69 Safety and Security
Occupant 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 impact exceeding
a preset severity level
in certain vehicle rollovers
if the restraint systems are operational
and functioning correctly, see
1indicator lamp (
page 60)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.
Belts should not be worn twisted. In a
crash, you wouldn’t 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 for the front seats will only
activate if the respective front seat belt
is fastened (latch plate properly insert-
ed into buckle).
The ETDs for the rear outer seats will
activate with or without the respective
seat belt fastened.
Warning!
G
A pyrotechnic emergency tensioning device
(ETD) that was activated must be replaced.
When disposing of the pyrotechnic emer-
gency tensioning device, our safety instruc-
tions must be followed. These are available
at your authorized Mercedes-Benz Center.
PRE-SAFE has electrically operated revers-
ible pre-tensioners that do not require
replacement after activation.
70 Safety and SecurityOccupant safetyAutomatic comfort-fit feature seat belt
An automatic comfort-fit feature for front
seats and for the rear outer seats (only for
vehicles with electrically adjustable rear
bench seat* or with individual seats* in the
rear) reduces the retracting force of the
seat belts when they are in normal use.
Preventive occupant safety (PRE-SAFE)
Your vehicle automatically takes preven-
tive measures to better protect the occu-
pants in the following hazardous
situations:
You execute an emergency braking ma-
neuver and the Brake Assist System
(page 81) is activated.
The PRE-SAFE system detects a critical
driving dynamics situation.In such cases, the following systems are
automatically activated:
A front seat belt with the seat belt
buckled is pre-tensioned electrically.
If the occupied front passenger seat or
rear seats are in an unfavorable posi-
tion, they are adjusted to a better posi-
tion. Rear seat adjustment occurs only
in vehicles with individual seats* in the
rear.
The tilt/sliding sunroof closes if the ve-
hicle is in a severe skid or is spinning.
!Do not place objects heavier than
20 lbs (9 kg) on the front passenger
seat. This could cause the front or side
impact air bag on the front passenger
side to deploy in a crash which exceeds
the system's deployment threshold.
Warning
G
The PRE-SAFE system is intended to reduce
the effects of an accident on properly seat
belted vehicle occupants. Despite having
the PRE-SAFE systems in your car, the pos-
sibility of injuries occurring as a result of an
accident cannot be totally eliminated.
Therefore you should always drive carefully
and adjust your driving to the prevailing
road, weather, and traffic conditions.
80 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)
4MATIC (Four Wheel Electronic Trac-
tion 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.
iIn winter operation, the maximum ef-
fectiveness of the ABS, ESP, BAS and
4MATIC is only achieved with winter
tires (M + S tires) or snow chains as re-
quired.
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 4MATIC cannot re-
duce 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.
82 Safety and SecurityDriving safety systemsFor more information, see the “Practical
hints” section (
page 338).
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 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 ma-
neuvers.
The ESP warning lamp v in the instru-
ment cluster flashes when the ESP is en-
gaged.
The ESP warning lamp v in the instru-
ment cluster comes on when you switch on
the ignition (
page 34). It goes out when
the engine is running.
Warning!
G
The 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.
Warning!
G
Never switch off the ESP when you see the
ESP warning lamp
v
flashing in the in-
strument cluster. In this case 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 resulting
from excessive speed.
83 Safety and Security
Driving safety systems
For more information, see “Practical hints”
(page 337).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
in 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 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.iDistronic* is switched off when ESP is
activated.iThe ESP will only function properly if
you use wheels of the recommended
tire size (
page 422).
!Because of the ESP’s automatic opera-
tion, the engine and 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/rear axle raised
Active braking action through the ESP
may otherwise seriously damage the
brake system.
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.iDistronic* cannot be activated when
the ESP has been deactivated.
84 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 upper part of
the center console.
1ESP off/on
Press ESP switch1 until the ESP
warning lampv in the speedometer
comes on.
The ESP is deactivated.Switching on the ESP
Press ESP switch1.
The ESP warning lampv in the in-
strument cluster goes out.
You are now again in normal driving
mode with the 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 illumi-
nated 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.
85 Safety and Security
Driving safety systems
Four wheel electronic traction system (4MATIC) with the ESP
Models with all-wheel drive only:
The 4MATIC improves the vehicle’s ability
to use available traction, e.g. during winter
operation in mountains under snowy con-
ditions, by applying power to all four
wheels.
Warning!
G
If you see the ESP warning lamp v flash-
ing in the speedometer dial, 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 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 ignition must be
shut off (SmartKey in starter switch
position0 or1 or KEYLESS-GO*
start/stop button (
page 35) in
position0 or1) when the parking
brake is being tested on a brake test
dynamometer.
Active braking action through the ESP
may otherwise seriously damage the
front or rear axle brake system.
Operational tests with the engine run-
ning can only be conducted on a
two-axle dynamometer.
87 Safety and Security
Anti-theft systems
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 (a door, for example) is immedi-
ately closed.The alarm system will also be triggered
when
someone attempts to raise the vehicle
the vehicle is opened with the
mechanical key
someone opens a door from the inside
if the vehicle was locked from the out-
side with the SmartKey
someone opens the trunk lid with the
emergency release buttonArming the alarm system
The indicator lamp located in the central
locking switch in on the upper part of the
front center console.
1Indicator lamp
Lock your vehicle.
The turn signal lamps flash three times
to indicate that the alarm system is ac-
tivated. The indicator lamp1 flashes
to indicate that the alarm system is
armed.
iIf the alarm stays on for more than
30 seconds, a call to the Response
Center is initiated automatically by the
by the Tele Aid system (
page 255)
provided Tele Aid service was sub-
scribed to and properly activated, and
that necessary cellular service and GPS
coverage are available.