
Useful information
iThis Operator's Manual describes all
models and all standard and optional equip- ment of your vehicle available at the time of
publication of the Operator's Manual.
Country-specific differences are possible.
Please note that your vehicle may not be
equipped with all features described. This
also applies to safety-related systems and
functions.
iRead the information on qualified special-
ist workshops ( Y page 27).
SmartKey
Important safety notes
GWARNING
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 shifting the automatic transmission out of
park position P
R Start the engine.
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.
GWARNING
If persons, particularly children are subjected to prolonged exposure to extreme heat or
cold, there is a risk of injury, possibly even
fatal. Never leave children unattended in the
vehicle.
GWARNING
If you attach heavy or large objects to the
SmartKey, the SmartKey could be uninten-
tionally turned in the ignition lock. This could
cause the engine to be switched off. There is arisk of an accident.
Do not attach any heavy or large objects to the
SmartKey. Remove any bulky key rings before
inserting the SmartKey into the ignition lock.
! Keep the SmartKey away from strong
magnetic fields. Otherwise, the remote
control function could be affected.
Strong magnetic fields can occur in the
vicinity of powerful electrical installations.
R Do not keep the KEYLESS-GO key:
- with electronic devices, e.g. a mobile
phone or another SmartKey
- with metallic objects, e.g. coins or metal
foil
- inside metallic objects e.g. a metal case
This can affect the functionality of the
SmartKey.
SmartKey functions
The SmartKey centrally locks/unlocks:
R the doors
R the tailgate
R the fuel filler flap
:& To lock the vehicle
;F To open/close the tailgate
=% To unlock the vehicle
78SmartKey
Opening and closing

The turn signals flash once when unlocking
and three times when locking.
When it is dark, the surround lighting also
comes on if it is activated in the on-board
computer (Y page 231).
You can also set an audible signal to confirm that the vehicle has been locked. The audiblesignal can be activated and deactivated using
the on-board computer ( Y page 232).
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 protection against theft is reactivated.
X To lock centrally: press the & button.
KEYLESS-GO
General notes
Bear in mind that the engine can be started by any of the vehicle occupants if there is a KEY-LESS-GO key in the vehicle.
Locking/unlocking centrally
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
functions of KEYLESS-GO with those of a con- ventional SmartKey. Unlock the vehicle by
using KEYLESS-GO, for instance, and lock it
using the & button on the SmartKey.
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). KEYLESS-GO checks whether a valid Smart-
Key is in the vehicle by periodically establish-
ing a radio connection between the vehicle
and the SmartKey. 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.
Further information on the convenience clos-
ing feature ( Y page 94).
If you pull on the handle of the tailgate, only
the cargo compartment of the vehicle is
unlocked.
Deactivating and activating
If you do not intend to use the vehicle for a
longer period of time, you can deactivate KEY-
LESS-GO. The SmartKey will then use very lit-
tle power, thereby conserving battery power.
For the purposes of activation/deactivation,
the vehicle must not be nearby.
SmartKey79
Opening and closing
Z

XTo deactivate: press the & button on
the SmartKey twice in rapid succession.
The battery check lamp of the SmartKey
( Y page 81) lights up twice briefly and
KEYLESS-GO is deactivated.
X To activate: press any button on the
SmartKey or insert the SmartKey into the
ignition lock.
KEYLESS-GO and all of its associated fea-
tures are available again.
Changing the settings of the locking
system
You can change the settings of the locking
system. 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 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 ( Y page 81)
flashes twice.
iIf the setting of the locking system is
changed within the signal range of the vehi- cle, pressing the & or % button:
R locks or
R unlocks the vehicle
The SmartKey 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.
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
( Y page 79).
X To restore the factory settings: press
and hold down the % and & buttons
simultaneously for approximately six sec-
onds until the battery check lamp flashes
twice.
Mechanical key
General notes
If the vehicle can no longer be locked or
unlocked with the SmartKey or the KEYLESS- GO key, use the mechanical key.
If you use the mechanical key to unlock and
open the driver's door, the anti-theft alarm
system will be triggered ( Y page 75).
X To end the alarm: insert the SmartKey into
the ignition lock.
iWith KEYLESS-GO: remove the Start/
Stop button from the ignition lock before-
hand.
If you unlock the vehicle using the mechanical key, the fuel filler flap will not be unlocked
automatically.
Removing the mechanical key
X Push release catch : in the direction of
the arrow and at the same time remove
mechanical key ; from the SmartKey.
80SmartKey
Opening and closing

Inserting the mechanical key
XPush mechanical key ; completely into
the SmartKey until it engages, and release
catch : is back in its basic position.
SmartKey battery
Important safety notes
Mercedes-Benz recommends that you have
the batteries replaced at a qualified specialist workshop.
GWARNING
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.
Checking the battery
X Press the & or % button.
The battery is working properly if battery
check lamp : lights up briefly.
If battery check lamp : does not light up
briefly during the test, the battery is dis-
charged.
iIf the SmartKey battery is checked within
the signal reception range of the vehicle,
pressing the & or % button:
R locks or
R unlocks the vehicle X
Change the battery ( Y page 81).
iYou can get a battery at a qualified spe-
cialist workshop.
Replacing the battery
You require a CR 2025 3 V cell battery.
X Take the mechanical key out of the Smart-
Key ( Y page 80).
X
Press mechanical key ; into the SmartKey
opening in the direction of the arrow until
battery compartment cover : opens. Do
not hold battery compartment cover :
closed while doing so.
X Remove battery compartment cover :.
X
Repeatedly tap the SmartKey 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 contaminants.
SmartKey81
Opening and closing
Z

