
example, the detected vehicle turns a corner
and reveals an obstacle or stationary vehicle,
DISTRONIC PLUS will not brake for these.
Crossing vehicles
DISTRONIC PLUS may detect vehicles that
are crossing your lane by mistake. Activating
DISTRONIC PLUS at traffic lights with
crossing traffic, for example, could cause
your vehicle to pull away unintentionally.
HOLD function
General notes
The HOLD function can assist the driver in the
following situations:
Rwhen pulling away, especially on steep
slopes
Rwhen maneuvering on steep slopes
Rwhen waiting in traffic
The vehicle is kept stationary without the
driver having to depress the brake pedal.
The braking effect is canceled and the HOLD
function deactivated when you depress the
accelerator pedal to pull away.
GWarning!
HYBRID vehicles: It is imperative that you read
the HYBRID Supplemental Operating
Instructions included in your vehicle literature
portfolio. You may otherwise not receive all
necessary safety information and warning for
the operation of your vehicle.
Activation conditions
You can activate the HOLD function if:
Rthe vehicle is stationary.
Rthe driver's door is closed or if your seat
belt is fastened.
Rthe electric parking brake is released.
Rthe hood is closed.
Rthe transmission is in position R, N or D.
The trunk lid must be closed in position R.
RDISTRONIC PLUS is deactivated.
Activating the HOLD function
XMake sure that the activation conditions
are met.
XDepress the brake pedal.XQuickly depress the brake pedal further
until HOLD display : appears in the
instrument cluster.
The HOLD function is activated. You can
release the brake pedal.
iIf depressing the brake pedal the first
time does not activate the HOLD function,
wait briefly and then try again.
GWarning
The vehicle's brakes are applied when the
HOLD function is activated. For this reason,
deactivate the HOLD function if the vehicle is
to be set in motion by other means (e.g. in a
car wash or by towing).
Driving systems335Driving and parkingZ

Deactivating the HOLD function
The HOLD function is deactivated
automatically if:
R you accelerate and the transmission is in
position D or R.
R the transmission is in position P.
R you apply the brakes again with a certain
amount of pressure until HOLD disappears
from the instrument cluster.
R you secure the vehicle using the electric
parking brake.
R you activate DISTRONIC PLUS.
i After a time, the electric parking brake
secures the vehicle and relieves the service
brake.
GWarning
Never get out of the vehicle when the HOLD
function is activated.
The HOLD function must never be operated
or deactivated by a passenger or from outside
the vehicle.
The HOLD function does not replace the
electric parking brake and must not be used
for parking.
The braking effect of the HOLD function is
canceled and the vehicle could roll away if:
R the HOLD function is deactivated by
depressing the accelerator pedal or the
brake pedal.
R there is a malfunction in the system or an
interruption in the power supply, e.g.
battery failure.
R the electrical system in the engine
compartment, the battery or the fuses are
tampered with.
R the battery is disconnected.
AIRMATIC
Vehicle level
Your vehicle regulates its height
automatically. All-round self-leveling ensures
the best possible suspension and constant
ground clearance, even with a laden vehicle.
When you drive fast, the vehicle is lowered
automatically to improve driving safety and to
reduce fuel consumption.
The following vehicle levels are possible on
vehicles without 4MATIC:
R normal.
R raised: the vehicle is raised above the
normal level by 1.00 in (25 mm).
R lowered: the vehicle is lowered beyond the
normal level by 0.60 in (15 mm).
The following vehicle levels are possible on
vehicles with 4MATIC:
R normal: in comfort mode, the vehicle is
raised above Sport mode by 0.40 in
(10 mm).
R raised: in comfort mode, the vehicle is
raised by about 0.60 in (15 mm) and in
Sport mode by about 1.00 in (25 mm) over
the normal level.
R lowered: the vehicle is lowered beyond the
normal level by 0.40 in (10 mm).
The "Normal" and "Raised" vehicle levels can
be set manually.
The "Lowered” vehicle level is set
automatically:
R in vehicles without 4MATIC at speeds
above 60 mph (100 km/h)
R in vehicles with 4MATIC at speeds above
50 mph (80 km/h)
Setting the vehicle level
Select the "Normal" setting for normal road
surfaces and "Raised" for driving with snow
chains or on particularly poor road surfaces.
Your selection remains stored even if you
remove the SmartKey from the ignition lock.
336Driving systemsDriving and parking

