Off-road ABS
An ABS system specifically suited to off-road
terrain is activated automatically once the off-
road program is activated on:
RVehicles without the Offroad Engineering
package (Ypage 237)
RVehicles with the Off-Road Engineering pack-
age (Ypage 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
iObserve the "Important safety notes" sec-
tion (Ypage 66).
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.
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 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:
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 67).
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.
Driving safety systems67
Safety
Z
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 in the event of:
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 traveling in front, e.g. a
motorbike
Ra vehicle traveling in front on a different line
Rvehicles quickly moving 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
Rthere is glare on the camera system, e.g. from
the sun being low in the sky
Rdarkness
Rif:
-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 (250 km/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
Robjects crossing your path and that are rec-
ognized in the detection range of the sensors
iIf BAS PLUS demands particularly high brak-
ing force, preventative passenger protection
measures (PRE-SAFE
®) are activated simulta-
neously (Ypage 58).
68Driving safety systems
Safety
XKeep 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:
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 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:
Rthere is dirt on the sensors or anything else
covering the sensors
Rthere is snow or heavy rain
Rthere is interference by other radar sources
Rthere are strong radar reflections, for exam-
ple in parking garages
Ra narrow vehicle traveling in front, e.g. a
motorbike
Ra vehicle traveling in front on a different line
Rnew vehicles or after a service on the COLLI-
SION PREVENTION ASSIST PLUS system
Observe the notes in the section on breaking-
in (
Ypage 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 (
Ypage 272). When deactivated, the dis-
tance warning function and the autonomous
braking function are also deactivated.
If COLLISION PREVENTION ASSIST PLUS is
deactivated, the æsymbol appears in the
assistance graphics display.
Distance warning function
General information
The distance warning function 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 the distance warning function
detects that there is a risk of a collision, you will
be warned visually and acoustically.
Important safety notes
iObserve the "Important safety notes" sec-
tion for driving safety systems (Ypage 66).
GWARNING
The distance warning function does not react:
Rto people or animals
Rto oncoming vehicles
Rto crossing traffic
Rwhen cornering
Thus, the distance warning function cannot
provide a warning in all critical situations.
There is a risk of an accident.
Driving safety systems69
Safety
Z
Always pay careful attention to the traffic sit-uation and be ready to brake.
GWARNING
The distance warning function cannot always
clearly identify objects and complex traffic
situations.
In such cases, the distance warning function
may:
Rgive an unnecessary warning
Rnot give a warning
There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and do not rely solely on the distance
warning function.
Function
Starting at a speed of around 4 mph (7 km/h),
the distance warning function warns you if you
rapidly approach a vehicle in front. An intermit-
tent warning tone will then sound, and the ·
distance warning lamp will light up in the instru-
ment cluster.
XBrake immediately in order to increase the
distance from the vehicle in front.
or
XTake evasive action, provided it is safe to do
so.
Due to the nature of the system, particularly
complicated but non-critical driving conditions
may also cause the system to display a warning.
With the help of the radar sensor system, the
distance warning function can detect obstacles
that are in the path of your vehicle for an exten-
ded period of time.
Up to a speed of around 44 mph (70 km/h), the
distance warning function can also react to sta-
tionary obstacles, such as stopped 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 58).
Adaptive Brake Assist
General information
iObserve the "Important safety notes" sec-
tion (Ypage 66).
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
70Driving safety systems
Safety
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 (Ypage 58).
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 66).
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.
GWARNING
Adaptive Brake Assist does not react:
Rto people or animals
Rto oncoming vehicles
Rto crossing traffic
Rwhen 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
iObserve the "Important safety notes" sec-
tion (Ypage 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:
XVehicles without the Offroad Engineering
package (Ypage 237)
XVehicles with the Off-Road Engineering pack-
age (Ypage 237)
Driving safety systems71
Safety
Z
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
iObserve the "Important safety notes" sec-
tion for driving safety systems (Ypage 66).
GWARNING
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 (
Ypage 319) as well as display
messages (Ypage 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 (
Ypage 204) and hill start
assist (Ypage 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.
iPay attention to the important safety notes
in the "Driving safety systems" section
(
Ypage 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.
iObserve the restrictions described in the
"Important safety notes" sec-
tion“ (
Ypage 74).
Important safety notes
GWARNING
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-
74Driving safet ysystem s
Safety
ularly whenapproaching at too high a speed.
There isa risk of an acc ident.
Alwa ysapply the brakes yourself and try to
take evasive action, provide dit is safe to do
so.
In the event of a partial application of the brakes,
the veh icle isbraked with up to 50% of the full
braking pressure.
GWAR NING
PRE-SAFE
®Brake cannot always clearly iden-
tify objects and co mplex traff icconditions.
