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X
To change the setting: press and hold
down the %and& buttons
simultaneously for approximately six
seconds until the battery check lamp
flashes twice (Y page 73).
i 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 SmartKey now functions as follows:
X To unlock the driver's door: press the
% button once.
X To unlock centrally: press the%
button twice.
X To lock centrally: press the&button.
The KEYLESS-GO function is 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 down the %and& buttons
simultaneously for approximately six
seconds until the battery check lamp
flashes twice (Y page 73). Mechanical key
General notes If the vehicle can no longer be locked or
unlocked with the SmartKey, 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 disarm 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
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 (Y page 78)
R unlocking the trunk ( Ypage 81)
R locking the vehicle (Y page 78)72
SmartKeyOpening and closing
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SmartKey battery
Important safety notes G
WARNING
Batteries contain toxic and corrosive
substances. 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.
Mercedes-Benz recommends that you have
the batteries replaced at a qualified specialist
workshop.
The SmartKey batteries contain perchlorate
material, which may require special handling
and regard for the environment. National
guidelines must be observed during disposal.
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 (Y page 73).
i If the SmartKey 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 get a battery at any qualified
specialist workshop.
Replacing the battery You require a CR 2025 3 V cell battery.
X
Take the mechanical key out of the
SmartKey (Y page 72). 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
terminal 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. SmartKey
73Opening and closing Z
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Problems with the SmartKey
Problem Possible causes/consequences and
M
MSolutions You can no longer lock
or unlock the vehicle
using the SmartKey. The SmartKey battery is discharged or nearly discharged.
X
Check the SmartKey battery (Y page 73) and replace it if
necessary (Y page 73).
If this does not work:
X Unlock (Y page 78) or lock (Y page 78) the vehicle using the
mechanical key. The SmartKey is faulty.
X
Unlock (Y page 78) or lock (Y page 78) 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. There is interference from a powerful source of radio waves.
X
Lock/unlock the vehicle using the remote control function of
the SmartKey. To do this, hold the SmartKey as close as possible
to the vehicle and press the %or& button.
If the vehicle can also not be locked/unlocked using the remote
control function:
X Unlock (Y page 78) or lock (Y page 78) the vehicle using the
mechanical key. KEYLESS-GO is malfunctioning.
X
Lock/unlock the vehicle using the remote control function of
the SmartKey.
X Have KEYLESS-GO checked at a qualified specialist workshop.
If the vehicle can also not be locked/unlocked using the remote
control function:
X Unlock (Y page 78) or lock (Y page 78) the vehicle using the
mechanical key.
X Have KEYLESS-GO checked at a qualified specialist workshop. You have lost a
SmartKey. 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
75Opening and closing Z
Page 241 of 356

Display messages Possible causes/consequences and
M
MSolutions Â
Replace Replace
Key KeyBattery
Battery The batteries of the KEYLESS-GO key are discharged.
X
Change the batteries ( Ypage 73). Â
Don't Forget Your Don't Forget Your
Key Key The display message is shown for a maximum of 60 seconds and
is only a reminder.
You have opened the driver's door with the engine switched off.
The KEYLESS-GO key is not in the ignition lock.
X
Remember to take the KEYLESS-GO key with you when you
leave the vehicle. Â
Key not detected Key not detected
(red display message) The KEYLESS-GO key is not in the vehicle.
A warning tone also sounds.
If the engine is switched off, you can no longer lock the vehicle
centrally or start the engine.
X
Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Ypage 159).
X Locate the KEYLESS-GO key. The KEYLESS-GO key is not detected while the engine is running
because there is interference from a strong source of radio waves.
A warning tone also sounds.
X
Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Ypage 159).
X Operate the vehicle with the SmartKey in the ignition lock. Â
Key Not Detected Key Not Detected
(white display
message) The KEYLESS-GO key cannot be detected at present.
X
Change the location of the SmartKey with the KEYLESS-GO
functions in the vehicle.
If the KEYLESS-GO key is still not detected:
X Operate the vehicle with the SmartKey in the ignition lock. Â
Key Detected in Key Detected in
Vehicle Vehicle The KEYLESS-GO key has been detected inside the vehicle during
locking.
X
Remove the KEYLESS-GO key from the vehicle. Display
messages
239On-board computer and displays Z