ticularly if a seat belt tensioner was triggered or
an airbag was deployed.
An electric motor is used by PRE-SAFE ®
to trig-
ger the tightening of the seat belt in hazardous
situations. This procedure is reversible.
If the belt tensioners are triggered or an airbag is
deployed, you will hear a bang, and a small
amount of powder may also be released. The
6 restraint system warning lamp lights up.
Only in rare cases will the bang affect your hear-
ing. In general, the powder released is not haz-
ardous to health but may cause short-term
breathing difficulties to persons suffering from
asthma or other pulmonary conditions. Provided it is safe to do so, you should leave the vehicle
immediately or open the window in order to pre- vent breathing difficulties.
Operation During the first stage of a collision, the restraint
system control unit evaluates important physi-
cal data relating to vehicle deceleration or accel-
eration, such as:
R duration
R direction
R intensity
Based on the evaluation of this data, the
restraint system control unit triggers the seat
belt tensioners in the event of a head-on or rear
collision.
A seat belt tensioner can only be triggered if:
R the ignition is switched on
R the components of the restraint system are
operational. You can find further information
under: "Restraint system warning lamp"
(Y page 44)
R the belt tongue has engaged in the belt buckle
of the respective front seat
The seat belt tensioners in the rear compart-
ment are triggered independently of the lock
status of the seat belts.
If the restraint system control unit detects a high severity accident, in certain head-on collisions,
additional components of the restraint system
are deployed independently of each other:
R front airbags and driver's kneebag
R windowbag, if the system determines that
deployment can offer additional protection to
that provided by the seat belt On vehicles with the automatic front-passenger
front airbag deactivation system: depending on the person in the front-passenger seat, the
front-passenger front airbag is either disabled or
enabled. The front-passenger front airbag can
only be deployed in an accident if the
PASSENGER AIR BAG ON indicator lamp is lit.
Observe the information on the PASSENGER AIR BAG indicator lamps (Y page 44).
Your vehicle has two-stage front airbags. In the
first deployment stage, the front airbag is filled
with propellant gas to reduce the risk of injuries. The front airbag is fully deployed if the second
deployment stage is activated within a few mil-
liseconds.
The activation threshold for the seat belt ten-
sioners and airbags is determined based on the
evaluation of the vehicle's rate of deceleration
or acceleration at various points in the vehicle.
This process is pre-emptive in nature. The trig-
gering/deployment process should take place
in good time at the start of the collision.
The rate of vehicle deceleration or acceleration
and the direction of the force are essentially
determined by:
R the distribution of forces during the collision
R the collision angle
R the deformation characteristics of the vehicle
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 deci-
sive role in the deployment of an airbag, nor do
they provide an indication of airbag deployment.
The vehicle may be deformed significantly with-out an airbag being deployed. This is the case if
only parts which are relatively easily deformed
are affected and the rate of deceleration 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 longitudinal 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 system are activa-
ted independently of each other depending on
the apparent type of accident.
R Sidebags on the side on which an impact
occurs, independent from the seat belt ten-
sioner and seat belt usage 56
Occupant safetySafety
Vehicles with the automatic front-passenger
airbag deactivation system: the sidebag on
the front-passenger side deploys under the
following conditions:
- an occupant is detected on the front-
passenger seat or
- the belt tongue is engaged in the belt
buckle of 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 Seat belt tensioners, if the system determines
that deployment can offer additional protec-
tion for the vehicle occupants in this situation
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 accident.
The different airbag systems work independ-
ently of each other.
How the airbag system works is determined
by the severity of the accident detected,
especially the vehicle deceleration or accel-
eration, and the apparent type of accident:
R frontal collision
R side impact
R overturn PRE-SAFE
®
(anticipatory occupant
protection)
Introduction In certain hazardous situations, PRE-SAFE
®
takes pre-emptive measures to protect the vehi- cle occupants.
Important safety notes !
Make sure that there are no objects in the
footwell or behind the seats. There is a risk
that the seats and/or the objects could be
damaged when PRE-SAFE ®
is activated.
Although your vehicle is equipped with PRE-
SAFE ®
, the possibility of injury in the event of an
accident cannot be ruled out. Always adapt your
driving style to suit the prevailing road and weather conditions and maintain a safe distance
from the vehicle in front. Drive carefully.
Function PRE-SAFE
®
intervenes:
R in emergency braking situations, e.g. when
BAS is activated
R in critical driving situations, e.g. when physi-
cal limits are exceeded and the vehicle under-
steers or oversteers severely
R on vehicles with the Driving Assistance pack-
age: if BAS PLUS intervenes powerfully or the
radar sensor system detects an imminent
danger of collision in certain situations
PRE-SAFE ®
takes the following measures
depending on the hazardous situation detected:
R the front seat belts are pre-tensioned.
