Page 83 of 442
83 Safety and Security
Anti-theft systems
Anti-theft systems
Immobilizer
The immobilizer prevents unauthorized
persons from starting your vehicle.
Activating
With the SmartKey: Removing the
SmartKey from the starter switch acti-
vates the immobilizer.
With KEYLESS-GO*: Turning off the en-
gine by means of the KEYLESS-GO
start/stop button on the gear selector
lever activates the immobilizer.Deactivating
With the SmartKey: Inserting the
SmartKey in the starter switch deacti-
vates the immobilizer.
With KEYLESS-GO*: Starting the en-
gine by means of the start/stop button
on the gear selector lever deactivates
the immobilizer.
iIn case the engine cannot be started
(yet the vehicle’s battery is charged),
the system is not operational. Contact
an authorized Mercedes-Benz Center
or call 1-800-FOR-MERCedes (in the
USA), or 1-800-387-0100 (in Canada).
Page 84 of 442

84 Safety and SecurityAnti-theft systemsAnti-theft alarm system
Once the alarm system has been armed, a
visual and audible alarm is triggered when
someone opens
a door
the trunk
the hood.
The alarm will stay on, even if the activat-
ing element (a door, for example) is imme-
diately closed.
The alarm system will also be triggered
when
someone attempts to raise the vehicle.Arming the alarm system
The alarm system is armed within approxi-
mately ten seconds after locking the vehi-
cle with the SmartKey or KEYLESS-GO*.
The turn signal lamps flash three times to
indicate that the alarm system is activated.
The indicator lamp in the central locking
switch (
page 25) begins to flash after
arming the alarm system.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
deactivated.
iIf the alarm stays on for more than
20 seconds, an emergency call is initi-
ated automatically by the Tele Aid sys-
tem* (
page 250) 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 do not flash
three times one of the following ele-
ments may not be properly closed:
a door
the trunk lid
Close the respective element and lock
the vehicle again.
Page 85 of 442

85 Safety and Security
Anti-theft systems
Canceling the alarm
With the SmartKey
Insert the SmartKey in the starter
switch.
or
Press the Œ or ‹ button on the
SmartKey.
The alarm is canceled.
With KEYLESS-GO*
Grasp the outside door handle.
or
Press the KEYLESS-GO* start/stop
button.
The alarm is canceled.
Tow-away alarm
Once the tow-away alarm is armed, a visual
and audible alarm will be triggered when
someone attempts to raise the vehicle.Arming the tow-away alarm
When you lock your vehicle, the tow-away
alarm is automatically armed after about
30 seconds.
When you unlock your vehicle, the
tow-away protection disarms automatical-
ly.
Disarming the tow-away alarm
To prevent triggering the tow-away alarm
feature, switch off the tow-away alarm be-
fore towing the vehicle, or when parking on
a surface subject to movement, such as a
ferry or auto train.
The button is located on the overhead con-
trol panel.
iThe tow-away protection alarm is trig-
gered, for example, if the vehicle is lift-
ed on one side.
If the alarm stays on for more than
20 seconds, an emergency call is initi-
ated automatically by the Tele Aid sys-
tem* (
page 250), provided that the
Tele Aid service was subscribed to and
properly activated, and that necessary
cellular service and GPS coverage are
available.
Page 86 of 442
86 Safety and SecurityAnti-theft systems1Tow-away alarm off button
Switch off the ignition and remove the
SmartKey.
Press button1.
The indicator lamp in the button comes
on briefly.
Exit and lock your vehicle with the
SmartKey or (vehicles with KEY-
LESS-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 but-
ton.
iYou cannot disarm the tow-away alarm
when the ignition is switched on.
Page 89 of 442

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 five 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 the vehicle. Do not leave children unat-
tended in the vehicle, or with access to an
unlocked vehicle. It is possible for children
to open a looked door from the inside, which
could result in an accident or serious 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
sliding / pop-up roof* (
page 201) or
panorama sliding / pop-up roof*
(
page 208) using the SmartKey.
Page 91 of 442

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*
Specially equipped vehicles come with two
SmartKeys with KEYLESS-GO, each with
remote controls and a removable mechan-
ical key. The locking tabs for the mechani-
cal key portion of the two SmartKeys are a
different color to help distinguish 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 355).
You can obtain the required batteries
at any authorized Mercedes-Benz
Center.
iIf the batteries are checked within sig-
nal range of the vehicle, pressing the
button‹ orŒ will lock or unlock
the vehicle accordingly.
Page 92 of 442

92 Controls in detailLocking and unlockingSmartKey 1‹ Lock button
2Š Unlock button for the trunk lid
3Mechanical key locking tab
4Œ Unlock button
5Battery check lamp
6Â Panic button (
page 73)
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.
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.
Warning!
G
When leaving the vehicle, always remove the
SmartKey from the starter switch, take the
SmartKey with KEYLESS-GO* with you and
lock the vehicle. Do not leave children unat-
tended in the vehicle, or with access to an
unlocked vehicle. Unsupervised use of vehi-
cle equipment may cause serious personal
injury.!To prevent possible malfunction, avoid
exposing the SmartKey with
KEYLESS-GO to high levels of electro-
magnetic radiation.iYou can also open and close the power
windows (
page 197) and
sliding / pop-up roof* (
page 201) or
panorama sliding / pop-up roof*
(
page 208) using the SmartKey.
Page 93 of 442

93 Controls in detail
Locking and unlocking
To lock or unlock the vehicle, the
SmartKey must be located outside the
vehicle within approximately 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 the doors must be closed.
The brake pedal must be firmly de-
pressed. Do not depress the accel-
erator.
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
selector lever is still in positionP and
then the SmartKey is inserted in the
starter switch. The SmartKey will then
have priority over the KEYLESS-GO
function and the vehicle’s electrical
system will operate according 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 and can no longer be recognized by
the system, the vehicle 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 igni-
tion is switched on (e.g. if passenger
exits the vehicle with the SmartKey),
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
recognized in vehicle!
will appear in
the multifunction display.