detected in the monitored area. If you then
switch on the corresponding turn signal to
change lanes, you will also receive a visual
and audible collision warning. If a risk of side impact is detected, corrective braking may
help you avoid a collision. Active Blind Spot
Assist evaluates the free space in the direc-
tion of travel and to the side before making a course-correcting brake application. For this,Active Blind Spot Assist uses the forward-
facing radar sensors.
Active Blind Spot Assist supports you from a
speed of approximately 30 km/h.
Important safety notes
Active Blind Spot Assist is only an aid and is
not a substitute for attentive driving. G
WARNING
Active Blind Spot Assist does not react to
vehicles:
R overtaking too closely on the side, placing
them in the blind spot area
R if the difference in the speed of approach
and overtaking is too great
As a result, Active Blind Spot Assist may nei-
ther give warnings nor intervene in such sit-
uations. There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and maintain a safe distance at the side of the vehicle.
Radar sensors
The Active Blind Spot Assist radar sensors are
integrated into the front and rear bumpers
and behind a cover in the radiator trim. Make sure that the bumpers and the cover in the
radiator trim are free of dirt, ice or slush. The rear sensors must not be covered, e.g. by
bicycle racks or overhanging loads. Following
a severe impact or in the event of damage to the bumpers, have the function of the radar
sensors checked at a qualified specialist
workshop. Active Blind Spot Assist may oth-
erwise no longer function properly. Monitoring range G
WARNING
Active Blind Spot Assist does not detect all
traffic situations and road users. There is a
risk of an accident.
Always make sure that there is sufficient dis-
tance to the side for other traffic or obstacles. Active Blind Spot Assist monitors the area up
to 3.0 mbehind your vehicle and directly next
to your vehicle, as shown in the diagram.
The detection of vehicles may be impaired in the case of:
R dirt on the sensors or obscured sensors
R poor visibility, e.g. due to rain, snow or
spray
Vehicles in the monitoring range are then not
indicated.
Active Blind Spot Assist may not detect nar-
row vehicles, such as motorcycles or bicy-
cles, or may only detect them too late.
If the lanes are narrow, vehicles driving in the
lane beyond the lane next to your vehicle may
be indicated, especially if the vehicles are not driving in the middle of their lane. This may be
the case if there are vehicles at the edge of
their lane nearest your vehicle. Driving systems
267Driving and parking Z
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
warning, a lane-correcting application of the
brakes can bring the vehicle back into the
original lane.
If you select km
km in the Display unit Display unit
Speed-/odometer
Speed-/odometer function on the on-board
computer (Y page 314), Active Lane Keeping
Assist is activated starting at a speed of
60 km/h. If the miles
miles display unit is selected,
the assistance range begins at 40 mph.
Important safety notes
If you fail to adapt your driving style, Active
Lane Keeping Assist can neither reduce the
risk of an accident nor override the laws of
physics. Active Lane Keeping Assist cannot
take account of road and weather conditions. It may not detect traffic situations. Active
Lane Keeping Assist 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 lane.
Active Lane Keeping Assist cannot continu-
ously keep your vehicle in its lane. G
WARNING
Active Lane Keeping Assist cannot always
clearly detect lane markings.
In such cases, Active Lane Keeping Assist
can:
R give an unnecessary warning and then
make a course-correcting brake application
to the vehicle
R neither give a warning nor intervene
There is a risk of an accident.
Always pay particular attention to the traffic
situation and keep within the lane, especially
if Active Lane Keeping Assist alerts you. Ter-
minate the intervention in a non-critical driv-
ing situation. 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 the radar sensors in the front or rear bump-
ers or the radiator trim are dirty, e.g.
obscured by snow
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
If no vehicle is detected in the adjacent lane
and broken lane markings are detected, no
lane-correcting brake application is made.
Warning vibration through the steering
wheel
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 seconds.
