If the autonomous braking function requires a
particularly high braking force, preventative
passenger protection measures (PRE-SAFE
®)
are activated simultaneously.
Adaptive Brake Assist
General information
iObserve the "Important safety notes" sec-
tion (Ypage 61).
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 (Ypage 55).
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 61).
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, particularly
complicated but non-critical driving conditions
may also cause 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 61).
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.
66Driving safety systems
Safety
the braking function, ADAPTIVE BRAKE also has
the HOLD function (Ypage 162) and hill start
assist (Ypage 130).
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 61).
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 69).
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-
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.
GWARNING
PRE-SAFE
®Brake cannot always clearly iden-
tify objects and complex traffic conditions.
In these cases, PRE-SAFE
®Brake may:
Rgive an unnecessary warning and then
brake the vehicle
Rnot 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.
GWARNING
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.
GWARNING
PRE-SAFE
®Brake does not react:
Rto small people, e.g. children
Rto animals
Rto oncoming vehicles
Rto crossing traffic
Rwhen 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.
Driving safet ysystem s69
Safety
Z
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
Ra 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:
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 . T
his 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
XTo activate/deactivate: activate or deacti-
vate PRE-SAFE®Brake in the on-board com-
puter (Ypage 197).
If the PRE-SAFE®Brake is not activated, the
æ symbol appears in the multifunction dis-
play. Starting at a speed of around 4 mph (7 km/h),
this function warns you if you rapidly approach a
vehicle in front. An intermittent warning tone
will then sound and the
·distance warning
lamp will light up in the instrument cluster.
XBrake immediately to defuse the situation.
or
XTake evasive action provided it is safe to do
so.
PRE-SAFE
®Brake can also brake the vehicle
automatically under the following conditions:
Rthe driver and front-passenger have their seat
belts fastened
and
Rthe vehicle speed is between approximately
4 mph (7 km/h) and 124 mph (200 km/h)
At speeds of up to approximately 44 mph
(70 km/h) PRE-SAFE
®Brake can also detect:
Rstationary objects in the path of your vehicle,
e.g. stopped or parked vehicles
Rpedestrians in the path of your vehicle
iIf there is an increased risk of a collision,
preventive passenger protection measures
(PRE-SAFE
®) are triggered (Ypage 55).
If the risk of collision with the vehicle in front
remains and you do not bra ke, ta
ke evasive
action or accelerate significantly, the vehicle
may perform automatic emergency braking, up
to the point of full brake application. Automatic
emergency braking is not performed until imme-
diately prior to an imminent accident.
You can prevent the intervention of the PRE-
SAFE
®Brake at any time by:
Rdepressing the accelerator pedal further.
Ractivating kickdown.
Rreleasing the brake pedal.
The braking action of PRE-SAFE®Brake is ended
automatically if:
Ryou maneuver to avoid the obstacle.
Rthere is no longer a risk of collision.
Rthere is no longer an obstacle detected in
front of your vehicle.
70Driving safety systems
Safety
Notes on breaking-in a new vehicle
Important safety notes
The sensor system of some driving and driving
safety systems adjusts automatically while a
certain distance is being driven after the vehiclehas been delivered or after repairs. Full system
effectiveness is not reached until the end of this
teach-in procedure.
New and replaced brake pads and discs only
reach their optimum braking effect after several hundred kilometers of driving. Compensate for
this by applying greater force to the brake pedal.
The first 1000 miles (1500 km)
The more you look after the engine when it is
new, the more satisfied you will be with its per-
formance in the future.
RYou should therefore drive at varying vehicle
and engine speeds for the first 1000 miles
(1500 km).
RAvoid heavy loads, e.g. driving at full throttle,during this period.
RChange gear in good time, before the tach-
ometer needle is Ôof the way to the red area
of the tachometer.
RTry to avoid depressing the accelerator pedal
beyond the point of resistance (kickdown).
After 1000 miles (1500 km), you can increase
the engine speed gradually and accelerate the
vehicle to full speed.
iYou should also observe these notes on
breaking in if the engine or parts of the drive
train on your vehicle have been replaced.
iAlways observe the respective maximum
permissible speed.
Driving
Important safety notes
GWARNING
Objects in the driver's footwell can restrict the pedal travel or obstruct a depressed pedal.
The operating and road safety of the vehicle is
jeopardized. There is a risk of an accident.
Make sure that all objects in the vehicle are
stowed correctly, and that they cannot enter
the driver's footwell. Install the floormats
securely and as specified in order to ensure
sufficient clearance for the pedals. Do not use
loose floormats and do not place floormats on
top of one another.
GWARNING
Unsuitable footwear can hinder correct usage of the pedals, e.g.:
Rshoes with thick soles
Rshoes with high heels
Rslippers
There is a risk of an accident.
Wear suitable footwear to ensure correct
usage of the pedals.
GWARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with limitations, or not at all. This could affect, for example, the power steering and the brake
boosting effect. You will require considerably
more effort to steer and brake. There is a risk
of an accident.
Do not switch off the ignition while driving.
