air bag must be deployed on time, at the start of
the collision.
The rate of vehicle deceleration or acceleration
and the direction of the force are essentially
determined by:
Rdistribution of the force during the impact
Rcollision angle
Rdeformation characteristics of the vehicle
Rcharacteristics of the object with which the
vehicle has collided
Factors which can only be seen and measured
after the collision has occurred do not play a
decisive role in the deployment of an air bag, nor
do they provide an indication of air bag deploy-
ment.
The vehicle may be considerably deformed with-
out an air bag being deployed. This is the case if
only relatively easily deformable parts have
been hit and a high rate of deceleration has not been reached. Conversely, an air bag may be
deployed even though the vehicle suffers only
minor deformation. This is the case if, for exam-
ple, very rigid vehicle parts such as the longitu-
dinal body members are hit in an accident and
the rate of deceleration is sufficient.
If the restraint system control unit detects a side impact or that the vehicle is rolling over, the rel-
evant restraint system components are
deployed independently of one another depend-
ing on the anticipated type of accident.
RSide impact air bags on the side of the colli-
sion, regardless of Emergency Tensioning
Device and use of the seat belt on the driver's
side and the outer seats on the second row
The side impact air bag on the front-
passenger side deploys under the following
conditions:
-the OCS system detects that the front-
passenger seat is occupied or
-the belt tongue has engaged in the belt
buckle of the front-passenger seat.
RWindow curtain air bag on the side of the col-
lision, regardless of seat belt use and whether
front-passenger seat is occupied
RFront Emergency Tensioning Devices, if the
system determines that they can offer addi-
tional protection for the vehicle occupants in
this situation
RRear Emergency Tensioning Devices in cer-
tain situations if the vehicle rolls over
RWindow curtain air bags on the driver's and
front-passenger sides in certain rollover sit- uations if the system determines that they
can offer additional protection to that provi-
ded by the seat belt
iNot all air bags are deployed in an accident.
The various air bag systems work independ-
ently of each other.
How the air bag system works is determined
by the severity of the accident detected,
especially the vehicle deceleration or accel-
eration, and the apparent type of accident:
Rfrontal collision
Rside impact
Rrollover
PRE-SAFE®(anticipatory occupant
protection system)
Introduction
PRE-SAFE®takes preemptive measures to pro-
tect occupants in certain hazardous situations.
Important safety notes
!Make sure that there are no objects in the
footwell or behind the seats. There is a danger
that the seats and/or objects could be dam-
aged when PRE-SAFE
®is activated.
Despite your vehicle being equipped with the
PRE-SAFE
®system, the possibility of personal
injuries occurring as a result of an accident can-
not be eliminated. 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:
Rin emergency braking situations, e.g. when
BAS is activated
Rin critical driving situations, e.g. when physi-
cal limits are exceeded and the vehicle under-
steers or oversteers severely
Rvehicles with the Driving Assistance package:
when a driver assistance system intervenes
powerfully or the radar sensor system detects
an imminent danger of collision in certain sit- uations
60Occupant safety
Safety
PRE-SAFE®takes the following measures
depending on the hazardous situation detected:
Rthe front seat belts are pre-tensioned.
Rif the vehicle skids, the side windows and the
sliding sunroof are closed.
Rvehicles with the memory function for the
front-passenger seat: the front-passenger
seat is adjusted if it is in an unfavorable posi-
tion.
If the hazardous situation passes without result-
ing in an accident, PRE-SAFE
®slackens the belt
pre-tensioning. All settings made by PRE-SAFE®
can then be reversed.
If the seat belt pre-tensioning is not reduced:
XMove the seat backrest or seat back slightly
when the vehicle is stationary.
The 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. You will
find information on the convenience function
under "Belt adjustment" (
Ypage 51).
PRE-SAFE®PLUS (anticipatory occu-
pant protection system PLUS)
Introduction
PRE-SAFE®PLUS is only available in vehicles
with the Driving Assistance package.
Using the radar sensor system, PRE-SAFE
®
PLUS is able to detect that a head-on or rear-end
collision is imminent. In certain hazardous sit-
uations, PRE-SAFE
®PLUS takes pre-emptive
measures to protect the vehicle occupants.
