
Ra vehicle is traveling in front on a different line
Rvehicles quickly move 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 person is not distin-
guishable 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
speeds where there is no visible damage to the
front of the vehicle.
Following damage to the windshield, have the
configuration and operation of the camera sys-
tem checked at a qualified specialist workshop.
Function
To avoid a collision, BAS PLUS calculates the
brake force necessary if:
Ryou approach an obstacle, and
RBAS PLUS has detected a risk of collision
When driving at a speed under 20 mph
(30 km/h) : if you depress the brake pedal, BAS
PLUS is activated. The increase in brake pres-
sure will be carried out at the last possible
moment.
When driving at a speed above 20 mph
(30 km/h): if you depress the brake pedal
sharply, BAS PLUS automatically raises the
brake pressure to a value adapted to the traffic
situation.
BAS PLUS provides braking assistance in haz-
ardous situations with vehicles in front within a
speed range between 4 mph (7 km/h) and
155 mph (250km/ h). At speeds of up to approximately 44 mph
(70 km/h), BAS PLUS can react to:
Rstationary objects in the path of your vehicle,
e.g. stopped or parked vehicles
Rpedestrians in the path of your vehicle
Robstacles crossing your path, which move in
the detection range of the sensors and are
recognized by them
iIf BAS PLUS demands particularly high brak-
ing force, preventative passenger protection
measures (PRE-SAFE
®) are activated simulta-
neously (Ypage 60).
XKeep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the whee ls fro
m locking.
BAS PLUS is deactivated and the brakes func-
tion as usual again, if:
Ryou release the brake pedal.
Rthere is no longer a risk of collision.
Rno obstacle is detected in front of your vehi-
cle.
Ryou depress the accelerator pedal
Ryou activate kickdown.
COLLISION PREVENTION ASSIST
PLUS
General information
iObserve the "Important safety notes" sec-
tion (Ypage 68).
COLLISION PREVENTION ASSIST PLUS consists
of a distance warning function with an autono-
mous braking function and adaptive Brake
Assist.
COLLISION PREVENTION ASSIST PLUS 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 COLLISION PREVENTION ASSIST PLUS
detects that there is a risk of a 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, the COLLISION PREVENTION
ASSIST PLUS adaptive Brake Assist assists you.
70Driving safety systems
Safety

that are in the path of your vehicle for an exten-
ded period of time.
Up to a speed of approximately 44 mph
(70 km/h), the distance warning function can
also react to stationary obstacles, such as stop-
ped or parked vehicles.
Autonomous braking function
If the driver does not react to the distance warn-ing signal in a critical situation, COLLISION PRE-
VENTION ASSIST PLUS can assist with the
autonomous braking function.
The autonomous braking function:
Rgives the driver more time to react to critical
driving situations
Rcan help the driver to avoid an accident or
Rreduces the effects of an accident
Vehicles without DISTRONIC PLUS: the
autonomous braking function is available in the
following speed ranges:
R4 - 65 mph (7 - 105 km/h) for moving objects
R4 - 31 mph (7 - 50 km/h) for stationary
objects
Vehicles with DISTRONIC PLUS: the autono-
mous braking function is available in the follow-
ing speed ranges:
R4 - 124 mph (7 - 200 km/h) for moving
objects
R4 - 31 mph (7 - 50 km/h) for stationary
objects
Due to the nature of the system, particularly
complicated but non-critical driving conditions
may also cause the Autonomous Braking Func-
tion to intervene.
If the autonomous braking function requires a
particularly high braking force, preventative
passenger protection measures (PRE-SAFE
®)
are activated simultaneously (Ypage 60).
Adaptive Brake Assist
General information
iObserve the "Important safety notes" sec-
tion (Ypage 68).
With the help of adaptive Brake Assist, the dis-
tance warning signal can detect obstacles that
are in the path of your vehicle for an extended
period of time. If adaptive Brake Assist detects a risk of colli-
sion with the vehicle in front, it calculates the
braking force necessary to avoid a collision. If
you apply the brakes forcefully, adaptive Brake
Assist will automatically increase the braking
force to a level suitable for the traffic conditions.
Adaptive Brake Assist provides braking assis-
tance in hazardous situations at speeds above
4 mph (7 km/h). It uses radar sensor technology
to assess the traffic situation.
Up to a speed of approximately 155 mph
(250 km/h), adaptive Brake Assist is capable of
reacting to moving objects that have already
been detected as such at least once over the
period of observation.
Up to a speed of approximately 44 mph
(70 km/h), adaptive Brake Assist reacts to sta-
tionary obstacles.
If Adaptive Brake Assist demands particularly
high braking force, preventative passenger pro-
tection measures (PRE-SAFE
®) are activated
si multaneously (Ypage 60).
XKeep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if:
Ryou release the brake pedal.
Rthere is no longer any danger of a collision.
Rno obstacle is detected in front of your vehi-
cle.
Adaptive Brake Assist is then deactivated.
Important safety notes
iObserve the "Important safety notes" sec-
tion for driving safety systems (Ypage 68).
GWARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions.
In such cases, Adaptive Brake Assist can:
Rintervene unnecessarily
Rnot intervene
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. Terminate the
intervention in a non-critical driving situation.
72Driving safet ysystem s
Safety

