
R
a narrow vehicle travelling in front, e.g. a
motorbike
R a vehicle travelling in front on a different
line G
WARNING
PRE-SAFE ®
Brake does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
As a result, PRE-SAFE ®
Brake may not give
warnings or intervene in critical situations.
There is a ris kofanaccident. Always pay
careful attention to the traffi csituation and be
ready to brake.
In order to maintain the appropriate distance
to the vehicle in front and thus prevent a col-
lision, you must apply the brakes yourself.
X To activate/deactivate: activate or deac-
tivate PRE-SAFE ®
Brake in the on-board
computer (Y page 189).
The Ä symbol appears in the multifunc-
tion display as long as the HOL Dfunction
is not activated (Y page 165).
On vehicles with parking guidance, the
Ä symbol is displayed when Pis
engaged or you are driving faste rthan
35 km/h.
Vehicles with COMAND and navigation sys-
tem: the radar sensor system is switched off
automatically in the vicinity of radio telescope
facilities (Y page 312).
Vehicles without COMAND and a navigation
system and vehicles for Australia: the radar
sensor system and on-board computer must
be switched off in the vicinity of radio tele-
scope facilities (Y page 194).
For PRE-SAFE ®
Brake to assist you when driv-
ing, the radar sensor system must be
switched on (Y page 194) and be opera-
tional.
Following damage to the front end of the vehi-
cle, have the configuration and operation of the radar sensors checked at a qualified spe-
cialist workshop. This also applies to colli-
sions at slow speeds where there is no visible
damage to the front of the vehicle. Anti-theft systems
Immobiliser
The immobiliser prevents your vehicle from
being started without the correct key.
X To activate with the key: remove the key
from the ignition lock.
X To activate with KEYLESS-GO: switch the
ignition off and open the driver's door.
X To deactivate: switch on the ignition.
i The immobiliser is always deactivated
when you start the engine. ATA (Anti-Theft Alarm system)
Av isual and audible alarm is triggered if the
alarm system is primed and you open:
R a door
R the vehicle with the emergency key ele-
ment
R the boot lid
R the bonnet
R the glove compartment
R the stowage space under the armrest
The alarm is not switched off, even if you
close the open door that has triggered it, for
example. Anti-theft systems
61Safety Z 

X
To prime: lock the vehicle with the key or
KEYLESS-GO.
Indicato rlamp :flashes. The alarm sys-
te mi s primed after approximately
15 seconds.
X To switch off: unlock the vehicle with the
key or KEYLESS-GO.
X To stop the alarm using the key: insert
the key into the ignition lock.
The alarm is switched off.
or
X Press the %or& button on the key.
The alarm is switched off.
X To stop the alarm using KEYLESS-GO:
grasp the outside door handle. The key
must be outside the vehicle.
The alarm is switched off.
or
X Press the Start/Stop button on the dash-
board. The key must be inside the vehicle.
The alarm is switched off. Tow-away protection
An audible and visual alarm is triggered if your
vehicle's angle of inclination is altered while
tow-away protection is primed. This occurs if
the vehicle is jacked up on one side, for exam-
ple.
X To prime: lock the vehicle with the key or
KEYLESS-GO.
Tow-away protection is primed after
approximately 30 seconds.
X To switch off: unlock the vehicle with the
key or KEYLESS-GO.
Tow-away protection is switched off auto-
matically. To prevent a false alarm, deactivate tow-away
protection manually if your vehicle:
R
is being transported
R is being loaded onto a ferry or car trans-
porter, for example
R is parked on a movable surface, e.g. in a
split-level garage
Deactivating:
X Remove the key from the ignition lock. X
Press button :.
Indicator lamp ;lights up briefly.
X Lock the vehicle with the key or KEYLESS-
GO.
Tow-away protection is deactivated.
Tow-away protection remains deactivated
until:
R the vehicle is unlocked again.
R a door is opened and closed again.
R the vehicle is locked again. Interior motion sensor
When the interior motion sensor is primed, a
visual and audible alarm is triggered if move-
ment is detected in the vehicle interior. This
occurs if someone reaches into the vehicle
interior, for example.
To activate:
X Make sure that: 62
Anti-theft systemsSafety 

