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87 Safety and Security
Driving safety systems
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)
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 spin-
ning or if the vehicle starts to skid. By ap-
plying brakes to the appropriate wheel and
by limiting engine output, the ESP works to
stabilize the vehicle. The ESP is especially
useful while driving off and on wet or slip-
pery road surfaces.
The ABS/ESP warning lamp v in the
instrument cluster flashes when the ESP is
engaged.
The ABS/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 capabili-
ties of a BAS equipped vehicle must never
be exploited in a reckless or dangerous
manner which could jeopardize the user’s
safety or the safety of others.
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88 Safety and SecurityDriving safety systems
For more information, see the “Practical
hints” section (
page 357).
Warning!
G
Never switch off the ESP when you see the
ABS/ESP warning lamp v fla s hi n g in th e
instrument cluster. In this case proceed as
follows:
While driving off, apply as little throttle
as possible.
While driving, ease up on 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 resulting
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. 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 ca-
pabilities of an ESP equipped vehicle must
never be exploited in a reckless or danger-
ous manner which could jeopardize the us-
er’s safety or the safety of others.!The ESP will only function properly if
you use wheels of the recommended
tire size (
page 453).
!Vehicles without 4MATIC:
Because of the ESP’s automatic opera-
tion, the engine and the ignition must
be shut 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.
For information on vehicles with
4MATIC, see “Four wheel electronic
traction system (4MATIC) with the
ESP” (
page 93).
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89 Safety and Security
Driving safety systems
Switching off the ESP
To improve the vehicle's traction, turn off
the ESP in driving situations where it would
be advantageous to have 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
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 brake a
spinning wheel
the ESP continues to operate when you
are braking
you cannot activate Distronic*The switch is located on the center con-
sole.
1ESP switch
Press ESP switch 1 until the
ABS/ESP warning lamp v in the in-
strument cluster comes on.
The ESP is deactivated.
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 driving
maneuvers.!Turn 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
ABS/ESP warning lamp v in the
speedometer flashes. However, the
ESP will then not stabilize the vehicle.
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90 Safety and SecurityDriving safety systems
Switching on the ESP
Press ESP button1.
The ABS/ESP warning lamp v in
the instrument cluster goes out.
You are now again in normal driving
mode.
SBC brake system
The SBC brake system combines a hydrau-
lic brake circuit with electronically con-
trolled brake servo assistance. You have
increased braking safety and improved
braking comfort.
Warning!
G
When the ABS/ESP warning lamp v 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.
!Turn on the ESP immediately if the
aforementioned circumstances do not
apply anymore.
Warning!
G
Never ignore a brake malfunction indicated
in the speedometer display, for example by
the ; (USA only) or 3 (Canada only)
warning lamp. Refer to the “Practical hints”
section (
page 358). Also read and ob-
serve the messages in the instrument clus-
ter display (page 367).
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91 Safety and Security
Driving safety systems
The SBC brake system is automatically ac-
tivated when you
unlock the vehicle with the SmartKey
or the KEYLESS-GO*
open the driver’s or passenger door
turn the SmartKey in the starter switch
to position1
in vehicles with KEYLESS-GO*, press
the start/stop button on the gear se-
lector lever once
depress the brake pedal
release the parking brake
Warning!
G
The SBC brake system requires electrical
power to operate.
A malfunction in the vehicle’s power supply
or electrical system may impair brake sys-
tem operation and switch it into its emer-
gency operation mode. In such a case, the
red brake warning lamp (
page 358) and
warning messages in the instrument cluster
(
page 367) come on while driving. To
brake, the driver must then apply signifi-
cantly greater brake pedal pressure and de-
press the pedal much further to obtain the
expected braking effect. If necessary, apply
full pressure to the brake pedal. Brakes may
only be applied to the front wheels. Stop-
ping distance is increased!
If there is a malfunction in the SBC brake
system, we recommend that the vehicle be
transported with all wheels off the ground
using flatbed or appropriate wheel lift/dolly
equipment.
A tow bar must be used if circumstances do
not permit the use of the recommended
towing methods and the vehicle requires
towing with all four wheels on the ground.
Towing the vehicle with all four wheels on
the ground is only permissible for distances
u p t o 3 0 m i l e s ( 5 0 k m ) a n d a t a s p e e d n o t t o
exceed 30 mph (50 km/h). For more infor-
mation, refer to “Towing the vehicle”
(page 439).
iIf the SBC brake system is activated as
the brake pedal is first depressed, you
may feel a reduced pedal resistance
and longer pedal travel than normal.
