
BAS (Brake Assist System)
General information
BAS operates in emergency braking situations.
If you depress the brake pedal quickly, BAS
automatically boosts the braking force, thus
shortening the stopping distance.
Important safety notes
iObserve the "Important safety notes" sec-
tion (Ypage 65).
GWARNING
If BAS is malfunctioning, the braking distance
in an emergency braking situation is
increased. There is a risk of an accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
Braking
XKeep the brake pedal firmly depressed until
the emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will function as usual once you
release the brake pedal. BAS is deactivated.
Active Brake Assist
General information
iObserve the "Important safety notes" sec-
tion (Ypage 65).
Active Brake Assist consists of a distance warn-
ing function with an autonomous braking func-
tion and Adaptive Brake Assist.
Active Brake Assist can help you to minimize the
risk of a collision with the vehicle traveling in
front or reduce the effects of such a collision.
If Active Brake Assist detects that there is a risk
of collision, you will be warned visually and
acoustically. If you do not react to the visual and
audible collision warning, autonomous braking
can be initiated in critical situations. If you apply
the brake yourself in a critical situation, Adap-
tive Brake Assist of the Active Brake Assist sys-
tem supports you.
Important safety notes
In particular, the detection of obstacles can be
impaired if:
Rthere is dirt on the sensors or anything else
covering the sensors
Rthere is snow or heavy rain
Rthere is interference by other radar sources
Rthere are strong radar reflections, for exam-
ple in parking garages
Ra narrow vehicle is traveling in front, e.g. a
motorbike
Ra vehicle is traveling in front on a different line
Ryou are driving a new vehicle or servicing on
the Active Brake Assist system has just been
carried out
Observe the important safety notes in the
"Breaking-in notes" section (
Ypage 129).
Following damage to the front end of the vehicle,
have the configuration and operation of the
radar sensor checked at a qualified specialist
workshop. This also applies to collisions at slow
speeds where there is no visible damage to the
front of the vehicle.
Activating/deactivating
Active Brake Assist is automatically active after
switching on the ignition.
You can activate or deactivate Active Brake
Assist (
Ypage 218) in the on-board computer.
When deactivated, the distance warning func-
tion and the autonomous braking function are
also deactivated.
If Active Brake Assist is deactivated, the æ
symbol appears on the assistant display.
Distance warning function
General information
The distance warning function can help you to
minimize the risk of a front-end collision with a
vehicle ahead or reduce the effects of such a
collision. If the distance warning function
detects that there is a risk of a collision, you will
be warned visually and acoustically.
Important safety notes
iObserve the "Important safety notes" sec-
tion for driving safety systems (Ypage 65).
66Driving safety systems
Safety

application of the brakes if a danger of colli-
sion is detected. There may be a collision
unless you brake yourself. Even after subse-
quent full application of the brakes a collision
cannot always be avoided, particularly when
approaching at too high a speed. There is a
risk of an accident.
Always apply the brakes yourself and try to
take evasive action, provided it is safe to do
so.
In the event of a partial application of the brakes,
the vehicle is braked with up to 50% of the full
braking pressure.
GWARNING
Active Brake Assist with cross-traffic function cannot always clearly identify objects and
complex traffic situations.
In such cases, Active Brake Assist with cross-
traffic function might:
Rissue an unnecessary warning or engage
Rneither give a warning nor intervene
There is a risk of an accident.
Always pay particular attention to the traffic
situation and be prepared to brake, especially
if Active Brake Assist with cross-traffic func-
tion alerts you. Terminate the intervention in a
non-critical driving situation.
GWARNING
Active Brake Assist with cross-traffic function cannot always clearly identify people, partic-
ularly if they are moving. Active Brake Assist
with cross-traffic function cannot intervene in
these cases. There is a risk of an accident.
Always pay particular attention to the traffic
situation and be prepared to brake, especially
if Active Brake Assist with cross-traffic func-
tion alerts you.
In order to maintain the appropriate distance to
the vehicle in front and thus prevent a collision,
you must apply the brakes yourself.
