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88 Safety and Security
Driving safety systems
In this section you will find information on
the following driving safety systems:
ABS (Antilock Brake System)
BAS (Brake Assist System)
ESP® (Electronic Stability Program)
ABS
The Antilock Brake System (ABS) regulates
the brake pressure so that the wheels do
not lock during braking. This allows you to
maintain the ability to steer your vehicle.
The ABS is functional above a speed of
approximately 5 mph (8 km/h) indepen-
dent of road surface conditions.
On slippery road surfaces, the ABS will
respond even to light brake pressure.
The - indicator lamp in the instrument
cluster (
page 26) comes on when you
switch on the ignition. It goes out when the
engine is running.
Warning!G
The following factors increase the risk of
accidents:
Excessive speed, especially in turns
Wet and slippery road surfaces
Following another vehicle too closely
The ABS, BAS, and ESP
® cannot reduce this
risk.
Always adjust your driving style to the
prevailing road and weather conditions.
iIn winter operation, the maximum effective-
ness of the ABS, the BAS, and the ESP® is only
achieved with winter tires (
page 351) or snow
chains as required.
Warning!G
Do not pump the brake pedal. Use firm,
steady brake pedal pressure instead. Pump-
ing the brake pedal defeats the purpose of
the ABS and significantly reduces braking
effectiveness.
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Braking
At the instant one of the wheels is about to
lock up, a slight pulsation can be felt in the
brake pedal, indicating that the ABS is in
the regulating mode.
Keep firm and steady pressure on the
brake pedal while experiencing the
pulsation.
Continuous, steady brake pedal pressure
yields the advantages provided by the ABS,
namely braking power and the ability to
steer the vehicle.
The pulsating brake pedal can be an
indication of hazardous road conditions
and functions as a reminder to take extra
care while driving.Emergency brake maneuver
Keep continuous full pressure on the
brake pedal.
For more information, see “Practical hints”
(
page 365).
Warning!G
When the ABS is malfunctioning, the BAS
and the ESP® are also switched off. The ba-
sic driving and braking functions are still
available
When the ABS is malfunctioning, the wheels
may lock during hard braking, reducing
steering capability and extending the brak-
ing distance.
Warning!G
The ABS cannot prevent the natural laws of
physics from acting on the vehicle, nor can
it increase braking or steering efficiency
beyond that afforded by the condition of the
vehicle brakes and tires or the traction avail-
able on the road surface. The ABS cannot
prevent accidents, including those resulting
from excessive speed in turns, following an-
other vehicle too closely, or hydroplaning.
Only a safe, attentive, and skillful driver can
prevent accidents. The capabilities of an
ABS equipped vehicle must never be exploit-
ed in a reckless or dangerous manner which
could jeopardize the user’s safety or the
safety of others.
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BAS
The Brake Assist System (BAS) operates in
emergency situations. If you apply the
brakes very quickly, the BAS automatically
provides full brake boost, thereby poten-
tially reducing the braking distance.
Apply continuous full braking pressure
until the emergency braking situation is
over.
The ABS will prevent the wheels from
locking.
When you release the brake pedal, the
brakes function again as normal. The BAS
is then deactivated.
ESP®
The Electronic Stability Program (ESP®) is
operational as soon as the engine is run-
ning and monitors the vehicle’s traction
(force of adhesive friction between the
tires and the road surface) and handling.
The ESP
® recognizes when a wheel is
spinning or if the vehicle starts to skid. By
applying the brakes to the appropriate
wheel and by limiting the engine output,
the ESP
® works to stabilize the vehicle.
The ESP® is especially useful while driving
off and on wet or slippery road surfaces.
The ESP
® also stabilizes the vehicle during
braking and steering maneuvers.
The ESP
® warning lamp v in the
instrument cluster flashes when the ESP®
is engaged.
The ESP
® warning lamp v in the
instrument cluster comes on when you
switch on the ignition. It goes out when the
engine is running.
Warning!G
If the BAS is malfunctioning, the brake sys-
tem is still functioning normally, but without
the additional brake boost available that
BAS would normally provide in an emergen-
cy braking maneuver. Therefore, the braking
distance may increase.
Warning!G
The BAS cannot prevent the natural laws of
physics from acting on the vehicle, nor can
it increase braking efficiency beyond that
afforded by the condition of the vehicle
brakes and tires or the traction. The BAS
cannot prevent accidents, including those
resulting from excessive speed in turns, fol-
lowing another vehicle too closely, or hydro-
planing. Only a safe, attentive, and skillful
driver can prevent accidents. The
capabilities of a BAS 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.
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91 Safety and Security
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For more information, see the "Practical
hints" section (
page 372) and
(
page 380).
