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-
orable position. R
vehicles with a multicontour seat: the air pres-
sure in the side bolsters of the seat 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.
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 48).
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: 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 offOccupant safety 59
Safety Z
Drivin g safet y systems
Overview of drivin g safet y systemsIn this section , you will fin d information about
th e followin g drivin g safet y systems :R
AB S ( A n ti-loc k B rakin g S ystem)
( Y
page 66)R
BA S ( B rak e A ssist S ystem) ( Y
page 67)R
BA S PLU S wit h Cross-Traffic Assis t ( B r ak e
A ssist S ystem PLU S wit h Cross-Traffic Assist)
( Y
page 67)R
COLLISION PREVENTION ASSIST PLU S
( Y
page 69 )R
ES P ®
( E lectronic S t ability P r ogram)
( Y
page 72)R
EB D ( E lectroni c B rak e forc e D istribution )
( Y
page 74 )R
ADAPTIV E BRAKE ( Y
page 74 )R
PRE-SAF E ®
Brak e ( Y
page 74 )R
STEE R CONTROL ( Y
page 76)
Important safet y notesIf you fail to adapt your drivin g style or if you are
inattentive , th e drivin g safet y systems can nei-
ther reduce th e ris k of an acciden t no r override
th e laws of physics. Driving safet y systems are
merely aids designed to assist driving. You are
responsible fo r maintainin g th e distanc e to th e
vehicle in front, fo r vehicle speed, fo r braking in
goo d time, and fo r stayin g in lane. Always adapt
your drivin g style to suit th e prevailin g road and
weather condition s and maintain a saf e distanc e
from th e vehicle in front. Drive carefully.
The drivin g safet y systems described only wor k
as effectively as possible when there is ade-
quat e contact between th e tires and th e road
surface. Pay particular attention to th e informa-
tion regardin g tires , recommended minimum
tire tread depths etc. in th e "Wheels and tires "
section ( Y
page 387).
In wintr y drivin g conditions, always use winte r
tires (M+ S tires ) and , if necessary, snow chains.
Only in this way will th e drivin g safet y systems
described in this section wor k as effectively as
possible. ABS (Anti-lock Braking System)
General information AB S regulates brake pressure in suc h a way that
th e wheels do no t loc k when you brake . Thi s
allow s you to continue steerin g th e vehicle when
braking .
The % AB S warnin g lamp in th e instrumen t
cluster lights up when th e ignition is switched
on . It goe s out when th e engin e is running .
AB S works from a speed of about 5 mph
(8 km/h), regardles s of road-surfac e conditions.
AB S works on slipper y surfaces, eve n when you
only brake gently.
Important safet y notes
i Observ e th e "Important safet y notes" sec -
tion ( Y
page 66).
G WARNING
If AB S is faulty, th e wheels could loc k when
braking . The steerability and braking charac -
teristics may be severely impaired. Addition -
ally, further drivin g safet y systems are deac -
tivated. There is an increase d danger of skid-
din g and accidents .
Drive on carefully. Hav e AB S checke d imme-
diately at a qualified specialis t workshop .
Whe n AB S is malfunctioning, other systems ,
includin g drivin g safet y systems , will also
becom e inoperative . Observ e th e information
on th e AB S warnin g lamp ( Y
page 319) and dis -
play messages whic h may be shown in th e
instrumen t cluster ( Y
page 281).
Braking X
If ABS intervenes: continue to depress th e
brake peda l vigorousl y until th e braking sit -
uation is over. X
To make a full brak e application: depress
th e brake peda l wit h full force.
If AB S intervenes when braking , you will feel a
pulsin g in th e brake pedal.
The pulsatin g brake peda l can be an indication
of hazardous road conditions, and function s as a
reminder to take extr a car e whil e driving.66
Driving safety systems
Safety
Off-road ABS An ABS system specifically suited to off-road
terrain is activated automatically once the off-
road program is activated on: R
Vehicles without the Offroad Engineering
package ( Y
page 237)R
Vehicles with the Off-Road Engineering pack-
age ( Y
page 237)
At speeds below 20 mph (30 km/h), the front
wheels lock cyclically during braking. The dig-
ging-in effect achieved in the process reduces
the stopping distance on off-road terrain. This
limits steering capability.
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
i Observe the "Important safety notes" sec-
tion ( Y
page 66).
G WARNING
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.
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 66).
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" sec-
tion“ ( Y
page 67).
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.Driving safety systems 67
Safety Z
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 again, 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 66).
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.
Important safety notes In particular, the detection of obstacles can be
impaired if: R
there is dirt on the sensors or anything else
covering the sensors R
there is snow or heavy rain R
there is interference by other radar sources R
there are strong radar reflections, for exam-
ple in parking garages R
a narrow vehicle traveling in front, e.g. a
motorbike R
a vehicle traveling in front on a different line R
new vehicles or after a service on the COLLI-
SION PREVENTION ASSIST PLUS system
Observe the notes in the section on breaking-
in ( Y
page 144).
Following damage to the front end of the vehicle,
have the configuration and operation of the
radar sensor 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.
Switching on/off The COLLISION PREVENTION ASSIST PLUS is
automatically active after switching on the igni-
tion.
