
injuries. The front airbag is fully deployed if
the second deployment stage is activated
within a few milliseconds.
The activation threshold for the seat belt ten-
sioners and airbags is determined based on
the evaluation of the vehicle's rate of decel-
eration or acceleration at various points in the vehicle. This process is pre-emptive in nature.The triggering/deployment process should
take place in good time at the start of the
collision.
The rate of vehicle deceleration or accelera-
tion and the direction of the force are essen-
tially determined by:
R the distribution of forces during the colli-
sion
R the collision angle
R the deformation characteristics of the vehi-
cle
R the characteristics of the object with which
the vehicle has collided
Factors which can only be seen and measured
after a collision has occurred do not play a
decisive role in the deployment of an airbag,
nor do they provide an indication of airbag
deployment.
The vehicle may be deformed significantly
without an airbag being deployed. This is the
case if only parts which are relatively easily
deformed are affected and the rate of decel-
eration is not high. Conversely, an airbag may be deployed even though the vehicle suffers
only minor deformation. This is the case if, for
example, very rigid vehicle parts such as lon-
gitudinal body members are hit, and sufficient deceleration occurs as a result. If the restraint system control unit detects a
side impact or if the vehicle overturns, the
applicable components of the restraint sys-
tem are activated independently of each
other depending on the apparent type of acci-
dent. If the system determines that, in this
situation, triggering can offer additional pro-
tection, the seat belt tensioners are also trig-
gered.
R Sidebags on the side on which an impact
occurs, independent from the seat belt ten-
sioner and seat belt usage
Vehicles with the automatic front-
passenger front airbag deactivation sys-
tem: the sidebag on the front-passenger
side (front) deploys under the following
conditions:
- an occupant is detected on the front-
passenger seat, or
- the belt tongue is engaged in the buckle
on the front-passenger seat
R Windowbag on the side on which an impact
occurs, independent of seat belt usage and
regardless of whether the front-passenger
seat is occupied
R Windowbags on the driver's and front-
passenger side in certain situations if the
vehicle overturns and if the system deter-
mines that deployment can offer additional protection to that provided by the seat belt
i Not all airbags are deployed in an acci-
dent. The different airbag systems work
independently of each other.
How the airbag system works is deter-
mined by the severity of the accident detec-
ted, especially the vehicle deceleration or
acceleration, and the apparent type of acci- dent:
R frontal collision
R side impact
R overturn 58
Occupant safetySafety

Driving safety systems
Driving safety systems overview
In this section, you will find information about the following driving safety systems:
R ABS (Anti-lock BrakingSystem)
(Y page 72)
R BAS (Brake Assist System) (Y page 73)
R COLLISION PREVENTION ASSIST (distance
warning function and adaptive Brake
Assist) (Y page 73)
R COLLISION PREVENTION ASSIST PLUS
(Y page 73)
R Adaptive brake lamps (Y page 76)
R ESP ®
(E lectronic StabilityProgram)
(Y page 76)
R EBD (electronic brake forcedistribution)
(Y page 80)
R ADAPTIVE BRAKE (Y page 80)
R STEER CONTROL (Y page 81)Important safety notes
If you fail to adapt your driving style or if you
are inattentive, the driving safety systems can
neither reduce the risk of accident nor over-
ride the laws of physics. Driving safety sys-
tems are merely aids designed to assist driv- ing. You are responsible for the distance to
the vehicle in front, for vehicle speed and forbraking in good time. Always adapt your driv- ing style to suit the prevailing road, weather
and traffic conditions and maintain a safe dis-
tance from the vehicle in front. Drive care-
fully.
i The driving safety systems described only
work as effectively as possible when there
is adequate contact between the tyres and
the road surface. Pay particular attention to the information regarding tyres, recom-
mended minimum tyre tread depths etc. inthe "Wheels and tyres" section
(Y page 352). In wintry driving conditions, always use
winter tyres (M+S tyres) and, if necessary,
snow chains. Only in this way will the driv-
ing safety systems described in this section
work as effectively as possible. ABS (Anti-lock Braking System)
General notes ABS regulates brake pressure in such a way
that the wheels do not lock when you brake.