R if the vehicle skids, the side windows and the
sliding sunroof are closed.
R vehicles with the memory function: the front-
passenger seat is adjusted if it is in an unfav-
ourable position.
R vehicles with a multicontour seat: the air pres-
sure in the side bolsters of the backrest is
increased.
If the hazardous situation passes without result- ing in an accident, PRE-SAFE ®
slackens the belt
pre-tensioning. On vehicles with multicontour
seats, the air pressure in the side bolsters is
reduced again. All settings made by PRE-SAFE ®
can then be reversed.
If the seat belt pre-tensioning is not reduced:
X Move the seat backrest or seat back slightly
when the vehicle is stationary.
Seat belt pre-tensioning is reduced and the
locking mechanism is released.
The seat-belt adjustment is an integral part of
the PRE-SAFE ®
convenience function. Informa-
tion about the convenience function can be
found under "Belt adjustment" (Y page 47). PRE-SAFE
®
PLUS (anticipatory occu-
pant protection PLUS)
Introduction PRE-SAFE
®
PLUS is only available in vehicles
with the Driving Assistance package. Occupant safety
57Safety Z
Suitability of the seats for attaching belt-secured child restraint systems
If you use a baby car seat of category 0 or 0+ or a rearward-facing child restraint system of category
I on a rear seat, you must adjust the driver's or front-passenger seat so that the seat does not touch
the child restraint system.
If you use a category I, forward-facing child restraint system, you should remove the head restraint from the respective seat, if possible (Y page 109). The backrest of the child restraint system must,
as far as possible, lie flat against the backrest of the seat.
Make sure that the child's feet are not touching the front seat. If necessary, move the front seat
forward slightly (Y page 109).
For certain child restraint systems in weight categories II or III, this can mean that the area of use is restricted. The maximum size setting of the child restraint system is not possible due to possible
contact with the roof.
Always observe the notes in the "Child restraint system" section (Y page 59) and the child restraint
system manufacturer's installation instructions.
When you remove the child restraint system you must replace the head restraints again immediately (Y page 109). All vehicle occupants must adjust their head restraints correctly before beginning the
journey.
Legend for the table:
XS eat which is unsuitable for children in this weight category.
US uitable for child restraint systems in the "Universal" category that are approved for use in this
weight category.
UF Suitable for forward-facing child restraint systems that belong to the "Universal" category and are approved for use in this weight category.
LS uitable for child restraint systems as recommended; see the following table of "Recommended
child restraint systems" (Y page 67).
Front-passenger seat Weight category Front-passenger
front airbag enabled The front-passenger
front airbag is disa- bled 0
up to 10 kg X
U
1
, L 1 0+
up to 13 kg X
U
1
, L 1 I
9 kg to 18 kg UF U, L
II
15 kg to 25 kg UF U, L
III
22 kg to 36 kg UF U, L
Rear seats
Weight category Left, right Centre
0
up to 10 kg U
U
2 0+
up to 13 kg U
U
2 I
9 kg to 18 kg U
U
2 1
The vehicle is equipped with an automatic front-passenger front airbag deactivation system. The PASSENGER
AIR BAG OFF indicator lamp must be lit.
2 Child restraint systems with a supporting bracket are not suitable for this seat. Children in the vehicle
65Safety Z
Weight category Left, right Centre
II
15 kg to 25 kg U U
III
22 kg to 36 kg U U
Suitability of the seats for attaching ISOFIX child restraint systems
If you use a baby car seat of category 0 or 0+ or a rearward-facing child restraint system of category
I on a rear seat, you must adjust the driver's or front-passenger seat so that the seat does not touch the child restraint system.
If you use a category I, forward-facing child restraint system, you should remove the head restraintfrom the respective seat, if possible (Y page 109). The backrest of the child restraint system must,
as far as possible, lie flat against the backrest of the seat.
Always observe the notes in the "Child restraint system" section (Y page 59) and the child restraint
system manufacturer's installation instructions.
When you remove the child restraint system you must replace the head restraints again immediately (Y page 109). All vehicle occupants must adjust their head restraints correctly before beginning the
journey.
Make sure that the child's feet are not touching the front seat. If necessary, move the front seat
forward slightly (Y page 109).
For certain child restraint systems in weight categories II or III, this can mean that the area of use is restricted. The maximum size setting of the child restraint system is not possible due to possible
contact with the roof.
Legend for the table:
XI SOFIX position that is not suitable for ISOFIX child restraint systems in this weight category
and/or size category.
IUF Suitable for forward-facing ISOFIX child seat securing systems that belong to the "Universal" category which are approved for use in this weight category.
IL Suitable for ISOFIX child restraint systems as recommended; see the "Recommended child restraint systems" table (Y page 67).
