Active Distance Assist DISTRONIC
Function ofActive Distance AssistDISTRONIC
Active Distance AssistDISTRONIC maintainstheset speed on free-flowingroads. Ifvehicles infront are detected,the set distance is main‐tained, if necessary,untilthevehicle comesto ahalt. Thevehicle accelerates or brakes depend‐ing onthe distancetothevehicle in front andthe set speed. The speed (intherange between15mph (20 km/h) and130mph (210km/h))andthe distancetothevehicle in front are setand saved onthesteering wheel.
Otherfeatures ofActive Distance AssistDISTRONIC:
RAdjuststhe drivingstyle depending ontheselected drive program (fuel-saving, comfort‐able or dynamic) (→page175)
RReactstostationaryvehicles detected inurban speedranges (except bicycles andmotorcycles)
RInitiates accelerationtothestored speed ifthe turn signal indicator is switched ontochangetotheovertaking lane.
RTakes one-sidedovertakingrestrictions intoaccount on highways or on multi-laneroadswith separateroadways (country-dependent).
Vehicles withActiveParking Assist:ifthevehicle has been brakedtoastandstill on multi-lane, separateroadwaysbyActive DistanceAssistDISTRONIC, it can automaticallyfollowthevehicle in front driving off again within30 seconds. If a critical situation is detectedwhen driving off, a visual and acousticwarning isgiven indicatingthatthe driver must nowtakecontrol ofthevehicle. Thevehicle is not acceler‐ated any further.
Active Distance AssistDISTRONIC is only an aid.The driver isresponsibleforkeeping a safe dis‐tancetothevehicle in front,forvehicle speedandfor braking in good time.
System limitations
The system may be impaired or may not functioninthefollowing instances:
RIn snow,rain,fog, heavy spray, ifthere isglare, in direct sunlight or in greatlyvaryingambient light.
RThe windshield inthe area ofthe camera isdirty,fogged up, damaged or covered.
RIftheradar sensors are dirty or covered.
RIn parkinggarages or onroads withsteepuphill or downhill gradients.
RIfthere are narrowvehicles in front, such asbicycles or motorcycles.
In addition, on slipperyroads, braking or accel‐erating can cause one or several wheelstolosetraction andthevehicle couldthen skid.
Do not useActive Distance AssistDISTRONIC inthese situations.
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System limitationsTemporary speedrestrictions (e.g.for a certaintime or duetoweather conditions) cannot beproperlydetectedbythe system. The maximumpermissible speed applyingfor avehicle with atrailer is not detectedbythe system. Inthese sit‐uationsyou must adjustyour speedyourself.
&WARNINGRisk of accident duetoActiveSpeed Limit Assistadaptingthevehicle'sspeed
The speed adoptedbyActive Speed LimitAssistmay betoo high or incorrect in someindividual cases, suchas:
RInthewet or infog
RWhentowing a trailer
#Ensurethatthe driven speed complieswith trafficregulations.
#Adjustthe driving speedtosuit currenttraffic andweather conditions.
Function ofroute-based speed adaptation
%Theavailability ofthefollowing function iscountry-dependent.
When Distance AssistDISTRONIC is active,thefunction adjuststhe speed depending ontherouteevents ahead. Depending onthe drive pro‐gram selected,thevehicle negotiatestherouteevent ahead in a fuel-saving, comfortable ordynamic manner. Whentherouteevent has beenpassed,thevehicle accelerates againtothestored speed. The set distancetothevehicle infront,vehicles detected ahead and speedrestric‐tions ahead aretaken into account.
Route-based speed adjustment canbyconfig‐ured inthe multimedia system (→page 208).
Routeevents ahead are:
RBends
RT-intersections, traffic circles andtollsta‐tions
RTurns andexits
%Whenthetollstation isreached,Active Dis‐tance AssistDISTRONIC adoptsthe speed asthestored speed.
Also,the speed isreduced ifthe turn signaltochange lanes is switched on and one ofthefol‐lowing situations is detected:
RTurning off at intersections
RDriving on slowing-down lanes
RDriving on lanes adjacenttoslowing-downlanes
The driver isresponsibleforchoosingtherightspeed and observingotherroad users. Thisapplies in particulartointersections, traffic cir‐cles and traffic lights, asroute-based speedadaptation does not brakethevehicletoastand‐still.