This allows you to continue steering the vehi- cle when braking.
The ! ABS warning lamp in the instrument
cluster lights up when the ignition is switched on. It goes out when the engine is running.
Important safety notes i
Observe the "Important safety notes" sec-
tion for driving safety systems (Y page 72). G
WARNING
If ABS is faulty, the wheels could lock when
braking. The steerability and braking charac-
teristics may be severely impaired. Addition-
ally, further driving safety systems are deac-
tivated. There is an increased danger of skid- ding and accidents.
Drive on carefully. Have ABS checked imme-
diately at a qualified specialist workshop.
If ABS is malfunctioning, other systems,
including driving safety systems, will also
become inoperative. Observe the information on the ABS warning lamp (Y page 289) and
display messages which may be shown in the
instrument cluster (Y page 255).
ABS works from a speed of about
8 km/hupwards, regardless of road-surface
conditions. ABS works on slippery surfaces,
even when you only brake gently. 72
Driving safety syste
msSafety

COLLISION PREVENTION ASSIST PLUS
General notes
COLLISION PREVENTION ASSIST PLUS is
only available on vehicles with DISTRONIC.
COLLISION PREVENTION ASSIST PLUS
extends the functionality of COLLISION PRE-
VENTION ASSIST with an automatic braking
function. COLLISION PREVENTION ASSIST
PLUS can help you to minimise the risk of a
front-end collision with a vehicle ahead or
reduce the effects of such a collision. If COL-
LISION PREVENTION ASSIST PLUS detects
that there is a risk of a collision, you will be
warned visually and acoustically. In critical
situations COLLISION PREVENTION ASSIST
PLUS also initiates automatic braking.
Function X To activate/deactivate: activate or deac-
tivate COLLISION PREVENTION ASSIST
PLUS in the on-board computer
(Y page 244).
If COLLISION PREVENTION ASSIST PLUS is
deactivated, the æsymbol appears in the
assistance graphics display.
If the driver's seat belt is fastened, COLLI-
SION PREVENTION ASSIST PLUS can brake
automatically within a speed range of
between 7 km/h and 200 km/h.
COLLISION PREVENTION ASSIST PLUS can
also react to stationary obstacles with auto-
matic braking within a speed range of
between 7 km/h and 30 km/h.
Vehicles with PRE-SAFE ®
:if the automatic
braking function of COLLISION PREVENTION
ASSIST PLUS intervenes powerfully, preven-
tive passenger protection measures (PRE-
SAFE ®
) are deployed simultaneously.
In particular, the detection of obstacles can
be impaired in the case of:
R dirt on the sensors or obscured sensors
R snow or heavy rain
R interference by other radar sources R
strong radar reflections, for example, in
multi-storey car parks
R a narrow vehicle travelling in front, e.g. a
motorcycle
R a vehicle travelling in front on a different
line
R new vehicles or after a service on the COL-
LISION PREVENTION ASSIST PLUS system
Please observe the information in the sec-
tion on running-in the vehicle
(Y page 158).
Following damage to the front end of the vehi-
cle, have the configuration and operation of
the radar sensor checked at a qualified spe-
cialist workshop. This also applies to colli-
sions at slow speeds where there is no visible
damage to the front of the vehicle. Adaptive brake lamps
The adaptive brake lights warn following traf- fic in an emergency braking situation:
R by means of flashing brake lamps
R the hazard warning lamps are activated
If you brake sharply from a speed of more
than 50 km/h or if braking is assisted by BAS
or BAS PLUS, the brake lamps flash rapidly. In
this way, traffic travelling behind you is
warned in an even more noticeable manner.
If you brake sharply from a speed of more
than 70 km/h to a standstill, the hazard warn- ing lamps are activated automatically. If the
brakes are applied again, the brake lamps
light up continuously. The hazard warning
lamps switch off automatically if you travel
faster than 10 km/h. You can also switch off
the hazard warning lamps using the hazard
warning button (Y page 123). ESP
®
(Electronic Stability Program)
General notes i
Observe the "Important safety notes" sec-
tion (Y page 72). 76
Driving safety systemsSafety

ESP
®
monitors driving stability and traction,
i.e. power transmission between the tyres
and the road surface.