Warning!G
Never switch off the ESP® when you see the
ESP® warning lamp v flashing in the
instrument cluster. In this case, proceed as
follows:
While driving off, apply as little throttle
as possible.
While driving, ease upon the accelera-
tor.
Adapt your speed and driving style to
the prevailing road conditions.
Failure to observe these guidelines could
cause the vehicle to skid.
The ESP
® cannot prevent accidents result-
ing from excessive speed.
Warning!G
The ESP® cannot prevent the natural laws of
physics from acting on the vehicle, nor can
it increase the traction afforded by the exist-
ing road and tire conditions. 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 dan-
gerous manner which could jeopardize the
user’s safety or the safety of others.
!Because the ESP® operates automatically,
the engine must be turned off (SmartKey in
starter switch position0 or1 or KEYLESS-GO*
start/stop button in position0 or1) 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 (
page 466).
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92 Safety and Security
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Electronic traction system
The electronic traction system is a
component of ESP
®.
The electronic traction system improves
the vehicle’s ability to utilize available
traction, especially under slippery road
conditions by applying the brakes to a
spinning wheel.
Except CLK 63 AMG:
When you switch off the ESP
®, the
electronic traction system is still enabled.Switching off the ESP
®
Switching off the ESP®
(except CLK 63 AMG)
To improve the vehicle's traction, switch
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:
when driving with snow chains
in deep snow
in sand or gravelWhen 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 apply the
brakes to a spinning wheel
the ESP® continues to operate when
you are braking
you cannot activate the cruise control
the cruise control switches off if
currently activated
Warning!G
If you are driving too fast, the electronic
traction system cannot reduce the risk of an
accident.
The electronic traction system cannot pre-
vent the natural laws of physics from acting
on the vehicle.
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.
Do not switch off the ESP
® when a spare
wheel is mounted.
!Switch on the ESP® immediately if the
aforementioned circumstances do not apply
anymore.
iWhen the ESP® is switched off and one or
more drive wheels are spinning, the ESP®
warning lampv in the instrument cluster
flashes. However, the ESP
® will then not
stabilize the vehicle.
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93 Safety and Security
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The ESP® switch is located on the center
console.
1ESP
® switch
With the engine running, press ESP®
switch1 until the ESP® warning
lampv in the instrument cluster
comes on.
The ESP
® is switched off.Switching off the ESP
®
(CLK 63 AMG only)
Warning!G
When the ESP® warning lampv is
illuminated continuously, the ESP® is
switched off or is not operational due to a
malfunction. Vehicle stability in standard
driving maneuvers reduces.
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.
Warning!G
The ESP® should not be switched off during
normal driving. Disabling of the system will
result in the following:
no restriction to engine torque
no differential brake support
loss of system supported traction
control
“ESP
® Off” is designed for driving on closed
tracks when the vehicle’s natural oversteer
and understeer characteristics are desired
and requires a highly skilled and
experienced driver able to handle these
critical driving situations.
You could lose control of your vehicle and
cause an accident.
Please be aware of these limits when you
switch off the ESP
®.
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94 Safety and Security
Driving safety systems
When 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 is not available
the ESP® operates while you are
braking
you cannot activate the cruise control
the cruise control switches off if
currently activatedThe ESP
® switch is located on the center
console.
1ESP
® switch
With the engine running, press ESP®
switch1 until the ESP® warning
lampv in the instrument cluster
comes on.
The ESP
® is switched off.
Switching on the ESP®
Press ESP® switch1 until the ESP®
warning lampv in the instrument
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 instrument 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 or is not operational due to a
malfunction. Vehicle stability in standard
driving maneuvers reduces.
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.
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95 Safety and Security
Anti-theft systems
Anti-theft systems
Immobilizer
The immobilizer prevents unauthorized
persons from starting your vehicle.
Activating
With the SmartKey
Remove the SmartKey from the starter
switch.
With KEYLESS-GO*
Turn off the engine by means of the
start/stop button (
page 37) on the
gear selector lever.
Open the driver’s door.
Deactivating
With the SmartKey
Insert the SmartKey in the starter
switch.With KEYLESS-GO*
Switch on the ignition (page 38).
Anti-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 will stay on even if the activating
element (e.g. a door) is immediately
closed.The alarm system will also be triggered
when
the vehicle is opened with the
mechanical key.
someone opens a door from the inside.
someone opens the trunk with the
emergency release button.
iStarting the engine will also deactivate the
immobilizer.
In case the engine cannot be started (yet the ve-
hicle’s battery is charged), the system is not op-
erational. Contact an authorized Mercedes-Benz
Center or call
1-800-FOR-MERCedes (in the USA), or
1-800-387-0100 (in Canada).
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 287) provided Tele Aid service was sub-
scribed to and properly activated, and that nec-
essary cellular service and GPS coverage are
available.