GWARNING
If the parking brake has not been fully
released when driving, the parking brake can:
Roverheat and cause a fire
Rlose its hold function.
There is a risk of fire and an accident. Release
the parking brake fully before driving off.
!Do not warm up the engine with the vehicle
stationary. Drive off immediately. Avoid high
engine speeds and driving at full throttle until
the engine has reached its operating temper-
ature.
Only shift the automatic transmission to the
desired drive position when the vehicle is sta-
tionary.
Driving127
Dr iving an d parking
Z
There are several ways to deactivate cruise con-
trol:
XBriefly press the cruise control lever for-
wards:.
or
XBrake.
Cruise control is automatically deactivated if:
Ryou depress the parking brake
Ryou are driving at less than 20 mph (30 km/h)
RESP®intervenes or you deactivate ESP®
Ryou shift the transmission to position Nwhile
driving
If cruise control is deactivated, you will hear a
warning tone. You will see the Cruise Con‐
trol Offmessage in the multifunction display
for approximately five seconds.
iWhen you switch off the engine, the last
speed stored is cleared.
DISTRONIC PLUS
General notes
DISTRONIC PLUS regulates the speed and auto-
matically helps you maintain the distance to the
vehicle detected in front. Vehicles are detected with the aid of the radar sensor system.
DISTRONIC PLUS brakes automatically so that
the set speed is not exceeded.
Change into a lower gear in good time on long
and steep downhill gradients. This is especially
important if the vehicle is laden. By doing so, you
will make use of the braking effect of the engine.
This relieves the load on the brake system and
prevents the brakes from overheating and wear-
ing too quickly.
If DISTRONIC PLUS detects that there is a risk of a collision, you will be warned visually and
acoustically. DISTRONIC PLUS cannot prevent a
collision without your intervention. An intermit-
tent warning tone will then sound and the dis-
tance warning lamp will light up in the instru-
ment cluster. Brake immediately in order to
increase the distance to the vehicle in front or
take evasive action provided it is safe to do so.
For DISTRONIC PLUS to assist you, the radar
sensor system must be operational.
DISTRONIC PLUS operates in range between
0 mph (0 km/h) and 120 mph (200 km/h). Do not use DISTRONI
C P
LUS while driving on
roads with steep gradients.
As DISTRONIC PLUS transmits radar waves, it
can resemble the radar detectors of the respon-
sible authorities. You can refer to the relevant
chapter in the Operator's Manual if questions
are asked about this.
iUSA only: This device has been approved by
the FCC as a "Vehicular Radar System". The
radar sensor is intended for use in an auto-
motive radar system only. Removal, tamper-
ing, or altering of the device will void any war-
ranties, and is not permitted by the FCC. Do
not tamper with, alter, or use in any non-
approved way.
Any unauthorized modification to this device
could void the user's authority to operate the
equipment.
iCanada only: This device complies with
RSS-210 of Industry Canada. Operation is
subject to the following two conditions:
1. This device may not cause harmful inter-
ference, and
2. This device must accept any interference
received, including interference that may
cause undesired operation of the device.
Removal, tampering, or altering of the device
will void any warranties, and is not permitted. Do not tamper with, alter, or use in any non-
ap prove
d way.
Any unauthorized modification to this device
could void the user's authority to operate the
equipment.
Important safety notes
GWARNING
DISTRONIC PLUS does not react to:
Rpeople or animals
Rstationary obstacles on the road, e.g. stop- ped or parked vehicles
Roncoming and crossing traffic
As a result, DISTRONIC PLUS may neither give
warnings nor intervene in such situations.
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake.
Driving system s153
Driving an d parking
Z
GWARNING
DISTRONIC PLUS cannot always clearly iden-
tify other road users and complex traffic sit-
uations.
In such cases, DISTRONIC PLUS may:
Rgive an unnecessary warning and then
brake the vehicle
Rneither give a warning nor intervene
Raccelerate or brake unexpectedly
There is a risk of an accident.
Continue to drive carefully and be ready to
brake, in particular when warned to do so by
DISTRONIC PLUS.
GWARNING
DISTRONIC PLUS brakes your vehicle with up to 50% of the maximum possible deceleration.
If this braking force is insufficient, DISTRONIC
PLUS warns you visually and audibly. There isa risk of an accident.
In such cases, apply the brakes yourself and
try to take evasive action.
!If DISTRONIC PLUS or the HOLD function is
activated, the vehicle brakes automatically in
certain situations.
To prevent damage to the vehicle, deactivate
DISTRONIC PLUS and the HOLD function in
the following or other similar situations:
Rwhen towing the vehicle
Rin the car wash
If you fail to adapt your driving style, DISTRONIC
PLUS can neither reduce the risk of accident nor
override the laws of physics. DISTRONIC PLUS
cannot take into account the road, traffic and
weather conditions. DISTRONIC PLUS is only an
aid. You are responsible for the distance to the
vehicle in front, for vehicle speed, for braking in good time and for staying in your lane. Do not use DISTRONIC PLUS:
Rin road and traffic conditions which do not
allow you to maintain a constant speed, e.g. in
heavy traffic or on winding roads
Ron slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose
traction and the vehicle could then skid
Rwhen there is poor visibility, e.g. due to fog,
heavy rain or snow
DISTRONIC PLUS may not detect narrow vehi-
cles driving in front, e.g. motorcycles, or vehi-
cles driving on a different line.
