74 Safety and SecurityOccupant safety
Emergency tensioning device (ETD),
seat belt force limiter
The seat belts are equipped with emergen-
cy tensioning devices, belt force limiters,
and automatic comfort-fit.The ETD is designed to activate in the fol-
lowing cases:
in frontal or rear-end impacts exceed-
ing a preset severity level
if the restraint systems are operational
and functioning correctly, see 1 in-
dicator lamp (
page 64).
In an impact, emergency tensioning devic-
es remove slack from the belts in such a
way that the seat belts fit more snugly
against the body. Belt force limiters reduce
the force exerted by the seat belts on oc-
cupants during a crash.
Never wear the shoulder belt under your
arm, against your neck or off your shoul-
der. In a crash, your body would move
too far forward. That would increase the
chance of head and neck injuries. The
belt would also apply too much force to
the ribs or abdomen, which could se-
verely injure internal organs such as
your liver or spleen.
Never wear belts over rigid or breakable
objects in or on your clothing, such as
eyeglasses, pens, keys, etc., as these
might cause injuries.
Position the lap belt as low as possible
on your hips and not across the abdo-
men. If the belt is positioned across your
abdomen, it could cause serious injuries
in a crash.
Never use a seat belt for more than one
person at a time. Do not fasten a seat
belt around a person and another per-
son or other objects.
Belts should not be worn twisted. In a
crash, you would not have the full width
of the belt to manage impact forces. The
twisted belt against your body could
cause injuries.
Pregnant women should also use a
lap-shoulder belt. The lap belt portion
should be positioned as low as possible
on the hips to avoid any possible pres-
sure on the abdomen.
Never place your feet on the instrument
panel, dashboard or on the seat. Always
keep both feet on the floor in front of the
seat.
iThe ETDs will only activate if the re-
spective seat belt is fastened (latch
plate properly inserted into buckle).
75 Safety and Security
Occupant safety
Automatic comfort-fit feature seat belt
The automatic comfort-fit feature reduces
the retracting force of the seat belts when
they are in normal use.
Roll barThe roll bar raises automatically in an acci-
dent or in a critical driving situation. You
can also raise and lower the roll bar manu-
ally using the buttons provided.
The buttons for the roll bar are on the cen-
ter console under the roof switch.
1Lower roll bar
2Raise roll bar
The roll bar can be moved manually when
the ignition is switched on (
page 36).
Warning!
G
An emergency tensioning device (ETD) that
was activated must be replaced.
When disposing of the emergency tension-
ing device, our safety instructions must be
followed. These are available at your autho-
rized Mercedes-Benz Center.!Do not place objects heavier than
20 lbs (9 kg) on the front passenger
seat. This could cause the front or side
impact airbag on the passenger side
and, with the seat belt fastened to
secure the object, the ETD to deploy in
a crash which exceeds the system's
deployment threshold.
Warning!
G
This vehicle is a two occupant vehicle. The
rear storage area is not intended for use by
occupants and is not equipped for properly
seating or restraining occupants. Thus this
area should never be used by any persons.
Before operating the roll bar switch make
sure that the roll bar’s path is clear and no
persons are injured by the moving roll bar
due to inattention. Raising or lowering of the
roll bar could injure someone inadvertently
occupying the rear storage area.
For your own safety, we recommend to drive
with the roll bar raised if the outside temper-
ature is below +5°F (-15°C).!If the outside temperature falls below
+5°F (-15°C), the roll bar must be
raised manually using the buttons pro-
vided to avoid damaging the hydraulics.
iWhen the roll bar is raised automatical-
ly, you will hear a ratcheting sound.
82 Safety and SecurityDriving safety systemsIn this section you will find information on
the following driving safety systems:
ABS (A
ntilock B
rake S
ystem)
BAS (B
rake A
ssist S
ystem)
ESP
® (E
lectronic S
tability P
rogram)
Electro-hydraulic brake system
iIn winter operation, the maximum ef-
fectiveness of the ABS, the BAS, the
ESP
®, and the electro-hydraulic brake
system is only achieved with winter
tires (page 315) or snow chains as
required.
Warning!
G
The following factors increase the risk of ac-
cidents:
Excessive speed, especially in turns
Wet and slippery road surfaces
Following another vehicle too closely
The ABS, BAS, ESP
®, and the electro-hy-
draulic brake system cannot reduce this
risk.
Always adjust your driving style to the pre-
vailing road and weather conditions.
84 Safety and SecurityDriving safety systemsFor more information, see the
“Practical hints” section (
page 332).
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.
Warning!
