If you change wheel size, make sure they corre-
spond to the correct wheel size category
(
Ypage 267). If the category is changed without
recoding the control units in the vehicle,t he
functioning of the distance warning feature may
be impaired. COLLISION PREVENTION ASSIST
may then detect amalfunction and switch itself
off.
Operation
XTo activate/deactivate: activate or deacti-
vate the distance warning function in the on-
board computer (
Ypage 184).
If the distance warning function of the COL-
LISION PREVENTION ASSISTisa ctivated, the
display shows the Äsymbol:
Rin the header
Rin the Status Overviewof the Assist.menu (Ypage 183)
At speedsuptoa pprox20m ph (30 km/h) the
display in vehiclesw ith Active Parking Assist
first shows the ístatus indicator. Only from
as peed of abou t20m ph (30 km/h )does the
display show the Äsymbolinstead of the
í status indicator.
The distance warning function can help you to
minimize the risk of afront-end collision with a
vehicle ahea dorreduce the effects of such a
collision. With the help of the rada rsensor sys-
tem, the distance warning function can detect
obstacles that are in the path of you rvehicle for
an extended period of time. If the distance warn-
ing function detects that there is arisk of acol-
lision, you wil lbewarned visually and, where
necessary ,acoustically.W ithout yourinterven-
tion, the distance warning function cannot pre-
vent acollision.
The distance warning function issues awarning
at speeds:
Rfrom abou t4mph (7 km/h) if you approach a
vehicle traveling in front or astationary vehi-
cle very quickly. The ·warning lamp in the
instrument cluster flashe sand an intermittent
warning tone also sounds.
At speedsuptoa bout45mph (70 km/h), the
system also detects stationary obstacles ,for
example stationary or parked vehicles.
XBrake immediately until the distance to the
obstacle increases and the risk of acollision
has passed.
or
XTake evasive action, provideditiss afe to do
so.
Adaptive Brake Assist
General notes
Adaptive Brake Assist evaluates the traffic sit-
uatio nwith the help of the rada rsensor system
and can detect obstacle swhich have been in
you rvehicle's path for an extended period of
time. From speedsa bove4mph (7 km/h), Adap-
tive Brake Assist aid syou in braking during haz-
ardou ssituations.
Up to aspeed of approximately 125 mph
(200 km/h), Adaptive Brake Assist is capable of
reacting to moving obstacle sthat have already
been detected as such at least once over the
period of observation.
Important safety notes
GWARNING
Adaptive Brake Assist does not react:
Rto peopleora nimals
Rto oncoming vehicles
Rto crossing traffic
Rto stationary obstacles
Rwhen cornering
As aresult, the Adaptive Brake Assist may not
intervene in all critical conditions. There is a
risk of an accident.
Alway spay careful attention to the traffic sit-
uatio nand be ready to brake.
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 arisk of an accident.
144Driving systems
Driving and parking
Alwayspaycarefu lattentio ntothe traffic sit-
uatio nand be ready to brake. Terminate the
interventio ninanon-critica ldriving situation.
In particular, the detection of obstacle scan be
impaired in the cas eof:
Rdirt on the sensors or anything else covering
the sensors
Rsnow or heavy rain
Rinterference from othe rradar sources
Rstrong rada rreflections, for example, in park-
ing garages
Ran arrow vehicl etraveling in front, e.g .a
motorbike
Rav ehicl etraveling in front on adifferent line
Due to the nature of the system ,particularly
complicate dbutnon-critica ldriving conditions
maya lsoc ause Adaptive Brake Assist to inter-
vene.
If yo ufailtoa dapt your driving style ,Adaptive
Brake Assist can neither reduce the ris kofacci-
dent nor override the laws of physics. Adaptive
Brake Assist canno ttake into account road,
weather or traffic conditions. Adaptive Brake
Assist is onlyana id.Y ou arer esponsibl efor the
distance to the vehicl einfront, for vehicle
speed ,braking in goo dtime and for staying in
your lane.