Important safety notes
The intervention of PRE-SAFE®PLUS cannot
prevent an imminent collision.
The driver is not warned about the intervention
of PRE-SAFE
®PLUS.
PRE-SAFE®PLUS does not intervene if the vehi-
cle is backing up.
When driving, or when parking or exiting a park-
ing space with assistance from Active Parking
Assist, PRE-SAFE
®PLUS will not apply the
brakes.
Function
PRE-SAFE®PLUS intervenes in certain situa-
tions if the radar sensor system detects an
imminent head-on or rear-end collision.
PRE-SAFE
®PLUS takes the following measures
depending on the hazardous situation detected:
Rif the radar sensor system detects that a
head-on collision is imminent, the seat belts
are pre-tensioned.
Rif the radar sensor system detects that a rear-
end collision is imminent:
-the brake pressure is increased if the driver
applies the brakes when the vehicle is sta- tionary.
-the seat belts are pre-tensioned.
The PRE-SAFE®PLUS braking application is can-
celed:
Rif the accelerator pedal is depressed when a
gear is engaged
Rif the risk of a collision passes or is no longer
detected
Rif DISTRONIC PLUS indicates an intention to
pull away
If the hazardous situation passes without result-
ing in an accident, the original settings are
restored.
Automatic measures after an acci-
dent
Immediately after an accident, the following
measures are implemented, depending on the
type and severity of the impact:
Rthe hazard warning lamps are activated
Rthe emergency lighting is activated
Rthe vehicle doors are unlocked
Rthe front side windows are lowered
Rvehicles with a memory function: the electri-
cally adjustable steering wheel is raised
Rthe engine is switched off and the fuel supply
is cut off
Rvehicles with mbrace: automatic emergency
call
Rvehicles with the hybrid drive system: the
hybrid system and the high-voltage electrical
system are deactivated
Occupant safety61
Safety
Z
Child-proof locks for the rear doors
You secure each door individually with the child-
proof locks on the rear doors. A door secured
with a child-proof lock cannot be opened from
inside the vehicle. When the vehicle is unlocked,
the door can be opened from the outside.
XTo activate:press the child-proof lock lever
up in the direction of arrow :.
XMake sure that the child-proof locks are work-
ing properly.
XTo deactivate:press the child-proof lock
lever down in the direction of arrow ;.
Override feature for the rear side win-
dows
XTo activate/deactivate:press button;.
If indicator lamp :is lit, operation of the rear
side windows is disabled. Operation is only
possible using the switches in the driver's
door. If indicator lamp :is off, operation is
possible using the switches in the rear com-
partment.
Pets in the vehicle
GWARNING
If you leave animals unattended or unsecured
in the vehicle, they could press buttons or
switches, for example.
As a result, they could:
Ractivate vehicle equipment and become
trapped, for example
Ractivate or deactivate systems, thereby
endangering other road users
Unsecured animals could also be flung around
the vehicle in the event of an accident or sud-
den steering or braking, thereby injuring vehi-
cle occupants. There is a risk of an accident
and injury.
Never leave animals unattended in the vehi-
cle. Always secure animals properly during
the journey, e.g. use a suitable animal trans-
port box.
Driving safety systems
Overview of driving safety systems
In this section, you will find information about
the following driving safety systems:
RABS (Anti-lock Braking System)
(Ypage 68)
RBAS (B rakeAssist System) (Ypage 68)
RBAS PLUS with Cross-Traffic Assist ( Brake
Assist System PLUS with Cross-Traffic Assist)
(
Ypage 69)
RCOLLISION PREVENTION ASSIST PLUS
(Ypage 70)
RESP®( Electronic StabilityProgram)
(Ypage 73)
REBD (Electronic Brake force Distribution)
(Ypage 76)
RADAPTIVE BRAKE (Ypage 76)
RPRE-SAFE®Brake (Ypage 77)
RSTEER CONTROL (Ypage 78)
Driving safety systems67
Safety
Z
Important safety notes
If you fail to adapt your driving style or if you are
inattentive, thedriving safet ysystems can nei-
ther reduce th eris kof an acciden tno roverride
th elaws of physics .Drivin gsafet ysystems are
merely aids designed to assist driving .You are
responsible for maintainin gth edistanc eto th e
vehicl ein front, for vehicl espeed, for braking in
goo dtime, and for staying in lane. Always adapt
your driving style to suit th eprevailing road and
weather condition sand maintai n asafedistanc e
from th evehicl ein front. Drive carefully.