GWARNING
Active Brake Assist with cross-traffic function does not react:
Rto small people, e.g. children
Rto animals
Rto oncoming vehicles
Rwhen cornering
As a result, Active Brake Assist with cross-
traffic function may not warn you or engage in
all critical situations. There is a risk of an acci-
dent.
Always pay careful attention to the traffic sit- uation and be ready to brake.
In the event of snowfall or heavy rain, the rec-
ognition can be impaired.
Recognition by the radar sensor system is also
impaired if:
Rthere is dirt on the sensors or anything else
covering the sensors
Rthere is interference by other radar sources
Rthere are strong radar reflections, for exam-
ple in parking garages
Ra narrow vehicle is traveling in front, e.g. a
motorbike
Ra vehicle is traveling in front on a different line
Rvehicles moving quickly into the radar sensor
system detection range
Recognition by the camera system is also
impaired in the event of:
Rdirt on the camera or if the camera is covered
Rglare on the camera system, e.g. from the sun
being low in the sky
Rdarkness
Ror if:
-pedestrians move quickly, e.g. into the path
of the vehicle
-the camera system no longer recognizes a
pedestrian as a person due to special cloth-
ing or other objects
-a pedestrian is concealed by other objects
-the typical outline of a pedestrian is not
distinguishable from the background
Following damage to the front end of the vehicle,
have the configuration and operation of the
radar sensors checked at a qualified specialist
workshop. This also applies to collisions at slow
Driving safety systems73
Safety
Z

Apply the brakes yourself in these situations
and try to take evasive action.
!When Distance Pilot DISTRONIC or the
HOLD function are activated, the vehicle
brakes automatically in certain situations.
To avoid damage to the vehicle, deactivate
these systems in the following or similar sit-
uations:
Rwhen towing the vehicle
Rin the car wash
Distance Pilot DISTRONIC can neither reduce
the risk of an accident if you fail to adapt your
driving style nor override the laws of physics.
Distance Pilot DISTRONIC cannot take into
account road, weather or traffic conditions. Dis-
tance Pilot DISTRONIC is only an aid. You are
responsible for maintaining a safe distance to
the vehicle in front, for vehicle speed, for brak-
ing in good time and for staying in lane.
Do not use Distance Pilot DISTRONIC:
Rin road and traffic conditions which do not
allow you to maintain a constant speed, e.g. in
heavy traffic or on winding roads
Ron slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose
traction and the vehicle could then skid
Rin poor visibility, e.g. due to fog, heavy rain or
snow
Distance Pilot DISTRONIC may not detect nar-
row vehicles driving in front, e.g . mo
torcycles, or
vehicles driving on a different line.
In particular, the detection of obstacles can be
impaired if:
Rthere is dirt on the sensors or anything else
covering the sensors
Rthere is snow or heavy rain
Rthere is interference by other radar sources
Rthere are strong radar reflections, for exam-
ple in parking garages
If Distance Pilot DISTRONIC no longer detects a
vehicle in front, it may unexpectedly accelerate
to the speed stored. This speed may:
Rbe too high if you are driving in a turning lane
or an exit lane
Rbe so high in the right lane that you pass vehi-
cles driving on the left (in countries where
they drive on the right)
Rbe so high in the left lane that you pass vehi-
cles driving on the right (in countries where
they drive on the left)
If there is a change of drivers, advise the new
driver of the speed stored.
Cruise control lever
:Activates or increases speed
;Activates or reduces speed
=Deactivates Distance Pilot DISTRONIC
?Activates at the current speed/last stored
speed
ASets a specified minimum distance
When you activate Distance Pilot DISTRONIC,
the stored speed will appear on the multifunc-
tion display for five seconds.
Speedometer with segments: when Distance
Pilot DISTRONIC is activated, the segments of
the stored speed light up to the end of the scale
or to a permanently set speed limit.
