Page 89 of 498

87 Safety and Security
Driving safety systems
For more information, see “Practical hints”
(page 353).Switching off the ESP
To improve the vehicle’s traction, turn off
the ESP in driving situations where it would
be advantageous to have the drive wheels
spin and thus cut into surfaces for better
grip such as:
starting out on slippery surfaces and in
deep snow in conjunction with snow
chains
sand or gravel
Warning!
G
The ESP cannot prevent the natural laws of
physics from acting on the vehicle, nor can
it increase the traction afforded. The ESP
cannot prevent accidents, including those
resulting from excessive speed in turns or
hydroplaning. Only a safe, attentive, and
skillful driver can prevent accidents. The
capabilities of an ESP equipped vehicle must
never be exploited in a reckless or danger-
ous manner which could jeopardize the
user’s safety or the safety of others.
!Because of the ESP’s automatic
operation, the engine must be shut off
when
the parking brake is being tested on
a brake test dynamometer
the vehicle is being towed with the
front axle raised
Active braking action through the ESP
may otherwise seriously damage the
brake system.
iThe ESP will only function properly if
you use wheels of the recommended
tire size.
Warning!
G
The ESP should not be switched off during
normal driving other than in the circum-
stances described below. Disabling of the
system will reduce vehicle stability in stan-
dard driving maneuvers.!Turn on the ESP immediately if the
aforementioned circumstances do not
apply anymore.
Page 90 of 498

88 Safety and SecurityDriving safety systemsWhen you switch off the ESP
the ESP does not stabilize the vehicle
the engine output is not limited, which
allows the drive wheels to spin and
thus cut into surfaces for better grip
the traction control will still brake a
spinning wheel
the ESP continues to operate when you
are brakingThe switch is located on the center con-
sole.
1ESP switch (off/on)
Press switch1.
The ESP warning lamp v in the in-
strument cluster comes on.
The ESP is deactivated.
Switching on the ESP
Press switch1 again.
The ESP warning lamp v in the in-
strument cluster goes out.
You are now again in normal driving
mode with ESP switched on.
iWhen the ESP is switched off and one
or more drive wheels are spinning, the
ESP warning lampv in the instru-
ment cluster flashes. However, the ESP
will then not stabilize the vehicle.
Warning!
G
When the ESP warning lampv is
illuminated continuously, the ESP is
switched off.
Adapt your speed and driving to the prevail-
ing road conditions and to the non-operating
status of the ESP.!Avoid spinning of a drive wheel for an
extended period with the ESP switched
off. This may cause serious damage to
the drivetrain which is not covered by
the Mercedes-Benz Limited Warranty.
Page 91 of 498
89 Safety and Security
Anti-theft systems
Anti-theft systems
Immobilizer
The immobilizer prevents unauthorized
persons from starting your vehicle.
Activating
With the SmartKey: Removing the
SmartKey from the starter switch acti-
vates the immobilizer.
With KEYLESS-GO*: Turning off the en-
gine by means of the start/stop button
on the gear selector lever activates the
immobilizer.Deactivating
With the SmartKey: Inserting the
SmartKey in the starter switch deacti-
vates the immobilizer.
With KEYLESS-GO*: Starting the en-
gine by means of the start/stop button
on the gear selector lever deactivates
the immobilizer.
iIn case the engine cannot be started
(yet the vehicle’s battery is charged),
the system is not operational. Contact
an authorized Mercedes-Benz Center
or call 1-800-FOR-MERCedes (in the
USA), or 1-800-387-0100 (in Canada).
Page 92 of 498

90 Safety and SecurityAnti-theft systemsAnti-theft alarm system
Once the alarm system has been armed, a
visual and audible alarm is triggered when
someone opens
a door
the trunk
the hood.
The alarm system will also be triggered
when
someone attempts to raise the vehicle
(page 91)
opening the vehicle with the
mechanical key.Arming the alarm system
The indicator lamp is in the switch for the
tow-away alarm in the center console.
1Indicator lamp
Lock the vehicle with the SmartKey or
KEYLESS-GO*.
The turn signal lamps flash three times
to indicate that the alarm system is
activated. Indicator lamp1 begins to
flash after approximately 30 seconds
after arming the alarm system.
iThe alarm will stay on, even if the
activating element (a door, for
example) is immediately closed.
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) provided
Tele Aid service was subscribed to and
properly activated, and that necessary
cellular service and GPS coverage are
available.
iIf the turn signal lamps do not flash
three times, one of the following
elements may not be properly closed:
a door
the trunk lid
the hood
Close the respective element and lock
the vehicle again.
Page 93 of 498

91 Safety and Security
Anti-theft systems
Disarming the alarm system
Unlock your vehicle with the SmartKey
or KEYLESS-GO*.
The turn signal lamps flash once to
indicate that the alarm system is
deactivatedCanceling the alarm
To cancel 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 the outside door handle.
or
Press the KEYLESS-GO start/stop
button.
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 after approximately 40 seconds if
no door or the trunk lid was opened.
iThe tow-away protection alarm is
triggered, 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) provided
Tele Aid service was subscribed to and
properly activated, and that necessary
cellular service and GPS coverage are
available.
Page 94 of 498

92 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 and remove the
SmartKey.
Press switch1.
Indicator lamp2 in switch1 comes
on briefly.
Exit 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
until you lock your vehicle again.
Canceling the alarm
To cancel 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 the outside door handle.
or
Press the KEYLESS-GO start/stop
button.
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 95 of 498
93 Controls in detail
Locking and unlocking
Seats
Memory function
Lighting
Instrument cluster
Control system
Automatic transmission
Good visibility
Climate control (CLK 320)
Automatic climate control (CLK 500/CLK 55 AMG)
Audio system
Power windows
Power tilt/sliding sunroof*
Driving systems
Loading
Useful features
Page 96 of 498

94 Controls in detailIn 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, refer to the “Getting
started” section of this manual. The corre-
sponding page numbers are given at the
beginning of each segment.Locking and unlocking
For more information on locking and
unlocking, see “Getting started”
(page 32) and (
page 55).
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 lid
3Mechanical key locking tab
4Œ Unlock button
5Battery check lamp
6Â Panic button (
page 83)