
Key
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 outside, the double lock function is activated as stand-
ard. It is then not possible to open the doors
from inside the vehicle. You can deactivate the
double lock function by deactivating the interior
motion sensor (see Digital Owner's Manual).
The doors can then be opened from the inside
after the vehicle has been locked from the out-
side. The anti-theft alarm system is triggered 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. G
WARNING
If you attach heavy or large objects to the key, the key could be unintentionally 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
key. Remove any bulky keyrings before insert-
ing the key into the ignition lock.
! Keep the key away from strong magnetic
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 key: R with electronic devices, e.g. a mobile phone
or another key
R with metallic objects, e.g. coins or metal foil
R inside metallic objects, e.g. a metal case
This can impair the key's function.
Vehicles with KEYLESS-GO start function: do
not keep the key in the boot. Otherwise, the key
may not be detected, e.g. when starting the
engine using the Start/Stop button.
A check that periodically establishes a radio
connection between the vehicle and the key
determines whether a valid key is in or in the
direct vicinity of the vehicle. This occurs, for
example:
R during engine start
R during driving
R when the external door handles are touched
R during convenience closing Key
81Opening and closing Z

Key functions
:
& Locks the vehicle
; F Opens the boot lid
= % Unlocks the vehicle
X To unlock centrally: press the%button.
If you do not open the vehicle within approx-
imately 40 seconds of unlocking:
R the vehicle locks again
R protection against theft is reactivated
X To lock centrally: press the&button.
The key centrally locks and unlocks the follow-
ing components:
R the doors
R the boot lid
R the glove compartment
R the fuel filler flap
During unlocking, the turn signals flash once.
During locking, they flash three times.
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 Digital Owner's Man-
ual).
Only when all the components have been locked is the visual or audible locking confirmation
issued.
When the locator lighting is activated via the
multimedia system, it lights up when it is dark
after the vehicle is unlocked with the key (see
Digital Owner's Manual).
X To open the boot lid automatically from
outside the vehicle: press and hold theF
button until the boot lid opens. KEYLESS-GO
General notes Note that the engine can be started by any of the
vehicle occupants if there is a key in the vehicle
(Y page 135).
Locking and unlocking centrally You can start, lock or unlock the vehicle using
KEYLESS-GO. To do this, you need to carry the
key with you. You can combine the KEYLESS-GO functions with the functions of a conventional
key. Unlock the vehicle using KEYLESS-GO, for
instance, and lock it using the &button on
the key.
The driver's door and the door at which the han- dle is used must both be closed. The key must beoutside the vehicle. When you lock or unlock the
vehicle with KEYLESS-GO, the distance between the key and the door handle must not be greater
than 1 m.
A check that periodically establishes a radio
connection between the vehicle and the key
determines whether a valid key is in or in the
direct vicinity of the vehicle. This occurs, for
example:
R during engine start
R during driving
R when the external door handles are touched
R during convenience closing X
To unlock the vehicle: touch the inner sur-
face of the door handle.
X To lock the vehicle: touch sensor surface :
or ;. 82
KeyOpening and closing

Make sure that you do not touch the inner
surface of the door handle.
X Convenience closing feature: touch
recessed sensor surface ;for an extended
period.
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 key. The key will then use very
little power, thereby conserving battery power.
For the purposes of activation or deactivation,
the vehicle does not have to be nearby.
X To deactivate: press the&button on the
key twice in rapid succession.
The battery indicator lamp (Y page 84) of
the key flashes twice briefly and lights up
once, then KEYLESS-GO is deactivated.
X To activate: press any button on the key.
or X Insert the key into the ignition lock.
KEYLESS-GO and all its associated features
are available again. KEYLESS-GO start function
General notes Bear in mind that the engine can be started by
any of the vehicle occupants if there is a key in
the vehicle (Y
page 135). Changing the settings of the locking
system
You can change the settings of the locking sys-
tem. This means that only the driver's door and
the fuel filler flap are unlocked when the vehicle is unlocked. This is useful if you frequently travel
alone.
X To change the setting: simultaneously press
the % and& buttons for approximately
six seconds until the battery check lamp
(Y page 84) flashes twice.
If the setting of the locking system is changed
within the signal range of the vehicle, pressing
the & or% button:
R locks or
R unlocks the vehicle The key now functions as follows:
X To unlock: press the%button once.
X To unlock centrally: press the%button
twice.
X To lock: press the &button.
The KEYLESS-GO functions can be changed as
follows: 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 surface
of the front-passenger door handle.
X To lock centrally: touch the outer sensor
surface on one of the door handles.
X To restore the factory settings: press and
hold the %and& buttons simultane-
ously for approximately six seconds until the
battery check lamp (Y page 84) flashes
twice. Emergency key element
General notes If the vehicle can no longer be unlocked with the
key or KEYLESS-GO, use the emergency key ele-
ment.
If you use the emergency key element to unlock
and open the driver's door, the anti-theft alarm
system will be triggered. Switch off the alarm
(Y page 78).
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
into the ignition lock. Key
83Opening and closing Z

