
Problems with PARKTRONIC
Problem
Possible causes/consequences and
M
MSolutions 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 been deactivated.
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 405).
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
PARKTRONIC (Y page 240).
Important safety notes Active Parking Assist is only an aid. It is not a
substitute for your attention to the immediate
surroundings. The responsibility for safe
manoeuvring and parking remains with you.
Make sure that no persons, animals or
objects are in the manoeuvring range.
When PARKTRONIC is switched off, Active
Parking Assist is also unavailable. For vehicles with the trailer tow hitch folded
out, the minimum length for parking spaces is
slightly longer.
If you have attached a trailer to your vehicle,
you should not use Active Parking Assist.
Once the electrical connection is established
between your vehicle and the trailer, Active
Parking Assist is no longer available.
PARKTRONIC is deactivated for the rear area. 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
cause you to collide with other road users.
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 kerbs slowly and not at a Driving systems
243Driving and parking Z 

appears in the multifunction display. You will
then have to steer and merge into traffic on
your own. PARKTRONIC is still available. You
can take over the steering before the vehicle has exited the parking space completely. This is useful, for example when you recognise
that it is already possible to pull out of the
parking space.
Cancelling Active Parking Assist X
Stop the movement of the multifunction
steering wheel or steer yourself.
Active Parking Assist will be cancelled at
once. The Park Assist cancelled
Park Assist cancelled mes-
sage appears in the multifunction display.
or
X Press the PARKTRONIC button
(Y page 242).
PARKTRONIC is switched off and Active
Parking Assist is immediately cancelled.
The Park Assist cancelled Park Assist cancelled message
appears in the multifunction display.
Active Parking Assist is cancelled automati-
cally if:
R the electric parking brake is applied
R transmission position Pis selected in vehi-
cles with automatic transmission
R parking using Active Parking Assist is no
longer possible
R you are driving faster than 10 km/h
R a wheel spins and ESP ®
intervenes or fails.
The ÷ warning lamp lights up in the
instrument cluster.
A warning tone sounds. The parking symbol
disappears and the multifunction display
shows the Park Assist cancelled
Park Assist cancelled mes-
sage.
When Active Parking Assist is cancelled, you
must steer and brake again yourself.
If a system malfunction occurs, the vehicle is braked to a standstill. To drive on, depress the
accelerator pedal again. Reversing camera
General notes Reversing camera
:is in the handle on the
tailgate.
Reversing camera :is an optical parking
and manoeuvring aid. It shows the area
behind your vehicle with guidelines in the
Audio 20/COMAND Online display.
The area behind the vehicle is displayed as a
mirror image, as in the rear-view mirror.
i The text shown in the Audio 20/COMAND
Online display depends on the language
setting. The following are examples of
reversing camera messages in the
Audio 20/COMAND Online display.
Important safety notes The reversing camera is only an aid. It is not a
substitute for your attention to the immediate surroundings. The responsibility for safe
manoeuvring and parking remains with you.
Make sure that there are no persons, animals
or objects in range while manoeuvring and
parking.
Under the following circumstances, the
reversing camera will not function, or will
function in a limited manner:
R if the tailgate is open
R in heavy rain, snow or fog
R at night or in very dark places
R if the camera is exposed to very bright light
R if the area is lit by fluorescent bulbs or LED
lighting (the display may flicker) 248
Driving systemsDriving and parking 

