
G
WARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions.
In such cases, Adaptive Brake Assist 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
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, 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 condi-
tions may also cause Brake Assist to inter-
vene.
If Adaptive Brake Assist is not available due to a malfunction in the radar sensor system, thebrake system remains available with full
brake boosting effect and BAS.
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.
With the help of Adaptive Brake Assist, the
distance 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 col-
lision with the vehicle in front, adaptive Brake
Assist calculates the necessary brake pres-
sure to avoid this collision. Should you apply the brakes vigorously, Adaptive Brake Assist
will automatically increase the braking force
to a level suitable for the traffic conditions.
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
vehicle.
Adaptive Brake Assist is then deactivated.
If adaptive Brake Assist demands particularly
high braking force, preventative passenger
protection measures (PRE-SAFE ®
) are activa-
ted simultaneously.
Up to vehicle speeds of around 155 mph
(250 km/h), adaptive Brake Assist is capable
of reacting to moving objects that have
already been recognized 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
stationary obstacles. ESP
®
(Electronic Stability Program)
General notes i
Observe the "Important safety notes" sec-
tion (Y page 64).
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 vehicle 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. 68
Driving safety systemsSafety

If you deactivate ESP
®
:
R ESP ®
no longer improves driving stability.
R engine torque is no longer limited and the
drive wheels are able to spin.
The spinning of the wheels results in a cut-
ting action for better traction on loose sur-faces.
R traction control is still activated.
R PRE-SAFE ®
is no longer available, nor is it
activated if you brake firmly and ESP ®
intervenes.
R COLLISION PREVENTION ASSIST is no lon-
ger available; nor is it activated if you brake
firmly with assistance from ESP ®
.
R ESP ®
still provides support when you
brake.
Off-road ESP ® An ESP
®
system specifically suited to off-road
terrain is activated automatically once the off- road program is activated (Y page 186).
Off-road ESP ®
intervenes with a delay if there
is oversteering or understeering, thus improv-
ing traction. EBD (electronic brake force distribu-
tion)
General information EBD monitors and controls the brake pres-
sure 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 64).G
WARNING
If EBD has malfunctioned, the rear wheels can still lock, e.g. under full braking. This increa-
ses 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 254) as well as dis-
play messages (Y page 224). ADAPTIVE BRAKE
ADAPTIVE BRAKE enhances braking safety
and offers increased braking comfort. In addi-
tion to the braking function, ADAPTIVE BRAKE
also has the HOLD function (Y page 181) and
hill start assist (Y page 144). For further
information, see Driving tips (Y page 164). STEER CONTROL
General information STEER CONTROL helps you by transmitting a
noticeable steering force to the steering
wheel in the direction required for vehicle
stabilization.
This steering assistance is provided in partic- ular if:
R both right wheels or both left wheels are on
a wet or slippery road surface when you
brake.
R the vehicle starts to skid.
Important safety notes No steering support is provided from STEER
CONTROL, if:
R ESP ®
is malfunctioning.
R the lighting is faulty.
Power steering will, however, continue to
function. Protection against theft
Immobilizer
The immobilizer prevents your vehicle from
being started without the correct SmartKey. 72
Protection against theftSafety

i
When you switch off the engine, the last
speed stored is cleared. DISTRONIC PLUS
General notes DISTRONIC PLUS regulates the speed and
automatically helps you maintain the dis-
tance to the vehicle detected in front. Vehi-
cles 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 espe-
cially 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 wearing too quickly.
If DISTRONIC PLUS detects that there is a risk of a collision, you will be warned visually and
acoustically. DISTRONIC PLUS cannot pre-
vent a collision without your intervention. An
intermittent warning tone will then sound and
the distance warning lamp will light up in the instrument 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.
DISTRONIC PLUS operates in range between0 mph (0 km/h) and 120 mph (200 km/h).
Do not use DISTRONIC PLUS while driving onroads with steep gradients.
As DISTRONIC PLUS transmits radar waves, it
can resemble the radar detectors of the
responsible authorities. You can refer to the
relevant chapter in the Operator's Manual if
questions are asked about this.
i 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-approved way.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
Important safety notes G
WARNING
DISTRONIC PLUS does not react to:
R people or animals
R stationary obstacles on the road, e.g. stop-
ped or parked vehicles
R oncoming 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. G
WARNING
DISTRONIC PLUS cannot always clearly iden- tify other road users and complex traffic sit-
uations.
In such cases, DISTRONIC PLUS may:
R give an unnecessary warning and then
brake the vehicle
R neither give a warning nor intervene
R accelerate 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. G
WARNING
DISTRONIC PLUS brakes your vehicle with up to 50% of the maximum possible deceleration.
If this braking force is insufficient, DISTRONIC 174
Driving systemsDriving and parking