Following damage to the front end of the vehicle,
have the configuratio nand operatio nofthe
rada rsensor checked at aquali fied specialist
workshop.T hisa lsoa pplies to collisions at slow
speed swhe
re the rei
snov isible damage to the
front of the vehicle.
If yo uchange whee lsize, make sure they corre-
spond to the correct whee lsizec ategory
(
Ypage 267). If the categor yischangedw ithout
recoding the contro lunits in the vehicle, the
functioning of Adaptive Brake Assist mayb e
impaired .COL LISION PREVENTION ASSIST may
then detect amalfunctio nand switch itsel foff.
If Adaptive Brake Assist is not availabl edueto a
malfunctio ninthe rada rsensor system ,the
brake system remains availabl ewithf ullb rake
boosting effect and BAS.
Operation
With the hel pofthe rada rsensor system ,Adap-
tive Brake Assist can detect obstacle sthath ave
been in the path of your vehicl efor an extended
perio doft ime.Adaptive Brake Assist does not
react to stationar yobstacles. If Adaptive Brake Assist detects
ariskofc ollision with avehicle
traveling in front or with astationar yobstacle,
the system calculate sthe braking forc eneces-
sary to avoidt hiscollision. If yo uapply the
brakes forcefully, Adaptive Brake Assist will
automaticall yincrease the braking forc etoa
level suitabl efor the traffic conditions.
XBrake unti lthe distance to the obstacle
increases and the ris kofacollision passes.
ABS
prevents the wheels from locking.
The brakes functio nasusual againif:
Ryour elease the brake pedal
Rther eisnol ongera ny dangerofac ollision
Rno obstacle is detecte dinfront of your vehicle
Braking assistance is then ended.
Blind SpotA ssist
General notes
Blind Spo tAssist monitors the area soneither
side of the vehicl ethata renot visible to the
driver with two lateral, rear-facing rada rsensors
in the bumper. It supports yo ufrom speed sof
approximately20m ph (30 km/h).Awarning
display in the exterio rmirrors draws your atten-
tio ntov ehicles detecte dinthe monitore darea.
If yo uthen switch on the corresponding turn
signaltoc hange lane, yo uwilla lsor eceive an
optica land audibl ecollision warning.
Important safety notes
GWARNING
Blind Spo tAssist does not react to:
Rvehicles overtake ntoo closel yonthe side,
placing them in the blind spo tarea
Rvehicles which approach with alarge speed
differential and overtake your vehicle
As aresult, Blind Spo tAssist mayn ot give
warning sinsuchs ituations. There is arisko f
an accident.
Alway sobserve the traffic conditions care-
fully, and maintain asafel atera ldistance.
Blind Spo tAssist is onlyana id.Itm ayfailto
detect som evehicles and is no substitute for
attentive driving .Alway sensure thatt hereis
Driving systems145
Driving an dparking
Z
sufficient distance to the side for other road
users and obstacles.
In particular, the detection of obstacles can be
impaired in the case of:
Rdirt on the sensors or anything else covering
the sensors
Rfog, heavy rain or snow
Rnarrow vehicles, e.g. motorcycles or bicycles
Rvery wide lanes
Rnarrow lanes
Rvehicles not driving in the middle of their lane
Rbarriers or other road boundaries
Vehicles in the monitoring range are then not
indicated.
iUSA only:
This device has been approved by the FCC as
a" Vehicular Rada rSystem". 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.
Monitoring range of the sensors
Blind Spot Assist monitors the area shown in the
diagramupt o118 in (3 m) behind and directly
next to your vehicle.
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 driv-
ing in the middle of their lane. This may be the
case if the vehicles are driving on the inner side
of their lane.
Due to the nature of the system:
Rwarnings may be issued in error when driving
close to crash barriers or similars olid lane
borders.
