Page 97 of 489

96 Safety and SecurityAnti-theft systemsArming tow-away alarm
Lock the vehicle with the SmartKey or
KEYLESS-GO*.
The tow-away alarm is automatically
armed after about 30 seconds.Disarming tow-away alarm
To prevent triggering the tow-away alarm,
switch off the tow-away alarm feature
before 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
console.
1Tow-away alarm off switch
2Indicator lamp
Switch off the ignition (
page 36).
Remove the SmartKey.
Press tow-away alarm off switch1.
Indicator lamp2 in tow-away alarm
off switch1 comes on briefly.
Exit the vehicle.
Lock the vehicle with the SmartKey or
(vehicles with KEYLESS-GO*) the lock
button on each outside door handle or
trunk.
The tow-away alarm remains disarmed
until you lock the vehicle again.
iWhen you unlock the vehicle, the
tow-away protection disarms
automatically. The tow-away alarm
remains disarmed until you lock the
vehicle again.
iYou cannot disarm the tow-away alarm
while the ignition is switched on.
Page 98 of 489
97 Controls in detail
Locking and unlocking
Seats
Memory function
Lighting
Instrument cluster
Control system
Automatic transmission
Good visibility
Climate control (CLK 350)
Automatic climate control (CLK 500)
Audio system
Power windows
Power tilt/sliding sunroof*
Driving systems
Loading
Useful features
Page 99 of 489

98 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 giv-
en at the beginning of each segment.Locking and unlocking
For more information on locking and
unlocking, see “Getting started”
(page 32) and (
page 57).
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
different 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 trunk
the fuel filler flap
SmartKey with remote control1‹Lock button
2Š Opening button for trunk
3Mechanical key locking tab
4Œ Unlock button
5Battery check lamp
6Â Panic button (
page 86)
Page 100 of 489

99 Controls in detail
Locking and unlocking
Warning!
G
When leaving the vehicle, always remove the
SmartKey from the starter switch, take it
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 children to open a locked door from the
inside, which could result in an accident
and/or serious injury.!To prevent possible malfunction, avoid
exposing the SmartKey to high levels of
electromagnetic 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
interference received, including
interference that may cause
undesired operation.
Any unauthorized modification to this
device could void the user’s authority
to operate the equipment.
iCanada only:
This device complies with RSS-210 of
Industry Canada. Operation is subject
to the following two conditions:
(1) This device may not cause interfer-
ence, and
(2) this device must accept any
interference received, including
interference that may cause
undesired operation of the device.
Any unauthorized modification to this
device could void the user’s authority
to operate the equipment.iYou can also open and close the power
windows and power tilt/sliding sun-
roof* using the SmartKey, see “Sum-
mer opening feature” (
page 249) and
see “Convenience closing feature”
(
page 250).
Page 101 of 489

100 Controls in detailLocking and unlockingFactory settingGlobal unlocking
Press buttonŒ.
All turn signal lamps flash once.
An acoustic signal sounds once (if
equipped and feature activated).
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
unlocking if:
neither a door nor the trunk is opened
the SmartKey is not inserted in the
starter switch
the central locking switch is not
activatedGlobal locking
Press button‹.
With the trunk and both doors closed:
All turn signal lamps flash three
times.
An acoustic signal sounds three
times (if equipped and feature acti-
vated).
The locking knobs in the doors
move down.
The anti-theft alarm system is
armed.
iYour vehicle may be equipped with an
acoustic lock and unlock confirmation
signal feature. If your vehicle is
equipped with this feature and the fea-
ture is activated, an acoustic signal will
sound when the vehicle is locked or un-
locked using the SmartKey.
To determine whether or not your vehi-
cle is equipped with this feature, con-
tact an authorized Mercedes-Benz
Center. If equipped and you wish to ac-
tivate or deactivate the feature, or ad-
just its signal volume, also contact an
authorized Mercedes-Benz Center.
Page 102 of 489

101 Controls in detail
Locking and unlocking
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 6 seconds un-
til 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.
An acoustic signal sounds once (if
equipped and feature activated).
The locking knob in the driver’s
door move up.
The anti-theft alarm system is dis-
armed.Global unlocking
Press buttonŒ twice.
All turn signal lamps flash once.
An acoustic signal sounds once (if
equipped and feature activated).
The locking knobs in the doors
move up.
The anti-theft alarm system is dis-
armed.
Global locking
Press button‹.
With the trunk and both doors closed:
All turn signal lamps flash three
times.
An acoustic signal sounds three
times (if equipped and feature acti-
vated).
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 6 seconds un-
til battery check lamp5 flashes twice.!If you can no longer lock or unlock the
vehicle with the SmartKey, then the
batteries in the SmartKey are dis-
charged, the SmartKey is malfunction-
ing or the vehicle battery is drained.
Check the batteries in the
SmartKey (
page 102) and re-
place them if necessary
(
page 409).
Use the mechanical key to unlock
the driver’s door (
page 404) and
the trunk (
page 405).
Use the mechanical key to lock the
driver’s door (
page 405) and the
trunk (
page 119).
Have the vehicle battery and the
battery connections checked
(page 426).
Page 103 of 489

102 Controls in detailLocking and unlockingChecking the batteries
Press button‹orŒ.
Battery check lamp5 comes on
briefly to indicate that the SmartKey
batteries are in order.Unlocking and opening the trunk
You can unlock and open the trunk
separately.
A minimum height clearance of 5.71 ft
(1.74 m) is required to open the trunk lid.
Press and hold button Š until trunk
unlocks and begins to open.
The trunk can also be opened from its
inside in an emergency, see “Trunk emer-
gency release” (
page 118).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
replacement. If the SmartKey is malfunctioning,
contact an authorized Mercedes-Benz
Center.
!If battery check lamp5 does not
come on briefly during check, then the
SmartKey batteries are discharged.
Replace the batteries (
page 409).
You can obtain the required batteries
at any authorized Mercedes-Benz
Center.
iIf the batteries are checked within
signal range of the vehicle, pressing
the‹orŒ button will lock or
unlock the vehicle accordingly.
!The trunk lid swings open upwards au-
tomatically. Always make sure there is
sufficient overhead clearance.
Vehicles with trunk opening/closing
system*: To stop the opening proce-
dure, press button Š. The trunk lid
stops moving.iIf the trunk does not open, it is still
locked separately (
page 119).
Page 104 of 489

103 Controls in detail
Locking and unlocking
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 KEYLESS-GO function is integrated
into the SmartKey. On these vehicles, the
validity of the SmartKey with KEYLESS-GO
is checked every time you pull an outside
door handle.
If the SmartKey with KEYLESS-GO is valid,
your vehicle unlocks
the doors
the trunk
the fuel filler flap
SmartKey with KEYLESS-GO1‹Lock button
2Š Opening button for trunk
3Mechanical key locking tab
4Œ Unlock button
5Battery check lamp
6Â Panic button (
page 86)
iWhen the passenger outside door han-
dle is pulled, the vehicle is centrally un-
locked.
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.