When releasing the pedal, you may also
feel the brake pedal pulsate and you
may hear a sound which is caused by
the activation of the SBC brake system
pump. This is normal and not an indica-
tion of a malfunction. Pedal travel re-
turns to normal when you release the
brake pedal and the sound soon ceas-
es.
If you experience the above while driv-
ing and the red brake warning lamp
(page 358) illuminates and/or warn-
ing messages appear in the instrument
cluster (
page 367), the brake system
is malfunctioning. Follow the instruc-
tions of the warning message(s) and
have the brake system checked imme-
diately.
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92 Safety and SecurityDriving safety systems
The SBC brake servo assistance switches
off automatically
approximately two minutes after you
turned the SmartKey in the starter
switch to position0 or removed the
SmartKey
approximately two minutes after you
pressed the KEYLESS-GO* start/stop
button to turn off the engine or power
supply and opened the driver’s door
(with driver’s door open, the starter
switch is set to position 0, same as
SmartKey removed from starter
switch)
approximately 20 seconds after you
locked the vehicle from outside
Note on driving with the SBC
Following extended periods of only mi-
nor loads to your brake system, you
should occasionally apply the brakes
when traveling at high speeds. This im-
proves the grip of the brake pads.
After driving on wet or snow-covered
roads, you should apply your brakes
firmly before parking your vehicle. This
produces heat which serves to dry the
brake disks and help prevent corro-
sion.
On long and steep grades, shift to a
lower gear (gear range1, 2, or 3) to
prevent the brakes from overheating
and to reduce brake wear.
After hard braking, it is advisable to
drive on for some time so that the air
stream will cool down the brakes fast-
er.
Only Mercedes-Benz approved compo-
nents (e.g. brake pads) should be in-
stalled on your vehicle. Brake pads not
approved by Mercedes-Benz may im-
pair the safety of your vehicle.
Warning!
G
Have brake pad replacement and other work
on the SBC brake system carried out by
qualified technicians only. Contact an au-
thorized Mercedes-Benz Center for further
information. The SBC brake system must be
deactivated prior to working on the system.
High pressure is intermittently built up in the
system as part of its automatic self-test. In
addition, the system is automatically acti-
vated when the vehicle is unlocked by
SmartKey, when the driver or passenger
door is opened, when the starter switch is
turned to position
1, when the brake pedal
is depressed or when the parking brake is
released. Failure to deactivate the system
prior to maintenance will cause brake pis-
tons to extend and brake fluid to leak, which
may result in injuries (contusions and acid
burns). Extended brake pistons may also
cause injury.
Warning!
G
Be very careful not to endanger other road
users when you apply the brakes.
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93 Safety and Security
Driving safety systems
Four wheel electronic traction system (4MATIC) with the ESP
Models with all-wheel-drive only.
The 4MATIC improves vehicle’s ability to
use available traction, e.g. during winter
operation in mountains under snowy
conditions, by applying power to all four
wheels.Warning!
G
If you see the ESP warning lampv flash-
ing in the speedometer, proceed as follows:
While driving off, apply as little throttle
as possible
While driving, ease up on 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 resulting
from excessive speed.
!Do not tow with one axle raised.
Otherwise the transfer case can be
damaged, which is not covered by the
Mercedes-Benz Limited Warranty.!Performance testing must only be con-
ducted on a two-axle dynamometer.
Otherwise the transfer case can be
damaged, which is not covered by the
Mercedes-Benz Limited Warranty.
!Because of the ESP’s automatic opera-
tion, the engine and the ignition must
be shut 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.
Active braking action through ESP may
otherwise seriously damage the front
or rear axle brake system.
Operational tests with the engine
running can only be conducted on a
two-axle dynamometer.
Page 96 of 506

94 Safety and SecurityAnti-theft systemsImmobilizer
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 KEYLESS-GO
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.
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 activat-
ing element (a door, for example) is imme-
diately closed.
The alarm system will also be triggered
when
someone attempts to raise the vehicle.Arming the alarm system
The alarm system is armed within approxi-
mately ten seconds after locking the vehi-
cle with the SmartKey or KEYLESS-GO*.
The turn signal lamps flash three times to
indicate that the alarm system is activated.
The indicator lamp in the central locking
switch (
page 27) begins to flash after
arming the alarm system.
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).
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 271) provid-
ed Tele Aid service was subscribed to
and properly activated, and that neces-
sary cellular service and GPS coverage
are available.