If DISTRONIC PLUS detects a faster-moving
vehicle in front, it increases the driving speed.
The vehicle is only accelerated up to the
speed you have stored.
Selecting the drive program
DISTRONIC Plus supports a sporty driving
style when you have selected the S or M driv- ing program (Y page 152). Acceleration
behind the vehicle in front or to the set speed is then noticeably more dynamic. If you have
selected the E driving program, the vehicle
accelerates more gently. This setting is rec-
ommended in stop-and-start traffic.
Changing lanes
If you change to the passing lane, DISTRONIC PLUS supports you when:
R you are driving faster than 43.5 mph
(70 km/h)
R DISTRONIC PLUS is maintaining the dis-
tance to a vehicle in front
R you switch on the appropriate turn signal
R DISTRONIC PLUS does not detect a danger
of collision
If these conditions are fulfilled, your vehicle is
accelerated. Acceleration will be interrupted
if changing lanes takes too long or if the dis-
tance between your vehicle and the vehicle in front becomes too small.
Stopping G
WARNING
When leaving the vehicle, even if it is braked
only by DISTRONIC PLUS, it could roll away if:
R there is a malfunction in the system or in
the voltage supply.
R DISTRONIC PLUS has been deactivated
with the cruise control lever, e.g. by a vehi-
cle occupant or from outside the vehicle.
R the electrical system in the engine com-
partment, the battery or the fuses have
been tampered with.
R the battery is disconnected.
R the accelerator pedal has been depressed,
e.g. by a vehicle occupant. There is a risk of an accident.
If you wish to exit the vehicle, always turn off
DISTRONIC PLUS and secure the vehicle
against rolling away.
For further information on deactivating DIS-
TRONIC PLUS (Y page 178).
If DISTRONIC PLUS detects that the vehicle in front is stopping, it brakes your vehicle until it
is stationary.
Once your vehicle is stationary, it remains
stationary and you do not need to depress the
brake.
i After a time, the electric parking brake
secures the vehicle and relieves the service brake.
i Depending on the specified minimum dis-
tance, your vehicle will come to a standstill
at a sufficient distance behind the vehicle in front. The specified minimum distance is
set using the control on the cruise control
lever.
The electric parking brake automatically
secures the vehicle if DISTRONIC PLUS is
activated and:
R the seat belt is unfastened and the driver's
door is open.
R the engine is switched off, unless it is auto-
matically switched off by the ECO start/
stop function.
R a system malfunction occurs.
R the power supply is not sufficient.
If a malfunction occurs, then the transmission may be shifted into position Pautomatically.
Setting a speed Keep in mind that it may take a brief moment
until the vehicle has accelerated or braked to the speed set. Driving systems
177Driving and parking Z

