Page 85 of 435

84 Safety and SecurityAnti-theft systemsArming the alarm system
The alarm system is armed after locking
the vehicle with the SmartKey or
KEYLESS-GO*. The turn signal lamps flash-
es three times to indicate that the alarm
system is activated. The indicator lamp in
the central locking switch (
page 107)
will flash after approximately ten seconds
when the alarm system is completely
armed.Disarming the alarm system
The alarm system is disarmed when you
unlock your vehicle with the SmartKey or
KEYLESS-GO*. The turn signal lamps flash
once to indicate that the alarm system is
deactivatedCanceling the alarm
To cancel the alarm:
With the SmartKey
Insert the SmartKey in the starter
switch.
or
Press the Œ or ‹ button on the
SmartKey.
With KEYLESS-GO*
Grasp the outside door handle.
or
Press the KEYLESS-GO* start/stop
button.
iIf the alarm stays on for more than
20 seconds, an emergency call is initi-
ated automatically by the Tele Aid sys-
tem (
page 242) provided Tele Aid
service was subscribed to and properly
activated, and that necessary cellular
service and GPS coverage are avail-
able.
iIf the turn signal lamps does not flash
three times one of the following ele-
ments may not be properly closed:
a door
the trunk lid
the hood
Close the respective element and lock
the vehicle again.
Page 87 of 435
86 Safety and SecurityAnti-theft systems
Press switch2.
The indicator lamp1 in the button
comes on briefly.
Exit vehicle and lock your vehicle with
the SmartKey or (vehicles with
KEYLESS-GO*) the lock button at each
door handle.
The tow-away alarm remains disarmed un-
til you lock your vehicle again.Canceling tow-away alarm
To cancel the alarm:
With the SmartKey
Insert the SmartKey in the starter
switch.
or
Press the Œ or ‹ button on the
SmartKey.With KEYLESS-GO*
Grasp the outside door handle.
or
Press the KEYLESS-GO* start/stop
button.
Page 90 of 435

89 Controls in detail
Locking and unlocking
Factory setting
Global unlocking
Press buttonŒ.
All turn signal lamps flash once. The
locking knobs in the doors move up.
The vehicle will lock again automatically
within approximately 40 seconds of un-
locking if:
neither door nor trunk is opened
the SmartKey is not inserted in the
starter switch
the central locking switch is not acti-
vated
Global locking
Press button‹.
All turn signal lamps flash three times.
The locking knobs in the doors move
down.Selective setting
If you frequently travel alone, you may wish
to reprogram the SmartKey so that
pressingŒ only unlocks the driver’s
door and the fuel filler flap.
Press and hold buttonsŒ and‹
simultaneously for about six seconds
until battery check lamp5 flashes
twice.
The SmartKey will then function as fol-
lows:
Unlocking driver’s door and fuel filler
flap
Press buttonŒ once.
Global unlocking
Press buttonŒ twice.
Global locking
Press button‹.
Warning!
G
When leaving the vehicle, always remove the
SmartKey from the starter switch, take the
SmartKey with KEYLESS-GO* with you and
lock your vehicle. Do not leave children un-
attended in the vehicle, or with access to an
unlocked vehicle. It is possible for children
to open a locked door from the inside, which
could result in an accident and/or serious
personal injury.!To prevent possible malfunction, avoid
exposing the SmartKey to high levels of
electromagnetic radiation.iYou can also open and close the power
windows (
page 197) and slid-
ing/pop-up roof (
page 201) using
the SmartKey.
Page 92 of 435

91 Controls in detail
Locking and unlocking
Checking the batteries
Press button‹ orŒ.
Battery check lamp5 comes on brief-
ly to indicate that the SmartKey batter-
ies are in order.Loss of SmartKey or mechanical key
If you lose a SmartKey or mechanical key,
you should do the following:
Have the SmartKey deactivated by an
authorized Mercedes-Benz Center.
Report the loss of the SmartKey or the
mechanical key immediately to your
car insurance company.
If necessary, have the mechanical lock
replaced.
Your authorized Mercedes-Benz Center
will be glad to supply you with a replace-
ment.
SmartKey with KEYLESS-GO*
Vehicles equipped with KEYLESS-GO come
with two SmartKeys with KEYLESS-GO,
each with remote control and a removable
mechanical key. The locking tabs for the
mechanical key portion of the two Smart-
Keys are a different color to help distin-
guish each SmartKey unit.
The KEYLESS-GO function is integrated
into the SmartKey. On these vehicles, the
validity of the SmartKey with KEYLESS-GO
is checked every time you grasp a door
handle.
If the SmartKey with KEYLESS-GO is valid,
your vehicle unlocks:
the doors
the trunk lid
the fuel filler flap
!If battery check lamp5 does not
come on briefly during check, then the
SmartKey batteries are discharged.
Replace the batteries (
page 349).
You can obtain the required batteries
at any authorized Mercedes-Benz Cen-
ter.
iIf the batteries are ckecked within sig-
nal range of the vehicle, pressing the
button‹ orŒ will lock or unlock
the vehicle accordingly.
Page 93 of 435