You can activate or deactivate COLLISION PRE-
VENTION ASSIST PLUS in the on-board com-
puter ( Y
page 272). When deactivated, the dis-
tance warning function and the autonomous
braking function are also deactivated.
If COLLISION PREVENTION ASSIST PLUS is
deactivated, the
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 58).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 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 66).
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.
ESP ®
(Electronic Stability Program)
General notes
i Observe the "Important safety notes" sec-
tion ( Y
page 66).
ESP ®
monitors driving stability and traction, i.e.
power transmission between the tires 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 stabilize 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 stabilize
the vehicle during braking.
ETS/4ETS (Electronic Traction System) ETS traction control is part of ESP ®
. On vehicles
with 4MATIC, 4ETS is part 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, even if you
deactivate ESP ®
.
In appropriate driving situations, activate the
offroad program: X
Vehicles without the Offroad Engineering
package ( Y
page 237) X
Vehicles with the Off-Road Engineering pack-
age ( Y
page 237)Driving safety systems 71
Safety Z
i Activate ESP ®
as soon as the situations
described above no longer apply. ESP ®
will
otherwise not be able to stabilize the vehicle if
the vehicle starts to skid or a wheel starts to
spin.
! Avoid spinning the driven wheels for an
extended period with ESP ®
deactivated. You
could otherwise damage the drivetrain.
Deactivating/activating ESP ®
X
To deactivate: press button C .
The
ESP ®
trailer stabilization does not work if ESP ®
is deactivated or disabled because of a malfunc-
tion.
Crosswind Assist General information Strong crosswinds can cause your vehicle to
deviate from a straight course. The crosswind
driving assistance function integrated in ESP ®
noticeably reduces these impairments.
ESP ®
intervenes automatically according to the
direction and intensity of the crosswinds affect-
ing your vehicle.
ESP intervenes with stabilizing braking to assist
you in keeping the vehicle in the lane.
Crosswind Assist is active at vehicle speeds
above 50 mph (80 km/h) when driving straight
ahead or cornering gently.
Important safety notes Crosswind Assist does not work if ESP ®
is deac-
tivated or disabled because of a malfunction.
EBD (electronic brake force distribu-
tion)
General information EBD monitors and controls the brake pressure
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 66).
G WARNING
If EBD is malfunctioning, the rear wheels can
lock, e.g. under full braking. This increases the
risk of skidding and an accident.
You should therefore adapt your driving style
to the different handling characteristics. Have
the brake system checked at a qualified spe-
cialist workshop.
Observe information regarding indicator and
warning lamps ( Y
page 319) as well as display
messages ( Y
page 283). ADAPTIVE BRAKE ADAPTIVE BRAKE enhances braking safety and
offers increased braking comfort. In addition to
the braking function, ADAPTIVE BRAKE also has
the HOLD function ( Y
page 204) and hill start
assist ( Y
page 149).
PRE-SAFE ®
Brake
General information PRE-SAFE ®
Brake can help you to minimize the
risk of a collision with a vehicle ahead or a
pedestrian, and reduce the effects of such a
collision. If PRE-SAFE ®
Brake has detected a risk
of collision, you will be warned visually and
acoustically as well as by automatic braking.
i Pay attention to the important safety notes
in the "Driving safety systems" section
( Y
page 66).
PRE ‑ SAFE ®
Brake is only available in vehicles
with the Driving Assistance Plus package.
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" sec-
tion“ ( 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-74
Driving safet y system s
Sa fety
Unlocking and opening doors from
the inside You can open a door from inside the vehicle
even if it has been locked. You can only open the
rear doors from inside the vehicle if they are not
secured by the child-proof locks ( Y
page 65).
If the vehicle has previously been locked from
the outside, opening a door from the inside will
trigger the anti-theft alarm system. Switch off
the alarm ( Y
page 77).
X
Front door: pull door handle D .
If the door is locked, locking knob C pops up.
The door is unlocked and can be opened. X
Rear door: pull door handle D .
If the door is locked, locking knob C pops up
and the door unlocks. X
Pull door handle D again.
The door can be opened.
Centrally locking and unlocking the
vehicle from the inside You can centrally lock or unlock the vehicle from
the inside. The buttons are located on both front
doors. X
To unlock: press button C .X
To lock: press button D .
If the front-passenger door is closed, the vehi-
cle locks.
Meanwhile, the fuel filler flap will not be locked
or unlocked.
You cannot unlock the vehicle centrally from the
inside if the vehicle has been locked from the
outside.
You can open a front door from inside the vehi-
cle even if it has been locked.
If a locked door is opened from the inside, the
previous unlock status of the vehicle will be
taken into consideration if: R
the vehicle was locked using the locking but-
ton for the central locking, or R
if the vehicle was locked automatically
The vehicle will be fully unlocked if it had previ-
ously been fully unlocked. If only the driver's
door had been previously unlocked, only the
door which has been opened from the inside is
unlocked.
Automatic locking feature
X
To deactivate: press and hold button C for
about five seconds until a tone sounds. X
To activate: press and hold button D for
about five seconds until a tone sounds.
If you press one of the two buttons and do not
hear a tone, the relevant setting has already
been selected.
The vehicle is locked automatically when the
ignition is switched on and the wheels are turn-
ing. Doors 85
Opening and closing Z