Page 106 of 561

105 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 67).
The turn signal lamps flash three times
to indicate that the vehicle is locked.
The alarm system is armed within ap-
proximately 10 seconds. Alarm system
indicator lamp 1 flashes.
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 311) provid-
ed Tele Aid* service was subscribed to
and properly activated, and that neces-
sary cellular service and GPS coverage
are available.
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.
Page 107 of 561

106 Safety and SecurityAnti-theft systemsDisarming the alarm system
Unlock the vehicle (
page 36).
The turn signal lamps flash once to
indicate that the vehicle is disarmed.Canceling 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) of the vehicle.
or
Press the KEYLESS-GO start / stop
button (
page 40).
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.
iThe alarm system will rearm automati-
cally again after approximately
40 seconds if neither a door nor the
tailgate is opened.
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 311) provid-
ed Tele Aid* service was subscribed to
and properly activated, and that neces-
sary cellular service and GPS coverage
are available.
Page 108 of 561

107 Safety and Security
Anti-theft systems
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 10 seconds.
Disarming the tow-away alarm
Unlock your vehicle.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 38).
With the tow-away alarm set to default
enabled (
on) in the control system, the
following message appears in the mul-
tifunction display.
If you now wish to deactivate the
tow-away alarm on a one-time basis,
press button + or - on the mul-
tifunction steering wheel.
The tow-away alarm is switched off.
The following message appears in the
multifunction display.
iWhen you unlock your vehicle, the
tow-away protection disarms automati-
cally.
The tow-away alarm remains disarmed
until you lock your vehicle again.
iThe tow-away alarm feature can be set
to default enabled (
on) or disabled (
off
)
using the control system (
page 191).
Page 111 of 561

110 Controls in detailIn the “Controls in detail” section you will
find detailed information on how to oper-
ate the equipment installed in your vehicle.
If you are already familiar with the basic
functions of your vehicle, this section will
be of particular interest to you.
To quickly familiarize yourself with the ba-
sic functions of the vehicle, refer to the
“Getting started” section of this manual.
The corresponding page numbers are
given at the beginning of each segment.Locking and unlocking
For more information on locking and un-
locking, see the “Getting started” section
(page 36) and (
page 67).
SmartKey
Your vehicle comes supplied with two
SmartKeys, each with remote control and
a removable mechanical key.
The locking tabs for the mechanical key
portion of the two SmartKeys are a differ-
ent color to help distinguish each
SmartKey unit.
The SmartKey provides an extended oper-
ating range. To prevent theft, however, it is
advisable to only unlock the vehicle when
you are in close proximity to it.
The SmartKey centrally locks and unlocks:
the doors
the tailgate
the fuel filler flap
SmartKey with remote control1‹Lock button
2ŠUnlock button* for tailgate
3Locking tab for mechanical key
4ŒUnlock button
5Battery check lamp
6ÂPanic button (
page 95)
Page 113 of 561

112 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
disarmed.
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
activatedGlobal locking
Press button‹.
With the tailgate and all doors closed,
the turn signal lamps flash three times.
The locking knobs on 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 5 seconds
until battery check lamp5
(page 110) 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.
Page 114 of 561

113 Controls in detail
Locking and unlocking
Global locking
Press button‹.
With the tailgate and all doors closed,
the turn signal lamps flash three times.
The locking knobs on the doors move
down. The anti-theft alarm system is
armed.
Restoring to factory setting
Press and hold buttonsŒ and‹
simultaneously for about 6 seconds
until battery check lamp5
(page 110) flashes twice.Checking the batteries
Press button‹orŒ.
Battery check lamp5 (
page 110)
comes on briefly to indicate that the
SmartKey batteries are in order.
!If you cannot lock or unlock the vehicle
with the SmartKey, then either the bat-
teries in the SmartKey are discharged,
the SmartKey is malfunctioning, or the
vehicle battery is drained.
Check the batteries in the
SmartKey and replace them if
necessary (
page 463).
Use the mechanical key to unlock
the driver’s door (
page 459).
Lock the vehicle as described in the
“Practical hints” section
(page 460).
Have the vehicle battery and the
vehicle battery connections
checked (
page 487).
If the SmartKey is malfunctioning, con-
tact an authorized Mercedes-Benz
Light Truck Center.
iIf battery check lamp5 does not
come on briefly during check, the
SmartKey batteries are discharged.
Replace the batteries (
page 463).
You can obtain the required batteries
at any authorized Mercedes-Benz Light
Truck Center.
iIf the batteries are checked within
signal range of the vehicle, pressing the
button‹orŒ will lock or un-
lock the vehicle accordingly.
Page 115 of 561

114 Controls in detailLocking and unlockingUnlocking and opening the tailgate
You can unlock and open the tailgate sep-
arately.
A minimum height clearance of 7.2 ft
(2.20 m) is required to open the tailgate.
Press and hold buttonŠ on the
SmartKey until the tailgate unlocks and
begins to open.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 Light Truck
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 Light
Truck Center will be glad to supply you
with a replacement.
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 SmartKeys with
KEYLESS-GO are a different color to help
distinguish each SmartKey with
KEYLESS-GO unit.
The function of the SmartKey overrules the
KEYLESS-GO function.
The KEYLESS-GO function is integrated
into the SmartKey. On these vehicles, the
validity of the SmartKey with KEYLESS-GO
is checked when you grasp an outside door
handle.
If the SmartKey with KEYLESS-GO is valid,
your vehicle unlocks
the doors
the tailgate
the fuel filler flap
!The tailgate swings open upwards auto-
matically. Always make sure there is
sufficient overhead clearance.
Vehicles with tailgate opening/closing
system*:
To stop the opening procedure, press
buttonŠ on the SmartKey. The tail-
gate stops moving.
iIf the vehicle was previously centrally
locked with the SmartKey, the tailgate
will lock automatically when closed.
The turn signals will flash three times to
confirm locking.
Page 116 of 561

115 Controls in detail
Locking and unlocking
SmartKey with KEYLESS-GO*1‹ Lock button
2Š Unlock button* for tailgate
3Mechanical key locking tab
4Œ Unlock button
5Battery check lamp
6Â Panic button (
page 95)
Warning!
G
When leaving the vehicle, always 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 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.
iUSA only:
This device complies with Part 15 of
the FCC Rules. Operation is subject to
the following two conditions:
(1) This device may not cause harmful
interference, and
(2) this device must accept any inter-
ference received, including interfer-
ence that may cause undesired
operation.
Any unauthorized modification to this
device could void the user’s authority
to operate the equipment.