This allows you to continue steering the vehi-
cle when braking.
ABS works from a speed of about 8 km/h
upwards, regardless of road-surface condi-
tions. ABS works on slippery surfaces, even
when you only brake gently. G
WARNING
If ABS is faulty, the wheels could lock when
braking. This limits the steerability of the vehi-
cle when braking and the braking distance
may increase.
If ABS is deactivated due to a malfunction,
then BAS and ESP are also deactivated. There
is an increased risk of your vehicle skidding in
certain situations.
You should always adapt your driving style to
suit the prevailing road and weather condi-
tions.
Braking If ABS intervenes when braking, you will feel
a pulsing in the brake pedal.
X If ABS intervenes: continue to depress the
brake pedal with force until the braking sit-
uation is over.
X To make a full brake application:
depress the brake pedal with full force.
The pulsating brake pedal can be an indica-
tion of hazardous road conditions and func-
tions as a reminder to take extra care while
driving. G
WARNING
Do not depress the brake pedal several times
in quick succession (pumping). Pumping the
brake pedal reduces the braking effect .You
might otherwise not be able to stop the vehi-
cle in time and could cause an accident.
Depress the brake pedal firmly and smoothly. BAS (Brake Assist)
i Observe the "Important safety notes" sec-
tion (Y page 72). BAS operates in emergency braking situa-
tions. If you depress the brake pedal quickly,
BAS automatically boosts the braking force,
thus shortening the stopping distance.
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. G
WARNING
If BAS has malfunctioned, the braking system
remains available with full brake boosting
effect. However, braking force is not auto-
matically increased in emergency braking sit-
uations and the stopping distance may
increase. BAS PLUS (Brake Assist System Plus)
BAS PLUS is only available on vehicles with
DISTRONIC PLUS.
i Observe the "Important safety notes" sec-
tion (Y page 72).
BAS PLUS assists you in braking during haz-
ardous situations at speeds above 30 km/h
and uses the radar sensor system to evaluate
the traffic situation.
With the help of the radar sensor system, BAS
PLUS can detect obstacles that are in the
path of your vehicle for an extended period of
time.
At speeds up to approximately 70 km/h, BAS
PLUS may also detect stationary obstacles,
for example, stopped or parked vehicles.
Should you approach an obstacle and BAS
PLUS has detected a ris kofcollision, BAS
PLUS calculates the braking force necessary
to avoid a rear-end collision. Should you apply
the brakes forcefully, BAS PLUS can auto-
matically increase the braking force to a level
suitable for the traffic conditions.
If BAS PLUS demands particularly high brak-
ing force, preventative passenger protection Driving safety systems
73Safety Z
measures (PRE-SAFE
®
) are activated simul-
taneously.
X Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if:
R you release the brake pedal.
R there is no longer any dange rofarear-end
collision.
R no obstacle is detected in front of your
vehicle.
BAS PLUS is then deactivated.
Vehicles with COMAND and navigation sys-
tem: the rada rsensor system is switched off
automatically in the vicinity of radio telescope
facilities (Y page 389).
Vehicles without COMAND and a navigation
system and vehicles for Australia: the radar
sensor system and on-board computer must
be switched off in the vicinity of radio tele-
scope facilities ( Ypage 242).
For BASP LUS to assist you when driving, the
radars ensor system must be switched on and
operational; see "Rada rsensor system" in the
index. G
WARNING
BAS PLUS cannot always clearly identify
objects and complex traffic situations. BAS
PLUS cannot intervene in these cases.
There is a risk of an accident. Always pay
careful attention to the traffic situation and be
ready to brake.
In particular, the detection of obstacles can
be impaired if there is:
R dirt on the sensors or anything else cover-
ing the sensors
R snow or heavy rain
R interference by other radar sources
R the possibility of strong radar reflections,
for example in multi-storey car parks R
a narrow vehicle travelling in front, e.g. a
motorbike
R a vehicle travelling in front on a different
line G
WARNING
BAS PLUS does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
As a result, BAS PLUS may not intervene in
critical situations. There is a risk of an acci-
dent .Always pay careful attention to the traf-
fic situation and be ready to brake.