ing the trailer lighting. Blind Spot Assist is
then deactivated. The Blind Spot Assist
Blind Spot Assist
not
not available
available when
whentowing
towing a
atrailer
trailer
See Owner's Manual
See Owner's Manual message appears in
the multifunction display.
Lane Keeping Assist General notes
Lane Keeping Assist monitors the area in
front of your vehicle by means of camera :
at the top of the windscreen. Lane Keeping
Assist detects lane markings on the road and
can warn you before you leave your lane unin-
tentionally.
This function is available within a speed range between 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 through the
steering wheel for up to 1.5 seconds.
Important safety notes G
WARNING
Lane Keeping Assist cannot always clearly
identify lane markings.
In these cases, 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 keep in lane, especially if Lane
Keeping Assist alerts you. G
WARNING
The Lane Keeping Assist warning does not
return the vehicle to the original lane. There is a risk of an accident.
Always steer, apply the brakes or accelerate
the vehicle yourself, especially if Lane Keep-
ing Assist alerts you.
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
road, weather or traffic conditions. Lane
Keeping Assist is only an aid. You are respon- sible for the distance to the vehicle in front,
for vehicle speed, for braking in good time,
and for staying in lane.
Lane Keeping Assist does not keep your vehi-
cle in its lane.
The system may be impaired or may not func-
tion if:
R there is poor visibility, e.g. due to insuffi-
cient illumination of the road, or due to
snow, rain, fog or spray
R there is glare, e.g. from oncoming traffic,
the sun or reflection from other vehicles
(e.g. if the road surface is wet)
R the windscreen is dirty, misted up, dam-
aged or covered, for instance by a sticker,
in the vicinity of the camera
R no or several, unclear lane markings are
present for one lane, e.g. in a construction
area
R the lane markings are worn away, dark or
covered up, e.g. by dirt or snow
R the distance to the vehicle in front is too
small and the lane markings thus cannot be
detected
R the lane markings change quickly, e.g.
lanes branch off, cross one another or
merge
R the road is narrow and winding
R there are highly variable shade conditions
on the road Driving systems
265Driving and parking Z 

Activating Lane Keeping Assist
X
Press button ;.
Indicator lamp :lights up. The Lane
Lane
Keeping Assist on
Keeping Assist onmessage appears in
the multifunction display. If all conditions
have been satisfied, there may be a warn-
ing.
If you drive at speeds above 60 km/h and
lane markings are detected, the lines in the assistance graphic display (Y page 308)
are shown in green. Lane Keeping Assist is
ready for use.
X To deactivate: press button;.
Indicator lamp :goes out. Lane Keeping
Assist is deactivated. The Lane Keeping
Lane Keeping
Assist off Assist off message appears in the multi-
function display.
Selecting Standard or Adaptive setting
X In the Assistance
Assistance menu on the on-board
computer, select the Lane Keeping
Lane Keeping
Assist
Assist function (Y page 311).
X Select Standard
Standard orAdaptive
Adaptive.
Standard
When Standard Standard is selected, no warning vibra-
tion occurs if:
R you have switched on the turn signals. In
this case, the warnings are suppressed for
a certain period of time.
R a driving safety system intervenes, such as
ABS, BAS or ESP ®
. Adaptive
When Adaptive
Adaptive is selected, no warning vibra-
tion occurs if:
R you have switched on the turn signals. In
this case, the warnings are suppressed for
a certain period of time.
R a driving safety system intervenes, such as
ABS, BAS or ESP ®
.
R you accelerate hard, e.g. kickdown.
R you brake hard.
R you steer actively, e.g. swerve to avoid an
obstacle or change lane quickly.
R you cut the corner on a sharp bend.
In order that you are warned only when nec-
essary and in good time if you cross the lane marking, the system detects certain condi-
tions and warns you accordingly.
The warning vibration occurs earlier if:
R you approach the outer lane marking on a
bend
R the road has very wide lanes, e.g. a motor-
way
R the system detects solid lane markings
The warning vibration occurs later if:
R the road has narrow lanes
R you cut the corner on a bend Driving Assistance PLUS package
General notes The Active Driving Assistance PLUS package
consists of DISTRONIC PLUS (Y
page 226),
Active Blind Spot Assist (Y page 266) and
Active Lane Keeping Assist (Y page 269).
Active Blind Spot Assist General notes
Active Blind Spot Assist monitors the areas
on either side of the vehicle that are not visi-
ble to the driver with two lateral, rear-facing
radar sensors. A warning display in the exte-
rior mirrors draws your attention to vehicles 266
Driving systemsDriving and pa
rking 

