98 Safety and Security
Anti-theft systems
Arming the alarm system
The indicator lamp is in the center console.
1Indicator lamp
Lock the vehicle with the SmartKey or
KEYLESS-GO*.The turn signal lamps flash three times,
and an acoustic signal sounds three
times, to indicate that the alarm sys-
tem is armed.
Indicator lamp1 begins to flash after
approximately 30 seconds after arming
the alarm system.
Disarming the alarm system
Unlock your vehicle with the SmartKey
or KEYLESS-GO*.
The turn signal lamps flash once, and
an acoustic signal sounds once, to
indicate that the alarm system is
disarmed.Canceling the alarm
With the SmartKey
Press the Œ or ‹button on the
SmartKey.
or
Insert the SmartKey in the starter
switch.
With KEYLESS-GO*
Pull 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 39).
The SmartKey with KEYLESS-GO must
be inside the vehicle.
iIf the alarm stays on for more than
30 seconds, a call to the Response Center is ini-
tiated automatically by the Tele Aid system
(
page 295) provided Tele Aid service was sub-
scribed to and properly activated, and that nec-
essary cellular service and GPS coverage are
available.
iIf the turn signal lamps do not flash three
times, and the acoustic signal do not sounds
three times (if equipped and feature activated),
one of the following elements may not be prop-
erly closed:
a door
the trunk
Close the respective element and lock the vehi-
cle again.
iThe alarm system will rearm automatically
after approximately 40 seconds if neither a door
nor the trunk lid was opened.
102 Controls in detail
Locking and unlocking
Factory setting
Global unlocking
Press buttonŒ.
All turn signal lamps flash once.
An acoustic signal sounds once.
The locking knobs in the doors
move up.
The anti-theft alarm system is dis-
armed.
The vehicle will lock again automatically
and rearm the anti-theft alarm system
within approximately 40 seconds of
unlocking if:
neither door nor trunk is opened
the SmartKey is not inserted in the
starter switch
the central locking switch is not
activated
Global locking
Press button‹.
With the trunk and both doors closed:
All turn signal lamps flash three
times.
An acoustic signal sounds 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 press-
ing buttonŒ only unlocks the driver’s
door and the fuel filler flap.
Press and hold buttonsŒ and‹
simultaneously for about 5 seconds un-
til battery check lamp5 (
page 100)
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.
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.
iWhen unlocking or locking the vehicle with
the SmartKey an acoustic signal sounds. The
acoustic signal is activated at the factory. If you
wish to deactivate the feature, or adjust its signal
volume, contact an authorized Mercedes-Benz
Center.
103 Controls in detail
Locking and unlocking
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.
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 5 seconds un-
til battery check lamp5 (
page 100)
flashes twice.Unlocking and opening the trunk
You can unlock and open the trunk
separately.
A minimum height clearance of 5.71 ft
(1.74 m) CLK coupe or 5.41 ft (1.65 m)
CLK cabriolet 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 117).
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 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
the glove box
!The trunk lid swings open upwards automat-
ically. Always make sure there is sufficient over-
head clearance.
Vehicles with trunk opening/closing system*: To
stop the opening procedure, press button Š.
The trunk lid stops moving.
iIf the trunk does not open, it is still locked
separately (
page 118).
106 Controls in detail
Locking and unlocking
with the starter switch position1,
the message:
Key Not Detected
appears in the multifunction display
with the engine running, the
message:
Key Not Detected
appears in the multifunction display
while driving off.
Find the SmartKey with KEYLESS-GO or
change its present location immediate-
ly (e.g. place it on the front passenger
seat or insert it in shirt pocket).
If you have started the engine with the
KEYLESS-GO start/stop button
(
page 39), you can turn it off again
with:
the KEYLESS-GO start/stop button
the SmartKey inserted in the starter
switch, when the gear selector le-
ver is in positionP
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 ap-
pears 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 trying to lock the ve-
hicle, the message
Key Detected In Vehicle
will appear in the multifunction display.
The vehicle will not be locked.Factory setting
Global unlocking
Pull an outside door handle (SmartKey
with KEYLESS-GO must be near this
door).
All turn signal lamps flash once.
An acoustic signal sounds once.
The locking knobs in the doors
move up.
The anti-theft alarm system is dis-
armed.
iWhen unlocking or locking the vehicle with
the SmartKey with KEYLESS-GO an acoustic sig-
nal sounds. The acoustic signal is activated at
the factory. If you wish to deactivate the feature,
or adjust its signal volume, contact an authorized
Mercedes-Benz Center.
107 Controls in detail
Locking and unlocking
The vehicle will lock again automatically
and rearm the anti-theft alarm system
within approximately 40 seconds of un-
locking if:
neither door nor trunk is opened.
the central locking switch is not
activated.
Global locking
Press the lock button on an outside
door handle (
page 62).
With the trunk and both doors closed:
All turn signal lamps flash three
times.
An acoustic signal sounds 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 with
KEYLESS-GO so when you, pull the driver’s
door handle only the driver’s door and the
fuel filler flap unlocks.
Press and hold buttonsŒ and‹
simultaneously for about 5 seconds un-
til battery check lamp5 (
page 104)
flashes twice.
The SmartKey with KEYLESS-GO will
then function as follows:Unlocking driver’s door and fuel filler
flap
Pull the driver’s outside door handle.
All turn signal lamps flash once.
An acoustic signal sounds once.
