Off-road ABS An ABS system specifically suited to off-road
terrain is activated automatically once the off-
road program is activated on: R
Vehicles without the Offroad Engineering
package ( Y
page 217)R
Vehicles with the Off-Road Engineering pack-
age ( Y
page 218)
At speeds below 20 mph (30 km/h), the front
wheels lock cyclically during braking. The dig-
ging-in effect achieved in the process reduces
the stopping distance on off-road terrain. This
limits steering capability.
BAS (Brake Assist System)
General information BAS operates in emergency braking situations.
If you depress the brake pedal quickly, BAS
automatically boosts the braking force, thus
shortening the stopping distance.
Important safety notes
i Observe the "Important safety notes" sec-
tion ( Y
page 63).
G WARNING
If BAS is malfunctioning, the braking distance
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 X
Keep the brake pedal firmly depressed until
the emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will function as usual once you
release the brake pedal. BAS is deactivated. Active Brake Assist
General information
i Observe the "Important safety notes" sec-
tion ( Y
page 63).
Active Brake Assist consists of a distance warn-
ing function with an autonomous braking func-
tion and Adaptive Brake Assist.
Active Brake Assist can help you to minimize the
risk of a collision with the vehicle traveling in
front or reduce the effects of such a collision.
If Active Brake Assist detects that there is a risk
of collision, you will be warned visually and
acoustically. If you do not react to the visual and
audible collision warning, autonomous braking
can be initiated in critical situations. If you apply
the brake yourself in a critical situation, Adap-
tive Brake Assist of the Active Brake Assist sys-
tem supports you.
Important safety notes In particular, the detection of obstacles can be
impaired if: R
there is dirt on the sensors or anything else
covering the sensors R
there is snow or heavy rain R
there is interference by other radar sources R
there are strong radar reflections, for exam-
ple in parking garages R
a narrow vehicle is traveling in front, e.g. a
motorbike R
a vehicle is traveling in front on a different line R
new vehicles or after servicing is carried out
on the Active Brake Assist system
Observe the notes in the section on breaking-
in ( Y
page 137).
Following damage to the front end of the vehicle,
have the configuration and operation of the
radar sensor checked at a qualified specialist
workshop. This also applies to collisions at slow
speeds where there is no visible damage to the
front of the vehicle.
Activating/deactivating
Active Brake Assist is automatically active after
switching on the ignition.
You can activate or deactivate Active Brake
Assist ( Y
page 237) in the on-board computer.
When deactivated, the distance warning func-64
Driving safety systems
Safety
Active Brake Assist with cross-traffic function
detects pedestrians using typical characteris-
tics such as body contours and the posture of a
person standing upright.
i Observe the restrictions described in the
"Important safety notes" section
( Y
page 70).
Important safety notes
G WARNING
Active Brake Assist with cross-traffic function
will initially brake your vehicle by a partial
application of the brakes if a danger of colli-
sion is detected. There may be a collision
unless you brake yourself. Even after subse-
quent full application of the brakes a collision
cannot always be avoided, particularly when
approaching at too high a speed. There is a
risk of an accident.
Always apply the brakes yourself and try to
take evasive action, provided it is safe to do
so.
In the event of a partial application of the brakes,
the vehicle is braked with up to 50% of the full
braking pressure.
G WARNING
Active Brake Assist with cross-traffic function
cannot always clearly identify objects and
complex traffic situations.
In such cases, Active Brake Assist with cross-
traffic function might: R
issue an unnecessary warning or engage R
neither give a warning nor intervene
There is a risk of an accident.
Always pay particular attention to the traffic
situation and be prepared to brake, especially
if Active Brake Assist with cross-traffic func-
tion alerts you. Terminate the intervention in a
non-critical driving situation.
G WARNING
Active Brake Assist with cross-traffic function
cannot always clearly identify people, partic-
ularly if they are moving. Active Brake Assist with cross-traffic function cannot intervene in
these cases. There is a risk of an accident.
Always pay particular attention to the traffic
situation and be prepared to brake, especially
if Active Brake Assist with cross-traffic func-
tion alerts you.
In order to maintain the appropriate distance to
the vehicle in front and thus prevent a collision,
you must apply the brakes yourself.