The manufacturer will also recommend a suitable ISOFIX child restraint system. For this, your
vehicle and the seat must be listed in the child restraint system manufacturer's model list. For more information, contact the child restraint system manufacturer or visit their website. Weight category Size category Equipment Rear seat left,
right Carry-cot
F ISO/L1 X
G ISO/L2 X
0
up to 10 kg
up to approximately 6 months E ISO/R1 IL
0+
up to 13 kg
up to approximately 15 months E ISO/R1 IL
D ISO/R2 IL
C ISO/R3
IL
3 3
If you are using a child restraint system of size category C (ISO/R3), move the front seat to the highest position
and move the backrest to an upright position. Make sure that the front seat backrest does not rest against the
child restraint system. 66
Children in the vehicleSafety
Pets in the vehicle
G
WARNING
If you leave animals unsupervised or unse-
cured in the vehicle, they may push a button
or a switch, for example.
They could:
R activate vehicle equipment and become
trapped, for example
R switch vehicle systems on or off, thus
endangering other road users
In the event of an accident, sudden braking or
abrupt changes of direction, unsecured ani-
mals could be flung around the vehicle, injur-
ing the vehicle occupants. There is a risk of an accident and injury.
Never leave animals unattended in the vehi-
cle. Always secure animals correctly during a
journey, e.g. in an animal transport box. 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 70)
R BAS ( Brake Assist System) (Y page 71)
R BAS PLUS with Cross-Traffic Assist ( Brake
Assist System PLUS with Cross-Traffic Assist)
(Y page 71)
R COLLISION PREVENTION ASSIST PLUS
(Y page 73)
R Adaptive brake lights (Y page 75)
R ESP ®
(Electronic StabilityProgram)
(Y page 76)
R EBD ( electronic brake force distribution)
(Y page 78)
R ADAPTIVE BRAKE (Y page 78)
R PRE-SAFE ®
Brake (Y page 78)
R STEER CONTROL (Y page 80) Important safety notes
If you fail to adapt your driving style or if you are
inattentive, the driving safety systems can nei-
ther reduce the risk of an accident nor override the laws of physics. Driving safety systems are
merely aids designed to assist driving. You are
responsible for maintaining the distance to the
vehicle in front, for vehicle speed, for braking in
good time, and for staying in lane. Always adapt your driving style to suit the prevailing road and
weather conditions and maintain a safe distance from the vehicle in front. Drive carefully.
The driving safety systems described only work
as effectively as possible when there is ade-
quate contact between the tyres and the road
surface. Pay particular attention to the informa- tion regarding tyres, recommended minimum
tyre tread depths etc. in the "Wheels and tyres" section (Y page 405).
In wintry driving conditions, always use winter
tyres (M+S tyres) and, if necessary, snow
chains. Only in this way will the driving safety
systems described in this section work as effec-
tively 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 vehicle 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.
ABS works from a speed of about 8 km/h,
regardless of road-surface conditions. ABS
works on slippery surfaces, even when you only brake gently.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 70). 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- 70
Driving safety systemsSafety
If the radar sensor system or the camera system
is malfunctioning, BAS PLUS functions are
restricted or no longer available. The brake sys- tem is still available with complete brake boost-ing effect and BAS.
i Observe the restrictions described in the
"Important safety notes" section
(Y page 72).
Important safety notes G
WARNING
BAS PLUS cannot always clearly identify
objects and complex traffic situations.
In such cases, BAS PLUS may:
R intervene unnecessarily
R not intervene
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. Terminate the
intervention in a non-critical driving situation. G
WARNING
BAS PLUS cannot always clearly identify peo- ple, this is especially the case if they are mov-
ing. BAS PLUS cannot intervene in these
cases. There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake. G
WARNING
BAS PLUS does not react:
R to small people, e.g. children
R to animals
R to oncoming vehicles
R when cornering
As a result, BAS PLUS may not intervene in all
critical situations. There is a risk of an acci-
dent.
Always pay careful attention to the traffic sit- uation and be ready to brake.
In the event of snowfall or heavy rain, detection
can be impaired. Detection by the radar sensor system is also
impaired in the event of:
R dirt on the sensors or obscured sensors
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 vehicles quickly moving into the radar sensor
system detection range
Detection by the camera system is also impaired
in the event of:
R dirt on the camera or if the camera is covered
R glare on the camera system, e.g. from the sun
being low in the sky
R darkness
R if:
- pedestrians move quickly, e.g. into the path
of the vehicle
- the camera system no longer detects a
pedestrian as a person due to special cloth-
ing or other objects
- a pedestrian is concealed by other objects
- the typical outline of a person is not distin-
guishable from the background
Following damage to the front end of the vehicle, have the radar sensor settings and operation
checked at a qualified specialist workshop. This also applies to collisions at slow speeds where
there is no visible damage to the front of the
vehicle.