Following damage to the front end of the vehi-
cle, have the configuration and operation of
the radar sensors checked at a qualified spe-
cialist workshop. This also applies to colli-
sions at slow speeds where there is no visible
damage to the front of the vehicle.
If BA SPLUS is not available due to a malfunc-
tion in the radars ensor system, the brake
system remains available with full brake
boosting effect and BAS. Adaptive brake lamps
i Adaptive brake lamps are only available in
certain countries.
If you brake sharply from a speed of more
than 50 km/ho rifbraking is assisted by BAS
or BAS PLUS, the brake lamps flash rapidly.
In this way, traffic travelling behind you is
warned in an even more noticeable manner.
If you brake sharply from a speed of more
than 70 km/h to a standstill, the hazard warn-
ing lamps are activated automatically.Ift he
brakes are applied again, the brake lamps
light up continuously.T he hazard warning
lamps switch off automatically if you travel
faster than 10 km/h .You can also switch off
the hazard warning lamps using the hazard
warning switch button (Y page 121).74
Driving safety systemsSafety
lection point for used batter-
ies.
Checking the battery X
Press the &or% button.
The battery is working properly if the bat-
tery check lamp :lights up briefly
If battery check lamp :does not light up
briefly during the test, the battery is dis-
charged.
X Changing the battery (Y page 87)
i If the key battery is checked within the
signal receptio nrange of the vehicle, press-
ing the &or% button locks or
unlocks the vehicle.
Changing the battery You require a CR 2025 3 V cell battery.
X Take the emergency key elemen tout of the
key (Y page 86). X
Press emergency key element ;into the
opening in the key in the direction of the
arrow until battery tray cover :opens.
When doing so, do no thold cover :shut.
X Remove battery tray cover :. X
Repeatedly tap the key against your palm
until battery =falls out.
X Insert the new battery with the positive ter-
minal facing upwards. Use a lint-free cloth
to do so.
X Make sure that the surface of the battery is
free from lint, grease and all other forms of
contamination.
X Insert the front tabs of battery tray
cover :and then press to close it.
X Insert the emergency key element into the
key.
X Check the function of all key buttons on the
vehicle. Key
87Opening and closing Z
Example: top view (Saloon)
Front sensors
Centre approximately 100 cm
Corners approximately 60 cm
Rea
rsensors Centre approximately 120 cm
Corners approximately 80 cm
!
When parking, pay particular attention to
objects above or below the sensors, such
as flower pots or trailer drawbars. PARK-
TRONIC does not detect such objects when
they are in the immediate vicinity of the
vehicle. You could damage th evehicle or
the objects.
The sensors may not detec tsnow and
objects which absorb ultrasoni csources.
Ultrasonic sources, such as an automatic
car wash, a lorry's compressed-air brakes
or a pneumatic drill, could cause PARK-
TRONIC to malfunction.
PARKTRONIC may not function correctly on
uneven terrain.
Minimum distance Centre approximately 20 cm
Corners approximately 15 cm
If there is an obstacle within this range, the
relevant warning displays light up and a warn-
ing tone sounds. If the distance falls below the minimum, the distance may no longer be
shown.
Warning displays The warning displays show the distance
between the sensors and the obstacle. The
warning display for the front area is located
on the dashboard above the centre air vents.
The warning display for the rear area is loca-
ted on the roof lining in the rear compart-
ment.
Warning display for the front area
:
Segments on the left-hand side of the
vehicle
; Segments on the right-hand side of the
vehicle
= Segments showing operational readiness
The warning display for each side of the vehi-
cle is divided into five yellow and two red seg-
ments. PARKTRONIC is operational if yellow
segments showing operational readiness =
light up.