G WARNING
Active Brake Assist with cross-traffic function
does not react: R
to small people, e.g. children R
to animals R
to oncoming vehicles R
when cornering
As a result, Active Brake Assist with cross-
traffic function may not warn you or engage in
all critical situations. There is a risk of an acci-
dent.
Always pay careful attention to the traffic sit-
uation and be ready to brake.
In the event of snowfall or heavy rain, the rec-
ognition can be impaired.
Recognition by the radar sensor system is also
impaired if: R
there is dirt on the sensors or anything else
covering the sensors R
there is interference by other radar sources R
there are strong radar reflections, for exam-
ple in parking garages R
a narrow vehicle is traveling in front, e.g. a
motorbike R
a vehicle is traveling in front on a different line
relative to the center of your vehicle R
vehicles quickly move into the radar sensor
system detection range
Recognition by the camera system is also
impaired in the event of: R
dirt on the camera or if the camera is covered R
glare on the camera system, e.g. from the sun
being low in the sky70
Driving safety systems
Safety
In such cases, Distance Pilot DISTRONIC may: R
give an unnecessary warning and then
brake the vehicle R
neither give a warning nor intervene R
accelerate or brake unexpectedly
There is a risk of an accident.
Continue to drive carefully and be ready to
brake, especially if Distance Pilot DISTRONIC
warns you.
G WARNING
Distance Pilot DISTRONIC brakes your vehicle
with up to 50% of the maximum possible
deceleration. If this deceleration is not suffi-
cient, Distance Pilot DISTRONIC alerts you
with a visual and acoustic warning. There is a
risk of an accident.
Apply the brakes yourself in these situations
and try to take evasive action.
! When Distance Pilot DISTRONIC or the
HOLD function is activated, the vehicle
brakes automatically in certain situations.
To avoid damage to the vehicle, deactivate
DISTRONIC PLUS and the HOLD function in
the following or similar situations: R
when towing the vehicle R
in the car wash
If you fail to adapt your driving style, Distance
Pilot DISTRONIC can neither reduce the risk of
an accident nor override the laws of physics.
Distance Pilot DISTRONIC cannot take into
account road, weather or traffic conditions. Dis-
tance Pilot DISTRONIC 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 your lane.
Do not use Distance Pilot DISTRONIC: R
in road and traffic conditions which do not
allow you to maintain a constant speed, e.g. in
heavy traffic or on winding roads R
on slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose
traction and the vehicle could then skid R
when there is poor visibility, e.g. due to fog,
heavy rain or snow Distance Pilot DISTRONIC may not detect nar-
row vehicles driving in front, e.g. motorcycles, or
vehicles driving on a different line.
In particular, the detection of obstacles can be
impaired if: R
there is dirt on the sensors or anything else
covering the sensors R
there is snow or heavy rain R
there is interference by other radar sources R
there are strong radar reflections, for exam-
ple, in parking garages
If Distance Pilot DISTRONIC no longer detects a
vehicle in front, it may unexpectedly accelerate
to the speed stored.
This speed may: R
be too high if you are driving in a filter lane or
an exit lane R
be so high when driving in the right-hand lane
that you overtake vehicles in the left-hand
lane R
be so high when driving in the left-hand lane
that you overtake vehicles in the right-hand
lane
If there is a change of drivers, advise the new
driver of the speed stored.
Cruise control lever
C
Activates or increases speed
D
Activates or reduces speed
Range of the sensors General notes Parking Assist PARKTRONIC does not take into
account obstacles located: R
below the detection range, e.g. people, ani-
mals or objects. R
above the detection range, e.g. overhanging
loads, truck overhangs or loading ramps.
C
Sensors in the front bumper, left-hand side
(example)
The sensors must be free from dirt, ice or slush.
They can otherwise not function correctly. Clean
the sensors regularly, taking care not to scratch
or damage them ( Y
page 328). Range
Front sensors
Center Approx. 40 in (approx.
100 cm)
Corners Approx. 24 in (approx.
60 cm)
Rear sensors
Center Approx. 48 in (approx.
120 cm)
Corners Approx. 32 in (approx.
80 cm)
Minimum distance
Center Approx. 8 in (approx. 20 cm)
Corners Approx. 6 in (approx. 15 cm)
If there is an obstacle within this range, the rel-
evant warning displays light up and a warning
tone sounds. If the distance falls below the min-
imum, the distance may no longer be shown.Driving systems 191
Driving and parking Z