SmartKey
Important safety notes
GWARNING
If children are left unsupervised in the vehicle,
they could:
Ropen the doors, thus endangering other
people or road users.
Rget out and disrupt traffic.
Roperate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
Rrelease the parking brake.
Rshifting the automatic transmission out of
park position P
RStart the engine.
There is a risk of an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children.
GWARNING
If you attach heavy or large objects to the
SmartKey, the SmartKey could be uninten-
tionally turned in the ignition lock. This could
cause the engine to be switched off. There is a risk of an accident.
Do not attach any heavy or large objects to the
SmartKey. Remove any bulky key rings before
inserting the SmartKey into the ignition lock.
!Keep the SmartKey away from strong mag-
netic fields. Otherwise, the remote control
function could be affected.
Strong magnetic fields can occur in the vicin-
ity of powerful electrical installations.
Do not keep the SmartKey:
Rwith electronic devices, e.g. a mobile phone
or another SmartKey.
Rwith metallic objects, e.g. coins or metal foil.
Rinside metallic objects, e.g. a metal case.
This can affect the functionality of the Smart- Key. Vehicles with KEYLESS-GO start function:
do
not keep the SmartKey on the parcel shelf or in
the trunk. Otherwise, the SmartKey may not be
detected, e.g. when starting the engine using
the Start/Stop button.
A check which periodically establishes a radio
connection between the vehicle and the Smart-
Key determines whether a valid SmartKey is in
the vehicle. This occurs, for example:
Rwhen starting the engine
Rwhile driving
Rwhen the external door handles are touched
Rduring convenience closing
SmartKey functions
:& To lock the vehicle
;FTo open/close the trunk lid
=%To unlock the vehicle
XTo unlock centrally: press the%button.
If you do not open the vehicle within approx-
imately 40 seconds of unlocking:
Rthe vehicle is locked again.
Ranti-theft protection is reactivated.
XTo lock centrally: press the&button.
The SmartKey centrally locks and unlocks the
following components:
Rthe doors
Rthe trunk lid
Rthe fuel filler flap
The turn signals flash once when unlocking and
three times when locking.
You can also set an audible signal to confirm
that the vehicle has been locked. The audible
signal can be activated and deactivated via the
multimedia system (see the Digital Operator's
Manual).
SmartKey81
Opening and closing
Z

You will receive visual and acoustic locking con-
firmation if all components were able to be
locked.
When the locator lighting is activated via the
multimedia system, it lights up when it is dark
after the vehicle is unlocked with the SmartKey
(see the Digital Operator's Manual).
XTo open the trunk lid automatically from
outside the vehicle:press and hold theF
button until the trunk lid opens.
XTo open the trunk lid automatically from
outside the vehicle: if the SmartKey is loca-
ted in the immediate vicinity of the vehicle,
press the Fbutton on the SmartKey.
When the trunk lid closes you can then
release the button.
KEYLESS-GO
General notes
Bear in mind that the engine can be started by
any of the vehicle occupants if there is a Smart-
Key in the vehicle.
Locking/unlocking centrally
You can start, lock or unlock the vehicle using
KEYLESS-GO. To do this, you only need carry the
SmartKey with you. You can combine the func-
tions of KEYLESS-GO with those of a conven-
tional SmartKey. Unlock the vehicle by using
KEYLESS-GO, for instance, and lock it using the
& button on the SmartKey.
The driver's door and the door at which the han-
dle is used, must both be closed. The SmartKey
must be outside the vehicle. When locking or
unlocking with KEYLESS-GO, the distance
between the SmartKey and the corresponding
door handle must not be greater than 3 ft (1 m).
A brief radio connection between the vehicle
and the key determines whether a valid Smart-
Key is in, or in the direct vicinity of, the vehicle.
This occurs, for example:
Rwhen starting the engine
Rwhile driving
Rwhen using HANDS-FREE ACCESS
Rwhen the external door handles are touched
Rduring convenience closing
XTo unlock the vehicle: touch the inner sur-
face of the door handle.
XTo lock the vehicle: touch sensor surface :
or ;.
Make sure that you do not touch the inner
surface of the door handle.
XConvenience closing feature: touch
recessed sensor surface ;for an extended
period.
Further information on the convenience clos-
ing feature (
Ypage 96).
XTo unlock the trunk lid: pull the handle on
the trunk lid.
Deactivating and activating
If you do not intend to use a key for an extended
period of time, you can deactivate the KEYLESS-
GO function of the SmartKey. The SmartKey will
then use very little power, thereby conserving
battery power. For the purposes of activation/
deactivation, the vehicle must not be nearby.
XTo deactivate: press the&button on the
SmartKey twice in rapid succession.
The battery check lamp of the SmartKey
flashes twice briefly and lights up once, then
KEYLESS-GO is deactivated (
Ypage 84).
XTo activate: press any button on the Smart-
Key.
or
XInsert the SmartKey into the ignition lock.
KEYLESS-GO and all of its associated features
are available again.
82SmartKey
Opening and closing