The locking knob in the driver’s
door move up.
The anti-theft alarm system is dis-
armed.
Global unlocking
Pull the outside door handle on the pas-
senger side.
All turn signal lamps flash once.
An acoustic signal sounds once.
The locking knobs in the doors
move up.
The anti-theft alarm system is dis-
armed.
iThe vehicle could inadvertently be unlocked
if the SmartKey with KEYLESS-GO is
within 3 ft (1 m) of the vehicle and:
an outside door handle is splashed with wa-
ter, or
you attempt to clean an outside door handle.
108 Controls in detail
Locking and unlocking
Global locking
Press the lock button on an outside
door handle.
With the trunk and both doors closed:
All turn signal lamps flash three
times.
An acoustic signal sounds 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 5 seconds un-
til Battery check lamp5 (
page 104)
flashes twice.Unlocking and opening the trunk
You can unlock and open the trunk sepa-
rately.
A minimum height clearance of 5.71 ft
(1.74 m) CLK coupe or 5.41 ft (1.65 m)
CLK cabriolet 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 in-
side in an emergency, see “Trunk emer-
gency release” (
page 117).Checking the batteries in the SmartKey
or SmartKey with KEYLESS-GO*
Press button‹orŒ.
Battery check lamp (
page 100) or
(
page 104) comes on briefly to indi-
cate that the SmartKey or SmartKey
with KEYLESS-GO batteries are in
order.
iVehicles with trunk opening/closing sys-
tem*, you can also lock the vehicle using the
KEYLESS-GO locking/closing switch
(
page 116) on the trunk lid.
!The trunk lid swings open upwards automat-
ically. Always make sure there is sufficient over-
head clearance.
Vehicles with trunk opening/closing system*: To
stop the opening procedure, press button Š.
The trunk lid stops moving.
iIf the trunk does not open, it is still locked
separately (
page 118).
!If battery check lamp does not come on
briefly during check, the SmartKey or SmartKey
with KEYLESS-GO batteries are discharged.
Replace the batteries (
page 441).
You can obtain the required batteries at any au-
thorized 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.
109 Controls in detail
Locking and unlocking
Loss of the SmartKey or SmartKey with
KEYLESS-GO*
If you lose your SmartKey, SmartKey with
KEYLESS-GO, or mechanical key, you
should do the following:
Have the SmartKey or SmartKey with
KEYLESS-GO deactivated at an autho-
rized Mercedes-Benz Center.
Report the loss of the SmartKey,
SmartKey with KEYLESS-GO, or the
mechanical key immediately to your
car insurance company.
Have the mechanical lock replaced if
necessary.
Any authorized Mercedes-Benz Center will
be glad to supply you with a replacement.
Opening the doors from the inside
You can open a locked door from the in-
side. Open doors only when conditions are
safe to do so.
Opening a door causes its windows to
open slightly. It will fully close when the
door is shut.
1Locking knob
2Inside door handle
!A side window will not work if it is blocked
with ice or if the battery needs charging. If you
cannot shut a door, do not force it or you could
damage the door or the side window. Fix whatev-
er is affecting the window before trying to shut
the door.
iIf the vehicle has been centrally locked with
the SmartKey or KEYLESS-GO*, opening a door
from the inside will trigger the anti-theft alarm
system.
To cancel the alarm, do one of the following:
With the SmartKey
Insert the SmartKey in the starter switch.
Press button‹orŒ on the
SmartKey.
With KEYLESS-GO*
Press the KEYLESS-GO* start/stop button
(
page 39).
116 Controls in detail
Locking and unlocking
Closing the trunk and locking the vehi-
cle from the outside (vehicles with
KEYLESS-GO*)
In vehicles with trunk opening/closing sys-
tem* and KEYLESS-GO, you can close the
trunk lid and lock the vehicle
simultaneously.
1KEYLESS-GO locking/closing switch
Make sure you have the SmartKey with
KEYLESS-GO with you.
Press switch1 briefly.
With all doors closed, the locking
knobs in the doors move down and the
trunk starts to close automatically. All turn signal lamps flash three times to
confirm locking once the trunk has
closed completely. The anti-theft alarm
system is armed.
If the trunk lid comes into contact with an
object while closing (e.g. luggage that has
been piled too high), the closing procedure
is stopped and the trunk reopens slightly.
iYou can also close the trunk by hand
(
page 113).
iTo prevent a possible inadvertent lockout,
the trunk will open automatically if a SmartKey
with KEYLESS-GO is recognized inside the vehi-
cle or in the trunk.
Warning!G
Monitor the closing procedure carefully to
ensure that no one is in danger of being in-
jured. To prevent possible personal injury,
always keep hands and fingers away from
the trunk opening when closing the trunk.
Be especially careful when small children
are around.
To stop the closing procedure, do one of the
following:
press KEYLESS-GO locking/closing
switch1
press trunk closing switch
press the Š button on the SmartKey
with KEYLESS-GO
press the remote trunk opening or clos-
ing switch (on driver’s door)
Even with the SmartKey with KEYLESS-GO
removed from the vehicle, the trunk closing
switch can be operated. Therefore, do not
leave children unattended in the vehicle, or
with access to an unlocked vehicle. Unsu-
pervised use of vehicle equipment may
cause an accident and/or serious personal
injury.
Warning!G
Only drive with the trunk closed as, among
other dangers such as blocked visibility, ex-
haust fumes may enter the vehicle interior.