Removing the emergency key element
X
Push release catch :in the direction of the
arrow and, at the same time, remove emer-
gency key element ;from the key.
Further information on locking/unlocking the
driver's door (Y page 89).
Inserting the emergency key element X
Push emergency key element ;completely
into the key until it engages and release
catch :is back in its basic position. Battery of the key
Important safety notes G
WARNING
Batteries contain toxic and corrosive substan- ces. If batteries are swallowed, it can result in
severe health problems. There is a risk of fatal injury.
Keep batteries out of the reach of children. If
a battery is swallowed, seek medical attention 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-
lection point for used batter-
ies.
Mercedes-Benz recommends that you have the
batteries replaced at a qualified specialist work- shop.
Checking the battery X
Press the &or% button.
The battery is working properly if battery
check lamp :lights up briefly.
The battery is discharged if battery check
lamp :does not light up briefly.
X Replace the battery (Y page 84).
If the key battery 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 qualified
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 84). 84
KeyOpening and closing

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 compart-
ment 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 contamination.
X Insert the front tabs of battery compartment
cover :into the housing and then press to
close it.
X Insert emergency key element ;into the key
(Y page 84).
X Check the function of all key buttons on the
vehicle. 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 weak or discharged.
X Check the key battery (Y page 84) and replace if necessary
(Y page 84).
If this does not work: X Lock or unlock the vehicle using the emergency key element
(Y page 89). Interference from a powerful source of radio waves.
X Lock or unlock the vehicle using the emergency key element
(Y page 89). The key is faulty.
X Lock or unlock the vehicle using the emergency key element
(Y page 89).
X Have the key checked at a qualified specialist workshop. Key
85Opening and closing Z

Problem
Possible causes/consequences and
M
MSolutions You can no longer lock or
unlock the vehicle using
KEYLESS-GO. KEYLESS-GO has been deactivated.
X Reactivate KEYLESS-GO (Y page 82). The key battery is weak or discharged.
X Check the key battery (Y page 84) and replace if necessary
(Y page 84).
If this does not work: X Lock or unlock the vehicle using the emergency key element
(Y page 89). Interference from a powerful source of radio waves.
X Lock or unlock the vehicle using the emergency key element
(Y page 89). Fault with KEYLESS-GO.
X Lock or 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 cannot be locked or unlocked even using the remote
control function:
X Lock or unlock the vehicle using the emergency key element
(Y page 89).
X Have the vehicle and key checked at a qualified specialist work-
shop. 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 332).
or X Jump-start the vehicle (Y page 333).
or X Consult a qualified specialist workshop. The engine cannot be
started using the Start/
Stop button. The key is in
the vehicle. The vehicle is locked.
X Unlock the vehicle and try to start the vehicle again. The key battery is weak or discharged.
X Check the key battery (Y page 84) and replace if necessary
(Y page 84).
If this does not work: X Start your vehicle with the key in the ignition lock. Interference from a powerful source of radio waves.
X Start your vehicle with the key in the ignition lock. 86
KeyOpening and closing

Problem
Possible causes/consequences and
M
MSolutions 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. 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 outside, the double lock function is activated as stand-
ard. It is then not possible to open the doors
from inside the vehicle. You can deactivate the
double lock function by deactivating the interior
motion sensor (see Digital Owner's Manual).
The doors can then be opened from the inside
after the vehicle has been locked from the out-
side. The anti-theft alarm system is triggered 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. Unlocking and opening the doors
from the inside
When a door is opened, the side window on that side opens slightly. When the door is closed, the
side window is raised again.
! The side windows will not open/close if the
battery is discharged or if the side windows
have iced up. It will then not be possible to
close the door. Do not attempt to force the
door to close. You could otherwise damage
the door or the side window.
United Kingdom only: if the vehicle has been
locked with the key or with KEYLESS-GO, the
double lock function is activated as standard. It is then not possible to open the doors from
inside the vehicle. You can deactivate the dou-
ble lock function by deactivating the interior
motion sensor (see Digital Owner's Manual).
The doors can then be opened from the inside
after the vehicle has been locked from the out-
side. The anti-theft alarm system is triggered if
the door is opened from the inside. Switch off
the alarm (Y page 78).
For all countries except the United Kingdom: Doors
87Opening and closing Z

You can open a door from inside the vehicle
even if it has been locked. If the vehicle has pre-
viously been locked with the key or with KEY-
LESS-GO, opening a door from the inside will
trigger the anti-theft alarm system. Switch off
the alarm (Y page 78). X
Pull door handle ;.
If the door is locked, locking knob :pops up.
The door is unlocked and 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. X
To unlock: press button :.
X To lock: press button ;.
When the front-passenger door is closed, the
vehicle is locked.
This does not lock or unlock the fuel filler flap or the glove compartment.
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 Kingdom: The doors can be opened from the inside.
If the vehicle 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 or with KEYLESS-GO, the
double lock function is activated as standard. It is then not possible to open the doors from
inside the vehicle. You can deactivate the dou-
ble lock function by deactivating the interior
motion sensor (see Digital Owner's Manual).
Opening/closing doors is then possible as fol-
lows: the doors can be opened from inside.
When a locked door is opened from inside the
vehicle, the previous unlocking process will be
observed if the vehicle has been:
R locked with the locking button for the central
locking or
R locked automatically
The vehicle will be fully unlocked if it had previ-
ously been fully unlocked. Only the door that has been opened from the inside is unlocked if only
the driver's door had previously been 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.
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 turn-
ing. 88
DoorsOpening and closing