the stopping distance on off-road terrain. Thislimits steering capability.
BAS (Brake Assist System)
General information
BAS operates in emergency braking situations.If you depress the brake pedal quickly, BASautomatically boosts the braking force, thusshortening the stopping distance.
Important safety notes
iObserve the "Important safety notes" sec-tion (Ypage 60).
GWARNING
If BAS is malfunctioning, the braking dis-
tance in an emergency braking situation is
increased. There is a risk of an accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
Braking
XKeep the brake pedal firmly depressed untilthe emergency braking situation is over.ABS prevents the wheels from locking.
The brakes will function as usual once yourelease the brake pedal. BAS is deactivated.
Active Brake Assist
General information
iObserve the "Important safety notes" sec-tion (Ypage 60).
Active Brake Assist consists of a distancewarning function with an autonomous brakingfunction and a situation-dependent brakeboosting effect.
Active Brake Assist can help you to minimizethe risk of a collision with the vehicle travelingin front or reduce the effects of such a colli-sion.
If Active Brake Assist detects that there is arisk of collision, you will be warned visuallyand acoustically. If you do not react to the vis-
ual collision warning or the warning tone,autonomous braking can be initiated in criticalsituations. If you apply the brake yourself in acritical situation, Active Brake Assist supportsyou with a situation-dependent brake boostingeffect.
Important safety notes
Detection of hazardous situations can be par-ticularly impaired if:
RThere is dirt on the sensors or anything elsecovering the sensors
RThere is snow or heavy rain
RThere is interference by other radar sources
RThere are strong radar reflections, for exam-ple in parking garages
RA narrow vehicle is traveling in front, e.g. amotorbike
RA vehicle is traveling in front on a differentline
RYou are driving a new vehicle or servicing onthe Active Brake Assist system has justbeen carried out
Observe the important safety notes in the"Breaking-in notes" section (Ypage 124).
Following damage to the front end of the vehi-cle, have the configuration and operation ofthe radar sensor checked at a qualified spe-cialist workshop. This also applies to collisionsat low speeds where no visible damage to thefront of the vehicle is apparent.
Activating/deactivating
Active Brake Assist is active after every igni-tion cycle.
You can activate or deactivate Active BrakeAssist (Ypage 197) in the on-board com-puter. When deactivated, the distance warningfunction and the autonomous braking functionare also deactivated.
If Active Brake Assist is deactivated, the
!When Active Distance Assist DISTRONICor the HOLD function is activated, the vehi-cle brakes automatically in certain situa-tions.
To avoid damage to the vehicle, deactivateActive Distance Assist DISTRONIC and theHOLD function in the following or similar sit-uations:
Rwhen towing the vehicle
Rin the car wash
Active Distance Assist DISTRONIC can neitherreduce the risk of an accident if you fail toadapt your driving style, nor override the lawsof physics. Active Distance Assist DISTRONICcannot take into account road, weather or traf-fic conditions. Active Distance AssistDISTRONIC is only an aid. You are responsiblefor the distance to the vehicle in front, forvehicle speed, for braking in good time and forstaying in your lane.
Do not use Active Distance Assist DISTRONIC:
RIn road and traffic conditions which do notallow you to maintain a constant speed, e.g.in heavy traffic or on winding roads
ROn slippery road surfaces. Braking or accel-erating could cause the drive wheels to losetraction and the vehicle could then skid
RIn poor visibility, e.g. due to fog, heavy rainor snow
Active Distance Assist DISTRONIC may notdetect narrow vehicles driving in front, e.g.motorcycles, or vehicles driving in a staggeredformation.
In particular, the detection of obstacles can beimpaired if:
RThere is dirt on the sensors or anything elsecovering the sensors
RThere is snow or heavy rain
RThere is interference by other radar sources
RThere are strong radar reflections, for exam-ple in parking garages
If Active Distance Assist DISTRONIC no longerdetects a vehicle in front, Distance PilotDISTRONIC may unexpectedly accelerate tothe speed stored.
This speed may:
RBe too high if you are driving in a turninglane or an exit lane
RBe so high when driving in the right-handlane that you overtake vehicles in the left-hand lane
RBe so high in the left lane that you passvehicles driving on the right
If there is a change of drivers, advise the newdriver of the speed stored.
Cruise control lever
CTo store the current speed or a higherspeed
DTo store the current speed or a lowerspeed
objects when they are in the immediatevicinity of the vehicle. You could damage thevehicle or the objects.
The sensors may not detect snow and otherobjects that absorb ultrasonic waves.
Ultrasonic sources such as an automatic carwash, the compressed-air brakes of a truckor a pneumatic drill could cause ParkingAssist PARKTRONIC to malfunction.
Parking Assist PARKTRONIC may not func-tion correctly on uneven terrain.
Parking Assist PARKTRONIC is activated auto-matically when you:
Rswitch on the ignition
Rshift the transmission to position [, ^or \\
Parking Assist PARKTRONIC is deactivated atspeeds above 11 mph (18 km/h). It is reacti-vated at lower speeds.
Range of the sensors
General notes
Parking Assist PARKTRONIC does not take intoaccount obstacles located:
Rbelow the detection range, such as persons,animals or objects
Rabove the detection range, e.g. overhangingloads, tail sections or loading ramps oftrucks
CSensors in the front bumper, left-hand side(example)
The sensors must be free from dirt, ice orslush. They can otherwise not function cor-rectly. Clean the sensors regularly, taking carenot to scratch or damage them (Ypage 282).
Range
CDetection range of front sensors
DDetection range of rear sensors
Front sensors
CenterApprox. 40 in (approx.100 cm)
CornersApprox. 24 in (approx.60 cm)
Rear sensors
CenterApprox. 48 in (approx.120 cm)
CornersApprox. 32 in (approx.80 cm)
Minimum distance
CenterApprox. 8 in (approx.20 cm)
CornersApprox. 6 in (approx.15 cm)
If an obstacle is detected within this range, therelevant warning displays light up and a warn-ing tone sounds. If the distance falls below theminimum, the distance may no longer beshown.
172Driving systems
Driving and parking