Following damage to the windscreen, have the
configuration and operation of the camera sys-
tem checked at a qualified specialist workshop.
Function To avoid a collision, BAS PLUS calculates the
brake force necessary if:
R you approach an obstacle and
R BAS PLUS has detected a risk of a collision
When driving at a speed under 30 km/h: if
you depress the brake pedal, BAS PLUS is acti-
vated. Braking assistance from BAS PLUS is car-
ried out at the last possible moment.
When driving at a speed above 30 km/h: if
you depress the brake pedal sharply, BAS PLUS automatically increases the brake pressure to adegree suited to the traffic situation. 72
Driving safety systemsSafety
braking force necessary to avoid a collision. If
you apply the brakes forcefully, Adaptive Brake
Assist will automatically increase the braking
force to a level suitable for the traffic conditions.
Adaptive Brake Assist provides braking assis-
tance in hazardous situations at speeds above
7 km/h. It uses radar sensor technology to
assess the traffic situation.
Up to a speed of approximately 250 km/h,
Adaptive Brake Assist is capable of reacting to
moving objects that have already been detected
as such at least once over the period of obser-
vation.
Up to a speed of approximately 70 km/h, Adap-
tive Brake Assist reacts to stationary obstacles.
If Adaptive Brake Assist demands particularly
high braking force, preventative passenger pro-
tection measures (PRE-SAFE ®
) are activated
simultaneously (Y page 57).
X Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if: R you release the brake pedal
R there is no longer any danger of a collision
R no obstacle is detected in front of your vehicle
Adaptive Brake Assist is then deactivated.
Important safety notes i Observe the "Important safety notes" sec-
tion for driving safety systems (Y page 70).G
WARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions.
In such cases, Adaptive Brake Assist can:
R intervene unnecessarily
R not intervene
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. Terminate the
intervention in a non-critical driving situation. G
WARNING
Adaptive Brake Assist does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
As a result, the Adaptive Brake Assist may not intervene in all critical conditions. There is a
risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake.
Due to the nature of the system, complicated
but non-critical driving situations may also
cause Adaptive Brake Assist to intervene.
If Adaptive Brake Assist is not available due to a malfunction in the radar sensor system, the
brake system remains available with full brake
boosting effect and BAS. Adaptive brake lights
The adaptive brake lights warn following traffic
in an emergency braking situation:
R by flashing brake lamps
R the hazard warning lamps are activated
If you brake sharply from a speed of more than
50 km/ hor 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 warning
lamps are activated automatically. If the brakes
are applied again, the brake lamps light up con- tinuously. 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 124). ESP
®
(Electronic Stability Program)
General notes i
Observe the "Important safety notes" sec-
tion (Y page 70). Driving safety systems
75Safety Z
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 vehi- cle 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) ETS traction control is part of ESP
®
. On vehicles
with 4MATIC, 4ETS is a component of ESP ®
.
Traction control brakes the drive wheels indi-
vidually 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 transfer-
red to the wheel or wheels with traction.
Traction control remains active if you deactivate
ESP ®
.
In appropriate driving situations, activate the
off-road programs:
X Vehicles without the Off-Road Engineering
package (Y page 254)
X Vehicles with the Off-Road Engineering pack-
age (Y page 254)
Off-road 4ETS (Electronic Traction Sys-
tem) An ETS system specifically suited to off-road
terrain is activated automatically once an off-
road program is activated:
R Vehicles without the Off-Road Engineering
package (Y page 254)
R Vehicles with the Off-Road Engineering pack-
age (Y page 254)
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.
! Only operate the vehicle for a maximum of
ten seconds on a brake dynamometer. Switch
off the ignition.
Application of the brakes by ESP ®
may oth-
erwise destroy the brake system.
! A function or performance test should only
be carried out on a twin-axle dynamometer.
Before you operate the vehicle on such a
dynamometer, please consult a qualified
workshop. You could otherwise damage the
drive train or the brake system.
When ESP ®
is deactivated, the åESP®
OFF
warning lamp lights up continuously.
If the ÷ warning lamp and the åwarning
lamp are lit continuously, ESP ®
is not available
due to a malfunction.
Observe the information on warning lamps
(Y page 343) and display messages which may
be shown in the instrument cluster
(Y page 301).
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.
If ESP ®
intervenes:
X Do not deactivate ESP ®
under any circum-
stances.
X When pulling away, only depress the acceler-
ator pedal as far as is necessary.
X Adapt your driving style to suit the prevailing
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 previ-
ously selected status. Example:if ESP®
was
deactivated before the engine was switched off, 76
Driving safety systemsSafety