The driving safet ysystems describe donly wor k
as effectivel yas possible when there is ade-
quat econtact between th etires and th eroad
surface. Pay particular attention to th einforma-
tion regarding tires ,recommended minimum
tire tread depths etc. in th e"Wheels and tires "
section (
Ypage 360).
In wintr ydriving conditions, always use winte r
tires (M+ Stires )and if necessary, snow chains.
Only in this way will the driving safety systems
described in this section work as effectively as
possible.
ABS (Anti-lock Braking System)
General information
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 5 mph
(8 km/h), regardless of road-surface conditions.
ABS works on slippery surfaces, even when you
only brake gently.
Important safety notes
iObserve the "Important safety notes" sec-
tion (Ypage 68).
GWARNING
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.
When ABS is malfunctioning, other systems,
including driving safety systems, will also
become inoperative. Observe the information
on the ABS warning lamp (
Ypage 289) and dis-
play messages which may be shown in the
instrument cluster (
Ypage 256).
Braking
XIf ABS intervenes: continue to depress the
brake pedal vigorously until the braking sit-
uation is over.
XTo make a full brake application: depress
the brake pedal with full force.
If ABS intervenes when braking, you will feel a
pulsing in the brake pedal.
The pulsating brake pedal can be an indication
of hazardous road conditions, and functions as a reminder to take extra care while driving.
BAS (Brake Assist System)
General information
BAS operates in emergency braking situations.
If you depress the brake pedal quickly, BAS
automatically boosts the braking force, thus
shortening the stopping distance.
Important safety notes
iObserve the "Important safety notes" sec-
tion (Ypage 68).
GWARNING
If BAS is malfunctioning, the braking distance
in an emergency braking situation is
increased. There is a risk of an accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
68Driving safety systems
Safety
Braking
XKeep the brake pedal firmly depressed until
the emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will function as usual once you
release the brake pedal. BAS is deactivated.
BAS PLUS (Brake Assist System
PLUS) with Cross-Traffic Assist
General information
BAS PLUS can help you to minimize the risk of a
collision with a vehicle or a pedestrian and
reduce the effects of such a collision. If BAS
PLUS detects a danger of collision, you are
assisted when braking.
iPay attention to the important safety notes
in the "Driving safety systems" section
(
Ypage 68).
BAS PLUS is only available on vehicles with the
Driving Assistance package.
For BAS PLUS to assist you when driving, the
radar sensor system and the camera system
must be operational.
With the help of a sensor system and a camera
system, BAS PLUS can detect obstacles:
Rthat are in the path of your vehicle for an
extended period of time
Rthat cross the path of your vehicle
In addition, pedestrians in the path of your vehi- cle can be detected.
BAS PLUS detects pedestrians by using typical
characteristics such as the body contours and
posture of a person standing upright.
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.
iObserve the restrictions described in the
"Important safety notes" sec-
tion“ (
Ypage 69).
Important safety notes
GWARNING
BAS PLUS cannot always clearly identify
objects and complex traffic situations.
In such cases, BAS PLUS may:
Rintervene unnecessarily
Rnot 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.
GWARNING
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.
GWARNING
BAS PLUS does not react:
Rto small people, e.g. children
Rto animals
Rto oncoming vehicles
Rwhen 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, the rec-
ognition can be impaired.
