Page 89 of 417

i
If the battery of the key is checked within
the signal reception range of the vehicle,
pressing the &or% button:
R locks or
R unlocks the vehicle
i You can obtain a battery from any quali-
fied specialist workshop.
Replacing the battery You require a CR 2025 3 V cell battery.
X Take the emergency key element out of the
key (Y page 85). X
Press emergency key element ;into the
opening in the key in the direction of the
arrow until battery compartment cover :
opens. When doing so, do not hold battery
compartment cover :shut.
X Remove battery compartment 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 of lint, grease and other contamina-
tion.
X Insert the front tabs of battery compart-
ment cover :into the housing and then
press to close it.
X Insert emergency key element ;into the
key.
X Check the function of all key buttons on the
vehicle. 86
KeyOpening and closing
Page 90 of 417

Problems with the key
Problem
Possible causes/consequences and
M
MSolutions You can no longer lock
or unlock the vehicle
using the key. The key battery is discharged or nearly discharged.
X Check the key battery (Y page 85) and replace it if necessary
(Y page 86).
If this does not work: X Lock (Y page 90) or unlock (Y page 90) the vehicle using the
emergency key element. The key is faulty.
X Lock (Y page 90) or unlock (Y page 90) 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. The key battery is discharged or nearly discharged.
X Check the key battery (Y page 85) and replace it if necessary
(Y page 86).
If this does not work: X Lock (Y page 90) or unlock (Y page 90) the vehicle using the
emergency key element. There is interference from a powerful source of radio waves.
X Lock (Y page 90) or unlock (Y page 90) the vehicle using the
emergency key element. There is a fault with KEYLESS-GO.
X Lock/unlock the vehicle using the remote control function of
the key.
X Have the vehicle and key checked at a qualified specialist work-
shop.
If the vehicle can also not be locked/unlocked using the remote
control function:
X Lock (Y page 90) or unlock (Y page 90) the vehicle using the
emergency key element.
X Have the vehicle and key checked at a qualified specialist work-
shop. 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. Key
87Opening and closing Z
Page 91 of 417

Problem
Possible causes/consequences and
M
MSolutions 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 353).
or
X Jump-start the vehicle (Y page 355).
or
X Consult a qualified specialist workshop. The engine cannot be
started using KEYLESS-
GO. The key is in the
vehicle. The vehicle is locked.
X Unlock the vehicle 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
United Kingdom only: G
WARNING
When the double locks are activated, the
doors can no longer be opened from the
inside. People in the vehicle can no longer get out, e.g. in hazardous situations. There is a
risk of injury.
Therefore, do not leave any people unsuper-
vised in the vehicle, particularly children, eld-
erly people or people in need of special assis-
tance. Do not activate the double lock when
people are in the vehicle.
If the vehicle has been locked from the out-
side, the double-lock function is activated as
standard. It is then not possible to open the
doors from inside the vehicle. You can deac-
tivate the double-lock function by deactivat-
ing the interior motion sensor (Y page 79).
The doors can then be opened from the inside after the vehicle has been locked from the
outside. The anti-theft alarm system is trig- gered if the door is opened from the inside.
Switch off the alarm (Y
page 78).
All countries: G
WARNING
If children are left unsupervised in the vehicle, they could:
R open doors, thereby endangering other per-
sons or road users
R get out and be struck by oncoming traffic
R operate vehicle equipment and become
trapped, for example
In addition, the children could also set the
vehicle in motion, for example, if they:
R release the parking brake
R shift the automatic transmission out of park
position P or shift manual transmission into
neutral
R start the engine
There is a risk of an accident and injury.
When leaving the vehicle, always take the key with you and lock the vehicle. Never leave
children and animals unattended in the vehi-
cle. Keep the keys out of the reach of children. 88
DoorsOpening and closing
Page 92 of 417

G
WARNING
If persons (particularly children) are exposed
to heat or cold for a prolonged period, there is a risk of serious or even fatal injuries. Never
leave persons (particularly children) unatten-
ded in the vehicle.
Stow luggage or loads preferably in the boot/ luggage compartment. Observe the loading
guidelines (Y page 300). 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. If the vehi- cle has previously been locked with the key or
with KEYLESS-GO, opening a door from the
inside will trigger the anti-theft alarm system. Switch off the alarm (Y page 78).
United Kingdom only: if the vehicle has
been locked with the key from the outside,
the double-lock function is activated as
standard. It is then not possible to open the
doors from inside the vehicle. You can deac-
tivate the double-lock function by deactivat-
ing the interior motion sensor (Y page 79).
The doors can then be opened from the inside
after the vehicle has been locked from the
outside. The anti-theft alarm system is trig-
gered if the door is opened from the inside.
Switch off the alarm (Y page 78).
For all countries: you can only open the rear
doors from inside the vehicle if they are not
secured by the child-proof locks (Y page 69). 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. X
To unlock: press button :.
X To lock: press button ;.
If all the doors are closed, the vehicle locks.
This does not lock or unlock the fuel filler flap.
You cannot unlock the vehicle centrally from
the inside if the vehicle has been locked with the key or KEYLESS-GO.
For all countries except the United King-
dom: you can open a door from inside the
vehicle even if it has been locked.
United Kingdom only: you can only open a
door from inside the vehicle if the double lock function has been deactivated. You can deac-
tivate the double lock function by deactivat-
ing the interior motion sensor (Y page 79).
For all countries: you can only open the rear
doors from inside the vehicle if they are not
secured by the child-proof locks (Y page 69). Doors
89Opening and closing Z
Page 93 of 417