In these cases, PRE-SAFE
®Brake may:
Rgive an unnecessary warning and then
brake the veh icle
Rnot give a warning or intervene
There isa risk of an acc ident.
Alwa ys pay particular attention to the traff ic
situation and beready to brake, especially if
PRE-SAFE
®Brake warns you. Terminate the
intervention ina non-critical driving situation.
GWAR NING
PRE-SAFE
®Brake cannot always clearly iden-
tify people, especially ifthey are moving. In
these cases, PRE-SAFE
®Brake cannot inter-
vene. There isa risk of an acc ident.
Alwa ys pay particular attention to the traff ic
situation and beready to brake, especially if
PRE-SAFE
®Brake warns you.
In order to maintain the appropriate distance to
the veh icle infront and thus prevent a co llision,
you must applythe brakes yourself.
GWARNING
PRE-SAFE
®Brake does not react:
Rto small people, e.g. ch ildren
Rto animals
Rto oncoming veh icles
Rto crossing traff ic
Rwhen cornering
As a result, PRE-SAFE®Brake may neither
give warnings nor intervene inall critical sit-
uations. There is a risk of an accident.
Alwa ys pay careful attention to the traff icsit-
uation and be ready to brake.
In the event of snowfall or heavy rain, the rec-
ognition can be impaired.
Recognition bythe radar sensor system is also
impaired inthe event of:
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 inparking garages
Ra narrow vehicle traveling in front, e.g. a
motorbike
Ra vehicle traveling in front on a different line
relative to the center of your vehicle
Recognition bythe camera system isalso
impaired inthe event of:
Rdirt on the camera or if the camera is covered
Rthere isglare on the camera system, e.g. from
the sun being low inthe sky
Rdarkness
Rif:
-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 isconcealed by other objects
-the typical outline of a person isnot distin-
guishable from the background
Fol lowin
g dam
age 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 vis ibledamage 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.
Driving safety systems75
Safety
Z
The SmartKey centrally locks and unlocks the
following components:
Rthe doors
Rthe tailgate
Rthe fuel filler flap
The turn signals flash once when unlocking and
three times when locking.
You can also set an audible signal to confirm
that the vehicle has been locked. The audible
signal can be activated and deactivated using
the on-board computer (
Ypage 275).
You will receive visual and acoustic locking con-
firmation if all components were able to be
locked.
If activated in COMAND or Audio 20, the locator
lighting also lights up in the dark (see separate
operating instructions).
XTo open the tailgate automatically from
outside the vehicle: press and hold theF
button until the tailgate opens.
Vehicles with KEYLESS-GO or KEYLESS-GO start function and EASY-PACK tailgate:
XTo close the tailgate automatically from
outside the vehicle: if the SmartKey is loca-
ted in the immediate vicinity of the vehicle,
press the Fbutton on the SmartKey.
When the tailgate closes you can then release
the button.
KEYLESS-GO
General notes
Bear in mind that the engine can be started by
any of the vehicle occupants if there is a KEY-
LESS-GO key in the vehicle (
Ypage 148).
Locking/unlocking centrally
You can start, lock or unlock the vehicle using
KEYLESS-GO. To do this, you only need carry the
SmartKey with you. You can combine the func-
tions of KEYLESS-GO with those of a conven-
tional SmartKey. Unlock the vehicle by using
KEYLESS-GO, for instance, and lock it using the
& button on the SmartKey.
The driver's door and the door at which the han-
dle is used, must both be closed. The SmartKey
must be outside the vehicle. When locking or
unlocking with KEYLESS-GO, the distance between the SmartKey and the corresponding
door handle must not be greater than 3 ft (1 m).
KEYLESS-GO checks whether a valid SmartKey
is in the vehicle by periodically establishing a
radio connection between the vehicle and the
SmartKey. This happens:
Rwhen starting the engine
Rwhile driving
Rwhen the external door handles are touched
Rduring convenience closing
XTo unlock the vehicle:
touch the inner sur-
face of the door handle.
XTo lock the vehicle: touch sensor surface :
or ;.
Make sure that you do not touch the inner
surface of the door handle.
XConvenience closing feature: touch
recessed sensor surface ;for an extended
period.
Further information on the convenience closing
feature (
Ypage 92).
If you pull on the handle of the tailgate, only the cargo compartment of the vehicle is unlocked.
Deactivating and activating
If you do not intend to use a SmartKey for an
extended period of time, you can deactivate the
KEYLESS-GO function of the SmartKey. The
SmartKey will then use very little power, thereby
conserving battery power. For the purposes of
activation/deactivation, the vehicle must not be
nearby.
SmartKey79
Opening and closing
Z