Recognition by the radar sensor system is also
impaired if:
Rthere is dirt on the sensors or anything else
covering the sensors
Rthere is interference by other radar sources
Rthere are strong radar reflections, for exam-
ple in parking garages
Ra narrow vehicle is traveling in front, e.g. a
motorbike
Driving safety systems69
Safety
Z
Ra vehicle is traveling in front on a different line
Rvehicles quickly move into the radar sensor
system detection range
Recognition by the camera system is also
impaired in the event of:
Rdirt on the camera or if the camera is covered
Rglare on the camera system, e.g. from the sun being low in the sky
Rdarkness
Ror if:
-pedestrians move quickly, e.g. into the path
of the vehicle
-the camera system no longer recognizes 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 configuration and operation of the
radar sensors 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 windshield, 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:
Ryou approach an obstacle, and
RBAS PLUS has detected a risk of collision
When driving at a speed under 20 mph
(30 km/h) : if you depress the brake pedal, BAS
PLUS is activated. The increase in brake pres-
sure will be carried out at the last possible
moment.
When driving at a speed above 20 mph
(30 km/h): if you depress the brake pedal
sharply, BAS PLUS automatically raises the
brake pressure to a value adapted to the traffic
situation.
BAS PLUS provides braking assistance in haz-
ardous situations with vehicles in front within a
speed range between 4 mph (7 km/h) and
155 mph (250km/ h). At speeds of up to approximately 44 mph
(70 km/h), BAS PLUS can react to:
Rstationary objects in the path of your vehicle,
e.g. stopped or parked vehicles
Rpedestrians in the path of your vehicle
Robstacles crossing your path, which move in
the detection range of the sensors and are
recognized by them
iIf BAS PLUS demands particularly high brak-
ing force, preventative passenger protection
measures (PRE-SAFE
®) are activated simulta-
neously (Ypage 60).
XKeep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the whee ls fro
m locking.
BAS PLUS is deactivated and the brakes func-
tion as usual again, if:
Ryou release the brake pedal.
Rthere is no longer a risk of collision.
Rno obstacle is detected in front of your vehi-
cle.
Ryou depress the accelerator pedal
Ryou activate kickdown.
COLLISION PREVENTION ASSIST
PLUS
General information
iObserve the "Important safety notes" sec-
tion (Ypage 68).
COLLISION PREVENTION ASSIST PLUS consists
of a distance warning function with an autono-
mous braking function and adaptive Brake
Assist.
COLLISION PREVENTION ASSIST PLUS can help
you to minimize the risk of a front-end collision
with a vehicle ahead or reduce the effects of
such a collision.
If COLLISION PREVENTION ASSIST PLUS
detects that there is a risk of a collision, you will
be warned visually and acoustically. If you do not
react to the visual and audible collision warning,
autonomous braking can be initiated in critical
situations. If you apply the brake yourself in a
critical situation, the COLLISION PREVENTION
ASSIST PLUS adaptive Brake Assist assists you.
70Driving safety systems
Safety
Important safety notes
In particular, thedetection of obstacles can be
impaired if:
Rthere is dirt on th esensor sor anythin gelse
covering th esensor s
Rthere is snow or heav yrain
Rthere is interferenc eby other radar source s
Rthere are strongradar reflections, for exam-
ple in parking garages
Ra narrow vehicl eis traveling in front, e.g. a
motorbike
Ra vehicl eis traveling in fron ton adifferen tlin e
Rthevehicl eis ne wor after aservic eon th e
COLLISION PREVENTION ASSIST PLU Ssys-
te m
Observ eth eimportant safet ynote sin th e
"Breaking-in notes" section (
Ypage 145).
Followin gdamag eto th efron ten dof th evehicle,
have th econfiguration and operation of th e
radar sensor checke dat aqualified specialist
workshop. This also applie sto collision sat slow
speeds wher ethere is no visible damag eto th e
fron tof th evehicle.
Switching on/off
The COLLISION PREVENTION ASSIST PLU Sis
automatically active after switching on th eigni-
tion .
You can activat eor deactivat eCOLLISION PRE -
VENTION ASSIST PLU Sin th eon-board com-
puter (
Ypage 247). When deactivated, th edis-
tance warning function and th eautonomous
braking function are also deactivated.
If COLLISION PREVENTION ASSIST PLU Sis
deactivated, th eæ symbol appear sin th e
assistanc egraphic sdisplay.
Distance warning function
Gene ral inform ation
The distanc ewarning function can help you to
minimiz eth eris kof afront-en dcollision wit h a
vehicl eahead or reduce th eeffects of suc h a
collision .If th edistanc ewarning function
detects that there is aris kof acollision ,you will
be warned visually and acoustically.