If the vehicle has been locked using the lock-
ing button for the central locking, or has been locked automatically, and a door is opened
from the inside:
R the vehicle will be fully unlocked if it had
previously been fully unlocked
R only the door which has been opened form
the inside is unlocked if only the driver's
door had been previously unlocked Automatic locking feature
X
To deactivate: press and hold button :
for approximately five seconds until a tone sounds.
X To activate: press and hold button ;for
approximately five seconds until a tone
sounds.
i If you press one of the two buttons and do
not hear a tone, the relevant setting has
already been selected.
The vehicle is locked automatically when the
ignition is switched on and the wheels are
turning.
You could therefore be locked out if:
R the vehicle is being pushed.
R the vehicle is being towed.
R the vehicle is being tested on a dynamom-
eter.
You can also switch the automatic locking
function on and off using the on-board com-
puter (Y page 255). Unlocking the driver's door (emer-
gency key element)
If the vehicle can no longer be unlocked with
the key, use the emergency key element.
X Take the emergency key element out of the
key (Y page 85).
X Insert the emergency key element into the
lock of the driver's door as far as it will go. X
Turn the emergency key element anti-
clockwise to position 1.
The door is unlocked.
i On right-hand-drive vehicles, turn the
emergency key element clockwise.
X Turn the emergency key element back and
remove it.
X Insert the emergency key element into the
key.
If you use the emergency key element to
unlock and open the driver's door, the anti-
theft alarm system will be triggered
(Y page 78). Locking the vehicle (emergency key
element)
If the vehicle can no longer be locked with the
key, use the emergency key element.
X Open the driver's door.
X Close the front-passenger door, the rear
doors and the boot lid/tailgate.
X Press the locking button (Y page 89).
X Check whether the locking knobs on the
front-passenger door and the rear doors 90
DoorsOpening and closing
Page 94 of 417

are still visible. Press down the locking
knobs by hand, if necessary.
X Close the driver's door.
X Take the emergency key element out of the
key (Y page 85).
X Insert the emergency key element into the
lock of the driver's door as far as it will go. X
Turn the emergency key element clockwise
as far as it will go to position 1.
i On right-hand-drive vehicles, turn the
emergency key element anti-clockwise.
X Turn the emergency key element back and
remove it.
X Make sure that the doors and the boot lid/
tailgate are locked.
X Insert the emergency key element into the
key. Boot/luggage compartment
Important safety notes
G
WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Exhaust
gases can enter the vehicle interior if the boot
lid/tailgate is open when the engine is run-
ning, especially if the vehicle is in motion.
There is a risk of poisoning.
Always switch off the engine before opening
the boot lid/tailgate. Never drive with the
boot lid/tailgate open. G
WARNING
If persons (particularly children) are exposed
to heat or cold for a prolonged period, there is a risk of serious or even fatal injuries. Never
leave persons (particularly children) unatten-
ded in the vehicle.
! The boot lid/tailgate swings upwards and
to the rear when opened. Therefore, make
sure that there is sufficient clearance
above and behind the boot lid/tailgate.
i Boot lid/tailgate opening dimensions
(Y page 407).
Stow luggage or loads preferably in the boot/ luggage compartment. Observe the loading
guidelines (Y page 300).
Do not leave the key in the boot/luggage
compartment. You could otherwise lock your- self out.
Vehicles without the boot lid remote clos-
ing feature: the boot lid can be:
R opened and closed manually from outside
R opened automatically from outside
R opened automatically from inside
R unlocked with the emergency key element
Vehicles with the boot lid remote closing feature: the boot lid can be:
R opened and closed manually from outside
R opened and closed automatically from the
outside
R opened and closed automatically from the
inside
R unlocked with the emergency key element
CLS Shooting Brake: you can:
R open and close the tailgate manually from
outside
R open and close the tailgate automatically
from outside
R open and close the tailgate automatically
from inside
R limit the opening angle of the tailgate
R unlock the tailgate using the emergency
key element Boot/luggage compartment
91Opening and closing Z
Page 95 of 417

