lock MERCEDES-BENZ C-CLASS SALOON 2011 Owner's Guide

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 237).
The Ä symbol appears in the multifunc-
tion display as long as the HOL Dfunction
is not activated (Y page 193).
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 389).
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 242).
For PRE-SAFE ®
Brake to assist you when driv-
ing, the radar sensor system must be
switched on (Y page 242) 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/tailgate
R the bonnet
The alarm is not switched off, even if you
close the open door that has triggered it, for
example. X
To prime: lock the vehicle with the key or
KEYLESS-GO.
Indicator lamp :flashes .The alarm sys-
tem is primed after approximately 15 sec-
onds.
X To deactivate: unlock the vehicle with the
key or KEYLESS-GO. 80
Anti-theft systemsSafety

X
To stop the alarm using the key: insert
the key into the ignition lock.
The alar mis 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 deactivate: unlock the vehicle with the
key or KEYLESS-GO.
Tow-away protection is deactivated 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
If the interior motion sensor is primed, a vis-
ual and audible alarm is triggered if move-
ment is detected in the vehicle interior while
the vehicle is locked. This occurs if someone
reaches into the vehicle interior, for example.
To activate:
X Make sure that:
R
the side windows are closed.
R the sliding sunroof/panorama sliding
sunroof is closed.
R there are no objects, e.g. mascots, hang-
ing on the rear-view mirror or on the grab
handles on the roof trim.
This will prevent false alarms.
X Lock the vehicle with the key or KEYLESS-
GO.
The interior motion sensor is primed after
approximately 30 seconds. Anti-theft systems
81Safety Z

To switch off:
X
Unlock the vehicle with the key or KEY-
LESS-GO.
The interio rmotion sensor is deactivated
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.
R the sliding sunroof/panorama sliding sun-
roof remains 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 90).
Deactivate the interior motion sensor
before locking 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 "Impor-
tant safety notes" (Y
page 89).82
Anti-theft systemsSafety

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 28).Key
Key functions
Locking an dunlocking centrally The key centrally locks/unlocks:
R
the doors
R the boot lid/tailgate
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 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 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/tailgate
= % To unlock the vehicle
When unlocking, the turn signals flash once.
When locking, they flash three times.
When it is dark, the surround lighting also
comes on if it is activated in the on-board
computer (Y page 241).84
KeyOpening and closing

If you activate the acoustic locking confirma-
tion function, you will hear the following,
depending on the date of production of the
vehicle:
R an acoustic signal when locking
or
R one acoustic signal when unlocking and
three when locking.
The audible signal can be activated and deac-
tivated using the on-board computer
(Y page 242).
X To unlockc entrally:press the%but-
ton.
If you do not open th evehicle within approx-
imately 40 seconds of unlocking:
R the vehicle is locked again.
R the anti-thef tsystem is primed again.
X To lock centrally: press the&button. KEYLESS-GO
You can start, loc korunlock the vehicle using
KEYLESS-GO .To do this, you only need carry
the key with you. When you touch the surface
of the sensors on the vehicle's outside door
handles, KEYLESS-GO establishes a radio
connection between the vehicle and the key.
When the engine is started and whilst you are
driving, KEYLESS-GO also checks whether a
valid key is in the vehicle by periodically
establishing radio contact.
When locking or unlockin gwith KEYLESS-GO,
the distance between the key and the door
handle you wish to lock or unloc kmust not
be greater than 1 m. 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 98).
If you pull on the handle of the boot lid/tail-
gate, only the boot/luggage compartmen tof
the vehicle is unlocked. Changing the settings of the locking
system
You can change the setting of the locking
syste mins uch a way that only the driver's
door and the fuel filler flap are unlocked. This
is useful if you frequently 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 (Y page 87)
flashes twice.
i If the setting of the locking system is
changed within the signal range of the vehi-
cle, pressing the &or% buttonlocks
or unlocks the vehicle.
The key now functions as follows:
X To unlock the driver's door: press the
% button once.
X To unlock centrally: press the%but-
ton twice.
X To lock centrally: press the&button. Key
85Opening and closing Z