GWarning!
Make sure no persons or animals are in or
near the area in which you are parking/
maneuvering. Otherwise, they could be
injured.
PARKTRONIC is an electronic parking aid with
ultrasonic sensors. It indicates visually and
audibly the distance between your vehicle
and an object.
PARKTRONIC is activated automatically when
you:
Rswitch on the ignition.
Rshift the transmission to position D, R or
N.
Rrelease the electric parking brake.
PARKTRONIC is deactivated at speeds above
11 mph (18 km/h). It is reactivated at lower
speeds.
PARKTRONIC monitors the area around your
vehicle using six sensors in the front bumper
and four sensors in the rear bumper.
:Sensors in the front bumper, left-hand
side (example)
Range of the sensors
The sensors must be free of dirt, ice and
slush; otherwise they may not function
correctly. Clean the sensors regularly, taking
care not to scratch or damage them
(Y page 456).
Side view
Top view
Front sensors
CenterApprox. 40 in (100 cm)CornersApprox. 24 in (60 cm)
Rear sensors
CenterApprox. 48 in (120 cm)CornersApprox. 32 in (80 cm)
! 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.
Ultrasonic sources such as an automatic
car wash, a truck's compressed-air brakes
or a pneumatic drill could cause
PARKTRONIC to malfunction.
340Driving systemsDriving and parking

Minimum distanceCenterApprox. 8 in (20 cm)CornersApprox. 8 in (20 cm)
If there is an obstacle within this range, all
warning displays light up and a warning tone
sounds. If the distance falls below the
minimum, the distance may no longer be
shown.
Warning displays
The warning displays show the distance
between the sensors and the obstacle. The
warning display for the front area is in the
instrument cluster. The warning display for
the rear area is located on the headliner in the
rear compartment.
Warning display for the front area
:Segments on the left-hand side of the
vehicle;Segments on the right-hand side of the
vehicle=Segments showing operational readiness
The warning display for each side of the
vehicle is divided into five yellow and two red
segments. PARKTRONIC is operational if
yellow segments showing operational
readiness = light up.
The selected transmission position
determines which warning display is active
when the engine is running.
Transmission
positionWarning displayDFront area activatedRRear and front areas
activatedNIf the electric parking
brake is engaged: no
areas activated
If the electric parking
brake is released:
rear and front areas
are activatedPNo areas activated
One or more segments light up as the vehicle
approaches an obstacle, depending on the
vehicle's distance from the obstacle.
When the first red segment lights up, you hear
an intermittent warning for about two
seconds. From the second red segment, you
hear a continuous warning. This indicates that
you have now reached the minimum distance.
Deactivating/activating PARKTRONIC
:To deactivate/activate PARKTRONIC;Indicator lamp
If indicator lamp ; lights up, PARKTRONIC is
deactivated.
Driving systems341Driving and parkingZ

The system may be impaired or may not
function if:
Rthere is poor visibility, e.g. due to
insufficient illumination of the road, or due
to snow, rain, fog or spray.
Rthere is glare, e.g. from oncoming traffic,
the sun, or reflection from other vehicles.
Rthe windshield is dirty, fogged up or
covered, for instance by a sticker, in the
vicinity of the camera.
Rseveral or no lane markings for a single lane
are present.
Rthe lane markings are worn away, dark or
covered up, e.g. by dirt or snow.
Rthe distance to the vehicle in front is too
small and the lane markings thus cannot be
detected.
Rthe lane markings on the road are unclear,
e.g. near roadworks.
Rthe lane markings change quickly, e.g.
lanes branch off, cross one another or
merge.
Rthe road is narrow and winding.
Lane Keeping Assist cannot detect road and
traffic conditions. It is not a substitute for
attentive driving. You are responsible for the
vehicle's speed, braking in good time, and
steering correctly. Always adapt your driving
style to suit the prevailing road and weather
conditions. Always pay attention to traffic
conditions and your surroundings. Otherwise,
you may fail to recognize dangers in time,
cause an accident and injure yourself and
others.
A warning can be given when a front wheel
passes over a lane marking. It will warn you
by means of intermittent vibration in the
steering wheel for up to 1.5 seconds.
In order that you are warned only when
necessary and in good time if you cross the
lane marking, the system recognizes certain
conditions and warns you accordingly.
The warning vibration occurs earlier if:
Ryou approach the outer lane marking on a
bend.
Rthe road has very wide lanes, e.g. a
freeway.
Rthe system recognizes solid lane markings.
The warning vibration occurs later if:
Rthe road has narrow lanes.
Ryou cut the corner on a bend.
No warning vibration occurs if:
Ryou clearly and actively steer, brake, or
accelerate.
Ryou cut the corner on a sharp bend.
Ra driving safety system intervenes, such as
ABS, BAS or ESP®.
Ryou switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
Activating Lane Keeping Assist
XActivate Lane Keeping Assist using the on-
board computer (Y page 376).
Symbol : appears in the multifunction
display.
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected,
symbol : is displayed in green. Lane
Keeping Assist is ready for use.
Active Driving Assistance package
General information
iThe Active Driving Assistance package is
only available on vehicles without HYBRID.
The Active Driving Assistance package
consists of DISTRONIC PLUS (Y page 325),
Driving systems355Driving and parkingZ