Lane-correcting brake application
If you leave your lane under certain circum-
stances, the vehicle will brake briefly on one
side. This is intended to help you return the
vehicle to the original lane. 270
Driving systemsDriving and parking
Useful information
i This Owner's Manual describes all mod-
els, series and optional equipment for your
vehicle that were available at the time of
going to press. National variations are pos- sible. Note that your vehicle may not be
equipped with all of the functions descri-
bed. This is also the case for systems and
functions relevant to safety.
i Read the information on qualified special-
ist workshops: (Y page 27). Important safety notes
G
WARNING
Operating the integrated information systems and communications equipment in the vehicle
while driving will distract you from traffic con-
ditions. You could then lose control of the
vehicle. There is a risk of an accident.
Only operate these devices if road traffic con-
ditions permit. If you are unsure about the
surrounding conditions, pull over to a safe
location and make entries only while the vehi-
cle is stationary.
You must observe the legal requirements for
the country in which you are currently driving when operating the on-board computer. G
WARNING
If the instrument cluster has failed or mal-
functioned, you may not recognise function
restrictions relevant to safety. The operating
safety of your vehicle may be impaired. There is a risk of an accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop immedi-
ately.
The on-board computer only shows messages
or warnings from certain systems in the mul- tifunction display. You should therefore make
sure your vehicle is operating safely at all
times. If the operating safety of your vehicle is
impaired, park the vehicle safely as soon as
possible. Contact a qualified specialist work-
shop.
For an overview, see the instrument cluster
illustration (Y
page 34). Displays and operation
Instrument cluster lighting
The lighting in the instrument cluster, in the
displays and the controls in the vehicle inte-
rior can be adjusted using brightness control
knob :.
X Turn brightness control knob :up or
down.
If the light switch (Y page 137) is set to
Ã, TorL the brightness is
dependent upon the brightness of the
ambient light.
i The light sensor in the instrument cluster
automatically controls the brightness of
the multifunction display.
In daylight, the displays in the instrument
cluster are illuminated. A dimming function
is not possible in daylight. Speedometer with segments
The segments in the speedometer indicate
which speed range is available. R Cruise control activated (Y page 220):294
Displays and operationOn-board computer and displays
Display messages
Possible causes/consequences and
M
MSolutions !
Turn on the igni‐ Turn on the igni‐
tion to release tion to release
the parking brake the parking brake The red
!indicator lamp lights up.
You attempted to release the electric parking brake while the igni-
tion was switched off.
X Switch the ignition on. J
Check brake fluid Check brake fluid
level level There is insufficient brake fluid in the brake fluid reservoir.
In addition, the red Jwarning lamp lights up in the instrument
cluster and a warning tone sounds.
G WARNING
Braking efficiency may be impaired.
There is a risk of an accident. X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Safeguard the vehicle against rolling away (Y page 211).
X Consult a qualified specialist workshop.
X Do not top up the brake fluid. This does not correct the fault. #
Check brake pad Check brake pad
wear wear The brake pads/linings have reached their wear limit.
X Visit a qualified specialist workshop. Collision Preven‐
Collision Preven‐
tion Assist Plus tion Assist Plus
currently unavail‐ currently unavail‐
able See Owner's able See Owner's
Manual Manual COLLISION PREVENTION ASSIST PLUS is temporarily inoperative.
Possible causes:
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation
R the system is outside the operating temperature range
R the on-board voltage is too low
Once the causes listed above no longer apply, the display message goes out.
COLLISION PREVENTION ASSIST PLUS is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Safeguard the vehicle against rolling away (Y page 211).
X Restart the engine. 324
Display
messagesOn-board computer and displays
Display messages
Possible causes/consequences and
M
MSolutions Collision Preven‐
Collision Preven‐
tion Assist Plus tion Assist Plus
inoperative inoperative COLLISION PREVENTION ASSIST PLUS is temporarily inoperative
due to a malfunction. Adaptive Brake Assist may also have failed.
X Visit a qualified specialist workshop. PRE-SAFE inopera‐
PRE-SAFE inopera‐
tive See Owner's tive See Owner's
Manual Manual
Important functions of PRE-SAFE
®
have failed. All other occupant
safety systems, e.g. airbags, remain available.
