Page 84 of 416

84 Safety and SecurityAnti-theft systemsTow-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 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 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 switch is located on the center con-
sole.
1Tow-away alarm off switch
2Indicator lamp
Turn off the ignition and remove the
SmartKey.
Press switch1.
Indicator lamp2 in the switch lights up
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.
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, provided Tele Aid service was
subscribed to and properly activated
and that necessary cellular service and
GPS coverage are available.
iYou cannot disarm the tow-away alarm
if the ignition is turned on.
Page 86 of 416

86 Controls in detailLocking and unlockingIn the “Controls in detail” section you will
find detailed information on how to oper-
ate the equipment installed on your vehi-
cle. 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, see “Getting
started” (
page 29). The corresponding
page numbers are given at the beginning of
each segment.
For information on locking and unlocking,
refer to the Getting started section on
(
page 30) and (
page 50).
Locking and unlockingSmartKey
Your vehicle comes supplied with two
SmartKeys with remote controls and a re-
movable mechanical key. The locking tabs
for the mechanical key portion of the two
SmartKeys are a different color to help dis-
tinguish 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 trunk
the fuel filler flap
SmartKey with remote controls1‹
Lock button
2
Š
Unlock button for trunk lid
3Mechanical key locking tab
4
Œ
Unlock button
5Battery check lamp
6
Â
Panic button (
page 75)
!To prevent possible malfunction, avoid
exposing the SmartKey to high levels of
electromagnetic radiation.
iYou can also open and close the power
windows (
page 190) and slid-
ing/pop-up roof (
page 194) using
the SmartKey.
Page 87 of 416

87 Controls in detail
Locking and unlocking
Factory setting
Global unlocking
Press button
Œ
.
All turn signal lamps blink once. The
locking knobs in the doors move up.
The anti-theft alarm system is switched
off. If it is dark, the locator lighting
switches on.
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-
vatedGlobal locking
Press button
‹
.
All turn signal lamps blink three times.
The locking knobs in the doors move
down.
The anti-theft alarm system is activat-
ed.Selective setting
If you frequently travel alone, you may wish
to reprogram the SmartKey so that
pressing
Œ
only unlocks the driver’s
door and the fuel filler flap.
Press and hold buttons
Œ
and
‹
simultaneously for about five seconds
until battery check lamp5 blinks twice.
The SmartKey will then function as fol-
lows:
Unlocking driver’s door and fuel filler
flap
Press button
Œ
once.
Global unlocking
Press button
Œ
twice.
Global locking
Press button
‹
.
Page 88 of 416

88 Controls in detailLocking and unlockingRestoring to factory setting
Press and hold buttons
Œ
and
‹
simultaneously for about six seconds
until battery check lamp5 blinks twice.Checking the batteries
Press button
‹
or
Œ
.
Battery check lamp5 lights up briefly
to indicate that the SmartKey batteries
are in order.
Warning!
G
When leaving the vehicle, always remove the
SmartKey from the starter switch, take the
KEYLESS-GO* card (if so equipped) with you
and lock the vehicle. Do not leave children
unattended in the vehicle, or with access to
an unlocked vehicle. It is possible for chil-
dren to open a locked door from the inside,
which could result in an accident and/or se-
rious injury.
!If you can no longer lock or unlock the
vehicle with the SmartKey, then either
the batteries in the SmartKey are dis-
charged or the SmartKey is malfunc-
tioning.
Check the batteries in the
SmartKey and replace them if nec-
essary (
page 328).
or
Use the mechanical key to unlock
the doors (
page 326) and trunk
(
page 327) as required. Lock the
vehicle using the mechanical key
(page 327).
If the SmartKey is malfunctioning, con-
tact an authorized Mercedes-Benz Cen-
ter.
!If battery check lamp5 does not light
up briefly during check, the SmartKey
batteries are discharged.
Replace the batteries (
page 328).
You can obtain the required batteries
at any authorized Mercedes-Benz Cen-
ter.
Page 89 of 416