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 door handle on the front-
passenger door or the rear door.
X To lock centrally: touch the outer sensor
surface on one of the door handles. Restoring the factory settings
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 emergenc
ykey element to
unlock and open the driver's door or the boot
lid/tailgate, the anti-thef talarm system will
be triggered (Y page 80).
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. Key battery
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. H
Environmental note Batteries contain pollutants.
It is illegal to dispose of them
with the household rubbish.
They must be collected sep-
arately and disposed of in an
environmentally responsible
recycling system. Dispose of batteries in an
environmentally responsible
manner. Take discharged
batteries to a qualified spe-
cialist workshop or to a col-86
KeyOpening and closing

lection point for used batter-
ies.
Checking the battery X
Press the &or% button.
The battery is working properly if the bat-
tery check lamp :lights up briefly
If battery check lamp :does not light up
briefly during the test, the battery is dis-
charged.
X Changing the battery (Y page 87)
i If the key battery is checked within the
signal receptio nrange of the vehicle, press-
ing the &or% button locks or
unlocks the vehicle.
Changing the battery You require a CR 2025 3 V cell battery.
X Take the emergency key elemen tout of the
key (Y page 86). X
Press emergency key element ;into the
opening in the key in the direction of the
arrow until battery tray cover :opens.
When doing so, do no thold cover :shut.
X Remove battery tray cover :. X
Repeatedly tap the key against your palm
until battery =falls out.
X Insert the new battery with the positive ter-
minal facing upwards. Use a lint-free cloth
to do so.
X Make sure that the surface of the battery is
free from lint, grease and all other forms of
contamination.
X Insert the front tabs of battery tray
cover :and then press to close it.
X Insert the emergency key element into the
key.
X Check the function of all key buttons on the
vehicle. Key
87Opening and closing Z

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 87) and replace it if necessary
(Y page 87).
X Lock (Y page 91) or unlock (Y page 91) the vehicle using
the emergency key element. The key is faulty.
X
Lock (Y page 91) or unlock (Y page 91) 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 87) and replace it if necessary
(Y page 87).
X Lock (Y page 91) or unlock (Y page 91) 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. 88
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 346).
or
X Jump-start the vehicle (Y page 350).
or
X Consult a qualified specialist workshop. The engine cannot be
started using the key. The steering lock is mechanically blocked.
X
Remove the key and reinsert it into the ignition lock. While doing
this, turn the steering wheel in both directions. 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 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. Doors
89Opening and closing Z

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
vehicle. Deactivate the interior motion sensor
(Y page 81) 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.
You can only open the rear doors from inside
the vehicle if they are not secured by the
child-proof locks (Y page 71).X
Pull door handle ;.
If the door is locked, locking knob :pops
up. The door is unlocked and can be
opened. Centrally locking and unlocking the
vehicle from the inside
You can centrally lock or unlock the vehicle
from the inside.
The central locking/unlocking button does
not lock or unlock the fuel filler flap.
i You cannot unlock the vehicle centrally
from the inside if the vehicle has been
locked with the key or KEYLESS-GO. i
It is only possible to lock the vehicle cen-
trally if the front-passenger door is closed. X
To unlock: press button :.
X To lock: press button ;. Automatic locking feature
The vehicle is locked automatically when the
ignition is switched on and the wheels are
turning.
You could therefore be locked out when:
R the vehicle is being pushed.
R the vehicle is being towed.
R the vehicle is being tested on a dynamom-
eter. X
To deactivate: press and hold button :
for about five seconds until a tone sounds.
X To activate: press and hold button ;for
about five seconds until a tone sounds.
i If you press one of the two buttons and
do not hear a tone, the relevan tsetting has
already been selected. 90
DoorsOpening and closing