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
If DISTRONIC PLUS no longer detects a vehicle
in front, DISTRONIC PLUS may unexpected ly
a
ccelerate the vehicle to the stored speed.
This speed may:
Rbe too high if you are driving in a filter lane or an exit lane
Rbe so high in the right lane that you pass vehi-cles driving on the left (left-hand drive coun-
tries)
Rbe so high in the left lane that you pass vehi-
cles driving on the right (right-hand drive
countries)
If there is a change of drivers, advise the new
driver of the speed stored.
Cruise control lever
:To store the current speed or a higher speed
;To store the current speed or a lower speed
154Driving systems
Driving and parking
maneuvering, parking and exiting a parking
space. When maneuvering, parking or pulling
out of a parking space, make sure that there are
no persons, animals or objects in the area in
which you are maneuvering.
!When parking, pay particular attention to
objects above or below the sensors, such as
flower pots or trailer drawbars. PARKTRONIC
does not detect such objects when they are in
the immediate vicinity of the vehicle. You
could damage the vehicle or the objects.
The sensors may not detect snow and other
objects that absorb ultrasonic waves.
Ultrasonic sources such as an automatic car
wash, the compressed-air brakes on a truck
or a pneumatic drill could cause PARKTRONIC
to malfunction.
PARKTRONIC may not function correctly on
uneven terrain.
PARKTRONIC is activated automatically when
you:
Rswitch on the ignition
Rshift the transmission to position D,R or N
Rrelease the parking brake
PARKTRONIC is deactivated at speeds above
11 mph (18 km/h). It is reactivated at lower
speeds.
Range of the sensors
General notes
PARKTRONIC does not take objects into con-
sideration that are:
Rbelow the detection range, e.g. people, ani-
mals or objects.
Rabove the detection range, e.g. overhanging
loads, truck overhangs or loading ramps.
:Sensors in the front bumper, left-hand side
(example)
The sensors must be free from dirt, ice or slush.
They can otherwise not function correctly. Clean
the sensors regularly, taking care not to scratch
or damage them (
Ypage 267).
Range
Example: side view
Example: top view
Front sensors
CenterApprox. 40 in (approx.
100 cm)
CornersApprox. 24 in (approx.
60 cm)
164Driving systems
Driving and parking
Problems with PARKTRONIC
ProblemPossible causes/consequences andMSolutions
Only the red segments in
the PARKTRONIC warn-
ing displays are lit. You
also hear a warning tone
for approximately two
seconds.
PARKTRONIC is then
deactivated and the indi-
cator lamp on the
PARKTRONIC button
lights up.PARKTRONIC has malfunctioned and has switched off.
XIf problems persist, have PARKTRONIC checked at a qualified spe-
cialist workshop.
Only the red segments in
the PARKTRONIC warn-
ing displays are lit.
PARKTRONIC is then
deactivated.The PARKTRONIC sensors are dirty or there is interference.
XClean the PARKTRONIC sensors (Ypage 267).
XSwitch the ignition back on.
The problem may be caused by an external source of radio or ultra-
sound waves.
XSee if PARKTRONIC functions in a different location.
Active Parking Assist
General notes
Active Parking Assist is an electronic parking aid
with ultrasound. It measures the road on both
sides of the vehicle. A parking symbol indicates a suitable parking space. Active steering inter-
vention and brake application can assist you
during parking. You may also use PARKTRONIC
(
Ypage 163).
iThe active braking application is only avail-
able on vehicles with automatic transmission.
Important safety notes
Active Parking Assist is merely an aid. It is not a
replacement for your attention to your immedi-
ate surroundings. You are always responsible
for safe maneuvering, parking and exiting a
parking space. Make sure that no persons, ani-
mals or objects are in the maneuvering range.
When PARKTRONIC is switched off, Active Park-
ing Assist is also unavailable.
GWARNING
While parking or pulling out of a parking
space, the vehicle swings out and can drive
onto areas of the oncoming lane. This could
result in a collision with another road user.
There is a risk of an accident.
Pay attention to other road users. Stop the
vehicle if necessary or cancel the Active Park- ing Assist parking procedure.
!If unavoidable, you should drive over obsta-
cles such as curbs slowly and not at a sharp
angle. Otherwise, you may damage the
wheels or tires.
Active Parking Assist may possibly indicate
parking spaces which are not suitable for park-
ing, for example:
Rwhere parking or stopping is prohibited
Rin front of driveways or entrances and exits
Ron unsuitable surfaces
Parking tips:
ROn narrow roads, drive as close to the parking
space as possible.
RParking spaces that are littered or overgrown
might be identified or measured incorrectly.
RParking spaces that are partially occupied by
trailer drawbars might not be identified as
such or be measured incorrectly.
166Driving systems
Driving and parking