The gear lever position or the transmission
position of the automatic transmission deter-
mines which warning display is active when
the engine is running. Driving systems
197Driving and parking Z
In order that you are warned only when nec-
essary and in good time if you cross the lane
marking, the system recognises certain con-
ditions and warns you accordingly.
The warning vibration occurs earlier if:
R you approach the outer lane marking on a
bend.
R the road has very wide lanes, e.g. a motor-
way.
R the system recognises solid lane markings.
The warning vibration occurs later if:
R the road has narrow lanes.
R you cut the corner on a bend.
No warning vibration occurs if:
R you clearly and actively steer, brake, or
accelerate.
R you cut the corner on a sharp bend.
R a driving safety system intervenes, such as
ABS, BAS or ESP ®
.
R you have switched on the turn signals. In
this event, the warnings are suppressed for
a certain period of time.
Activating Lane Keeping Assist Example: vehicles with automatic transmission
X
Activate Lane Keeping Assist using the on-
board computer (Y page 238).
Symbol :appears in the multifunction
display.
If you drive at speeds above 60 km/h and
lane markings are detected, symbol :is
shown in green. Lane Keeping Assist is
ready for use. Active Driving Assistance package
General notes The Active Driving Assistance package con-
sists of DISTRONIC PLUS (Y
page 183), Active
Blind Spot Assist (Y page 209) and Active
Lane Keeping Assist (Y page 212).
Active Blind Spot Assist Important safety notes
Active Blind Spot Assist uses a radars
ensor
system to monitor the side areas of your vehi-
cle which are in back of the driver. Awarning
display in the exterior mirrors draws your
attentio nto vehicles detected in the moni-
tored area. If you then switch on the corre-
sponding turn signal to change lane, you will
also receive an optical and audible collision
warning. If a risk of lateral collision is detec-
ted, corrective braking may help you avoid a
collision. To support the course-correcting
brake application, Active Blind Spot Assist
also uses the forward-facing radar sensor sys-
tem. Active Blind Spot Assist supports you
from a speed of approximately 30 km/h. G
WARNING
Active Blind Spot Assist is only an aid and may
detect vehicles/obstacles incorrectly or not
at all.
The system may be impaired or may not func-
tion if:
R there is poor visibility, e.g. due to snow,
rain, fog or spray.
R the rear and/or front sensors are dirty.
Active Blind Spot Assist may not detect nar-
row vehicles, such as motorcycles or bicycles,
or only detect them too late. It cannot detect
vehicles which are overtaken at a small dis-
tance and then enter the blind spot area.
Active Blind Spot Assist cannot detect road
and traffic conditions. It is not a substitute for
attentive driving. You are responsible for the
vehicle's speed, braking in good time, and
steering correctly. Always adapt your driving Driving systems
209Driving and parking
Z
may detect the lane markings on the road
incorrectly or not at all.
The system may be impaired or may not func-
tion if:
R
several or no lane markings for a single lane
are present.
R there is poor visibility, e.g. due to insuffi-
cient illumination of the road, or due to
snow, rain, fog or spray.
R there is glare, e.g. from oncoming traffic,
the sun, or reflection from other vehicles.
R the windscreen is dirty, misted up or cov-
ered, for instance by a sticker, in the vicinity
of the camera.
R the lane markings are worn away, dark or
covered up, e.g. by dirt or snow.
R the distance to the vehicle in front is too
small and the lane markings thus cannot be
detected.
R the lane markings on the road are unclear,
e.g. near roadworks.
R the lane markings change quickly, e.g.
lanes branch off, cross one another or
merge.
R the road is narrow and winding.
Active Lane Keeping Assist cannot detect
road and traffic conditions. It is not a substi-
tute for attentive driving. You are responsible
for the vehicle's speed, braking in good time,
and steering correctly. Always adapt your
driving style to suitt he prevailing road and
weather conditions.A lways pay attention to
traffic conditions and your surroundings. Oth-
erwise, you may fail to recognise dangers in
time, cause an accident and injure yourself
and others.
