turn or if the preceding
vehicle is in a sharp turn, the DISTRONIC
PLUS could lose sight of the preceding
vehicle. Your vehicle could then accelerate
to the previously selected speed.
The DISTRONIC PLUS regulates only the
distance between your vehicle and those
directly ahead of it. It may not register
stationary objects in the road, e.g.:
Ra stopped vehicle in a traffic jam
Ra disabled vehicle
Ran oncoming vehicle
The driver must always be alert, observe all
traffic and intercede as required by means of
steering or braking the vehicle.
Driving systems333Driving and parkingZ  

GWarning!
Make sure no persons or animals are in or
near the area in which you are parking/
maneuvering. Otherwise, they could be
injured.
PARKTRONIC is an electronic parking aid with
ultrasonic sensors. It indicates visually and
audibly the distance between your vehicle
and an object.
PARKTRONIC is activated automatically when
you:
Rswitch on the ignition.
Rshift the transmission to position D, R or
N.
Rrelease the electric 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.
:Sensors in the front bumper, left-hand
side (example)
Range of the sensors
The sensors must be free of dirt, ice and
slush; otherwise they may not function
correctly. Clean the sensors regularly, taking
care not to scratch or damage them
(Y page 456).
Side view
Top view
Front sensors
CenterApprox. 40 in (100 cm)CornersApprox. 24 in (60 cm)
Rear sensors
CenterApprox. 48 in (120 cm)CornersApprox. 32 in (80 cm)
! When parking, pay particular attention to
objects above or below the sensors, such
as flower pots or trailer drawbars.
PARKTRONIC does not detect such objects
when they are in the immediate vicinity of
the vehicle. You could damage the vehicle
or the objects.
Ultrasonic sources such as an automatic
car wash, a truck's compressed-air brakes
or a pneumatic drill could cause
PARKTRONIC to malfunction.
340Driving systemsDriving and parking    

Minimum distanceCenterApprox. 8 in (20 cm)CornersApprox. 8 in (20 cm)
If there is an obstacle within this range, all
warning displays light up and a warning tone
sounds. If the distance falls below the
minimum, the distance may no longer be
shown.
Warning displays
The warning displays show the distance
between the sensors and the obstacle. The
warning display for the front area is in the
instrument cluster. The warning display for
the rear area is located on the headliner in the
rear compartment.
Warning display for the front area
:Segments on the left-hand side of the
vehicle;Segments on the right-hand side of the
vehicle=Segments showing operational readiness
The warning display for each side of the
vehicle is divided into five yellow and two red
segments. PARKTRONIC is operational if
yellow segments showing operational
readiness  = light up.
The selected transmission position
determines which warning display is active
when the engine is running.
Transmission 
positionWarning displayDFront area activatedRRear and front areas
activatedNIf the electric parking
brake is engaged: no
areas activated
If the electric parking
brake is released:
rear and front areas
are activatedPNo areas activated
One or more segments light up as the vehicle
approaches an obstacle, depending on the
vehicle's distance from the obstacle.
When the first red segment lights up, you hear
an intermittent warning for about two
seconds. From the second red segment, you
hear a continuous warning. This indicates that
you have now reached the minimum distance.
Deactivating/activating PARKTRONIC
:To deactivate/activate PARKTRONIC;Indicator lamp
If indicator lamp  ; lights up, PARKTRONIC is
deactivated.
Driving systems341Driving and parkingZ   

Active Blind Spot Assist (Y page 356) and
Active Lane Keeping Assist ( Y page 359).
Active Blind Spot Assist
Important safety notes
Active Blind Spot Assist uses a radar sensor
system to monitor the side areas of your
vehicle. In addition, it uses the radar sensor
system to monitor the front area as well.
Active Blind Spot Assist is active at speeds
above approximately 20 mph (30 km/h). A
warning lamp in the exterior mirrors calls your
attention to a vehicle or certain obstacles in
the area monitored. If you switch on the
corresponding turn signal before changing
lane, you will also receive visual and audible
collision warnings. If a risk of lateral collision
is detected, corrective braking may help you
avoid a collision.
GWarning
Active Blind Spot Assist is only an aid, and
may detect vehicles/obstacles incorrectly or
not at all.
The system may be impaired or may not
function if:
R there is poor visibility, e.g. due to snow,
rain, fog or spray.
R the rear and/or front sensors are dirty.
Active Blind Spot Assist may not detect
narrow vehicles, such as motorcycles or
bicycles, or only detect them too late. It
cannot detect vehicles that are overtaken at
a small distance and then enter the blind spot
area.
Active Blind Spot Assist cannot detect road
and traffic conditions. It is not a substitute for
attentive driving. You are responsible for the
vehicle's speed, braking in good time, and
steering correctly. Always adapt your driving
style to suit the prevailing road and weather
conditions. Always pay attention to traffic
conditions and your surroundings. Otherwise,
you may fail to recognize dangers in time,
cause an accident and injure yourself and
others.
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 automotive
radar system only. Removal, tampering, or
altering of 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.
For Active Blind Spot Assist to assist you
when driving, the radar sensor system must
be activated ( Y page 378) and operational.
Monitoring range
Active Blind Spot Assist monitors the area up
to 10 ft (3 m) behind your vehicle and directly
next to your vehicle as shown in the diagram.
For this purpose, Active Blind Spot Assist
uses sensors in the rear bumper.GWarning
Active Blind Spot Assist monitors certain
areas in the immediate vicinity of your vehicle.
Vehicles that approach and drive past at high
speeds are not detected. No visual nor
audible warnings are emitted and the system
does not brake the vehicle to correct your
course.
356Driving systemsDriving and parking  