XInsert the front tabs of battery compart-
ment cover : into the housing first and
then press to close it.
X Insert mechanical key ; into the Smart-
Key ( Y page 80).
X Check the function of all SmartKey buttons
on the vehicle.
82SmartKey
Opening and closing

Problems with the SmartKey
ProblemPossible causes/consequences and M Solutions
You cannot lock or
unlock the vehicle
using the SmartKey.The SmartKey battery is discharged or nearly discharged.
X Try again to lock/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 % or
& button.
If this does not work:
X Check the SmartKey battery ( Y page 81) and replace it if nec-
essary ( Y page 81).
X Lock ( Y page 86) or unlock ( Y page 86) the vehicle using the
mechanical key.
The SmartKey is faulty.
X Lock ( Y page 86) or unlock ( Y page 86) the vehicle using the
mechanical key.
X Have the SmartKey checked at a qualified specialist wor kshop.
You can no longer lock
or unlock the vehicle
using KEYLESS-GO.KEYLESS-GO is in standby mode because the vehicle has not b een
unlocked for a long time.
X Pull the door handle and then turn the SmartKey to posit ion 2 in
the ignition lock.
There is interference from a powerful source of radio waves.
X Lock/unlock the vehicle using the remote control function of
the SmartKey. Point the tip of the SmartKey at the driv er's door
handle from close range and press the % or & button.
There is a malfunction with KEYLESS-GO. X
Lock/unlock the vehicle using the remote control function of
the SmartKey. Point the tip of the SmartKey at the driv er's door
handle from close range and press the % or & button.
X Have KEYLESS-GO checked at a qualified specialist workshop.
If this does not work:
X Check the SmartKey battery ( Y page 81) and replace it if nec-
essary ( Y page 81).
X Lock ( Y page 86) or unlock ( Y page 86) the vehicle using the
mechanical key.
You have lost a Smart-
Key.X Have the SmartKey deactivated at a qualified specialist work-
shop.
X Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well.
SmartKey83
Opening and closing
Z

ProblemPossible causes/consequences and M Solutions
You have lost the
mechanical key.X
Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well.
The engine cannot be
started using the
SmartKey.The on-board voltage is too low.
X Switch off non-essential consumers, e.g. seat heating or i nterior
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 319).
or
X Jump-start the vehicle ( Y page 323).
or
X Consult a qualified specialist workshop.
The engine cannot be
started using KEYLESS-
GO. The SmartKey is in
the vehicle.A door is open. Therefore, the SmartKey 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 SmartKey in the ignition lock.
Doors
Important safety notes
GWARNING
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 shifting the automatic transmission out of
park position P
R Start the engine.
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.
GWARNING
If persons, particularly children are subjected to prolonged exposure to extreme heat or
cold, there is a risk of injury, possibly even
fatal. Never leave children unattended in the
vehicle.
You should preferably place luggage or loads
in the cargo compartment. Observe the load- ing guidelines ( Y page 274).
Unlocking and opening doors from
the inside
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
84Doors
Opening and closing

are not secured by the child-proof locks
(Y page 67).
You can open a door from inside the vehicle
even if it has been locked.
Only open the door when the traffic situation permits.
If the vehicle has been locked with the Smart-
Key or with KEYLESS-GO, opening a door from the inside will trigger the anti-theft alarm sys-
tem. Switch off the alarm ( Y page 75).
X
To unlock a front door: pull door han-
dle ;.
Locking knob : pops up.
The door is unlocked and can be opened.
X To open a front door: pull door handle ;.
X To unlock a rear door: pull up locking
knob :.
The door is unlocked and can be opened.
X To open a rear door: pull door handle ;.
Centrally locking and unlocking the
vehicle from the inside
You can centrally lock or unlock the vehicle
from the inside.
You cannot unlock the vehicle centrally from
the inside if the vehicle has been locked with
the SmartKey or KEYLESS-GO.
X To unlock: press button :.
X To lock: press button ;.
If the front-passenger door is closed, the
vehicle locks.
Meanwhile, the fuel filler flap will not be
locked or unlocked.
You can open a door from inside the vehicle
even if it has been locked.
Only open the door when the traffic situation permits.
If the vehicle was previously locked with the
SmartKey or with KEYLESS-GO, opening the
vehicle from the inside will activate the anti-
theft alarm system. Switch off the alarm
( Y page 75).
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
button for the central locking, or
R if the vehicle was locked automatically
The vehicle will be fully unlocked if it had pre- viously 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.
If the vehicle has been locked centrally with
the SmartKey or with KEYLESS-GO, it is not
unlocked when the release button for the
central locking is used.
Doors85
Opening and closing
Z