Page 101 of 539

100 Safety and SecurityAnti-theft systemsImmobilizer
The immobilizer prevents unauthorized
persons from starting your vehicle.
Activating
With the SmartKey
Remove the SmartKey from the starter
switch.
With KEYLESS-GO*
Press the start/stop button on the
starter switch once.
The engine is turned off.
Open the driver’s door.Deactivating
With the SmartKey
Turn the SmartKey in the starter switch
to position2 (
page 34).
With KEYLESS-GO*
Switch on the ignition (
page 34).
Anti-theft alarm system
Once the alarm system has been armed, a
visual and audible alarm is triggered when
someone opens
a door
the tailgate
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 vehi-
cle, see “Tow-away alarm” (
page 102).
iStarting the engine will also deactivate
the immobilizer.
In case the engine cannot be started
(yet the vehicle’s battery is charged),
the system is not operational. Contact
an authorized Mercedes-Benz Light
Truck Center or call
1-800-FOR-MERCedes (in the USA), or
1-800-387-0100 (in Canada).
iIf the alarm stays on for more than
30 seconds, a call to the Response
Center is initiated automatically by the
Tele Aid* system (
page 280) provid-
ed Tele Aid service was subscribed to
and properly activated, and that neces-
sary cellular service and GPS coverage
are available.
Page 102 of 539

101 Safety and Security
Anti-theft systems
Arming the alarm system
The alarm system is armed after you have
locked the vehicle with the SmartKey or
SmartKey with KEYLESS-GO*.
The alarm system indicator lamp is located
to the lower left of the hazard warning
flasher.
1Alarm system indicator lamp
Make sure all doors and the tailgate are
closed.
Lock the vehicle (
page 60).
The turn signal lamps flash three times
to indicate that the alarm system is
activated.
Indicator lamp1 flashes permanently
to indicate that the alarm system is
armed.Disarming the alarm system
Unlock the vehicle (
page 32).
The turn signal lamps flash once to
indicate that the alarm system is
disarmed. Indicator lamp1 goes out.
iIf the turn signal lamps do not flash
three times, one of the following ele-
ments may not be properly closed:
a door
the tailgate
Close the respective element and lock
the vehicle again.
iThe alarm system will rearm automati-
cally again after approximately
40 seconds if one of the doors or the
tailgate is not opened.
Page 103 of 539

102 Safety and SecurityAnti-theft systemsCanceling the alarm
To cancel the alarm:
With the SmartKey
Insert the SmartKey in the starter
switch.
or
Press theŒ or ‹button on the
SmartKey.
With KEYLESS-GO*
Grasp an outside door handle.
The SmartKey with KEYLESS-GO must
be within 3 ft (1 m) away from the
respective door.
or
Press the KEYLESS-GO start/stop
button.
The SmartKey with KEYLESS-GO must
be inside the vehicle.
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
Make sure all doors and the tailgate are
closed.
Lock your vehicle.
The tow-away alarm is automatically
armed after about ten seconds.
Disarming the tow-away alarm
Unlock your vehicle.
iThe tow-away protection alarm is trig-
gered, for example, if the vehicle is
lifted on one side.
If the alarm stays on for more than
30 seconds, a call to the Response
Center is initiated automatically by the
Tele Aid* system (
page 280), provid-
ed that the Tele Aid service was sub-
scribed to and properly activated, and
that necessary cellular service and GPS
coverage are available.
iWhen you unlock your vehicle, the
tow-away protection disarms automati-
cally.
The tow-away alarm remains disarmed
until you lock your vehicle again.
Page 104 of 539

103 Safety and Security
Anti-theft systems
Switching off 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.
If the tow-away alarm is set to default en-
abled (On) in the control system and you
wish to retain the default setting, you can
switch off the tow-away alarm temporarily
on a one-time basis as follows:
Switch off the ignition (
page 34).
With the tow-away alarm set to default
enabled (On) in the control system, the
following message appears in the
multifunction display.
If you now wish to deactivate the
tow-away alarm on a one-time basis,
pressæ orç button on the
multifunction steering wheel.
The tow-away alarm is switched off.
The following message appears in the
multifunction display.
Exit vehicle and lock the vehicle
(page 60).
The alarm system is armed indepen-
dently of whether the tow-away alarm
is switched on or off.
iThe tow-away alarm feature can be set
to default enabled (On) or disabled (Off)
using the control system (
page 176).
iThe tow-away alarm is switched off on
a one-time basis only. It will be armed
automatically the next time you lock
the vehicle.
If you have disabled the tow-away
alarm feature in the control system
(page 176), you can also switch on
the tow-away alarm on a one-time basis
as described above.
Page 105 of 539
104 Safety and SecurityAnti-theft systemsCanceling tow-away alarm
To cancel the alarm after it has been
triggered:
With the SmartKey
Insert the SmartKey in the starter
switch.
or
Press theŒ or ‹button on the
SmartKey.With KEYLESS-GO*
Grasp an outside door handle.
The SmartKey with KEYLESS-GO must
be within 3 ft (1 m) of the vehicle.
or
Press the KEYLESS-GO start/stop
button.
The SmartKey with KEYLESS-GO must
be inside the vehicle.
Page 109 of 539