Warning vibration in the steering wheel
A warning may be given if a front wheel
passes over a lane marking. You will the nbe
warned by means of an intermittent vibration
in the steering wheel for up to 1. 5seconds.
In order that you are warned only when nec-
essary and in good time if you cross the lane marking, the system recognises certain con-
ditions and warns you accordingly.
The warning vibration occurs earlier if:
R
you approach the outer lane marking on a
bend.
R the road has very wide lanes, e.g. a motor-
way.
R the system recognises solid lane markings.
The warning vibration occurs later if:
R the road has narrow lanes.
R you cut the corner on a bend.
No warning vibration occurs if:
R you clearly and actively steer, brake, or
accelerate.
R you cut the corner on a sharp bend.
R a driving safety system intervenes, such as
ABS, BAS or ESP ®
.
R you have switched on the turn signals. In
this event, the warnings are suppressed for
a certain period of time.
Lane-correcting brake application
If you leave your lane under certain circum-
stances, the vehicle will brake briefly on one
side. This is designed to help you bring the
vehicle back into the original lane.
This function is available in the range between
60 km/h and 200 km/h.
A lane-correcting brake application can only
be made after driving over a solid, recognis-
able lane marking. Befor ethis, a warning
must be emitted by means of intermittent
vibration in the steering wheel. In addition, a
lane with lane markings on both sides must
be recognised. The brake application also
slightly reduces driving speed.
If a lane-correcting brake application occurs,
the following appears in the multifunction dis-
play: Driving systems
213Driving and parking Z
Safety systems (4-button multifunction steering wheel)
Display messages Possible causes/consequences and
M Solutions
ABS
curr. unavail. G
Risk of accident
ABS (Anti-lock Braking System), ESP ®
(Electronic Stability Pro-
gram), BAS (Brake Assist), PRE-SAFE ®
, the HOLD function, hill
start assist and ESP ®
trailer stabilisation are temporarily not avail-
able.
The adaptive brake lights may also have failed.
In addition, the ÷,åand! warning lamps light up in
the instrument cluster.
The self-diagnosis function might not be complete, for example.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
X Carefully drive on a suitable stretch of road, making slight steer-
ing movements, at a speed above 20 km/h.
If the display message disappears, the functions mentioned
above are available again.
If the display message continues to be displayed:
X Drive on carefully.
X Visit a qualified specialist workshop. G
Risk of accident
ABS, ESP ®
, BAS, PRE-SAFE ®
, the HOLD function, hill start assist
and ESP ®
trailer stabilisation are temporarily not available.
The adaptive brake lights may also have failed.
In addition, the ÷,åand! warning lamps light up in
the instrument cluster.
For example, the on-board voltage may be insufficient.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
X Drive on carefully.
If the display message disappears, the functions mentioned
above are available again.
If the display message continues to be displayed:
X Drive on carefully.
X Visit a qualified specialist workshop. 250
Display messagesOn-board computer and displays
Display messages Possible causes/consequences and
M Solutions
ABS
inoperative G
Risk of accident
ABS, ESP ®
, BAS, PRE-SAFE ®
, the HOLD function, hill start assist
and ESP ®
trailer stabilisation are no tavailable due to a malfunc-
tion.
The adaptive brake lights may also have failed.
In addition, the ÷,å,!andJ warning lamps light
up in the instrument cluster.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
X Drive on carefully.
X Visi taqualified specialist workshop. EBD and ABS
inoperative G
Risk of accident
EBD (electronic brake force distribution), ABS, ESP ®
, BAS,
PRE-SAFE ®
, hill start assist and ESP ®
trailer stabilisation are not
available due to a malfunction.
The adaptive brake lights may also have failed.
In addition, the ÷,åand! warning lamps light up in
the instrument cluster and a warning tone sounds.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
X Drive on carefully.
X Visit a qualified specialist workshop immediately. J
Release parking
brake You are driving with the parking brake applied.
Awarning tone also
sounds.
X Release the parking brake. Display messages
251On-board computer and displays Z