Whenroute guidance is active,thefirst speedadjustment is carried out automatically. Iftheturn signal indicator is switched on,the selectedroute is confirmed and further speed adjustmentis activated.
Speed adjustment is canceled inthefollowingcases:
RIfthe turn signal indicator is switched offbeforetherouteevent.
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Ifthe systemreaches a system limitation orthedriver has notsteeredthevehiclefor a consider‐able period of time or hasremovedtheir handsfromthesteering wheel,the system will,depending onthe situation,first alertthe driverwith a visualwarning. Display1appears inthemultifunction display.Ifthe driverstill does notsteerthevehicle, or hasstill nottaken hold ofthesteering wheel, arepeatedwarningtonesounds in additiontothe visualwarning mes‐sagetoremindthe drivertotakecontrol ofthevehicle.
Thewarning message does not appear or disap‐pears if one ofthefollowing conditions are met:
RThe driversteersthevehicle.
RThe driver presses asteering wheel button oroperatesTouch Control.
ActiveSteering Assist is only an aid. The driver isresponsibleforthe distancetothevehicle infront,forvehicle speed,for braking in good timeandforstaying in lane. Beforechanging lanes,the driver must make surethatthe neighboringlane is free (glanceoverthe shoulder).
System limitationsActiveSteering Assist has a limitedsteeringtor‐quefor lateral guidance. In some cases,thesteering intervention is not sufficienttokeepthevehicle inthe lane.
Ifthe detection of lane markings andvehiclesahead is impaired,ActiveSteering Assistswitchestopassive mode. The system providesno support inthis case. Duringthe transitionfromthe activetopassivestatus,theèsym‐bol is shown as enlarged andflashesyellow.Oncethe system is passivetheèsymbol isgrayed out inthe multifunction display.
The system may be impaired or may not functioninthefollowing instances:
RIn snow,rain,fog, heavy spray, ifthere isglare, direct sunlight,greatlyvarying ambientlight,reflections orstrong shadowsontheroadway.
RInsufficientroad illumination.
RThe windshield inthe area ofthe camera isdirty,fogged up, damaged or covered.
RAbsence of lane markings, or several unclearlane markings, or ifthe markingschangerap‐idly.
RThe distancetothevehicle in front istoosmall andthe lane markingsthus cannot bedetected.
RTheroad is narrow and winding.
RObstacles onthe lane or projecting out intothe lane.
The system does not provide assistance inthefollowing conditions:
ROn tight bends, traffic circles and when turn‐ing.
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If novehicle is detected inthe adjacent lane anda lanechange is permitted,thesteering wheelsymbol andthe arroware shown in green2.TheLane Change to the Leftmessage appears,forexample. IfActive Lane Change Assisthasbeen activated withthe turn signal indicator buta lanechange is not immediately possible,thesteering wheel symbolremains green andthearrowappearsgray1. Whenthe lanechangesupportstarts,the turn signal indicator is auto‐matically activated.
If a lanechange is not possible,the arrow fadesout after afew seconds and a new lanechangemust be initiated. An immediate lanechange is
only possible on freeway sections without speedlimits.
Ifthe system is impaired,Active Lane ChangeAssistmay be canceled. If it is canceled,theLane Change Canceledmessage appears inthemultifunction display and awarningtone sounds.
&WARNINGRisk of accident fromchang‐ing lanetoan occupied adjacent lane
Lane ChangeAssistcannot alwaysdetectclearlyifthe adjacent lane is free.
The lanechange might be initiated althoughthe adjacent lane is not free.
#Beforechanging lanes, make surethatthe neighboring lane is free andthere isno dangerto otherroad users.
#Monitorthe lanechange.
&WARNINGRisk of accident if LaneChange Assistunexpectedlystops func‐tioning
Ifthe system limitationsfor Lane ChangeAssist havebeenreached,there is no guar‐anteethatthe system willremain active.
Lane Change Assist cannotthen assistyoubyapplyingsteeringtorques.
#Always monitorthe lanechange andkeepyour hands onthesteering wheel.Observethe traffic conditions andsteerand/or brake if necessary.
System limitationsThe system limitations ofActiveSteering AssistapplytoActive Lane Change Assist(→page 208).
The system may also be impaired or may notfunction inthefollowing situations:
RThe sensors intherear bumper are dirty,damaged or covered,for instanceby asticker or ice and snow.
RTheexterior lighting is malfunctioning.
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