Important safety notes
iObserv eth e"Importan tsafet ynotes" sec -
tion for driving safet ysystems (Ypage 68).
GWARNIN G
The distanc ewarning function does no treact:
Rto people or animals
Rto oncomin gvehicles
Rto crossing traffic
Rwhen cornering
Thus ,th edistanc ewarning function canno t
provide awarning in all critical situations.
Ther eis aris kof an accident.
Always pay careful attention to th etraffic sit -
uation and be read yto brake.
GWARNIN G
The distanc ewarning function canno talways
clearly identify objects and comple xtraffic
situations.
In suc hcases, th edistanc ewarning function
may:
Rgiv ean unnecessary warning
Rno tgiv e a warning
Ther eis aris kof an accident.
Always pay careful attention to th etraffic sit -
uation and do no trel ysolely on th edistanc e
warning function .
Function
Starting ataspee dof approximately 4mph
(7 km/h), th edistanc ewarning function warn s
you if you rapidly approac h avehicl ein front. An
intermittent warning tone will then sound, and
th e· distanc ewarning lamp will ligh tup in
th einstrumen tcluster.
XBrake immediately in order to increas eth e
distanc efrom th evehicl ein front.
or
XTak eevasive action ,provide dit is saf eto do
so.
Due to th enature of th esystem, particularly
complicated but non-critical driving condition s
may also caus eth esystem to display awarning .
Wit hth ehelp of th eradar sensor system, th e
distanc ewarning function can detec tobstacles
Driving safety systems71
Safety
Z
that are in the path of your vehicle for an exten-
ded period of time.
Up to a speed of approximately 44 mph
(70 km/h), the distance warning function can
also react to stationary obstacles, such as stop-
ped or parked vehicles.
Autonomous braking function
If the driver does not react to the distance warn-ing signal in a critical situation, COLLISION PRE-
VENTION ASSIST PLUS can assist with the
autonomous braking function.
The autonomous braking function:
Rgives the driver more time to react to critical
driving situations
Rcan help the driver to avoid an accident or
Rreduces the effects of an accident
Vehicles without DISTRONIC PLUS: the
autonomous braking function is available in the
following speed ranges:
R4 - 65 mph (7 - 105 km/h) for moving objects
R4 - 31 mph (7 - 50 km/h) for stationary
objects
Vehicles with DISTRONIC PLUS: the autono-
mous braking function is available in the follow-
ing speed ranges:
R4 - 124 mph (7 - 200 km/h) for moving
objects
R4 - 31 mph (7 - 50 km/h) for stationary
objects
Due to the nature of the system, particularly
complicated but non-critical driving conditions
may also cause the Autonomous Braking Func-
tion to intervene.
If the autonomous braking function requires a
particularly high braking force, preventative
passenger protection measures (PRE-SAFE
®)
are activated simultaneously (Ypage 60).
Adaptive Brake Assist
General information
iObserve the "Important safety notes" sec-
tion (Ypage 68).
With the help of adaptive Brake Assist, the dis-
tance warning signal can detect obstacles that
are in the path of your vehicle for an extended
period of time. If adaptive Brake Assist detects a risk of colli-
sion with the vehicle in front, it calculates the
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
4 mph (7 km/h). It uses radar sensor technology
to assess the traffic situation.
Up to a speed of approximately 155 mph
(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 observation.
Up to a speed of approximately 44 mph
(70 km/h), adaptive Brake Assist reacts to sta-
tionary obstacles.
If Adaptive Brake Assist demands particularly
high braking force, preventative passenger pro-
tection measures (PRE-SAFE
®) are activated
si multaneously (Ypage 60).
XKeep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if:
Ryou release the brake pedal.
Rthere is no longer any danger of a collision.
Rno obstacle is detected in front of your vehi-
cle.
Adaptive Brake Assist is then deactivated.
Important safety notes
iObserve the "Important safety notes" sec-
tion for driving safety systems (Ypage 68).
GWARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions.
In such cases, Adaptive Brake Assist can:
Rintervene unnecessarily
Rnot 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.
72Driving safet ysystem s
Safety