Activating Distance Pilot DISTRONIC
Activation conditions
To activate Distance Pilot DISTRONIC, the fol-
lowing conditions must be fulfilled:
Rthe engine must be started. It may take up to
two minutes of driving before Distance Pilot
DISTRONIC is ready for use.
Rthe electric parking brake must be released.
RESP®must be activated, but not intervening
at present.
162Driving systems
Driving an d parking

while the vehicle is exiting the parking space.
You are responsible for braking in good time.
XStart the engine.
XRelease the electric parking brake.
XSwitch on the turn signal in the direction you
are pulling away.
XShift the transmission to positionhork.
The Start Parking Pilot?Yes: OKNo:% message appears in the multifunction
display.
XTo cancel the procedure: press the%
button on the multifunction steering wheel or
pull away.
or
XTo exit a parking space using Parking
Pilot: press the abutton on the multi-
function steering wheel.
The Parking Pilot Active Accelerate
and BrakeObserve Surroundingsmes-
sage appears in the multifunction display.
XLet go of the multifunction steering wheel.
XPull away, being ready to brake at all times. Do
not exceed a maximum speed of approx-
imately 6 mph (10 km/h) when exiting a park-
ing space. Otherwise, Parking Pilot is can-
celed immediately.
XDepending on the message or as required,
shift the transmission to position hork.
Parking Pilot immediately steers in the other
direction. The Parking Pilot Active
Accelerate and BrakeObserve Sur‐roundingsmessage appears in the multi-
function display.
iYou will achieve the best results by waiting
for the steering procedure to complete before
pulling away.
If you back up after activation, the steering
wheel is moved to the straight-ahead posi-
tion.
XDrive forwards and reverse as prompted by
Parking Assist PARKTRONIC warning dis-
plays, several times if necessary.
Once you have exited the parking space com-
pletely, the steering wheel is moved to the
straight-ahead position. You hear a tone and the
Parking
PilotFinishedmessage appears in
the multifunction display. You will then have to
steer and merge into traffic on your own. Park-
ing Assist PARKTRONIC is still available. You can
take over the steering before the vehicle has
exited the parking space completely. This is useful if you recognize that it is already possible
to pull out of the parking space.
Canceling Active Parking Pilot
XStop the movement of the multifunction
steering wheel or steer yourself.
Parking Pilot is canceled immediately. The
Parking
PilotCanceledmessage appears
on the multifunction display.
or
XPress the Parking Assist PARKTRONIC button
(Ypage 179).
Parking Assist PARKTRONIC is switched off
and Parking Pilot is immediately canceled.
The Parking Pilot Canceled
message
appears on the multifunction display.
Parking Pilot is canceled automatically when:
Rthe electric parking brake is engaged
Rtransmission position jis selected
Rparking using Parking Pilot is no longer pos-
sible
Ryou are driving faster than 6 mph (10 km/h)
Ra wheel spins, ESP®intervenes or fails. In
such cases the ÷warning lamp lights up in
the instrument cluster
A warning tone sounds. The parking symbol dis-
appears and the multifunction display shows the
Parking Pilot Canceled
message.
When Parking Pilot is canceled, you must steer
and brake again yourself.
If a system malfunction occurs, the vehicle is
braked to a standstill. To drive on, depress the
accelerator again.
Parking Assist PARKTRONIC
Important safety notes
Parking Assist PARKTRONIC is an electronic
parking aid with ultrasound. It monitors the area
around your vehicle using six sensors in the
front bumper and six sensors in the rear
bumper. Parking Assist PARKTRONIC visually
and audibly indicates the distance between your
vehicle and an object.
Parking Assist PARKTRONIC is only an aid. It is
not a replacement for your attention to your
immediate surroundings. You are always
responsible for safe maneuvering, parking and
exiting a parking space. Make sure that there
Driving systems177
Driving and parking
Z

are no persons, animals or objects in the maneu-
vering area while maneuvering and parking in/
leaving parking spaces.