X Visit a qualified specialist workshop immediately. PRE-SAFE
PRE-SAFE
Functions
Functions
currently limited
currently limited
See Owner's Manual See Owner's Manual PRE
‑SAFE ®
PLUS or PRE ‑SAFE®
Brake is temporarily inoperative.
Possible causes:
R the function is impaired due to heavy rain or snow
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation
R the system is outside the operating temperature range
R the on-board voltage is too low
Once the causes listed above no longer apply, the display message
goes out.
PRE ‑SAFE ®
PLUS and PRE ‑SAFE®
Brake are operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Safeguard the vehicle against rolling away (Y page 211).
X Restart the engine. PRE-SAFE PRE-SAFE
Functions
Functions
limited See Own‐
limited See Own‐
er's Manual er's Manual PRE
‑SAFE ®
PLUS or PRE‑ SAFE®
Brake is unavailable due to a mal-
function. BAS PLUS might also be deactivated.
X Visit a qualified specialist workshop. Display
messages
325On-board computer and displays Z
Display messages
Possible causes/consequences and
M
MSolutions Radar sensors
Radar sensors
dirty See Owner's dirty See Owner's
Manual Manual At least one of the following driving systems or driving safety sys-
tems is temporarily restricted or inoperative:
R PRE-SAFE ®
PLUS
R PRE-SAFE ®
Brake
R COLLISION PREVENTION ASSIST PLUS
R Active Lane Keeping Assist
R Active Blind Spot Assist
R DISTRONIC PLUS
Possible causes:
R the sensors in the radiator trim and/or in the bumpers are dirty
R the function of the driving system and/or driving safety system
is impaired due to heavy rain or snow
A warning tone also sounds.
Once the causes listed above no longer apply, the display message
goes out. All driving systems/driving safety systems are operative again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Safeguard the vehicle against rolling away (Y page 211).
X Switch off the engine.
X Clean the sensors (Y page 405) in the following locations:
R in the radiator trim
R in the front bumper
R in the rear bumper, particularly in the middle of the rear
bumper
X Restart the engine.
The display message disappears. ü ü If this symbol appears in the multifunction display, a seat belt
tongue has been inserted into a rear seat belt buckle.
Further information on the status indicator for the rear seat belts
(Y page 50). 326
Display
messagesOn-board computer and displays
Display messages
Possible causes/consequences and
M
MSolutions b
Malfunction See Malfunction See
Owner's Manual Owner's Manual The exterior lighting is faulty.
X Visit a qualified specialist workshop. Vehicles with trailer tow hitch: a fuse may have blown.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Safeguard the vehicle against rolling away (Y page 211).
X Check the fuses (Y page 428).
X If necessary, replace the blown fuse. Observe the warning notes
as you do so.
If the display message continues to be displayed: X Visit a qualified specialist workshop. b
AUTO AUTO
lights
lights inoper‐
inoper‐
ative
ative The light sensor is faulty.
X Visit a qualified specialist workshop. b
Switch off lights Switch off lights The lights are still switched on when you leave the vehicle. A
warning tone also sounds.
X Turn the light switch to Ã.Adaptive Highbeam Adaptive Highbeam
Assist Assist
Plus
Plusinoper‐
inoper‐
ative
ative Adaptive Highbeam Assist Plus is faulty.
X Visit a qualified specialist workshop. Adaptive Highbeam
Adaptive Highbeam
Assist Plus cur‐ Assist Plus cur‐
rently rently
unavailable
unavailable
See Owner's Manual
See Owner's Manual Adaptive Highbeam Assist Plus is deactivated and temporarily
inoperative. Possible causes:
R the windscreen is dirty in the camera's field of vision
R visibility is impaired due to heavy rain, snow or fog
X Clean the windscreen.
If the system detects that the camera is fully operational, display
message Adaptive
Adaptive Highbeam
HighbeamAssist
Assist Plus
Plusavailable
available again
again
is displayed.
Adaptive Highbeam Assist Plus is operational again. 334
Display
messagesOn-board computer and displays