
Locking and unlocking
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 0037 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 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:
R when starting the drive system
R while 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 0043
or 0044.
Make sure that you do not touch the inner
surface of the door handle.
X Convenience closing feature: touch
recessed sensor surface 0044for an extended
period.
Further information on the convenience clos-
ing feature (Y page 77). X
To unlock the tailgate: pull tailgate han-
dle 0043.
Deactivating and activating If you do not intend to use the vehicle for a lon-
ger period of time, you can deactivate KEYLESS-
GO. The SmartKey will then use very little power, thereby conserving battery power. For the pur-
poses of activation/deactivation, the vehicle
must not be nearby.
X To deactivate: press the0037button 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 (Y page 69).
X To activate: press any button on the Smart-
Key.
or X Insert the SmartKey into the ignition lock.
KEYLESS-GO and all of its associated features
are available again. 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 charge socket flap are unlocked when the
vehicle is unlocked. This is useful if you fre-
quently travel on your own.
X To change the setting: press and hold the
0036 and0037 buttons simultaneously for SmartKey
67Opening and closing Z

approximately six seconds until the battery
check lamp flashes twice (Y page 69).
If the setting of the locking system is changed
within the signal range of the vehicle, pressing
the 0037 or0036 button:
R locks or
R unlocks the vehicle
The SmartKey now functions as follows:
X To unlock: press the0036button once.
X To unlock centrally: press the0036button
twice.
X To lock centrally: press the0037button.
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 surface
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.
X To restore the factory settings: press and
hold the 0036and0037 buttons simultane-
ously for approximately six seconds until the
battery check lamp flashes twice
(Y page 69). Mechanical key
General notes If the vehicle can no longer be locked or
unlocked with the SmartKey or KEYLESS-GO,
use the mechanical key.
If you use the mechanical key to unlock and
open the driver's door or the trunk lid, the anti-
theft alarm system will be triggered (Y page 65).
There are several ways to turn off the alarm:
X To deactivate the alarm with the key: press
the 0036 or0037 button on the key.
or X Insert the SmartKey into the ignition lock.
or X To deactivate the alarm with KEYLESS-GO:
press the Start/Stop button in the ignition
lock. The SmartKey must be in the vehicle. or
X Lock or unlock the vehicle using KEYLESS-
GO. The SmartKey must be outside the vehi-
cle.
If you unlock the vehicle using the mechanical
key, the charge socket flap will not be unlocked automatically.
X To unlock the charge socket flap: insert the
SmartKey into the ignition lock.
Removing the mechanical key X
Push release catch 0043in the direction of the
arrow and at the same time remove mechan- ical key 0044from the SmartKey.
For further information about:
R Unlocking the driver's door (Y page 73)
R Unlocking the cargo compartment
(Y page 75)
R Locking the vehicle (Y page 73)
Inserting the mechanical key X
Push mechanical key 0044completely into the
SmartKey until it engages and release
catch 0043is back in its basic position. SmartKey battery
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. 68
SmartKeyOpening and closing

Keep batteries out of the reach of children. If
a battery is swallowed, seek medical attention
immediately.
The SmartKey batteries contain perchlorate
material, which may require special handling
and regard for the environment. National guide- lines must be observed during disposal. In Cal-
ifornia, see www.dtsc.ca.gov/
HazardousWaste/Perchlorate/index.cfm .
Mercedes-Benz recommends that you have the
battery replaced at a qualified specialist work-
shop.
Checking the battery X
Press the 0037or0036 button.
The battery is working properly if battery
check lamp 0043lights up briefly.
The battery is discharged if battery check
lamp 0043does not light up briefly.
X Change the battery (Y page 69).
i If the SmartKey battery is checked within
the signal reception range of the vehicle,
pressing the 0037or0036 button:
R locks or
R unlocks the vehicle
i You can get a battery at any qualified spe-
cialist workshop.
Replacing the battery You require a CR 2025 3 V cell battery. X
Take the mechanical key out of the SmartKey
(Y page 68). X
Press mechanical key 0044into the opening in
the SmartKey in the direction of the arrow
until battery tray cover 0043opens. When doing
so, do not hold cover 0043shut.
X Remove battery tray cover 0043. X
Repeatedly tap the SmartKey against your
palm until battery 0087falls 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 contaminants.
X Insert the front tabs of battery tray cover 0043
and then press to close it.
X Insert mechanical key into the SmartKey
(Y page 68).
X Check the function of all SmartKey buttons on
the vehicle. SmartKey
69Opening and closing Z