92 Controls in detailLocking and unlockingSmartKey with KEYLESS-GO1‹ Lock button
2Š Unlock button for trunk lid
3Locking tab for mechanical key
4Œ Unlock button
5Battery check lamp
6Â Panic button (
page 76)
For more information on using the
SmartKey buttons, see “SmartKey”
(
page 88).Important notes on using KEYLESS-GO
You can also use the SmartKey with
KEYLESS-GO like a normal
SmartKey (
page 88).
You can combine KEYLESS-GO func-
tions with normal SmartKey functions
(e.g. unlocking with KEYLESS-GO and
locking with the remote control).
Always carry the SmartKey with
KEYLESS-GO with you.
Warning!
G
When leaving the vehicle, always remove the
SmartKey from the starter switch, take the
SmartKey with KEYLESS-GO* with you and
lock your vehicle. Do not leave children un-
attended in the vehicle, or with access to an
unlocked vehicle. Unsupervised use of vehi-
cle equipment may cause an accident
and/or serious personal injury.!To prevent possible malfunction, avoid
exposing the SmartKey with
KEYLESS-GO to high levels of electro-
magnetic radiation.
iIf the vehicle has been parked for a
longer period of time, you must pull the
door handle in order to activate the
KEYLESS-GO function.
You can also close the power windows
(page 198) and sliding/pop-up roof
(page 202) using the SmartKey with
KEYLESS-GO.
Page 94 of 435

93 Controls in detail
Locking and unlocking
Never store the SmartKey with
KEYLESS-GO together with:
Electronic items such as a cellular
phone or another SmartKey with
KEYLESS-GO
Metallic objects such as coins or
metal foil
Doing so could impair the function of
the KEYLESS-GO system.
To lock or unlock the vehicle, the
SmartKey with KEYLESS-GO must be
located outside the vehicle within ap-
proximately 3 ft. (1 m) of a door or the
trunk.
In order to start the engine with the
SmartKey with KEYLESS-GO:
The SmartKey with KEYLESS-GO
must be located in the vehicle.
All doors must be closed.
The brake pedal must be firmly dep-
resed. Do not depress the accelera-
tor.
If you have started the engine with the
KEYLESS-GO start/stop button, you
can only turn it off again with this but-
ton, even if you have put the SmartKey
in the starter switch in the meantime.
This does not apply if, after starting, the
gear selector lever is still in positionP
and the SmartKey is then inserted in
the starter switch. The SmartKey will
then have priority over the SmartKey
with KEYLESS-GO and the vehicle’s
electrical system will operate accord-
ing to the position of the SmartKey in
the starter switch, even stopping the
engine.
If the SmartKey with KEYLESS-GO is
positioned farther away from the vehi-
cle, the system may no longer recog-
nize the SmartKey with KEYLESS-GO.
The vehicle then cannot be locked or
the engine started via the KEYLESS-GO
system.
If the SmartKey with KEYLESS-GO is re-
moved from the vehicle while the en-
gine is switched on (e.g. if passenger
exits the vehicle with the SmartKey
with KEYLESS-GO), the message
KEY
NOT RECOGNIZED!
will appear in the
multifunction display.
Find the SmartKey or change its
present location immediately
(e.g. place it on the front passenger
seat or insert it in shirt pocket).
Remember that the engine can be
started by anyone with a SmartKey
with KEYLESS-GO that is left inside the
vehicle. If you leave the SmartKey with-
KEYLESS-GO behind when exiting and
locking the vehicle, the message
KEY
DETECTED IN VEHICLE!
will appear in
the multifunction display.
Page 95 of 435

94 Controls in detailLocking and unlockingFactory setting
Global unlocking
Grasp the door handle.
The vehicle will lock again automatically
within approximately 40 seconds of un-
locking if neither door nor trunk is opened.
Global locking
Press lock button at door handle
(page 55) or trunk (
page 95).Selective setting
If you frequently travel alone, you may wish
to reprogram the SmartKey with
KEYLESS-GO so when you, grasp the driv-
er’s door handle only the driver’s door and
the fuel filler flap unlocks.
Press and hold buttonsŒ and‹
simultaneously for about six seconds
until battery check lamp5 flashes
twice.
The SmartKey with KEYLESS-GO will
then function as follows:
Unlocking the driver’s door
Grasp the driver’s door handle.
Global unlocking
Grasp the door handle on the pas-
senger side.
Global locking
Press lock button at door handle or
trunk lid.Restoring to factory setting
Press and hold buttonsŒ and‹
simultaneously for about six seconds
until battery check lamp5 flashes
twice.
iThe vehicle could inadvertently be un-
locked if the SmartKey with
KEYLESS-GO is within 3 ft. (1 m) of the
vehicle and:
the door handle is splashed with
water, or
you attempt to clean the door
handle
!If you can not lock or unlock the vehicle
with the SmartKey with KEYLESS-GO,
then the battery in the SmartKey is dis-
charged, the SmartKey with
KEYLESS-GO is malfunctioning or the
vehicle battery is drained.
Check the battery in the SmartKey
with KEYLESS-GO and replace them
if necessary (
page 349).
Use the mechanical key to unlock
the doors (
page 348) and the
trunk lid (if applicable)
(
page 349) as required.
Have the vehicle battery and the
battery connections checked.
Page 96 of 435

95 Controls in detail
Locking and unlocking
Locking the vehicle
1Vehicle lock button
Press vehicle lock button1.
or
Press the lock button at the outside
door handle (
page 55).
or
Vehicles with trunk lid opening/closing
system*, press the KEYLESS-GO lock-
ing/closing switch at the trunk
(page 103).
The vehicle locks. The turn signals
flashes three times to confirm locking.Checking the battery
Press button‹ orŒ.
Battery check lamp5 comes on brief-
ly to indicate that the SmartKey battery
is in order.
Use the mechanical key to lock the
doors (
page 348) and the trunk
lid (
page 349) as required.
If the SmartKey with KEYLESS-GO is
malfunctioning, contact an authorized
Mercedes-Benz Center.
!If battery check lamp5 does not
come on briefly during check, the
SmartKey battery is discharged.
Replace the battery (
page 349).
You can obtain the required battery at
any authorized Mercedes-Benz Center.
iIf the battery is ckecked within signal
range of the vehicle, pressing the
button‹ orŒ will lock or unlock
the vehicle accordingly.