Due to the nature of the system:
R warnings may be issued in error when driv-
ing close to crash barriers or similar solid
lane borders
R warnings may be interrupted when driving
alongside particularly long vehicles, for
example lorries, for a prolonged time
Warning display :
Warning display
Active Blind Spot Assist is not operational at
speeds below approximately 30 km/h. Vehi-
cles in the monitoring range are then not indi-
cated.
If a vehicle is detected within the monitoring
range of Blind Spot Assist at speeds above
30 km/h, warning lamp :on the corre-
sponding side lights up red. This warning lamp
always lights up when a vehicle enters the
blind spot monitoring range from behind or
from the side. When you overtake a vehicle,
the warning only occurs if the difference in
speed is less than 12 km/h.
If you select the reverse gear, Active Blind
Spot Assist is not operational.
The brightness of the warning lamps is auto-
matically adapted to the brightness of the
surroundings. When Active Blind Spot Assist is activated,
grey radar waves propagating backwards
appear next to the vehicle in the assistance
display in the multifunction display. Above a
speed of 30 km/h, the colour of the radar
waves in the assistance display changes to
green ;. Active Blind Spot Assist is then
ready for use.
Visual and acoustic collision warning
If you switch on the turn signals to change
lanes and a vehicle is detected in the side
monitoring range, you receive a visual and
acoustic collision warning. You will then hear a double warning tone and red warning
lamp :flashes. If the turn signal remains on,
detected vehicles are indicated by the flash-
ing of red warning lamp :. There are no fur-
ther warning tones.
Course-correcting brake application
If Active Blind Spot Assist detects a risk of a
side impact in the monitoring range, a course- correcting brake application is carried out.
This is designed to help you avoid a collision. G
WARNING
A course-correcting brake application cannot always prevent a collision. There is a risk of an
accident.
Always steer, brake or accelerate yourself,
especially if Active Blind Spot Assist warns
you or makes a course-correcting brake appli-
cation. Always maintain a safe distance at the sides. 268
Driving systemsDriving an
d parking 

If a course-correcting brake application
occurs, red warning lamp :flashes in the
exterior mirror and a dual warning tone
sounds. In addition, display ;underlining
the danger of a side collision appears in the
multifunction display.
In very rare cases, the system may make an
inappropriate brake application. A course-
correcting brake application may be interrup-
ted at any time if you steer slightly in the
opposite direction or accelerate.
The course-correcting brake application is
available in the speed range between
30 km/h and 200 km/h.
Either a course-correcting brake application
appropriate to the driving situation, or none at all, may occur if:
R there are vehicles or obstacles, e.g. crash
barriers, on both sides of your vehicle
R a vehicle approaches too closely on the
side
R you have adopted a sporty driving style with
high cornering speeds
R you clearly brake or accelerate
R a driving safety system intervenes, such as
ESP ®
or PRE-SAFE ®
Brake
R ESP ®
is deactivated
R a loss of tyre pressure or a defective tyre is
detected Activating Active Blind Spot Assist
X Make sure that Active Blind Spot Assist is
activated in the on-board computer
(Y page 311).
X Turn the key to position 2in the ignition
lock.
Warning lamps :in the exterior mirrors
light up red for approximately 1.5 seconds. Grey radar waves propagating backwards
appear next to the vehicle in the assistance
display in the multifunction display.
Towing a trailer
If you couple up a trailer, make sure that you have correctly established the electrical con-
nection. This can be accomplished by check- ing the trailer lighting. Active Blind Spot Assist
is then deactivated. The radar waves next to
the vehicle are hidden in the assistance dis-
play. The Active
Active Blind BlindSpot
SpotAssist
Assist not
not
available
available when
whentowing
towing a
atrailer
trailer See
See
Owner's Manual
Owner's Manual message appears in the
multifunction display.
Active Lane Keeping Assist General notes
Active Lane Keeping Assist monitors the area
in front of your vehicle by means of camera
system :at the top of the windscreen. Var-
ious different areas to the front, rear and side
of your vehicle are also monitored with the aid
of the radar sensor system. Active Lane Keep-
ing Assist detects lane markings on the road
and can warn you before you leave your lane
unintentionally. If you do not react to the Driving systems
269Driving and parking Z 