KEYLESS-GOstart function
Gene ral notes
Bear in min dthat th eengin ecan be started by
any of th evehicl eoccupant sif there is aSmart -
Key in th evehicle.
Changing the settings ofthe locking
system
You can chang eth esetting sof th elocking sys-
tem. This mean sthat only th edriver's door and
th efuel filler flap are unlocke dwhen th evehicl e
is unlocked. This is useful if you frequentl ytravel
on your own .
XTo change th esetting: press and hold down
th e% and& buttons simultaneousl y
for approximately six seconds until th ebat -
tery chec klamp flashes twice (
Ypage 84).
If th esetting of th elocking system is changed
within th esignal range of th evehicle, pressing
th e& or% button:
Rlocks or
Runlocks th evehicl e
The SmartKey no wfunction sas follows :
XTo unlock: press the% buttononce .
XTo unlock centrally: press the% button
twice .
XTo lock: press the& button.
The KEYLESS-GO function scan be changed as
follows :
XTo unlock th edriver's door :touch th einner
surfac eof th edoor handle on th edriver's
door .
XTo unlock centrally: touch theinner surfac e
of th edoor handle on th efront-passenger
door or th erear door .
XTo lock centrally: touch theouter sensor
surfac eon on eof th edoor handles .
XTo restoreth efactory settings: press and
hold th e% and& buttons sim ultane-
ousl yfor approximately six seconds until th e
battery chec klamp flashes twice
(
Ypage 84) .
Mechanical key
Gene ral notes
If th evehicl ecan no longer be locke dor
unlocke dwit hth eSmartKey or KEYLESS-GO ,
use th emechanical key.
If you use th emechanical ke yto unloc kand
open th edriver's door ,th eanti-thef talarm sys-
te m will be triggered .Switc hoff th ealarm
(
Ypage 79) .
If you unloc kth evehicl eusin gth emechanical
key, th efuel filler flap will no tbe unlocke dauto -
matically.
XTo unlock th efuel filler flap: insert the
SmartKey int oth eignition lock.
Removing the mechanical key
XPush release catch :in th edirection of th e
arrow and at th esam etime remove mechan -
ical ke y; from th eSmartKey.
Further information :
RUnlocking thedriver's door (Ypage 89)
RLocking th evehicl e (Ypage 89 )
Inserting the mechanical key
XPush mechanical ke y; completely int oth e
SmartKey until it engage sand release
catch :is bac kin it sbasic position .
SmartKey83
Opening and closing
Z

Unlocking and opening doors from
the inside
You can open a door from inside the vehicle
even if it has been locked. You can only open the
rear doors from inside the vehicle if they are notsecured by the child-proof locks (
Ypage 67). If
the vehicle has been locked with the SmartKey
or with KEYLESS-GO, opening a door from the
inside will trigger the anti-theft alarm system.
Switch off the alarm (
Ypage 79).
XTo unlock and open a front door: pull door
handle ;.
If the door is locked, locking knob :pops up.
The door is unlocked and opens.
XTo unlock a rear door: pull door handle;.
Locking knob :pops up and the door
unlocks.
XTo open a rear door: pull door handle;
again.
The door opens.
Centrally locking and unlocking the
vehicle from the inside
You can centrally lock and unlock the vehicle
from the inside. The switches are on the driver’s
door.
XTo unlock: press button :.
XTo lock:press button ;.
When the front-passenger door is closed, the
vehicle is locked.
Meanwhile, the fuel filler flap will not be locked
or unlocked.
You cannot unlock the vehicle centrally from the
inside if the vehicle has been locked with the
SmartKey or KEYLESS-GO.
The doors can be opened from the inside. You
can only open the rear doors from inside the
vehicle if they are not secured by the child-proof
locks (
Ypage 67).
If the vehicle has been locked with the SmartKey or with KEYLESS-GO, opening a door from the
inside will trigger the anti-theft alarm system.
Switch off the alarm (
Ypage 79).
When a locked door is opened from inside the
vehicle, the previous unlocking process will be
acknowledged if the vehicle:
Rhas been locked with the locking button for
the central locking or
Rhas been locked automatically
The vehicle will be fully unlocked if it had previ-
ously been fully unlocked. If only the driver's
door had been previously unlocked, only the
door which has been opened from the inside is
unlocked.
88Doors
Opening and closing

