76 Safety and SecurityOccupant safety
Emergency tensioning device (ETD),
seat belt force limiter
The seat belts for the front and rear outer
seats are equipped with emergency ten-
sioning devices and belt force limiters.
The ETD is designed to activate in the fol-
lowing cases:
in frontal or rear-end impacts exceed-
ing a preset severity level
in certain vehicle rollovers
if the restraint systems are operational
and functioning correctly, see
1indicator lamp (
page 66)In an impact, emergency tensioning devic-
es remove slack from the belts. Belt force
limiters reduce the force exerted by the
seat belts on occupants during a crash.
Automatic comfort-fit feature seat belt
An automatic comfort-fit feature for front
seats reduces the retracting force of the
seat belts when they are in normal use.
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.
When using a seat belt to secure infant
or toddler restraints or children in boost-
er seats, always follow the child seat
manufacturer’s instructions.
iThe ETDs for the front seats will only
activate if the front seat belts are fas-
tened (latch plate properly inserted
into buckle).
The ETDs for the rear outer seats will
activate with or without the respective
seat belts fastened.
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.
92 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)
Electrohydraulic brake system
4MATIC (Four Wheel Electronic
Traction System)
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 ap-
proximately 5 mph (8 km/h) independent
of road surface conditions.
On slippery road surfaces, the ABS will re-
spond even to light brake pressure.
The - indicator lamp in the instrument
cluster comes on when you switch on the
ignition. It goes out when the engine is run-
ning.
iIn winter operation, the maximum ef-
fectiveness of the ABS, the BAS, the
ESP
®, electrohydraulic brake system
and 4MATIC is only achieved with win-
ter tires (
page 358), 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
®, electrohydraulic brake
system and 4MATIC cannot reduce this risk.
Always adjust your driving style to the pre-
vailing road and weather conditions.
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.
93 Safety and Security
Driving safety systems
Braking
If the ABS activates during braking, the
ABS/ESP
® warning lamp v in the in-
strument cluster dial flashes. Because of
the electrohydraulic brake system, you will
not feel any pulsation in the brake pedal.
Keep firm and steady pressure on the
brake pedal.
Continuous, steady brake pedal pressure
yields the advantages provided by the ABS,
namely braking power and the ability to
steer the vehicle.
The ABS/ESP
® warning lamp v flashes
whenever the ABS is activated which can
be an indication of hazardous road condi-
tions 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 the “Practical
hints” section (
page 375).
Warning!
G
When the ABS is malfunctioning, the BAS
and the ESP
® are also switched off.
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 be-
yond that afforded by the condition of the
vehicle brakes and tires or the traction af-
forded. The ABS cannot prevent accidents,
including those resulting from excessive
speed in turns, following another vehicle too
closely, or hydroplaning. Only a safe, atten-
tive, and skillful driver can prevent acci-
dents. The capabilities of an ABS equipped
vehicle must never be exploited in a reck-
less or dangerous manner which could jeop-
ardize the user’s safety or the safety of
others.
94 Safety and SecurityDriving safety systemsBAS
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 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 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 afforded.
The BAS cannot prevent accidents, includ-
ing those resulting from excessive speed in
turns, following another vehicle too closely,
or hydroplaning. Only a safe, attentive, and
skillful driver can prevent accidents. The ca-
pabilities of a BAS 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.
95 Safety and Security
Driving safety systems
For more information, see the “Practical
hints” section (
page 375).
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.
!The ESP
® will only function properly if
you use wheels of the recommended
tire size (page 473).
!Vehicles without 4MATIC:
Because of the ESP’s
® automatic oper-
ation, 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 100).
96 Safety and SecurityDriving safety systemsSwitching 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:
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*The switch is located on the center con-
sole.
1ESP
® switch (off/on)
Press ESP
® switch 1 until the
ABS/ESP®warning lamp v in the
instrument 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.
Do not switch off the ESP
® when a
Minispare or collapsible tire 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.
97 Safety and Security
Driving safety systems
Switching on the ESP
®
Press ESP
® switch1.
The ABS/ESP® warning lamp v in
the instrument cluster goes out.
You are now again in normal driving
mode with the ESP
® switched on.
Electrohydraulic brake system
The electrohydraulic 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
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 376). Also read and ob-
serve the messages in the instrument clus-
ter display (page 386).
100 Safety and SecurityDriving safety systems
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.
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
flashing in the speedometer, proceed as fol-
lows:
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.
!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 oper-
ation, 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.