Boot lid/tailgate reversing function
The boot lid/tailgate is equipped with an
automatic reversing feature. It reacts if a solid
object obstructs or restricts the boot lid/tail-
gate during the closing procedure. The boot
lid/tailgate opens again automatically. The
automatic reversing function is only an aid
and is not a substitute for your attentiveness to the boot lid/tailgate while it is closing. G
WARNING
The reversing function does not react:
R to soft, light and thin objects, e.g. small fin-
gers
R over the last 8 mm of the closing path
This means that the reversing feature cannot
prevent someone being trapped in these sit-
uations. There is a risk of injury.
When closing make sure that no parts of the
body are in the closing area.
If someone is trapped:
R press the Fbutton on the key, or
R press the remote operating switch on the
driver's door, or
R press the closing or locking button on the
boot lid/tailgate, or
R pull the handle on the boot lid/tailgate Opening/closing from the outside
Opening Example: CLS Coupé, handle X
Press the %button on the key.
X CLS Coupé: pull handle:.
X Raise the boot lid.
CLS Shooting Brake: if you pull handle:
and keep it in this position, you can open the
tailgate manually. If you release the handle,
the tailgate opens automatically.
Closing Recess (example: CLS Coupé)
X Pull the boot lid/tailgate down using
recess :.
X CLS Shooting Brake: let the tailgate drop
into the lock.
X If necessary, lock the vehicle with the &
button on the key (Y page 83)or with KEY-
LESS-GO (Y page 83).
i If a KEYLESS-GO key is detected in the
boot/luggage compartment, the boot lid/
tailgate will not lock.
The boot lid/tailgate then opens again. Opening/closing automatically from
the outside
Important safety notes United Kingdom only:
G
WARNING
When the double locks are activated, the
doors can no longer be opened from the
inside. People in the vehicle can no longer get 92
Boot/luggage compartmentOpening and closing
Page 96 of 417

out, e.g. in hazardous situations. There is a
risk of injury.
Therefore, do not leave any people unsuper-
vised in the vehicle, particularly children, eld- erly people or people in need of special assis-
tance. Do not activate the double lock when
people are in the vehicle.
If the vehicle has been locked from the out-
side, the double-lock function is activated as
standard. It is then not possible to open the
doors from inside the vehicle. You can deac-
tivate the double-lock function by deactivat-
ing the interior motion sensor (Y page 79).
The doors can then be opened from the inside after the vehicle has been locked from the
outside. The anti-theft alarm system is trig-
gered if the door is opened from the inside.
Switch off the alarm (Y page 78).
All countries: G
WARNING
Parts of the body could become trapped dur-
ing automatic closing of the boot lid or tail-
gate. Moreover, people, e.g. children, may be standing in the closing area or may enter the
closing area during the closing process. There
is a risk of injury.
Make sure that nobody is in the vicinity of the closing area during the closing process.
Use one of the following options to stop the
closing process:
R Press the Fbutton on the key.
R Press the remote operating switch on the
driver's door.
R Press the closing or locking button on the
boot lid/tailgate.
R Pull the handle on the boot lid/tailgate.
! The boot lid/tailgate swings upwards and
to the rear when opened. Therefore, make
sure that there is sufficient clearance
above and behind the boot lid/tailgate.
i Boot lid/tailgate opening dimensions
(Y page 407). Opening You can open the boot lid/tailgate automati-
cally with the key or the handle in the boot
lid/tailgate.
X Press and hold the Fbutton on the key
until the boot lid/tailgate opens.
or
X If the boot lid/tailgate is unlocked, pull the
handle of the boot lid/tailgate and release
it again immediately (Y page 92).
Closing Closing button and locking button (example: CLS
Coupé)
X To close: press closing button :in the
boot lid/tailgate.
CLS Coupé with boot lid remote closing
feature and KEYLESS-GO: you can simulta-
neously close the boot lid and lock the vehi-
cle. The KEYLESS-GO key must be in the rear
detection range of the vehicle.
X Press locking button ;in the boot lid.
If all the doors are closed, the vehicle locks.
CLS Shooting Brake: you can simultane-
ously close the tailgate and lock the vehicle.
The KEYLESS-GO key must be in the rear
detection range of the vehicle.
X Press locking button ;on the tailgate.
If all the doors are closed, the vehicle locks.
i If KEYLESS-GO detects a key in the boot/
luggage compartment, the boot lid/tail-
gate opens again after it is closed. Boot/luggage compartment
93Opening and closing Z