Problems with PARKTRONIC
Problem
Possible causes/consequences and
0050
0050Solutions Only the red segments
in the PARKTRONIC
warning displays are lit.
You also hear a warning
tone for approximately
two seconds.
PARKTRONIC is then
deactivated and the
indicator lamp on the
PARKTRONIC button
lights up. PARKTRONIC has malfunctioned and has switched off.
X If problems persist, have PARKTRONIC checked at a qualified
specialist workshop. Only the red segments
in the PARKTRONIC
warning displays are lit.
PARKTRONIC is then
deactivated. The PARKTRONIC sensors are dirty or there is interference.
X Clean the PARKTRONIC sensors (Y page 301).
X Switch the ignition back on. The problem may be caused by an external source of radio or
ultrasound waves.
X See 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 intervention and brake application
can assist you during parking and when exit-
ing a parking space. You may also use PARK- TRONIC (Y page 186).
Important safety notes Active Parking Assist is merely an aid. It is not
a replacement for your attention to your
immediate surroundings. You are always
responsible for safe maneuvering, parking
and exiting a parking space. Make sure that
no persons, animals or objects are in the
maneuvering range.
When PARKTRONIC is switched off, Active
Parking Assist is also unavailable. G
WARNING
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
obstacles 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
parking, for example:
R where parking or stopping is prohibited
R in front of driveways or entrances and exits
R on unsuitable surfaces Driving systems
189Driving and parking Z

Parking tips:
R On narrow roads, drive as close to the park-
ing space as possible.
R Parking spaces that are littered or over-
grown might be identified or measured
incorrectly.
R Parking spaces that are partially occupied
by trailer drawbars might not be identified
as such or be measured incorrectly.
R Snowfall or heavy rain may lead to a parking
space being measured inaccurately.
R Pay attention to the PARKTRONIC
(Y page 188) warning messages during the
parking procedure.
R You can intervene in the steering procedure
to correct it at any time. Active Parking
Assist will then be canceled.
R When transporting a load which protrudes
from your vehicle, you should not use
Active Parking Assist.
R Never use Active Parking Assist when snow
chains are installed.
R Make sure that the tire pressures are
always correct. This has a direct influence
on the parking characteristics of the vehi-
cle.
Use Active Parking Assist for parking spaces:
R parallel or at right angles to the direction of
travel
R that are on straight roads, not bends
R that are on the same level as the road, e.g.
not on the pavement
Detecting parking spaces Objects located above the height range of
Active Parking Assist will not be detected
when the parking space is measured. These
are not taken into account when the parking
procedure is calculated, e.g. overhanging
loads, tail sections or loading ramps of goods vehicles. G
WARNING
If there are objects above the detection range, Active Parking Assist may turn prematurely.
You may cause a collision as a result. There is
a risk of an accident.
If there are objects above the detection range,
stop and deactivate Active Parking Assist.
For further information on the detection
range (Y page 187).
Active Parking Assist does not assist you
parking in spaces at right angles to the direc-
tion of travel if:
R two parking spaces are located directly
next to one another
R the parking space is directly next to a low
obstacle such as a low curb
R you park forwards
Active Parking Assist does not assist you
parking in spaces that are parallel or at right
angles to the direction of travel if:
R the parking space is on a curb
R the parking space is apparently blocked,
for example by foliage or grass paving
blocks
R the range of movement is too small
R the parking space is bordered by an obsta-
cle which is not clearly defined such as a
tree or a trailer 0043
Detected parking space on the left
0044 Parking symbol
0087 Detected parking space on the right
Active Parking Assist is automatically activa-
ted when driving forwards. The system is
operational at speeds of up to approximately
22 mph (35 km/h). While in operation, the 190
Driving systemsDriving and parking