!When parking, pay particular attention to
objects above or below the sensors, such as
flower pots or trailer drawbars. Parking Assist
PARKTRONIC does not detect such objects
when they are in the immediate vicinity of the vehicle. You could damage the vehicle or the
objects.
The sensors may not detect snow and other
objects that absorb ultrasonic waves.
Ultrasonic sources such as an automatic car
wash, the compressed-air brakes of a truck or
a pneumatic drill could cause Parking Assist
PARKTRONIC to malfunction.
Parking Assist PARKTRONIC may not function
correctly on uneven terrain.
!If you do not need the trailer tow hitch,
remove the detachable ball coupling. Parking Assist PARKTRONIC measures the minimum
detection range to an obstacle from the
bumper, not the ball coupling.
Parking Assist PARKTRONIC is activated auto-
matically when you:
Rswitch on the ignition
Rshift the transmission to position h,kor
i
Parking Assist PARKTRONIC is deactivated at
speeds above 11 mph (18 km/h). It is reactiva-
ted at lower speeds.
Parking Assist PARKTRONIC is deactivated for
the rear area when you establish an electrical
connection between your vehicle and a trailer.
Range of the sensors
Parking Assist PARKTRONIC does not take into
account obstacles located:
Rbelow the detection range, such as persons,
animals or objects
Rabove the detection range, e.g. overhanging
loads, tail sections or loading ramps of trucks
:Sensors in the front bumper, left-hand side
(example)
:Approx. 24 in (approx. 60 cm) (corners)
;Approx. 32 in (approx. 80 cm) (corners)
=Approx. 48 in (approx. 120 cm) (center)
?Approx. 40 in (approx. 100 cm) (center)
The sensors must be free from dirt, ice or slush.
They can otherwise not function correctly. Clean
the sensors regularly, taking care not to scratch
or damage them (
Ypage 312).
Minimum distance
CenterApprox. 8 in (approx. 20 cm)
CornersApprox. 6 in (approx. 15 cm)
178Driving systems
Driving and parking

If there is an obstacle within this range, the rel-
evant warning displays light up and a warning
tone sounds. If the distance falls below the min-
imum, the distance may no longer be shown.
Warning displays
:Segments on the left-hand side of the vehi-
cle
;Segments on the right-hand side of the vehi-
cle
=Segments showing operational readiness
The warning displays show the distance
between the sensors and the obstacle. The
warning display for the front area is in the instru-
ment cluster. The warning display for the rear
area is located on the headliner in the rear com- partment.
The warning display for each side of the vehicle
is divided into five yellow and two red segments.
Parking Assist PARKTRONIC is operational if
operational readiness indicator =lights up.
The selected transmission position and the
direction in which the vehicle is rolling deter-
mine which warning display is active when the
engine is running.
Transmission posi-
tionWarning display
hFront area activated
k, ior the vehicle
is rolling backwardsRear and front areas
activated
jNo areas activated
One or more segments light up as the vehicle
approaches an obstacle, depending on the vehi-
cle's distance from the obstacle. In addition,
warning tones are issued.
When the distance to the obstacle is sufficient,
you will hear an intermittent warning tone. The
shorter the distance to the obstacle, the shorter
the frequency of the intermittent warning tones
becomes. When the minimum distance is
reached, you hear a continuous warning tone.
Deactivating/activating Parking Assist
PARKTRONIC
dSwitch on the dashboard
eSwitch in the center console
:Deactivates or activates Parking Assist
PARKTRONIC
;Indicator lamp
If indicator lamp ;lights up, Parking Assist
PARKTRONIC is deactivated. Parking Pilot is
then also deactivated.
iParking Assist PARKTRONIC is automati-
cally activated when you turn the SmartKey to position 2in the ignition lock.
Driving systems179
Driving and parking
Z

Problems with Parking Assist PARKTRONIC
ProblemPossible causes/consequences andMSolutions
Only the red segments in
the Parking Assist
PARKTRONIC warning
displays are lit. You also
hear a warning tone for
approximately two sec-
onds.