Active Blind Spot Assist (Y page 356) and
Active Lane Keeping Assist ( Y page 359).
Active Blind Spot Assist
Important safety notes
Active Blind Spot Assist uses a radar sensor
system to monitor the side areas of your
vehicle. In addition, it uses the radar sensor
system to monitor the front area as well.
Active Blind Spot Assist is active at speeds
above approximately 20 mph (30 km/h). A
warning lamp in the exterior mirrors calls your
attention to a vehicle or certain obstacles in
the area monitored. If you switch on the
corresponding turn signal before changing
lane, you will also receive visual and audible
collision warnings. If a risk of lateral collision
is detected, corrective braking may help you
avoid a collision.
GWarning
Active Blind Spot Assist is only an aid, and
may detect vehicles/obstacles incorrectly or
not at all.
The system may be impaired or may not
function if:
R there is poor visibility, e.g. due to snow,
rain, fog or spray.
R the rear and/or front sensors are dirty.
Active Blind Spot Assist may not detect
narrow vehicles, such as motorcycles or
bicycles, or only detect them too late. It
cannot detect vehicles that are overtaken at
a small distance and then enter the blind spot
area.
Active Blind Spot Assist cannot detect road
and traffic conditions. It is not a substitute for
attentive driving. You are responsible for the
vehicle's speed, braking in good time, and
steering correctly. Always adapt your driving
style to suit the prevailing road and weather
conditions. Always pay attention to traffic
conditions and your surroundings. Otherwise,
you may fail to recognize dangers in time,
cause an accident and injure yourself and
others.
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 automotive
radar system only. Removal, tampering, or
altering of 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.
For Active Blind Spot Assist to assist you
when driving, the radar sensor system must
be activated ( Y page 378) and operational.
Monitoring range
Active Blind Spot Assist monitors the area up
to 10 ft (3 m) behind your vehicle and directly
next to your vehicle as shown in the diagram.
For this purpose, Active Blind Spot Assist
uses sensors in the rear bumper.GWarning
Active Blind Spot Assist monitors certain
areas in the immediate vicinity of your vehicle.
Vehicles that approach and drive past at high
speeds are not detected. No visual nor
audible warnings are emitted and the system
does not brake the vehicle to correct your
course.
356Driving systemsDriving and parking

