
Important safety notes
ATTENTION ASSIST is only an aid to the driver.It might not always recognize fatigue orincreasing inattentiveness in time or fail torecognize them at all. The system is not a sub-stitute for a well-rested and attentive driver.
The functionality of ATTENTION ASSIST isrestricted and warnings may be delayed or notoccur at all:
Rif the length of the journey is less thanapproximately 30 minutes
Rif the road condition is poor, e.g. if the sur-face is uneven or if there are potholes
Rif there is a strong side wind
Rif you have adopted a sporty driving stylewith high cornering speeds or high rates ofacceleration
Rif you are predominantly driving slower than37 mph (60 km/h) or faster than 125 mph(200 km/h)
Rif the time has been set incorrectly
Rin active driving situations, such as whenyou change lanes or change your speed
ATTENTION ASSIST is reset when you continueyour journey and starts assessing your tired-ness again if:
Ryou switch off the engine
Ryou take off your seat belt and open thedriver's door, e.g. for a change of drivers orto take a break
Displaying the attention level
You can have current status information dis-played in the assistance menu (Ypage 196)of the on-board computer.
XSelect the Assistance display for AttentionAssist using the on-board computer(Ypage 197).
The following information is displayed:
RThe length of the journey since the lastbreak.
RTheAttention LevelAttention Leveldetermined byATTENTION ASSIST, displayed in a bar dis-play in five levels from high to low.
RIf ATTENTION ASSIST is unable to calculatethe attention level and cannot output awarning, theSystem SuspendedSystem Suspendedmessageappears. The bar display then changes thedisplay, such as when you are driving at aspeed below 37 mph (60 km/h) or above125 mph (200 km/h).
Activating ATTENTION ASSIST
XActivate ATTENTION ASSIST using the on-board computer (Ypage 198).The system determines the attention level ofthe driver depending on the setting selec-ted:
StandardStandardselected: the sensitivity with whichthe system determines the attention level isset to normal.
SensitiveSensitiveselected: the sensitivity is sethigher. The attention level detected by Atten-tion Assist is adapted accordingly and thedriver is warned earlier.
When ATTENTION ASSIST is deactivated, the

still detects increasing lapses in concentra-tion, you will be warned again after 15 minutesat the earliest. This will only happen if ATTEN-TION ASSIST still detects typical indicators offatigue or increasing lapses in concentration.
Vehicles with the COMAND multimediasystem:if a warning is output in the multi-function display, a service station search isperformed in the multimedia system. You canselect a service station and navigation to thisservice station will then begin. This functioncan be activated or deactivated in the multi-media system; see the Digital Operator's Man-ual.
Lane Tracking package
General notes
The Lane Tracking package consists of BlindSpot Assist (Ypage 185) and Lane KeepingAssist (Ypage 186).
Blind Spot Assist
General notes
Blind Spot Assist monitors the areas on eitherside of the vehicle that are not visible to thedriver with two lateral, rear-facing radar sen-sors. A warning display in the exterior mirrorsdraws your attention to vehicles detected inthe monitored area. If you then switch on thecorresponding turn signal to change lane, youwill also receive an optical and audible warn-ing.
Blind Spot Assist supports you from a speed ofapproximately 20 mph (30 km/h).
Important safety notes
GWARNING
Blind Spot Assist does not react to:
Rvehicles overtaken too closely on the side,
placing them in the blind spot area
Rvehicles which approach with a large
speed differential and overtake your vehi-
cle
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 todetect some vehicles and is no substitute forattentive driving. Always ensure that there issufficient distance to the side for other roadusers and obstacles.
iUSA only:
This device has been approved by the FCCas a "Vehicular Radar System". The radarsensor is intended for use in an automotiveradar system only. Removing, tamperingwith, or altering the device will void any war-ranties, and is not permitted by the FCC. Donot tamper with, alter, or use in any non-approved way.
Any unauthorized modification to this devicecould void the user’s authority to operatethe equipment.
Radar sensors
The radar sensors for Blind Spot Assist areintegrated into the rear bumper. Make surethat the bumpers are free from dirt, ice orslush. The sensors must not be covered, forexample by cycle racks or overhanging loads.Following a severe impact or in the event ofdamage to the bumpers, have the function ofthe radar sensors checked at a qualified spe-cialist workshop. Blind Spot Assist may no lon-ger work properly.
Monitoring range of the sensors
In particular, the detection of obstacles can beimpaired if:
Rthere is dirt on the sensors or anything elsecovering the sensors
Rthere is poor visibility, e.g. due to fog, heavyrain or snow
Ra narrow vehicle traveling in front, e.g. amotorbike or bicycle
Rthe road has very wide lanes
Rthe road has narrow lanes
Ryou are not driving in the middle of the lane
Rthere are barriers or other road boundaries
Vehicles in the monitoring range are then notindicated.
Blind Spot Assist monitors the area up to 10 ft(3 m) behind your vehicle and directly next toit.
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If the lanes are narrow, vehicles driving in thelane beyond the lane next to your vehicle maybe indicated, especially if the vehicles are notdriving in the middle of their lane. This may bethe case if the vehicles are driving on the innerside of their lane.
Due to the nature of the system:
Rwarnings may be issued in error when driv-ing close to crash barriers or similar solidlane borders.