R
the side windows are closed.
R the stowage compartment under the
armrest is closed.
This will prevent false alarms.
X Make sure tha tthe roof is closed.
The interior motion sensor can only be
primed when the roof is closed (with the
exception of vehicles in the Netherlands).
Vehicles in the Netherlands: the interior
motion sensor is primed even when the
roof is open. However, the roof should be
closed so as to prevent afalse alarm.
X Make sure that the boot lid is closed.
Only then can the interio rmotion sensor be
primed.
X Lock the vehicle with the key or KEYLESS-
GO.
The interior motion sensor is primed after
approximately 30 seconds.
To deactivate:
X Unlock the vehicle with the key or KEY-
LESS-GO.
The interior motion sensor is switched off
automatically.
To prevent a false alarm, deactivate the inte-
rior motion sensor if you lock your vehicle
and:
R people or animals remain in the vehicle.
R the side windows remain open.
Deactivating:
X Remove the key from the ignition lock. X
Press button :.
Indicator lamp ;flashes briefly. X
Lock the vehicle with the key or KEYLESS-
GO.
The interior motion sensor is deactivated.
The interior motion sensor remains deactiva-
ted until:
R the vehicle is unlocked again.
R a door is opened and closed again.
R the vehicle is locked again.
i UK only: your vehicle is equipped with a
double lock function. The doors cannot be
opened from the inside if the vehicle has
been locked with the key (Y page 71).
Deactivate the interior motion sensor
before you lock the vehicle with the key.
The doors can then be opened from the
inside after the vehicle has been locked
from the outside with the key. Observe the
"Important safety notes" (Y page 71). Anti-theft systems
63Safety Z 

Useful information
i This Owner's Manual describes all models
and all standard and optional equipment
available to your vehicle at the time of pub-
lication of the Owner's Manual. Country-
specific deviations are possible. Please
note that your vehicle may not be equipped
with all features described. This also
applies to safety-relevan tsystems and
functions.
i Please read the information on qualified
specialist workshops (Y page 22).Key
Key functions
The key centrally locks/unlocks:
R the doors
R the boo tlid
R the glove compartment
R the stowage compartment in the centre
console
R the fuel filler flap G
WARNING
Only for the United Kingdom: if the vehicle
has been locked with the key, the double lock
function is activated as standard. It is the nnot
possible to open the doors from inside the
vehicle.
Therefore, do not leave any people behind in
the vehicle, particularly children, elderly peo-
ple or people in need of special assistance if
the vehicle has been locked with the key. As
a result, they may not be able to free them-
selves in the event of an emergency. As a
result, they could be seriously or even fatally
injured by prolonged exposure to extremely
high or low temperatures, for example. In this
case, rescuing people from outside the vehi-
cle is difficult.
Deactivate the interior motion sensor before
you lock the vehicle with the key. The doors can then be opened from the inside after the
vehicle has been locked from the outside with
the key. G
WARNING
If children are left unsupervised in the vehicle,
they could:
R open a door from inside the vehicle at any
time, even if it has been locked
R start the vehicle using akey which has been
left in the vehicle
R release the electric parking brake
They could thereby endanger themselves and
others. Never leave children unsupervised in
the vehicle. Always take the key with you
when leaving the vehicle, even if you are only
leaving it for a short time. G
WARNING
If a key ring is too heavy or too large, the
weight acting on the key could cause it to turn
in the ignition lock or catch on the steering
wheel. This could cause the engine to be
switched off suddenly. You may lose control
of the vehicle and cause an accident. Do not
attach any heavy or large key rings to the key
that is inserted in the ignition. :
& To lock the vehicle
; F To unlock the boot lid
= % To unlock the vehicle
When unlocking, the turn signals flash once.
When locking, they flash three times. 66
KeyOpening and closing 