Optical and acoustic collision warning
When you switch on the appropriate turn
signals to change lanes, and a vehicle is
detected in the side monitoring range of
Active Blind Spot Assist, you receive an
optical and acoustic collision warning. You
then hear a double warning tone, and red
warning lamp : flashes. If the turn signal
remains on, detected vehicles are indicated
by the flashing of red warning lamp :. There
are no further warning tones.
Course-correcting brake application
If Active Blind Spot Assist detects a risk of
lateral collision in the monitoring range,
under certain circumstances, it will brake the
vehicle briefly on one side. This is designed to
help you avoid a collision.
This function is available in the range between
20 mph and 120 mph (30 km/h and
200 km/h).
When a course-correcting brake application
occurs, red warning lamp : flashes in the
exterior mirror and the following message, for
example, appears in the multifunction
display:
GWarning
Active Blind Spot Assist is only an aid
designed to assist driving. It is not a substitute
for attentive driving. In some cases, the
course-correcting brake application is not
sufficient to avoid a collision. In such a case,
you must steer, brake or accelerate.
In very rare cases, the system may
erroneously detect a danger of collision in the
area of crash barriers or similar lane borders
and apply the brakes. Active Blind Spot Assist
does not detect all traffic situations and road
users. Always make sure that there is
sufficient distance to the side for other traffic
or obstacles. An inappropriate brake
application may be interrupted at any time if
you steer slightly in the opposite direction or
accelerate.
You are responsible for the vehicle's speed,
braking in good time, and steering correctly.
Always adapt your driving style to suit the
prevailing road and weather conditions.
Always pay attention to traffic conditions and
your surroundings. Otherwise, you may fail to
recognize dangers in time, cause an accident
and injure yourself and others.
Either a very slight course-correcting brake
application, or none at all, may occur if:
Rother vehicles and/or objects, such as
crash barriers, are detected in the
immediate vicinity of your vehicle.
Ra vehicle approaches you too closely at the
side.
Ryou have adopted a sporty driving style with
high cornering speeds.
Ryou brake or accelerate decisively.
Ra driving safety system intervenes, such as
ESP® or PRE-SAFE® Brake.
RESP® is deactivated.
Ra loss of tire pressure or a defective tire has
been detected and displayed.
Activating Active Blind Spot Assist
XMake sure that the radar sensor system
(Y page 378) and Active Blind Spot Assist
(Y page 376) are activated in the on-board
computer.
XTurn the key to position 2 in the ignition
lock.
Warning lamps : light up red in the
exterior mirrors for approximately 1.5
seconds and then turn yellow.
358Driving systemsDriving and parking

Active Lane Keeping Assist
Important safety notes
Active Lane Keeping Assist monitors the area
in front of your vehicle by means of a camera
at the top of the windshield. Active Lane
Keeping Assist detects lane markings on the
road and warns you before you leave your
lane unintentionally. If you do not react to the
warning, a lane-correcting application of the
brakes can bring the vehicle back into the
original lane.
:Active Lane Keeping Assist camera
If you select km on the on-board computer in
the Display Unit Speed-/
Odometer (Y page 377) function, Active Lane
Keeping Assist is activated starting at a speed
of 60 km/h. If the mph display unit is selected,
the assistance range begins at 40 mph.
GWarning
Active Lane Keeping Assist does not keep
your vehicle in its lane. It is only an aid and
may detect the lane markings on the road
incorrectly or not at all.
The system may be impaired or may not
function if:
Rseveral or no lane markings for a single lane
are present.
Rthere is poor visibility, e.g. due to
insufficient illumination of the road, or due
to snow, rain, fog or spray.
Rthere is glare, e.g. from oncoming traffic,
the sun, or reflection from other vehicles.
Rthe windshield is dirty, fogged up or
covered, for instance by a sticker, in the
vicinity of the camera.
Rthe lane markings are worn away, dark or
covered up, e.g. by dirt or snow.
Rthe distance to the vehicle in front is too
small and the lane markings thus cannot be
detected.
Rthe lane markings on the road are unclear,
e.g. near roadworks.
Rthe lane markings change quickly, e.g.
lanes branch off, cross one another or
merge.
Rthe road is narrow and winding.
Active Lane Keeping Assist cannot detect
road and traffic conditions. It is not a
substitute for attentive driving. You are
responsible for the vehicle's speed, braking in
good time, and steering correctly. Always
adapt your driving style to suit the prevailing
road and weather conditions. Always pay
attention to traffic conditions and your
surroundings. Otherwise, you may fail to
recognize dangers in time, cause an accident
and injure yourself and others.
Warning vibration in the steering wheel
A warning can be given when a front wheel
passes over a lane marking. It will warn you
by means of intermittent vibration in the
steering wheel for up to 1.5 seconds.
In order that you are warned only when
necessary and in good time if you cross the
lane marking, the system recognizes certain
conditions and warns you accordingly.
The warning vibration occurs earlier if:
Ryou approach the outer lane marking on a
bend.
Rthe road has very wide lanes, e.g. a
freeway.
Rthe system recognizes solid lane markings.
The warning vibration occurs later if:
Rthe road has narrow lanes.
Ryou cut the corner on a bend.
Driving systems359Driving and parkingZ