Rwarnings may be interrupted when driving
alongside long vehicles, for example trucks,
for aprolonged time
The two sensors for Blind Spot Assist are inte-
grated into the sides of the rear bumper. Make
sure that the bumper is free of dirt, ice or slush
in the vicinity of the sensors. The radar sensors
must not be covered, for example by rear-moun-
ted cycle racks or overhanging loads. Following
as evere impact or in the event of damage to the
bumper, have the function of the radar sensors
checked at aqualified specialist workshop.
Blind Spot Assist may otherwise not work prop-
erly.
Warning display
Blind Spot Assist is not active at speeds below
approximately 20 mph (30 km/h). Vehicles in
the monitoring range are then not indicated.
If av ehicle is detected within the monitoring
range of Blind Spot Assist at speeds above
approximately 20 mph (30 km/h), warning
lamp :lights up red in the exterior mirror on
the corresponding side. Warning lamp :
always lights up when avehicle enters the blind
spot monitoring range from behind or from the
side. When you overtake avehicle, the warning
only occurs if the difference in speed is less than
7m ph (11 km/h).
If you select reverse gear, Blind Spot Assist is
inactive.
146Driving systems
Driving and parking
Standard:the sensitivity with which the sys-
tem determines the attention level is set to
normal.
Sensitive: the sensitivity is set higher. The
driver is warned earlier.
When ATTENTION ASSIST is switched on and
the vehicle engine is running:
Ron vehicles without steering wheel buttons,
the À indicator lamp in the instrument
cluster lights up
Ron vehicles with steering-wheel buttons, the
display shows the Àsymbol:
-in the status area
-in the Status Overviewof the Assist.menu (Ypage 183)
For vehicles with steering wheel buttons, if you
deactivate ATTENTION ASSIST, the system is
automatically re-activated when you start the
engine. The system sensitivity then corresponds to the last selection activated –standard or sen-
sitive.
If you switch off ATTENTION ASSIST in avehicle
without steering wheel buttons, the system
remains switched off even after you start the
engine. The status of the system after switching
on the engine always corresponds to the status
last selected.
Warning in the display
If the system detectst iredness or increasing
lapses in concentration, the warning Atten‐
tion Assist: TakeaBreak!orAttent.Asst: Take Break!is shown in the display.
An additional warning tone sounds.
XIf necessary, take abreak.
XConfirm the message by pressing the a
button on the steering wheel.
On long journeys, take regular breaks in good
time to allow yourself to rest. If you do not take
ab reak and ATTENTION ASSIST continues to
detect increasing lapses in concentration, you
will be warned again after 15 minutes at the
earliest. This will only happen if ATTEN-
TION ASSIST still detectst ypical indicators of
fatigue or increasing lapses in concentration.
PARKTRONIC
General notes
PARKTRONIC is an electronic parking aid. The
system is equipped with ultrasonic sensors in
the front and rear bumpers to monitor the area
around your vehicle. PARKTRONIC indicates vis-
uallya nd audibly the distance between your
vehicle and an object.
Your vehicle features two separate sound emit-
ters with different frequencies for the warning
tones. The warning ranges in front of and behind the vehicle are indicated by different warning
tones.
PARKTRONIC is activated automatically when
you:
Rturn the key to position 2in the ignition lock
Rrelease the parking brake and
Rmove the selector lever to D,Nor R
PARKTRONIC is deactivated at speeds above
11 mph (18 km/h). PARKTRONIC is reactivated
at speeds below 10 mph (16 km/h).
Important safety notes
PARKTRONIC is only an aid. It cannot replace
your own awareness of the immediate surround-
ings. You are responsible for safe maneuvering,
parking and pulling away.W hen maneuvering,
parking and pulling away,m ake sure that there
are no persons, animals or object sinthe maneu-
vering area.
!Pay particular attention to obstacles above
or below the sensors when parking, such as
flower pots or trailer towbars. PARKTRONIC
does not recognizes uch objectswhen they
are in the immediate vicinity of the vehicle.
You could damage the vehicle or objects.