When it is dark, the surround lighting also
comes on if it is activated in the on-board
computer (Y page 192).
You can also set an audible signal to confirm
that the vehicle has been locked. The audible
signal can be activated and deactivated using
the on-board computer (Y page 193).
X To unlock centrally: press the%but-
ton.
If you do not open the vehicle within approx-
imately 40 seconds of unlocking:
R the vehicle is locked again.
R the anti-theft system is primed again.
X To lock centrally: press the&button. KEYLESS-GO
Important notes on the use of KEYLESS-
GO R
Do not keep the KEYLESS-GO key together
with:
- electronic devices, e.g. a mobile phone
or another key
- metallic objects, e.g. coins or metal foil
This can affect the functionality of KEY-
LESS-GO.
R Bear in mind that the engine can be started
by any of the vehicle occupants if there is
a KEYLESS-GO key in the vehicle.
Locking and unlocking centrally You can start, lock or unlock the vehicle using
KEYLESS-GO. To do this, you only need carry
the key with you. You can combine the KEY-
LESS-GO functions with those of a conven-
tional key, e.g. using KEYLESS-GO to unlock
and pressing the &button to lock.
When locking or unlocking with KEYLESS-GO,
the distance between the key and the corre-
sponding door handle must not be greater
than 1 m. KEYLESS-GO checks whether a valid key is in
the vehicle by periodically establishing a radio
connection between the vehicle and the key.
This happens:
R when the external door handles are
touched
R when starting the engine
R while the vehicle is in motion X
To unlock the vehicle: touch the inner
surface of the door handle.
X To lock the vehicle: touch sensor sur-
face :.
X Convenience closing feature: touch
recessed sensor surface ;for an exten-
ded period (Y page 77).
If you pull on the handle of the boot lid, only
the boot of the vehicle is unlocked. Changing the settings of the locking
system
You can change the settings of the locking
system so that when unlocking, only the driv-
er's door, the lockable stowage compart-
ments in the vehicle interior and the fuel filler
flap are unlocked. This is useful if you fre-
quently travel on your own.
X To change the setting: press and hold
down the %and& buttons simulta-
neously for approximately six seconds until
the battery check lamp flashes twice
(Y page 69). Key
67Opening and closing Z 

i
If the setting of the locking system is
changed within the signal range of the vehi-
cle, pressing the &or% button locks
or unlocks the vehicle.
The key now functions as follows:
X To unlock the driver's door: press the
% button once.
X To unlockc entrally:press the %but-
ton twice.
X To lock centrally: press the&button.
The KEYLESS-GO function is changed as fol-
lows:
X To unlock the driver's door: touch the
inner surface of the door handle on the
driver's door.
X To unlock centrally: touch the inner sur-
face of the front-passenger door handle.
X To lock centrally: touch the outersensor
surface on one of the door handles. Restoring factor
ysettings
X Press the %and& buttons simulta-
neously for approximately six seconds until
the battery check lamp flashes twice. Emergency key element
General notes If the vehicle can no longer be locked or
unlocked with the key, use the emergency
key element.
If you use the emergency key element to
unlock and open the driver's door or the boot
lid, the anti-thef talarm system will be trig-
gered (Y page 61).
There are several ways to tur noff the alarm:
X To turn the alarm off with the key: press
the % or& button on the key.
or
X Insert the key into the ignition lock.
or X
To deactivate the alarm with KEYLESS-
GO: press the Start/Stop button in the igni-
tion lock. The key must be in the vehicle.
or
X Lock or unlock the vehicle using KEYLESS-
GO. The key must be outside the vehicle.
If you unlock the vehicle using the emergency
key element, the fuel filler flap will not be
unlocked automatically.
X To unlock the fuel filler flap: insert the
key in the ignition lock.
Removing the emergency key element X
Push release catch :in the direction of
the arrow and at the same time, remove
emergency key element ;from the key. Battery of the key
Important safety notes Have the batteries changed at a qualified spe-
cialist workshop. G
WARNING
Batteries are toxic and contain caustic sub-
stances. For this reason, keep batteries out of
the reach of children.
If a battery has been swallowed, visi tadoctor
immediately. 68
KeyOpening and closing 