If ESP ®
detects that the vehicle is deviating
from the direction desired by the driver, one
or more wheels are braked to stabilise the
vehicle. The engine output is also modified to keep the vehicle on the desired course within
physical limits. ESP ®
assists the driver when
pulling away on wet or slippery roads. ESP ®
can also stabilise the vehicle during braking.
ETS/4ETS (Electronic Traction System) i
Observe the "Important safety notes" sec-
tion (Y page 72).
ETS/4ETS traction control is part of ESP ®
.
ETS brakes the drive wheels individually if
they spin. This enables you to pull away and
accelerate on slippery surfaces, for example
if the road surface is slippery on one side. In
addition, more drive torque is transferred to
the wheel or wheels with traction.
ETS remains active when you deactivate
ESP ®
.
Off-road 4ETS (Electronic Traction Sys-
tem) A 4ETS system specifically suited to off-road
terrain is activated automatically once the off-
road program is activated (Y page 205).
Important safety notes G
WARNING
If ESP ®
is malfunctioning, ESP ®
is unable to
stabilise the vehicle. In addition, other driving
safety systems are switched off. This increa-
ses the risk of skidding and an accident.
Drive on carefully. Have ESP ®
checked at a
qualified specialist workshop.
! When testing the electric parking brake
on a braking dynamometer, switch off the
ignition. Application of the brakes by ESP ®
may otherwise destroy the brake system. !
Vehicles with 4MATIC: switch off the igni-
tion when the electric parking brake is
being tested using a dynamometer.
Application of the brakes by ESP ®
may oth-
erwise destroy the brake system.
! Vehicles with 4MATIC: function or per-
formance tests may only be carried out on
a 2-axle dynamometer. Before operating
the vehicle on such a dynamometer, please
consult a qualified specialist workshop.
You could otherwise damage the drive train
or the brake system.
! Do not tow vehicles with 4MATIC with the
front or rear axle raised.
Vehicles without 4MATIC: when towing your
vehicle with the front axle raised, it is impor-
tant that you observe the notes on ESP ®
(Y page 346).
Vehicles with 4MATIC: when towing your
vehicle with both axles on the ground, it is
important that you observe the notes on ESP ®
(Y page 347).
ESP ®
is deactivated if the åESP®
OFF
warning lamp in the instrument cluster lights up continuously when the engine is running.
If the ÷ ESP®
warning lamp and the å
ESP ®
OFF warning lamp are lit continuously,
ESP ®
is not available due to a malfunction.
Observe the information on warning lamps
(Y page 291) and display messages which
may be shown in the instrument cluster
(Y page 255).
i Only use wheels with the recommended
tyre sizes. Only then will ESP ®
function
properly.
Characteristics of ESP ® General notes
If the
÷ ESP warning lamp goes out before
beginning the journey, ESP ®
is automatically
active.
If ESP ®
intervenes, the ÷ESP®
warning
lamp flashes in the instrument cluster. Driving safety systems
77Safety Z

If ESP
®
intervenes:
X Do not deactivate ESP ®
under any circum-
stances.
X When pulling away, only depress the accel-
erator pedal as far as is necessary.
X Adapt your driving style to suit the prevail-
ing road and weather conditions.
ECO start/stop function
The ECO start/stop function switches the
engine off automatically if the vehicle stops
moving. When pulling away again, the engine
starts automatically. ESP ®
remains in its pre-
viously selected status. Example:if ESP®
was deactivated before the engine was
switched off, ESP ®
remains deactivated when
the engine is switched on again.
Deactivating/activating ESP ®
(except
AMG vehicles) Important safety notes
You can select between the following states
of ESP
®
:
R ESP ®
is activated.
R ESP ®
is deactivated. G
WARNING
If you deactivate ESP ®
, ESP ®
no longer sta-
bilises the vehicle. There is an increased risk
of skidding and an accident.
Only deactivate ESP ®
in the situations descri-
bed in the following.