Problems with the SmartKey
Problem
Possible causes/consequences and
0050
0050Solutions You cannot lock or
unlock the vehicle using
the SmartKey. The SmartKey battery is discharged or nearly discharged.
X Vehicles without KEYLESS-GO: try again to lock or unlock the
vehicle using the remote control function of the SmartKey. Point the tip of the SmartKey at the driver's door handle from close range and
press the 0036or0037 button.
X Check the SmartKey battery (Y page 69) and replace it if necessary
(Y page 69).
If this does not work: X Unlock (Y page 73) or lock (Y page 73) the vehicle using the
mechanical key. There is interference from a powerful source of radio waves.
X Vehicles without KEYLESS-GO: try again to lock or unlock the
vehicle using the remote control function of the SmartKey. Point the
tip of the SmartKey at the driver's door handle from close range and press the 0036or0037 button.
If this does not work: X Unlock (Y page 73) or lock (Y page 73) the vehicle using the
mechanical key. The SmartKey is faulty.
X Unlock (Y page 73) or lock (Y page 73) the vehicle using the
mechanical key.
X Have the SmartKey checked at a qualified specialist workshop. You can no longer lock or
unlock the vehicle using
KEYLESS-GO. The SmartKey battery is discharged or nearly discharged.
X Check the SmartKey battery (Y page 69) and replace it if necessary
(Y page 69).
If this does not work: X Unlock (Y page 73) or lock (Y page 73) the vehicle using the
mechanical key. There is interference from a powerful source of radio waves.
X Unlock (Y page 73) or lock (Y page 73) the vehicle using the
mechanical key. 70
SmartKeyOpening and closing

Problem
Possible causes/consequences and
0050
0050Solutions KEYLESS-GO is malfunctioning.
X Lock/unlock the vehicle using the remote control function of the
SmartKey.
X Have the vehicle and SmartKey checked at a qualified specialist
workshop.
If the vehicle can also not be locked/unlocked using the remote con-
trol function:
X Unlock (Y page 73) or lock (Y page 73) the vehicle using the
mechanical key.
X Have the vehicle and SmartKey checked at a qualified specialist
workshop. The drive system cannot
be started using the
SmartKey. 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 drive system again.
If this does not work:
X Check the 12 V battery and charge it if necessary (Y page 248).
or
X Check the high-voltage battery and charge it if necessary
(Y page 118).
or
X Jump-start the vehicle (Y page 249).
or
X Consult a qualified specialist workshop. The drive system cannot
be started using the
Start/Stop button. The
SmartKey is in the vehi-
cle. The vehicle is locked.
X Unlock the vehicle and try to start the vehicle again. The SmartKey battery is discharged or nearly discharged.
X Check the SmartKey battery (Y page 69) and replace it if necessary
(Y page 69).
If this does not work: X Start your vehicle with the SmartKey in the ignition lock. There is interference from a powerful source of radio waves.
X Start your vehicle with the SmartKey in the ignition lock. You have lost a Smart-
Key. X
Have the SmartKey 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
mechanical key. X
Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. SmartKey
71Opening and closing Z