G
The ABS cannot prevent the natural laws of
physics from acting on the vehicle, nor can
it increase braking or steering efficiency be-
yond that afforded by the condition of the
vehicle brakes and tires or the traction
afforded. The ABS cannot prevent acci-
dents, including those resulting from exces-
sive speed in turns, following another
vehicle too closely, or hydroplaning. Only a
safe, attentive, and skillful driver can pre-
vent accidents. The capabilities of an ABS
equipped vehicle must never be exploited in
a reckless or dangerous manner which
could jeopardize the user’s safety or the
safety of others.
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
BAS cannot prevent the natural laws of
physics from acting on the vehicle, nor can
it increase braking efficiency beyond that af-
forded by the condition of the vehicle brakes
and tires or the traction afforded. 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.
85 Safety and Security
Driving safety systems
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 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 espe-
cially useful while driving off and on wet or
slippery road surfaces. The ESP® also sta-
bilizes the vehicle during braking maneu-
vers.
The ABS/ESP
® warning lamp v in the
instrument cluster (
page 25) 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
Never switch off the ESP
® when you see the
ABS/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 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 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. 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.
iThe ESP
® will only function properly if
you use wheels of the recommended
tire size (page 434).
86 Safety and SecurityDriving safety systemsFor more information, see the
“Practical hints” section (
page 332).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:
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 brake a
spinning wheel
the ESP
® continues to operate when
you are braking
you cannot activate Distronic*
!Because of the ESP
®’s automatic oper-
ation, the engine must be shut off
(SmartKey in starter switch position 0
or 1 or KEYLESS-GO* start/stop but-
ton in position 0 or 1) when
the parking brake is being tested on
a brake test dynamometer
the vehicle is being towed with the
front/rear axle raised
Active braking action through the ESP
®
may otherwise seriously damage the
brake system.
The ESP
® will only function properly if
you use wheels of the recommended
tire size (page 434).
Warning!
G
ESP
® should not be switched off during nor-
mal driving other than in the circumstances
described below. Disabling of the system
will reduce vehicle stability in standard driv-
ing maneuvers.
Do not switch off the ESP
® when a spare
wheel is mounted.
!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.
88 Safety and SecurityDriving safety systemsElectro-hydraulic brake system
The electro-hydraulic brake system com-
bines a hydraulic brake circuit with elec-
tronically controlled brake servo
assistance. You have increased braking
safety and improved braking comfort.Warning!
G
Never ignore a brake malfunction indicated
in the speedometer display, for example by
the;(USA only) or3(Canada only)
indicator lamp. Refer to the “Practical hints”
section (
page 334). Also read and ob-
serve the messages in the instrument clus-
ter multifunction display (
page 361).
Warning!
G
The electro-hydraulic 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 334)
comes on and warning messages
(
page 361) appear in the multifunction
display while driving. To brake, the driver
must then apply significantly greater brake
pedal pressure and depress the pedal much
further to obtain the expected braking ef-
fect. If necessary, apply full pressure to the
brake pedal. Brakes are only applied to the
front wheels. Stopping distance is in-
creased!
If there is a malfunction in the
electro-hydraulic brake system, we recom-
mend that the vehicle be transported with
all wheels off the ground using flatbed or ap-
propriate 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
up to 30 miles (50 km) and at a speed not to
exceed 30 mph (50 km/h). For more infor-
mation, see “Towing the vehicle”
(page 421).
89 Safety and Security
Driving safety systems
The electro-hydraulic brake system is auto-
matically activated when you
unlock the vehicle with the SmartKey
or the SmartKey with 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
iIf the electro-hydraulic brake system is
activated as the brake pedal is first de-
pressed, 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 elec-
tro-hydraulic brake system pump. This
is normal and not an indication of a
malfunction. Pedal travel returns to
normal when you release the brake
pedal and the sound soon ceases.
If you experience the above while driv-
ing and the red brake warning lamp
(page 334) illuminates and/or warn-
ing messages appear in the multifunc-
tion display (
page 361), the brake
system is malfunctioning. Follow the in-
structions of the warning message(s)
and have the brake system checked
immediately.
Warning!
G
Have brake pad replacement and other work
on the electro-hydraulic brake system car-
ried out by qualified technicians only. Con-
tact an authorized Mercedes-Benz Center
for further information. The electro-hydrau-
lic 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 activated when the
vehicle is unlocked by remote control, when
the driver or passenger door is opened,
when the SmartKey in the starter switch is
turned to position1 or the KEYLESS-GO*
start/stop button is pressed once, when the
brake pedal is depressed or when the park-
ing brake is released. Failure to deactivate
the system prior to maintenance will cause
brake pistons to extend and brake fluid to
leak, which may result in injuries (contu-
sions and acid burns). Extended brake pis-
tons may also cause injury.