Page 73 of 346

The SmartKey centrally locks/unlocks:R the doors
R the tailgate
R the fuel filler flap
The turn signals flash once when unlocking
and three times when locking.
iWhen the locator lighting is activated in
Audio 20/COMAND, it also lights up when
it is dark after the vehicle is unlocked with
the remote control (see the separate oper- ating instructions).
iYou can also set an audible signal to con-
firm that the vehicle has been locked. The
audible signal can be activated and deacti- vated using the on-board computer( Y page 205).
KEYLESS-GO
General notes
Bear in mind that the engine can be started by
any of the vehicle occupants if there is a
SmartKey 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.
The driver's door and the door at which the
handle 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 cor-
responding door handle must not be greater
than 3 ft (1 m). A check which periodically establishes a radio
connection between the vehicle and the
SmartKey determines whether a valid Smart- Key is in the vehicle. This occurs, for example:
R when starting the engine
R whilst driving
R when the external door handles aretouched
R during convenience closing
X To unlock the vehicle: touch the inner
surface of the door handle.
X To lock the vehicle: touch sensor sur-
face :or; .
Make sure that you do not touch the inner
surface of the door handle.
X Convenience closing feature: touch
recessed sensor surface ;for an exten-
ded period.
Further information on the convenience
closing feature ( Ypage 83).
X
To unlock the tailgate: pull the tailgate
handle.
SmartKey71
Opening and closing
Z
Page 74 of 346

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. X To deactivate: press the&button on
the SmartKey twice in rapid succession.
The battery check lamp of the SmartKey( Y page 73) 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.
KEYLESS-GO start function
Bear in mind that the engine can be started by any of the vehicle occupants if there is a
SmartKey in the vehicle.
Changing the settings of the locking
system
You can change the settings of the locking
system. This means that only the driver's doorand 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: simultaneously
press the %and& buttons for
approximately 6 seconds until the battery
check lamp ( Ypage 73) 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.
X To restore the factory settings: simulta-
neously press the %and& buttons
for approximately 6 seconds until the bat-
tery check lamp flashes twice( Y page 73).
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 67).
There are several ways to turn off the alarm:
X To turn the alarm off with the SmartKey:
press the %or& button on the
SmartKey.
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 igni-
72SmartKey
Opening and closing
Page 75 of 346

tion lock. The SmartKey must be in the
vehicle.
or
X Lock or unlock the vehicle using KEYLESS-
GO. The SmartKey must be outside the
vehicle.
If you unlock the vehicle using the mechanical key, the fuel filler flap will not be unlocked
automatically. X To unlock the fuel filler flap: insert the
SmartKey into the ignition lock.
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.
For further information about:
R unlocking the driver's door ( Ypage 78)
R unlocking the cargo compartment(Y page 80)
R locking the vehicle ( Ypage 79)
Inserting the mechanical key
X
Push mechanical key ;completely into
the SmartKey until it engages and release
catch :is back in its basic position.
SmartKey battery
Important safety notes
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.
The SmartKey batteries contain perchlorate
material, which may require special handling
and regard for the environment. National
guidelines must be observed during disposal.
In California, see www.dtsc.ca.gov/
HazardousWaste/Perchlorate/
index.cfm .
Mercedes-Benz recommends that you have
the battery replaced at a qualified specialist
workshop.
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 Change the battery ( Ypage 74).
SmartKey73
Opening and closing
Z
Page 76 of 346

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
iYou 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 Smart-
Key ( Ypage 72).
X
Press mechanical key ;into the opening
in the SmartKey in the direction of the
arrow until battery tray cover :opens.
When doing so, do not hold cover :shut.
X Remove battery tray 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.
X Insert the front tabs of battery tray cover :
and then press to close it.
X Insert mechanical key into the SmartKey(Y page 73).
X Check the function of all SmartKey buttons
on the vehicle.
74SmartKey
Opening and closing
Page 77 of 346

Problems with the SmartKey
ProblemPossible causes/consequences andMSolutions
You cannot lock or
unlock the vehicle
using the SmartKey.The SmartKey battery is discharged or nearly discharged.
X Vehicles without KEYLESS-GO or KEYLESS-GO start func- tion: try again to lock/unlock the vehicle using the remote con-
trol 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 ( Ypage 73) and replace it if nec-
essary ( Ypage 74).
X Unlock ( Ypage 78) or lock ( Ypage 79) the vehicle using the
mechanical key.
There is interference from a powerful source of radio waves.
X Vehicles without KEYLESS-GO or KEYLESS-GO start func- tion: try again to lock/unlock the vehicle using the remote con-
trol function of the SmartKey. Point the tip of the SmartKey at
the driver's door handle from close range and press the %/
& button.
If this does not work: X Unlock ( Ypage 78) or lock ( Ypage 79) the vehicle using the
mechanical key.
The SmartKey is faulty.
X Unlock ( Ypage 78) or lock ( Ypage 79) 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 ( Ypage 73) and replace it if nec-
essary ( Ypage 74).
If this does not work:
X Unlock ( Ypage 78) or lock ( Ypage 79) the vehicle using the
mechanical key.
There is interference from a powerful source of radio waves.
X Unlock ( Ypage 78) or lock ( Ypage 79) the vehicle using the
mechanical key.
SmartKey75
Opening and closing
Z
Page 78 of 346

ProblemPossible causes/consequences andMSolutions
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
control function: X Unlock ( Ypage 78) or lock ( Ypage 79) the vehicle using the
mechanical key.
X Have the vehicle and SmartKey checked at a qualified specialist
workshop.
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 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 291).
or
X Jump-start the vehicle ( Ypage 293).
or
X Consult a qualified specialist workshop.
The engine 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 ( Ypage 73) and replace it if nec-
essary ( Ypage 74).
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.
76SmartKey
Opening and closing
Page 79 of 346

ProblemPossible causes/consequences andMSolutions
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.
You have lost the
mechanical key.XReport the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well.
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.
You should preferably place luggage or loads in the cargo compartment. Observe the load-
ing guidelines ( Ypage 248).
Unlocking and opening doors from
the inside
X
To unlock and open a front door: pull
door handle ;.
If the door is locked, locking knob :pops
up. The door is unlocked and opens.
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;.
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 59).
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 67).
Doors77
Opening and closing
Z
Page 80 of 346

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.
XTo unlock: press button :.
X To lock: press button ;.
If all the doors and the tailgate are closed,
the vehicle locks.
Meanwhile, the fuel filler flap will not be
locked or unlocked.
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 59).
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 67).
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.
Automatic locking feature
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.
iIf 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 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
function on and off using the on-board com-
puter ( Ypage 205).
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
system will be triggered ( Ypage 67).
78Doors
Opening and closing