89 Controls in detail
Locking and unlocking
Unlocking the trunk lid
You can unlock the trunk separately.
Press and hold button
Š
until trunk
unlocks.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.
KEYLESS-GO card*
Specially equipped vehicles come with two
KEYLESS-GO cards. On these vehicles, the
validity of the KEYLESS-GO card is
checked every time you grasp a door
handle.
If the card is valid, your vehicle unlocks:
the doors
the trunk lid
the fuel filler flap
!The trunk lid swings open upwards au-
tomatically. Always make sure that
there is sufficient overhead clearance.
A minimum height clearance of 6 ft.
(1.85 m) is required to open the trunk
lid.iIf the vehicle was previously centrally
locked with the SmartKey, the trunk lid
will lock automatically after closing it.
The turn signals will flash three times to
confirm locking.
If the trunk lid was previously locked
separately (
page 98), it will remain
locked.
Page 90 of 416

90 Controls in detailLocking and unlocking
Important notes on using KEYLESS-GO
Always carry the KEYLESS-GO card
with you.
Never store the KEYLESS-GO card to-
gether with:
Electronic items such as a cellular
phone or another KEYLESS-GO card
Metallic objects such as coins or
metal foil
Doing so could impair the function of
the KEYLESS-GO system.
Always take a SmartKey with you in
case of a malfunction in the
KEYLESS-GO system.
To lock or unlock the vehicle, the card
must be located outside the vehicle
within approximately 3 ft. (1 m) of a
door or the trunk lid.
In order to start the engine with the
KEYLESS-GO card:
The KEYLESS-GO card must be lo-
cated in the vehicle.
All doors must be closed.
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. The
SmartKey will then have priority over
the card and the vehicle’s electrical
system will operate according to the
position of the SmartKey in the starter
switch, even stopping the engine.
Warning!
G
When leaving the vehicle, always remove the
SmartKey from the starter switch, take the
KEYLESS-GO card (if so equipped) with you
and lock the vehicle. Do not leave children
unattended in the vehicle, or with access to
an unlocked vehicle. Unsupervised use of
vehicle equipment may cause an accident
and/or serious personal injury.!To prevent possible malfunction, avoid
exposing the KEYLESS-GO card to high
levels of electromagnetic radiation.
Page 91 of 416

91 Controls in detail
Locking and unlocking
If the KEYLESS-GO card is positioned
farther away from the vehicle (e.g. in-
side clothing or briefcase) and can no
longer be recognized by the system,
the vehicle cannot be locked or the en-
gine started via the KEYLESS-GO sys-
tem.
If the KEYLESS-GO card is removed
from the vehicle while the ignition is
switched on (e.g. if passenger exits the
vehicle with the card), the message CHIP CARD NOT RECOGNIZED!
will ap-
pear in the multifunction display.
Find the card or change its present lo-
cation 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 KEYLESS-GO
card that is left inside the vehicle. If you
leave the card behind when exiting and
locking the vehicle, the message
CHIP
CARD DETECTED IN VEHICLE!
will ap-
pear in the multifunction display.Factory 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 53) or trunk (
page 93).Individual setting
If you frequently travel alone, you may wish
to reprogram the KEYLESS-GO card so that
grasping a door handle only unlocks the
driver’s door, interior lockable storage
compartments and the fuel filler flap.
1Programming button
2“Driver’s door” symbol
3“Global unlock” symbol
iThe vehicle could inadvertently be un-
locked if the KEYLESS-GO card is with-
in 3 ft. (1 m) of the vehicle and:
the door handle is splashed with
water, or
you attempt to clean the door
handle
Page 92 of 416

92 Controls in detailLocking and unlocking
Press and hold programming button1
until “Driver’s door” symbol2 lights up.
The KEYLESS-GO card will then func-
tion 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 programming button1
until “Central unlock” symbol3 lights
up.Checking the batteries
Briefly press programming button1.
The KEYLESS-GO card batteries are in
order if the indicator lamp for either
“Driver’s door”2 or “Central unlock”3
comes on red or green.
!If you cannot lock or unlock the vehicle
with the KEYLESS-GO card, then either
the batteries of the KEYLESS-GO card
are discharged or the KEYLESS-GO
card is malfunctioning.
Check the batteries of the
KEYLESS-GO card (
page 89) and
replace them if necessary
(
page 328).
or
Use the SmartKey to unlock the
doors (
page 30) and trunk
(
page 98) as required. Lock the
vehicle using the SmartKey
(page 93).
If your KEYLESS-GO card is malfunc-
tioning, contact your authorized
Mercedes-Benz Center.
!If symbols2 or3 do not light up during
the check, then the batteries of the
KEYLESS-GO card are discharged.
Change the batteries (
page 328).
You can obtain the batteries at any au-
thorized Mercedes-Benz Center.