Automa tic locking featu re
XTo deactivate:press and hold butto n: for
approximately fiv eseconds until atone
sounds.
XTo activate: press and hold butto n; for
approximately fiv eseconds until atone
sounds.
If you press on eof th etwo buttons and do no t
hear atone ,th erelevan tsetting has already
been selected.
The vehicl eis locke dautomatically when th e
ignition is switched on and th ewheels are turn-
ing .
You could therefor ebe locke dout if:
Rth evehicl eis bein gpushed.
Rth evehicl eis bein gtowed.
Rth evehicl eis on aroller dynamometer.
iYou can also activat eand deactivat eth e
automatic locking function via COMAND or
Audio 20 (see th eDigital Operator' sManual).
Unlocking/locking driver's doorwith
mechanical key
i
If you want to centrally loc kth evehicl eusin g
th emechanical key, begi nby pressing th e
locking butto nfor th einterior locking mech-
anism while th edriver's door is open .The n
loc kth edriver's door usin gth emechanical
key.
XInser tth emechanical ke yint oopening :in
th eprotective cap .
XPull and hold th edoor handle.
XPull th eprotective cap on th emechanical ke y
as straight as possibl eaway from th evehicl e
until it releases.
XReleas eth edoor handle.
XTo unlock: turnth emechanical ke ycounter-
clockwise as far as it will go to position 1.
XTo lock:turnth emechanical ke yclockwise as
far as it will go to position 1.
If you use th emechanical ke yto unloc kand
open th edriver's door ,th eanti-thef talarm sys-
te m will be triggered .Switc hoff th ealarm
(
Ypage 79).
Trunk
Import ant safety notes
GWARNIN G
Combustion engines emi tpoisonous exhaust
gase ssuc has carbon monoxide. Exhaust
gase scan ente rth evehicl einterior if th e
trunk lid is open when th eengin eis running,
Trunk89
Opening and closing
Z

especially if the vehicle is in motion. There is a
risk of poisoning.
Always switch off the engine before opening
the trunk lid. Never drive with the trunk lid
open.
GWARNING
If objects, luggage or loads are not secured or
not secured sufficiently, they could slip, tip
over or be flung around and thereby hit vehicle
occupants. There is a risk of injury, particu-
larly in the event of sudden braking or a sud-
den change in direction.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping before the
journey.
!The trunk lid swings upwards when opened.
Therefore, make sure that there is sufficient
clearance above the trunk lid.
The opening dimensions of the trunk lid can be
found in the "Vehicle data" section
(
Ypage 394).
You can limit the opening angle of the trunk lid in
COMAND or Audio 20 (see the Digital Opera-
tor's Manual).
Do not leave the SmartKey in the trunk. You
could otherwise lock yourself out.
You should preferably place luggage or loads in
the trunk. Observe the loading guidelines
(
Ypage 308).
Obstruction recognition with trunk lid
reversing feature
Vehicles with trunk lid remote closing fea-
ture:
The trunk lid is equipped with automatic
obstruction detection with a reversing feature. If
a solid object blocks or restricts the trunk lid
when automatically opening, this procedure is
stopped. If a solid object blocks or restricts the
trunk lid when automatically closing, the trunk
lid opens again automatically. The automatic
obstruction detection with reversing feature is
only an aid. It is not a substitute for your atten-
tiveness when opening and closing the trunk lid.
GWARNING
The reversing feature does not react:
Rto soft, light and thin objects, e.g. small fin-
gers
Rover the last 1/3 in (8 mm) of the closing
movement
This means that the reversing feature cannot
prevent someone being trapped in these sit-
uations. There is a risk of injury.
Make sure that no body parts are in close
proximity during the closing procedure.
If somebody becomes trapped:
Rpress the Fbutton on the SmartKey, or
Rpull or press the remote operating switch
on the driver's door or
Rpress the closing or locking button on the
trunk lid, or
Rpull on the trunk lid handle
Vehicles with HANDS-FREE ACCESS:
It is also possible to stop the closing process by
performing a kicking movement under the rear
bumper.
Opening and closing manually
Opening
XPress the Fbutton on the SmartKey.
or
XPull handle :.
The trunk lid opens.
90Trunk
Opening and closing