Parking Assist
PARKTRONIC is then
deactivated and the indi-
cator lamp on the
PARKTRONIC button
lights up.Parking Assist PARKTRONIC has malfunctioned and has been deacti-
vated.
XIf problems persist, have Parking Assist PARKTRONIC checked at a
qualified specialist workshop.
Only the red segments in
the Parking Assist
PARKTRONIC warning
displays are lit. Parking
Assist PARKTRONIC is
then deactivated.The Parking Assist PARKTRONIC sensors are dirty or there is inter-
ference.
XClean the Parking Assist PARKTRONIC sensors (Ypage 312).
XSwitch the ignition back on.
The problem may be caused by an external source of radio or ultra-
sound waves.
XCheck to see if Parking Assist PARKTRONIC works at a different
location.
Reversing camera
General notes
Rear view camera :is an optical parking and
maneuvering aid. It shows the area behind the
vehicle with guide lines in the multimedia sys-
tem.
The area behind the vehicle is displayed as a
mirror image, as in the rear view mirror.
iThe text shown in the multimedia system
depends on the language setting. The follow- ing are examples of rear view camera displays
in the multimedia system.
Important safety notes
The rear view camera is only an aid. It is not a
replacement for your attention to your immedi-
ate surroundings. You are always responsible
for safe maneuvering and parking. Make sure
that there are no persons, animals or objects in
the maneuvering area while maneuvering and
parking in parking spaces.
Under the following circumstances, the rear
view camera will not function, or will function in
a limited manner:
Rif the tailgate is open
Rin heavy rain, snow or fog
Rat night or in very dark places
Rif the camera is exposed to very bright light
Rif the area is lit by fluorescent bulbs or LED
lighting (the display may flicker)
180Driving systems
Driving and parking

sors. 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 lane, you will also receive an optical and
audible warning.
Blind Spot Assist supports you from a speed of
approximately 20 mph (30 km/h).
Important safety notes
GWARNING
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
As a result, Blind Spot Assist may not give
warnings in such situations. There is a risk of
an accident.
Always observe the traffic conditions care-
fully, and maintain a safe lateral distance.
Blind Spot Assist is only an aid. It may fail to
detect some vehicles and is no substitute for
attentive driving. Always ensure that there is
sufficient distance to the side for other road
users and obstacles.
iUSA 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. Removing, tampering with, or
altering the device will void any warranties,
and is not permitted by the FCC. Do not tam-
per 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.
Radar sensors
The radar sensors for Blind Spot Assist are inte-grated into the rear bumper. Make sure that the
bumpers are free from dirt, ice or slush. The
sensors must not be covered, for example by
cycle racks or overhanging loads. Following a
severe impact or in the event of damage to the
bumpers, have the function of the radar sensors
checked at a qualified specialist workshop.
Blind Spot Assist may no longer work properly.
Monitoring area
In particular, the detection of obstacles can be
impaired if:
Rthere is dirt on the sensors or anything else
covering the sensors
Rthere is poor visibility, e.g. due to fog, heavy
rain, snow or spray
Rthere are narrow vehicles, e.g. motorcycles or
bicycles
Rthe road has very wide lanes
Rthe road has narrow lanes
Ryou are not driving in the middle of the lane
Rthere are barriers or other road boundaries
Vehicles in the monitoring range are then not
indicated.
At a distance of around 1.6 ft (0.5 m) ;from the
vehicle, Blind Spot Assist monitors the area up
to 10 ft (3 m) next to =and behind :your
vehicle, as shown in the picture.
If the lanes are narrow, vehicles driving in the
lane beyond the lane next to your vehicle may be
indicated, especially if the vehicles are not driv-
ing in the middle of their lane. This may be the
case if the vehicles are driving on the inner side
of their lane.
Due to the nature of the system:
Rwarnings may be issued in error when driving
close to crash barriers or similar solid lane
borders
Rwarnings may be interrupted when driving
alongside long vehicles, e.g. trucks, for a pro-
longed time
192Driving systems
Driving and parking