PARKTRONIC can suffer interference from:
Rultrasonic sources such as atruck's
compressed-air brakes, an automatic car
wash or apneumatic drill
Rattachments to the vehicle, e.g. rear moun-
ted racks
Rnumber plates (vehicle license plates) that
are not affixed flat against the bumper
Rdirty or icy sensors
Remove adetachable trailer coupling if it is no
longer required. PARKTRONIC measures the
minimum detection range to an obstacle from
the bumper, not the ball coupling.
150Driving systems
Driving and parking
Rangeoft he sensors
PARKTRONIC doe snot account for obstacles
that are:
Rbeneath its detection range, e.g. persons,a ni-
mal soro bjects
Rabove its detection range, e.g. overhanging
loads, overhangs or truck loading ramps
The sensors mus tbefree of dirt, ice or slush.
Otherwise, they canno tfunction correctly.
Cleant he sensors regularly, taking care not to
scratch or damag ethem (
Ypage 257).
Front sensors
CenterApprox. 39 in
(100 cm)
CornersApprox. 24 in (60 cm)
Rear sensors
CenterApprox. 47 in
(120 cm)
CornersApprox. 31 in (80 cm)
Minimum distance
CenterApprox. 8in(20 cm)
CornersApprox. 8in(20 cm)
If an obstacl eiswithin this range, the corre-
sponding segments of the warning display slight
up and yo uhearaw arning tone. If the distance
falls below the minimum ,the distance from an
obstacl emay no longer be shown.
Driving systems151
Driving and parking
Z
Warning displays
Front area warning display in center of dashboard.
Reararea warning display on the dashboard
Rea rarea warning display in center of headliner in
rear compartment.
:
Warning segments for the left side of the
vehicle
;Warning segments for the right side of the
vehicle
=Segments showing operational readiness
The warning display sshow the distance
between the sensor and the obstacle.
The warning display is divided into five yellow
and two red segments for each side of the vehi- cle. PARKTRONIC is operational if operational
readiness indicator
=lights up.
There is amalfunction if only the red segments
of the warning display light up (
Ypag e154).
The selected transmission position determines
whethe rthe front and/or rear area is monitored.
Selector lever posi-
tionMonitoring
DFront area
R or NFront and rear area
PNo area sactivated
One or more segments light up as the vehicle
approache sanobstacle, depending on the vehi-
cle's distance from the obstacle.
From the:
Rsixth segment, an intermittent warning tone
sound sfor approximately 2seconds.
Rseventh segment, acontinuou swarning tone
sounds. This indicates that you have now
reache dthe minimu mdistance.
Roll-back warning
Regardless of transmission position,
PARKTRONIC automatically monitors the area
behind the vehicl eifthe vehicl ebegins to roll
backwards, e.g. after stopping on an uphill gra-
dient.
Activating/deactivating PARKTRONIC
XPress the fbutton.
If PARKTRONIC is deactivated, the indicator
lam pint he switch lights up.
152Driving systems
Driving and parking
Problems with PARKTRONIC
ProblemPossible causes/consequences andMSolutions
Only the red segments in
the PARKTRONIC warn-
ing displaysare lit.
Aw arning tone also
sounds for approx-
imately 2seconds.
PARKTRONIC is then
deactivated.
The indicator lamp of the
f button lights up
and the red segments in
the PARKTRONIC warn-
ing display go out.PARKTRONIC has malfunctioned and has switched itself off.
XIf problems persist, have PARKTRONIC checked at aqualified spe-
cialist workshop.
The PARKTRONIC warn-
ing displaysi mplausible
distances.
For example, all the seg-
mentsm ay be lit even
though there is no obsta-
cle present.The PARKTRONIC sensors are dirty or iced up.
XClean the PARKTRONIC sensors (Ypage 257).
XTurn the key to position 2again in the ignition lock.
The license plate or other parts attached near the sensors may not be
secured correctly.
XCheck the license plate and attachmentp arts near the sensors for
correct seating.
An external radio or ultrasonic source may be causing interference.