108 Controls in detailLocking and unlockingFactory setting
Global unlocking
Press buttonŒ.
All turn signal lamps flash once. The
locking knobs in the doors move up.
The anti-theft alarm system is dis-
armed.
The vehicle will lock again automatically
and reactivate the anti-theft alarm system
within approximately 40 seconds of un-
locking if:
neither door nor tailgate is opened
the SmartKey is not inserted in the
starter switch
the central locking switch is not acti-
vatedGlobal locking
Press button‹.
All turn signal lamps flash three times.
The locking knobs in the doors move
down. The anti-theft alarm system is
armed.
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.
All turn signal lamps flash once. The
locking knob in the driver’s door moves
up. The anti-theft alarm system is
disarmed.
Global unlocking
Press buttonŒ twice.
All turn signal lamps flash once. The
locking knobs in the doors move up.
The anti-theft alarm system is
disarmed.
Global locking
Press button‹.
All turn signal lamps flash three times.
The locking knobs in the doors move
down. The anti-theft alarm system is
armed.
Page 114 of 539

113 Controls in detail
Locking and unlocking
Remember that the engine can be
started by anyone with a SmartKey
with KEYLESS-GO that is left inside the
vehicle.
Possibility 1 (One SmartKey with
KEYLESS-GO in the vehicle, one
SmartKey with KEYLESS-GO outside
the vehicle):
If you leave the SmartKey with
KEYLESS-GO behind when exiting and
locking the vehicle, no message
appears in the multifunction display.
Possibility 2 (One SmartKey with
KEYLESS-GO in the vehicle, no
SmartKey with KEYLESS-GO outside
the vehicle):
When exiting and locking the vehicle,
the message
Key recognized in
vehicle
will appear in the multifunction
display.Factory setting
Global unlocking
Grasp an outside door handle.
All turn signal lamps flash once. The
locking knobs in the doors move up.
The anti-theft alarm system is switched
off.
The vehicle will lock again automatically
and reactivate the anti-theft alarm system
within approximately 40 seconds of
unlocking if:
neither a door nor the tailgate is
opened
the central locking switch is not
activated.Global locking
Press lock button on an outside door
handle (
page 64) or tailgate
(
page 116).
All turn signal lamps flash three times.
The locking knobs in the doors move
down. The anti-theft alarm system is
armed.
i If the vehicle has been parked for more
t h a n 7 2 h o u r s , y o u m u s t p u l l a n o u t s i d e
door handle in order to activate the
KEYLESS-GO function.
iThe vehicle could be inadvertently
unlocked if the SmartKey with
KEYLESS-GO is within 3 ft (1 m) of the
vehicle and
an outside door handle is splashed
with water, or
you attempt to clean an outside
door handle.
Page 115 of 539

114 Controls in detailLocking and unlockingSelective 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 five seconds
until battery check lamp5
(page 110) flashes twice.
The SmartKey with KEYLESS-GO will
then function as follows:
Unlocking driver’s door and fuel filler
flap
Grasp the driver’s outside door handle.
All turn signal lamps flash once. The
locking knob in the driver’s door moves
up. The anti-theft alarm system is dis-
armed.Global unlocking
Grasp any outside door handle other
than the driver’s outside door handle.
All turn signal lamps flash once. The
locking knobs in the doors move up.
The anti-theft alarm system is dis-
armed.
Global locking
Press lock button on an outside door
handle (
page 64).
All turn signal lamps flash three times.
The locking knobs in the doors move
down. The anti-theft alarm system is
armed.Restoring to factory setting
Press and hold buttonsŒ and‹
simultaneously for about five seconds
until battery check lamp5
(page 110) flashes twice.
!If you can no longer lock or unlock the
vehicle with the SmartKey with
KEYLESS-GO, then the batteries in the
SmartKey are discharged, the
SmartKey with KEYLESS-GO is mal-
functioning or the vehicle battery is
drained.
Check the batteries in the
SmartKey with KEYLESS-GO
(page 115) and replace them if
necessary (
page 440).
Use the mechanical key to unlock
the driver’ door (
page 436).