It may be best to deactivate ESP ®
in the fol-
lowing situations:
R when using snow chains
R in deep snow
R on sand or gravel
i Activate ESP ®
as soon as the situations
described above no longer apply. ESP ®
will
otherwise not be able to stabilise the vehi-
cle if the vehicle starts to skid or a wheel
starts to spin. Deactivating/activating ESP
®
You can deactivate or activate ESP ®
via the
on-board computer.
X To deactivate:(Y page 244).
The å ESP®
OFF warning lamp in the
instrument cluster lights up.
X To activate:(Y page 244).
The å ESP®
OFF warning lamp in the
instrument cluster goes out.
Characteristics when ESP ®
is deactivated
If ESP ®
is deactivated and one or more wheels
start to spin, the ÷ESP®
warning lamp in
the instrument cluster flashes. In such situa-
tions, ESP ®
will not stabilise the vehicle.
If you deactivate ESP ®
:
R ESP ®
no longer improves driving stability.
R engine torque is no longer limited and the
drive wheels are able to spin.
The spinning of the wheels results in a cut-
ting action for better traction on loose sur- faces.
R traction control is still activated.
R ESP ®
still provides support when you
brake.
Deactivating/activating ESP ®
(AMG
vehicles) Important safety notes
i Observe the "Important safety notes" sec-
tion (Y page 72).
You can select between the following states
of ESP ®
:
R ESP ®
is activated.
R SPORT handling mode is activated.
R ESP ®
is deactivated. G
WARNING
When SPORT handling mode is activated,
there is a greater risk of skidding and acci-
dents. 78
Driving safety systemsSafety

Only activate SPORT handling mode in the sit-
uations described in the following. G
WARNING
If you deactivate ESP ®
, ESP ®
no longer sta-
bilises the vehicle. There is an increased risk
of skidding and an accident.
Only deactivate ESP ®
in the situations descri-
bed in the following.
In the following situations, it may be better to activate SPORT handling mode or deactivate
ESP ®
:
R when using snow chains
R in deep snow
R on sand or gravel
R on specially designated roads when the
vehicle's own oversteering and understeer-
ing characteristics are desired
Driving in SPORT handling mode or without
ESP ®
requires an extremely qualified and
experienced driver.
i Activate ESP ®
as soon as the situations
described above no longer apply. ESP ®
will
otherwise not be able to stabilise the vehi-
cle if the vehicle starts to skid or a wheel
starts to spin.
Deactivating/activating ESP ®X
To activate SPORT handling mode:
briefly press button :.
The M handling mode warning lamp in
the instrument cluster lights up. The SPORT handling mode
SPORT handling mode message appears
in the multifunction display.
X To deactivate SPORT handling mode:
briefly press button :.
The M handling mode warning lamp in
the instrument cluster goes out.
X To deactivate ESP ®
:press button :until
the å ESP®
OFF warning lamp lights up
in the instrument cluster.
The ÷ OFF OFFmessage appears in the mul-
tifunction display.
X To activate ESP ®
:briefly press button :.
The å ESP®
OFF warning lamp in the
instrument cluster goes out. The ÷
ESP ®
ON
ON message appears in the multifunc-
tion display.
Characteristics of activated SPORT han-
dling mode
If SPORT handling mode is activated and one or more wheels start to spin, the ÷ESP®
warning lamp in the instrument cluster
flashes. ESP ®
only stabilises the vehicle to a
limited degree.
When SPORT handling mode is activated:
R ESP ®
only improves driving stability to a
limited degree.
R traction control is still activated.
R engine torque is restricted to a limited
degree and the drive wheels are able to
spin.
The spinning of the wheels results in a cut-
ting action for better traction on loose sur- faces.
R ESP ®
still provides support when you
brake.
Characteristics when ESP ®
is deactivated
If ESP ®
is deactivated and one or more wheels
start to spin, the ÷ESP®
warning lamp in
the instrument cluster does not flash. In such
situations, ESP ®
will not stabilise the vehicle. Driving safety systems
79Safety Z

If you deactivate ESP
®
:
R ESP ®
no longer improves driving stability.
R engine torque is no longer limited and the
drive wheels are able to spin.
The spinning of the wheels results in a cut-
ting action for better traction on loose sur-faces.
