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
panorama roof with power tilt/sliding panel
are closed. R
vehicles 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: X
Move 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. Informa-
tion about the convenience function can be
found under "Belt adjustment" ( Y
page 47).
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:R
if the vehicle is backing up R
when the vehicle is towing a trailer and there
is a risk of a rear-end collision
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: R
if the radar sensor system detects that a
head-on collision is imminent, the seat belts
are pre-tensioned. R
if 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: R
if the accelerator pedal is depressed when a
gear is engaged R
if the risk of a collision passes or is no longer
detected R
if 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: R
the hazard warning lamps are activated R
the emergency lighting is activated R
the vehicle doors are unlocked R
the front side windows are lowered R
vehicles with a memory function: the electri-
cally adjustable steering wheel is raised R
the engine is switched off and the fuel supply
is cut off R
vehicles with mbrace: automatic emergency
call58
Occupant safety
Safety
Braking X
Keep 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.
i Pay attention to the important safety notes
in the "Driving safety systems" section
( Y
page 65).
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: R
that are in the path of your vehicle for an
extended period of time R
that 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.
i Observe the restrictions described in the
"Important safety notes" section
( Y
page 66). 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, the rec-
ognition can be impaired.
Recognition by the radar sensor system is also
impaired if: R
there is dirt on the sensors or anything else
covering the sensors R
there is interference by other radar sources R
there are strong radar reflections, for exam-
ple in parking garages R
a narrow vehicle is traveling in front, e.g. a
motorbike66
Driving safety systems
Safety
R
a vehicle is traveling in front on a different line R
vehicles quickly move into the radar sensor
system detection range
Recognition 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
or 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 pedestrian is not
distinguishable 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: R
you approach an obstacle, and R
BAS PLUS has detected a danger of collision
At speeds of more than20 mp h( 30 km/h) : if
you depress the brake pedal, BAS PLUS is acti-
vated. The increase in brake pressure will be
carried out at the last possible moment.
At speeds of above20 mph(30 km/h) : if you
depress the brake pedal sharply, BAS PLUS
automatically increases the brake pressure to a
degree suited 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 (250 km/ h) . At speeds of up to approximately 44 mph
(70 km/h), BAS PLUS can react to: R
stationary objects in the path of your vehicle,
e.g. stopped or parked vehicles R
pedestrians in the path of your vehicle R
obstacles crossing your path, which move in
the detection range of the sensors and are
recognized by them
i If BAS PLUS demands particularly high brak-
ing force, preventative passenger protection
measures (PRE-SAFE ®
) are activated simulta-
neously ( Y
page 57). X
Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
BAS PLUS is deactivated and the brakes func-
tion as usual, if: R
you release the brake pedal. R
there is no longer a risk of collision. R
no obstacle is detected in front of your vehi-
cle. R
you depress the accelerator pedal. R
you activate kickdown.
COLLISION PREVENTION ASSIST
PLUS
General information
i Observe the "Important safety notes" sec-
tion ( Y
page 65).
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.Driving safety systems 67
Safety Z
Important safety notes In particular, th e detection of obstacles can be
impaired if: R
there is dirt on th e sensor s or anythin g else
covering th e sensor sR
there is snow or heav y rainR
there is interferenc e by other radar source sR
there are stron g radar reflections, for exam-
ple in parking garages R
a narrow vehicl e is traveling in front, e.g. a
motorbike R
a vehicl e is traveling in fron t on a differen t lin eR
ne w vehicles or after a servic e on th e COLLI-
SION PREVENTION ASSIST PLU S system
Observ e th e important safet y note s in th e
"Breaking-in notes" section ( Y
page 131).
Followin g damag e to th e fron t en d of th e vehicle,
hav e th e configuration and operation of th e
radar sensor checke d at a qualified specialist
workshop. This also applie s to collision s at slow
speeds wher e there is no visible damag e to th e
fron t of th e vehicle.
Activating/deactivating The COLLISION PREVENTION ASSIST PLU S is
automatically active after switching on th e igni-
tion .
You can activat e or deactivat e COLLISION PRE -
VENTION ASSIST PLU S in th e on-board com-
puter ( Y
page 220). When deactivated, th e dis-
tance warning function and th e autonomous
braking function are also deactivated.
If COLLISION PREVENTION ASSIST PLU S is
deactivated, th e
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.
Vehicles without DISTRONIC PLUS: the
autonomous braking function is available in the
following speed ranges: R
4–65 mph (7–105 km/h) for moving objects R
4–31 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: R
4–124 mph (7–200 km/h) for moving objects R
4–31 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 ( Y
page 57).
Adaptive Brake Assist
General information
i Observe the "Important safety notes" sec-
tion ( Y
page 65).
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
simultaneously ( Y
page 57). X
Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from loc king.
The br ak
es 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 vehi-
cle.
Adaptive Brake Assist is then deactivated.
Important safety notes
i Observe the "Important safety notes" sec-
tion for driving safety systems ( Y
page 65).
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.Driving safety systems 69
Safety Z
For PRE-SAFE ®
Brake to assist you when driving,
the radar sensor system and the camera system
must be switched on and be operational.
With the help of the radar sensor system and the
camera system, PRE-SAFE ®
Brake can detect
obstacles that are in front of your vehicle for an
extended period of time.
In addition, pedestrians in the path of your vehi-
cle can be detected.
PRE-SAFE ®
Brake detects pedestrians using
typical characteristics such as the body con-
tours and posture of a person standing upright.
i Observe the restrictions described in the
"Important safety notes" section
( Y
page 74).
Important safety notes
G WARNING
PRE-SAFE ®
Brake will initially brake your vehi-
cle by a partial application of the brakes if a
danger of collision is detected. There may be
a collision unless you brake yourself. Even
after subsequent full application of the brakes
a collision cannot always be avoided, partic-
ularly when approaching at too high a speed.
There is a risk of an accident.
Always apply the brakes yourself and try to
take evasive action, provided it is safe to do
so.
In the event of a partial application of the brakes,
the vehicle is braked with up to 50% of the full
braking pressure.
G WARNING
PRE-SAFE ®
Brake cannot always clearly iden-
tify objects and complex traffic conditions.
In these cases, PRE-SAFE ®
Brake may:R
give an unnecessary warning and then
brake the vehicle R
not give a warning or intervene
There is a risk of an accident.
Always pay particular attention to the traffic
situation and be ready to brake, especially if
PRE-SAFE ®
Brake warns you. Terminate the
intervention in a non-critical driving situation. G WARNING
PRE-SAFE ®
Brake cannot always clearly iden-
tify people, especially if they are moving. In
these cases, PRE-SAFE ®
Brake cannot inter-
vene. There is a risk of an accident.
Always pay particular attention to the traffic
situation and be ready to brake, especially if
PRE-SAFE ®
Brake warns you.
In order to maintain the appropriate distance to
the vehicle in front and thus prevent a collision,
you must apply the brakes yourself.
G WARNING
PRE-SAFE ®
Brake does not react: R
to small people, e.g. children R
to animals R
to oncoming vehicles R
to crossing traffic R
when cornering
As a result, PRE-SAFE ®
Brake may neither
give warnings nor intervene in all critical sit-
uations. There is a risk of an accident.
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: R
there is dirt on the sensors or anything else
covering the sensors R
there is interference by other radar sources R
there are strong radar reflections, for exam-
ple in parking garages R
a narrow vehicle is traveling in front, e.g. a
motorbike R
a vehicle is traveling in front on a different line
relative to the center of your vehicle
Recognition 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 sky74
Driving safety systems
Safety