Doors
Important safety notes
G
WARNING
If children are left unsupervised in the vehicle, they could:
R open the doors, thus endangering other
people or road users.
R get out and disrupt traffic.
R operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
R release the parking brake.
R shift the transmission out of park position P
R start the vehicle's drive system.
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.
You should preferably place luggage or loads in
the cargo compartment. Observe the loading
guidelines (Y page 207). Unlocking and opening doors from
the inside X
To unlock and open a front door: pull door
handle 0044.
If the door is locked, locking knob 0043pops up.
The door is unlocked and opens.
X To unlock a rear door: pull up locking
knob 0043.
The door is unlocked and can be opened.
X To open a rear door: pull door handle0044.
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 not
secured by the child-proof locks (Y page 58).
If the vehicle has previously been locked with
the SmartKey from the outside, opening a door
from the inside will trigger the anti-theft alarm
system. Switch off the alarm (Y page 65). Centrally locking and unlocking the
vehicle from the inside
You can centrally lock or unlock the vehicle from
the inside. This can be useful if you wish to lock the vehicle before pulling away, for example. X
To unlock: press button 0043.
X To lock: press button 0044.
If all the doors and the tailgate are closed, the
vehicle locks.
This does not lock or unlock the charge socket
flap.
You cannot unlock the vehicle centrally from the
inside if the vehicle has been locked with the
SmartKey or KEYLESS-GO.
You can open a door from inside the vehicle
even if it has been locked. You can open the rear
doors from inside the vehicle unless they are
secured by the child-proof lock (Y page 58).
If the vehicle has previously been locked with
the SmartKey from the outside, opening a door 72
DoorsOpening and closing

from the inside will trigger the anti-theft alarm
system. Switch off the alarm (Y page 65).
If a locked door is opened from the inside, the
previous unlock status of the vehicle will be
taken into consideration if:
R the vehicle was locked using the locking but-
ton for the central locking, or
R if the vehicle was 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. Automatic locking feature
X
To deactivate: press and hold button 0043for
approximately five seconds until a tone
sounds.
X To activate: press and hold button 0044for
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.
You could therefore lock yourself out if:
R the vehicle is being pushed.
R the vehicle is being towed.
R the vehicle is on a roller dynamometer.
You can also switch the automatic locking func-
tion on and off using the on-board computer
(Y page 166). Unlocking the driver's door (mechan-
ical key)
If the vehicle can no longer be locked or
unlocked with the SmartKey or KEYLESS-GO,
use the mechanical key.
If you use the mechanical key to unlock and
open the driver's door, the anti-theft alarm sys- tem will be triggered (Y page 65).
X Take the mechanical key out of the SmartKey
(Y page 68).
X Insert the mechanical key into the lock of the
driver's door as far as it will go. X
Turn the mechanical key counter-clockwise
as far as it will go to position 0047.
The door is unlocked.
X Turn the mechanical key back and remove it.
X Insert mechanical key into the SmartKey
(Y page 68). Locking the vehicle (mechanical key)
If the vehicle can no longer be locked with the
SmartKey or KEYLESS-GO, use the mechanical
key.
X Open the driver's door.
X Close the front-passenger door, the rear
doors and the tailgate.
X Press the locking button on the driver’s door
(Y page 72).
X Check whether the locking knobs on the
front-passenger door and the rear doors are
still visible. Press down the locking knobs by
hand, if necessary.
X Close the driver's door. Doors
73Opening and closing Z

X
Take the mechanical key out of the SmartKey
(Y page 68).
X Insert the mechanical key into the lock of the
driver's door as far as it will go. X
Turn the mechanical key clockwise as far as it
will go to position 0047.
X Turn the mechanical key back and remove it.
X Make sure that the doors and the tailgate are
locked.
X Insert mechanical key into the SmartKey
(Y page 68).
i If you lock the vehicle as described above,
the socket flap is not locked. The anti-theft
alarm system is not armed. Cargo compartment
Important safety notes
G
WARNING
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 tailgate swings upwards and to the rear
when opened. Therefore, make sure that
there is sufficient clearance above and behind
the tailgate. The opening dimensions of the tailgate can be
found in the "Vehicle data" section
(Y
page 286).
You should preferably place luggage or loads in the cargo compartment. Observe the loading
guidelines (Y page 207).
Do not leave the SmartKey in the cargo com-
partment. You could otherwise lock yourself
out.
The tailgate can be:
R opened and closed manually from outside
R released with the emergency release from the
inside Opening/closing from outside
Opening X
Press the 0036button on the SmartKey.
X Pull handle 0043.
X Raise the tailgate.
Closing 74
Cargo compartmentOpening and closing