Warning and display messages in the
multifunction display X
Activate ATTENTION ASSIST using the on-
board computer (Y page 214).
If ATTENTION ASSIST is active, you will be
warned no sooner than 20 minutes after
your journey has begun. You then hear an
intermittent warning tone twice and the
Attention Assist: Take a Break!
Attention Assist: Take a Break!
message appears in the multifunction dis-
play.
X If necessary, take a break.
X Press the 0076or0038 button to confirm
the message.
On long journeys, take regular breaks in good time to allow yourself to rest properly. If you
do not take a break, you will be warned again
after 15 minutes at the earliest. The precon-
dition for this is that ATTENTION ASSIST still
detects typical indicators of fatigue or
increasing lapses in concentration.
ATTENTION ASSIST is reset when you con-
tinue your journey and starts assessing your
tiredness again if:
R you switch off the engine.
R you take off your seat belt and open the
driver's door, e.g. for a change of drivers or
to take a break
When ATTENTION ASSIST is deactivated, the 00D7 symbol appears in the multifunction
display in the assistance graphic display. Lane Tracking package
General notes The Lane Tracking package consists of Blind
Spot Assist (Y page 198) and Lane Keeping
Assist (Y page 200). Blind Spot Assist General notes
Blind Spot Assist uses a radar sensor system
to monitor the areas on both sides of your
vehicle. It supports you from a speed of
approximately 20 mph (30 km/h). A warning
display in the exterior mirrors draws your
attention to vehicles detected in the moni-
tored area. If you then switch on the corre-
sponding turn signal to change lanes, you will
also receive a visual and audible collision
warning. For this purpose, Blind Spot Assist
uses sensors in the rear bumper.
Important safety notes G
WARNING
Blind Spot Assist does not react to:
R vehicles overtaken too closely on the side,
placing them in the blind spot area
R vehicles which approach with a large speed
differential and overtake your vehicle
As a result, Blind Spot Assist may not give
warnings in such situations. There is a risk of an accident.
Always observe the traffic conditions care-
fully, and maintain a safe lateral distance.
Blind Spot Assist is only an aid. It may fail to
detect some vehicles and is no substitute for
attentive driving.
i USA only:
This device has been approved by the FCC as a "Vehicular Radar System". The radar
sensor is intended for use in an automotiveradar system only. Removing, tampering
with, or altering the device will void any
warranties, 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. 198
Driving systemsDriving and parking

enters the blind spot monitoring range from
behind or from the side. When you overtake a vehicle, the warning only occurs if the differ-
ence in speed is less than 7 mph (12 km/h).
The yellow indicator lamp goes out if reverse gear is engaged. In this event, Blind Spot
Assist is no longer active.
The brightness of the indicator/warning
lamps is adjusted automatically according to
the ambient light.
Collision warning
If a vehicle is detected in the monitoring range
of Blind Spot Assist and you switch on the
corresponding turn signal, a double warning
tone sounds. Red warning lamp 0043flashes. If
the turn signal remains on, vehicles detected
are indicated by the flashing of red warning
lamp 0043. There are no further warning tones.
Switching on Blind Spot Assist
X Make sure that Blind Spot Assist is activa-
ted in the on-board computer
(Y page 214).
X Turn the SmartKey to position 2in the igni-
tion lock.
Warning lamps 0043in the exterior mirrors
light up red for approximately 1.5 seconds
and then turn yellow.
Lane Keeping Assist General notes
Lane Keeping Assist monitors the area in
front of your vehicle with camera 0043, which is
mounted at the top of the windshield. Active Lane Keeping Assist detects lane markings on
the road and can warn you before you leave
your lane unintentionally.
This function is available in the range between
40 mph and 120 mph (60 km/h and
200 km/h).
A warning may be given if a front wheel
passes over a lane marking. It will warn you by means of intermittent vibration in the steer-
ing wheel for up to 1.5 second s.
Im portant safety notes G
WARNING
Lane Keeping Assist may not always clearly
recognize lane markings.
In this case, Lane Keeping Assist may:
R give an unnecessary warning
R not give a warning
There is a risk of an accident.
Always pay particular attention to the traffic
situation and stay in lane, in particular if
warned by Lane Keeping Assist. G
WARNING
The Lane Keeping Assist warning does not
return the vehicle to the original lane. There is a risk of an accident.
You should always steer, brake or accelerate
yourself, in particular if warned by Lane Keep- ing Assist.
If you fail to adapt your driving style, Lane
Keeping Assist can neither reduce the risk of
an accident nor override the laws of physics.
Lane Keeping Assist cannot take into account the road, traffic and weather conditions. Lane
Keeping Assist is merely 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.
The Lane Keeping Assist does not keep the
vehicle in the lane. 200
Driving systemsDriving and parking