Rwarnings may be interrupted when you aredriving alongside particularly long vehicles,such as trucks, for a prolonged time.
Warning display
CWarning display
Blind Spot Assist is not active at speeds belowapproximately 20 mph (30 km/h). Vehicles inthe monitoring range are then not indicated.
When Blind Spot Assist is activated, indicatorlamp Cin the exterior mirrors lights up yellowat speeds of up to 20 mph (30 km/h). Atspeeds above 20 mph (30 km/h), the indicatorlamp goes out and Blind Spot Assist is opera-tional.
If a vehicle is detected within the blind spotmonitoring range at speeds above 20 mph(30 km/h), warning lamp Con the corre-sponding side lights up red. This warning isalways emitted when a vehicle enters the blindspot monitoring range from behind or from theside. When you overtake a vehicle, the warningonly occurs if the difference in speed is lessthan 7 mph (12 km/h).
The yellow indicator lamp goes out if reversegear is engaged. In this event, Blind SpotAssist is no longer active.
The brightness of the indicator/warning lampsis adjusted automatically according to theambient light.
Collision warning
If a vehicle is detected in the monitoring rangeof Blind Spot Assist and you switch on the cor-responding turn signal, a double warning tonesounds. Red warning lamp Cflashes. If theturn signal remains on, vehicles detected areindicated by the flashing of red warninglamp C. There are no further warning tones.
Switching on Blind Spot Assist
XMake sure that Blind Spot Assist is activa-ted in the on-board computer (Ypage 198).
XTurn the SmartKey to position Hin the igni-tion lock.Warning lamps Cin the exterior mirrorslight up red for approximately 1.5 secondsand then turn yellow.
Lane Keeping Assist
General notes
Lane Keeping Assist monitors the area in frontof your vehicle by means of multifunction cam-era Cwhich is attached behind the top of thewindshield. Lane Keeping Assist detects lanemarkings on the road and can warn you beforeyou leave your lane unintentionally.
This function is available in the range between40 mph and 120 mph (60 km/h and200 km/h).
A warning may be given if a front wheel passesover a lane marking. It will warn you by meansof intermittent vibration in the steering wheelfor up to 1.5 seconds.
Important safety notes
GWARNING
Lane Keeping Assist cannot always clearly
detect lane markings.
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In such cases, Lane Keeping Assist can:
Rgive an unnecessary warning
Rnot give a warning
There is a risk of an accident.
Always pay particular attention to the traffic
situation and keep within the lane, espe-
cially if Lane Keeping Assist alerts you.
GWARNING
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
Keeping Assist.
If you fail to adapt your driving style, LaneKeeping Assist can neither reduce the risk ofan accident nor override the laws of physics.Lane Keeping Assist cannot take into accountthe road, traffic and weather conditions. LaneKeeping Assist is merely an aid. You areresponsible for the distance to the vehicle infront, for vehicle speed, for braking in goodtime and for staying in your lane.
The Lane Keeping Assist does not keep thevehicle in the lane.
The system may be impaired or may not func-tion if:
Rthere is poor visibility, e.g. due to insuffi-cient illumination of the road, or due tosnow, rain, fog or spray
Rthere is glare, e.g. from oncoming traffic,the sun or reflection from other vehicles(e.g. if the road surface is wet)
Rthe windshield is dirty, fogged up, damagedor covered, for instance by a sticker, in thevicinity of the camera
Rthere are no or several unclear lane mark-ings for one lane, e.g. roadworks
Rthe lane markings are worn away, dark orcovered up, e.g. by dirt or snow
Rthe distance to the vehicle in front is tooshort and thus the lane markings cannot bedetected
Rthe lane markings change quickly, e.g. lanesbranch off, cross one another or merge
Rthe road is narrow and winding
Rthere are highly variable shade conditionson the roadway
Switching on Lane Keeping Assist
XSwitch on Active Lane Keeping Assist usingthe on-board computer; to do so, selectStandardStandardorAdaptiveAdaptive(Ypage 186).If you drive at speeds above 40 mph(60 km/h) and lane markings are detected,the lines in the assistance graphic areshown in green (Ypage 197). Lane KeepingAssist is ready for use.
IfStandardStandardis selected, no warning vibrationoccurs if:
Ryou have switched on the turn signal. In thisevent, the warnings are suppressed for acertain period of time.
Ra driving safety system intervenes, e.g. ABS,
BAS or ESP®.
WhenAdaptiveAdaptiveis selected, no warning vibra-tion occurs if:
Ryou have switched on the turn signal. In thisevent, the warnings are suppressed for acertain period of time.
Ra driving safety system intervenes, e.g. ABS,
BAS or ESP®.
Ryou accelerate hard, e.g. kickdown.
Ryou brake hard.
Ryou steer actively, e.g. swerve to avoid anobstacle or change lanes quickly.
Ryou cut the corner on a sharp bend.
In order that you are warned only when neces-sary and in good time if you cross the lanemarking, the system detects certain condi-tions and warns you accordingly.
The warning vibration occurs earlier if:
Ryou approach the outer lane marking on abend
Rthe road has very wide lanes, e.g. a freeway
Rthe system detects solid lane markings
The warning vibration occurs later if:
Rthe road has narrow lanes.
Ryou cut the corner on a bend
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