R traction control is still activated.
R PRE-SAFE ®
is no longer available; nor is it
activated if you brake firmly with assis-
tance from ESP ®
.
R COLLISION PREVENTION ASSIST is no lon-
ger available; nor is it activated if you brake
firmly with assistance from ESP ®
.
R ESP ®
still provides support when you
brake.
Off-road ESP ® An ESP
®
system specifically suited to off-road
terrain is activated automatically once the off-
road program is activated (Y page 205).
The off-road ESP ®
intervenes with a delay if
there is oversteering or understeering, thus
improving traction.
ESP ®
trailer stabilisation General notes
If your vehicle/trailer combination begins to
lurch, ESP
®
assists you in this situation. ESP ®
slows the vehicle down by braking and limit-
ing the engine output until the vehicle/trailer
combination has stabilised.
Important safety notes G
WARNING
If road and weather conditions are poor,
trailer stabilisation will not be able to prevent the vehicle/trailer combination from swerv-
ing. Trailers with a high centre of gravity can
tip over before ESP ®
can detect this. There is
a risk of an accident.
Always adapt your driving style to the prevail-
ing road and weather conditions. If your vehicle/trailer combination begins to
lurch, you can only stabilise the vehicle/
trailer combination by depressing the brake
firmly.
ESP
®
trailer stabilisation is active above
speeds of about 65 km/h.
ESP ®
trailer stabilisation does not work if
ESP ®
is deactivated or disabled because of a
malfunction. EBD (electronic brake force distribu-
tion)
General notes EBD monitors and controls the brake pres-
sure on the rear wheels to improve driving
stability while braking.
Important safety notes i
Observe the "Important safety notes" sec-
tion for driving safety systems (Y page 72). G
WARNING
If EBD has malfunctioned, the rear wheels can still lock, e.g. under full braking. This increa-
ses the risk of skidding and an accident.
You should therefore adapt your driving style
to the different handling characteristics. Havethe brake system checked at a qualified spe-
cialist workshop.
Observe information regarding indicator and
warning lamps (Y page 289) as well as dis-
play messages (Y page 257). ADAPTIVE BRAKE
ADAPTIVE BRAKE enhances braking safety
and offers increased braking comfort. In addi-
tion to the braking function, ADAPTIVE BRAKE
also has the HOLD function (Y page 201) and
hill start assist (Y page 161). For further
information, see Driving tips (Y page 183).80
Driving safety systemsSafety

STEER CONTROL
General notes STEER CONTROL helps you by transmitting a
noticeable steering force to the steering
wheel in the direction required for vehicle
stabilisation.
This steering support is provided in particular
if:
R both right wheels or both left wheels are on
a wet or slippery road surface when you
brake.
R the vehicle starts to skid.
Important safety notes No steering support is provided from STEER
CONTROL, if
R ESP ®
is malfunctioning.
R the steering is faulty.
Power steering will, however, continue to
function. Anti-theft systems
Immobiliser
The immobiliser prevents your vehicle from
being started without the correct key.
X To activate: remove the key from the igni-
tion lock.
X To deactivate: switch on the ignition.
When leaving the vehicle, always take the key
with you and lock the vehicle. The engine can
be started by anyone with a valid key that is
left inside the vehicle.
i The immobiliser is always deactivated
when you start the engine. ATA (Anti-Theft Alarm system)
X
To prime: lock the vehicle with the key.
Indicator lamp :flashes. The alarm sys-
tem is primed after approximately
15 seconds.
X To switch off: unlock the vehicle with the
key.
or
X Insert the key into the ignition lock.
A visual and audible alarm is triggered if the
alarm system is primed and you open:
R the vehicle with the emergency key ele-
ment
R a door
R the tailgate
R the bonnet
X To stop the alarm: insert the key into the
ignition lock.
The alarm is switched off.
or
X Press the %or& button on the key.
The alarm is switched off.
The alarm is not switched off, even if you
close the open door that has triggered it, for
example. Tow-away protection
Function An audible and visual alarm is triggered if your
vehicle's angle of inclination is altered while
tow-away protection is primed. This can occur Anti-theft systems
81Safety Z