XCheck PARKTRONIC functions in adifferent location.
Active Parking Assist
General notes
Active Parking Assist is an electronic parking
aid. The system uses ultrasound sensors to
measure the road on both sides of the vehicle
and indicates suitable parking spaces. It can
then actively steer and brake the vehicle to help
you to park and exit the parking space.
Active Parking Assist includes the PARKTRONIC
parking aid which indicates visuallya nd audibly
the distance between your vehicle and an
object .Todot his, PARKTRONIC uses the ultra-
sonic sensors of the Active Parking Assist
(
Ypage 150).
Important safety notes
Active Parking Assist is only an aid. It is not a
substitute for your attention to the immediate
surroundings. You are responsible for safe maneuvering, parking and pulling away.M
ake
sure that no persons, animals or object sare in
the maneuvering range.
When you deactivate PARKTRONIC, Active Park-
ing Assist will also be deactivated.
For vehicles with atrailer coupling installed, the
minimum length for parking spaces will be
slightly increased.
If you have attached atrailer 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
then deactivated for the rear area.
GWARNING
While parking or pulling out of aparking
space, the vehicle swings out and can drive
onto areas of the oncomingl ane. This could
result in acollision with another road user.
There is arisk of an accident.
154Driving systems
Driving and parking
On vehicles with steering wheel buttons, the
light sensor in the instrument cluster automati-
cally controls the brightness of the displaylight-
ing.
While the lights are on, the brightness is depend-
ent upon the brightness of the ambient light.
You can also adjust the brightness of the instru-
ment lighting and the displayl ighting
Rby pressing thefand gbuttons on the
instrument cluster on vehicles without steer-
ing wheel buttons (not in the Settings
menu)
Rby turning control:on vehicles with steer-
ing wheel buttons.
Speedometer
If you change the wheel size on your vehicle,
make sure it is assigned to the correct wheel
size category (
Ypage 267). If you change wheel
size category without recoding the control unit,
the speedometer indication will be inaccurate.
The current vehicle speed may then be higher
than the speed displayed in the speedometer.
The speed can also be shown in the displayi n
the form of adigital speedometer:
Ron vehicles without steering wheel buttons
(Ypage 172)
Ron vehicles with steering wheel buttons
(Ypage 178)
iIn some countries, awarning sounds and/or
the displays howsamessage when the vehi-
cle reaches the maximum legally permissible
speed limit, e.g. at 75 mph (120 km/h).
Tachometer
!
Do not drive in the overrevving range, as this
could damage the engine.
HEnvironmental note
Avoid driving at high engine speeds. This
unnecessarily increases the fuel consumption
of your vehicle and harms the environment as
ar esult of increased emissions.
The red band in the tachometer indicates the
engine's overrevving range.
To protect the engine, the fuel supply is inter-
rupted when the red band is reached.
Outside temperatured isplay
You should pay special attention to road condi-
tions when temperatures are around freezing
point.
Please bear in mind that the outside tempera-
ture displayshows the air temperature meas-
ured and not the road temperature.
The displays hows the outside temperature in
the header:
Ron vehicles without steering-wheel buttons
(Ypage 170)
Ron vehicles with steering wheel buttons
(Ypage 176).
Changes in the outside temperature are dis-
played after ashort delay.
Coolant temperatureg auge
GWARNING
Opening the hood when the engine is over-
heated or when there is afire in the engine
compartment could expose you to hot gases
or other service products. There is arisk of
injury.
Let an overheated engine cool down before
opening the hood. If there is afire in the
engine compartment,k eep the hood closed
and contact the fire department.
On vehicles without steering wheel buttons, you
can have the coolant temperature shown in the
display(
Ypage 172).
On vehicles with steering wheel buttons, an ana-
log coolant temperature gage is located in the
tachometer in the instrument cluster
(
Ypage 37).
Under normal operating conditions and with the
specified coolant level, the gage may rise to
248 ‡(120† ).
Display and operation169
On-board computer and displays
Z