G
WARNING
A lane-correcting brake application cannot
always bring the vehicle back into the original lane. There is a risk of an accident.
Always steer, brake or accelerate yourself,
especially if Active Lane Keeping Assist warns
you or makes a lane-correcting brake appli-
cation. If a lane-correcting brake application occurs,
display :appears in the multifunction dis-
play. The brake application also slightly
reduces driving speed.
This function is available within a speed range
between 60 km/h and 200 km/h.
A lane-correcting brake application can be
made after driving over a lane marking detec- ted as being solid or broken. Before this, a
warning must have been issued by means of
intermittent vibration through the steering
wheel. In addition, a lane with lane markings
on both sides must be detected.
In the case of a broken lane marking being
detected, a lane-correcting brake application can only be made if a vehicle has been detec-
ted in the adjacent lane. Oncoming vehicles,
overtaking vehicles and vehicles in adjacent
lanes can be detected.
i A further lane-correcting brake applica-
tion can only occur after your vehicle has
returned to the original lane. No lane-correcting brake application occurs
if:
R you clearly and actively steer, brake or
accelerate
R you cut the corner on a sharp bend
R you have switched on the turn signals
R a driving safety system intervenes, such as
ESP ®
, PRE-SAFE ®
Brake or Active Blind
Spot Assist
R you have adopted a sporty driving style with
high cornering speeds or high rates of
acceleration
R ESP ®
is deactivated
R the transmission is not in position D
R on vehicles with a trailer tow hitch, the
electrical connection to the trailer has been
correctly established
R a loss of tyre pressure or a defective tyre
has been detected and displayed
R an obstacle in the lane in which you are
driving has been detected
Active Lane Keeping Assist may not detect
other road users or traffic situations. An inap- propriate brake application may be interrup-
ted at any time if:
R you steer slightly in the opposite direction
R you switch on the turn signal
R you clearly brake or accelerate
A lane-correcting brake application is inter-
rupted automatically if:
R a driving safety system intervenes, such as
ESP ®
, PRE-SAFE ®
Brake or Active Blind
Spot Assist
R lane markings are no longer detected Driving systems
271Driving and parking Z 

Activating Active Lane Keeping Assist
X
Press button ;.
Indicator lamp :lights up. The Lane
Lane
Keeping Assist on
Keeping Assist on message appears in
the multifunction display. If all conditions
have been satisfied, a warning or steering
intervention may be made.
If you drive at speeds above 60 km/h and
lane markings are detected, the lines in the assistance graphic display (Y page 308)
are shown in green. Active Lane Keeping
Assist is ready for use.
X To deactivate: press button;.
Indicator lamp :goes out. Active Lane
Keeping Assist is deactivated. The Lane Lane
Keeping
Keeping Assist
Assistoff
offmessage appears in
the multifunction display.
Selecting Standard or Adaptive setting X In the Assistance
Assistance menu on the on-board
computer, select the Active Lane Keep‐
Active Lane Keep‐
ing Assist
ing Assist function (Ypage 311).
X Select Standard
Standard orAdaptive
Adaptive.
When Standard
Standard is selected, no warning
vibration occurs if:
R you have switched on the turn signals. In
this event, the warnings are suppressed
for a certain period of time.
R a driving safety system intervenes, such
as ABS, BAS or ESP ®
.
When Adaptive
Adaptive is selected, no warning
vibration occurs if: R
you have switched on the turn signals. In
this event, the warnings are suppressed
for a certain period of time.
R a driving safety system intervenes, such
as ABS, BAS or ESP ®
.
R you accelerate hard, e.g. kickdown.
R you brake hard.
R you steer actively, e.g. swerve to avoid an
obstacle or change lane quickly.
R you cut the corner on a sharp bend.
In order that you are warned only when nec-
essary and in good time if you cross the lane marking, the system detects certain condi-
tions and warns you accordingly.
The warning vibration occurs earlier if:
R you approach the outer lane marking on a
bend
R the road has very wide lanes, e.g. a motor-
way
R the system detects solid lane markings
The warning vibration occurs later if:
R the road has narrow lanes
R you cut the corner on a bend
Towing a trailer
If you couple up a trailer, make sure that you have correctly established the electrical con- nection. This can be accomplished by check-
ing the trailer lighting. Hybrid operation
Points to remember
General notes Hybrid technology combines a fuel efficient
internal combustion engine with a powerful
electric motor. The hybrid system automati-
cally selects the most efficient operating
mode for every driving situation. Drive the
vehicle in the usual manner.
To save fuel, the hybrid system switches off
the combustion engine as often as possible
during the journey when power output 272
Hybrid operationDriving and pa
rking