Optical and acoustic collision warning
When you switch on the appropriate turn
signals to change lanes, and a vehicle is
detected in the side monitoring range of
Active Blind Spot Assist, you receive an
optical and acoustic collision warning. You
then hear a double warning tone, and 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
If Active Blind Spot Assist detects a risk of
lateral collision in the monitoring range,
under certain circumstances, it will brake the
vehicle briefly on one side. This is designed to
help you avoid a collision.
This function is available in the range between
20 mph and 120 mph (30 km/h and
200 km/h).
When a course-correcting brake application
occurs, red warning lamp : flashes in the
exterior mirror and the following message, for
example, appears in the multifunction
display:
GWarning
Active Blind Spot Assist is only an aid
designed to assist driving. It is not a substitute
for attentive driving. In some cases, the
course-correcting brake application is not
sufficient to avoid a collision. In such a case,
you must steer, brake or accelerate.
In very rare cases, the system may
erroneously detect a danger of collision in the
area of crash barriers or similar lane borders
and apply the brakes. Active Blind Spot Assist
does not detect all traffic situations and road
users. Always make sure that there is
sufficient distance to the side for other traffic
or obstacles. An inappropriate brake
application may be interrupted at any time if
you steer slightly in the opposite direction or
accelerate.
You are responsible for the vehicle's speed,
braking in good time, and steering correctly.
Always adapt your driving style to suit the
prevailing road and weather conditions.
Always pay attention to traffic conditions and
your surroundings. Otherwise, you may fail to
recognize dangers in time, cause an accident
and injure yourself and others.
Either a very slight course-correcting brake
application, or none at all, may occur if:
Rother vehicles and/or objects, such as
crash barriers, are detected in the
immediate vicinity 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 decisively.
Ra driving safety system intervenes, such as
ESP® or PRE-SAFE® Brake.
RESP® is deactivated.
Ra loss of tire pressure or a defective tire has
been detected and displayed.
Activating Active Blind Spot Assist
XMake sure that the radar sensor system
(Y page 378) and Active Blind Spot Assist
(Y page 376) are activated in the on-board
computer.
XTurn the key to position 2 in the ignition
lock.
Warning lamps : light up red in the
exterior mirrors for approximately 1.5
seconds and then turn yellow.
358Driving systemsDriving and parking  

The selected unit of measurement for
distance applies to:
R the analog speedometer
R the digital speedometer in the  Trip menu
R the odometer and the trip odometer
R the trip computer
R the navigation instruction in the  Navi menu
R DISTRONIC PLUS
R ASSYST PLUS service interval display
The digital speedometer shows alternative
speed units ( Y page 377).XPress the  = or ;  button on the
steering wheel to select the  Settings
menu.XPress  9 or :  to select  Units.XPress the  a button to confirm.XPress the  a button to save the setting.
The unit switches  km/h and mph.
Switching the belt adjustment on/off
Further information on belt adjustment:
( Y  page 58).
XPress  = or ;  on the steering wheel
to select the  Settings menu.XPress the  9 or :  button to select
Belt Adjustment .XPress the a button to confirm.XTo activate/deactivate:  press a
again.
Activating/deactivating the acoustic
locking confirmation
If you activate the  Acoustic Lock Feedb.
function, an audible signal sounds when the
vehicle is locked or unlocked. When
unlocking, the signal sounds once. When
locking, it sounds three times.
XPress the  = or ;  button on the
steering wheel to select the  Settings
menu.XPress  9 or :  to select  Acoustic 
Lock Feedb. .XPress the a button to confirm.XTo activate/deactivate:  press a
again.
Activating/deactivating the radar
sensor system
The following systems are switched off when
the radar sensor system is deactivated:
R DISTRONIC PLUS ( Y page 325)
R BAS PLUS ( Y page 68)
R PRE-SAFE ®
 Brake ( Y page 71)
R Blind Spot Assist ( Y page 352)
R Active Blind Spot Assist ( Y page 356)
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
automotive radar system only. Removal,
tampering, or altering of 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.
i Canada only:
This device complies with RSS-210 of
Industry Canada. Operation is subject to
the following two conditions:
1. This device may not cause interference,
and
2. This device must accept any interference
received, including interference that may
cause undesired operation of the device.
Any unauthorized modification to this
device could void the user’s authority to
operate the equipment.
378Menus and submenusOn-board computer and displays