Problems with the key
Problem Possible causes/consequences and
M Solutions
You cannot lock or
unlock the vehicle
using the key. The key battery is discharged or nearly discharged.
X
Try again to lock/unlock the vehicle using the remote control
function of the key. Point the tip of the key at the driver's door
handle from close range and press the %/& button.
If this does not work:
X Check the key battery (Y page 69) and replace it if necessary
(Y page 69).
X Lock (Y page 73) or unlock (Y page 73) the vehicle using
the emergency key element. The key is faulty.
X
Lock (Y page 73) or unlock (Y page 73) the vehicle using
the emergency key element.
X Have the key checked at a qualified specialist workshop. You can no longer lock
or unlock the vehicle
using KEYLESS-GO. There is interference from a powerful source of radio waves.
X
Lock/unlock the vehicle using the remote control function of
the key. Point the tip of the key at the driver's door handle from
close range and press the %/& button. There is a fault with KEYLESS-GO.
X
Lock/unlock the vehicle using the remote control function of
the key. Point the tip of the key at the driver's door handle from
close range and press the %/& button.
X Have KEYLESS-GO checked at a qualified specialist workshop.
If this does not work:
X Check the key battery (Y page 69) and replace it if necessary
(Y page 69).
X Lock (Y page 73) or unlock (Y page 73) the vehicle using
the emergency key element. You have lost a key. X
Have the key deactivated at a qualified specialist workshop.
X Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. You have lost the emer-
gency key element. X
Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. 70
KeyOpening and closing 

Problem Possible causes/consequences and
M Solutions
The engine cannot be
started using the key. The on-board voltage is too low.
X
Switch off non-essential consumers, e.g. seat heating or interior
lighting, and try to start the engine again.
If this does not work:
X Check the starter battery and charge it if necessary
(Y page 273).
or
X Jump-start the vehicle (Y page 277).
or
X Consult a qualified specialist workshop. The engine cannot be
started using KEYLESS-
GO. The key is in the
vehicle. Ad
oor is open. Therefore, the key cannot be detected as easily.
X Close the door and try to start the vehicle again. There is interference from a powerful source of radio waves.
X
Start your vehicle with the key in the ignition lock. Doors
Important safety notes
G
WARNING
Only for the United Kingdom: if the vehicle
has been locked with the key, the double lock
function is activated as standard. It is then not
possible to open the doors from inside the
vehicle.
Therefore, do not leave any people behind in
the vehicle, particularly children, elderly peo-
ple or people in need of special assistance if
the vehicle has been locked with the key. As
a result, they may not be able to free them-
selves in the event of an emergency. As a
result, they could be seriously or even fatally
injured by prolonged exposure to extremely
high or low temperatures, for example. In this
case, rescuing people from outside the vehi-
cle is difficult.
Deactivate the interior motion sensor before
you lock the vehicle with the key. The doors
can then be opened from the inside after the
vehicle has been locked from the outside with
the key. G
WARNING
If children are left unsupervised in the vehicle,
they could:
R open a door from inside the vehicle at any
time, even if it has been locked
R start the vehicle using akey which has been
left in the vehicle
R release the electric parking brake
They could thereby endanger themselves and
others. Never leave children unsupervised in
the vehicle. Always take the key with you
when leaving the vehicle, even if you are only
leaving it for a short time. Unlocking and opening the doors
from the inside
For all countries except the United King-
dom: you can open a door from inside the
vehicle even if it has been locked.
Only for the United Kingdom: if the vehicle
has been locked with the key, the double lock
function is activated as standard. It is then
not possible to open the doors from inside the Doors
71Opening and closing Z