2013 MERCEDES-BENZ CLA-CLASS ABS

the braking force to a level suitable for the
traffic conditions.XKeep 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 danger of a collision
R no obstacle is detected in front of your
vehicle
Adaptive Brake Assist is then deactivated.
Vehicles with PRE-SAFE ®
: if adaptive Brake
Assist requires particularly high brake pres-
sure, preventive passenger protection meas-
ures (PRE-SAFE ®
) are deployed simultane-
ously.
Up to vehicle speeds of around 250 km/h,
adaptive Brake Assist is capable of reacting
to moving objects that have already been rec-
ognised as such at least once over the period
of observation. Adaptive Brake Assist does
not react to stationary obstacles.
If adaptive Brake Assist is not available due
to a malfunction in the radar sensor system,
the brake system remains available with full
brake boosting effect and BAS.
In particular, the detection of obstacles can
be impaired if there is:
R dirt on the sensors or the sensors are
obscured
R snow or heavy rain
R interference by other radar sources
R strong radar reflections, for example, in
multi-storey car parks
R a narrow vehicle travelling in front, e.g. a
motorcycle
R a vehicle travelling in front on a different
line
Following damage to the front end of the vehi-
cle, have the configuration and operation of
the radar sensor 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.
COLLISION PREVENTION ASSIST PLUS
General notes
COLLISION PREVENTION ASSIST PLUS is
only available on vehicles with DISTRONIC.
COLLISION PREVENTION ASSIST PLUS
extends the functionality of COLLISION PRE-
VENTION ASSIST with an automatic braking
function. COLLISION PREVENTION ASSIST
PLUS can help you to minimise the risk of a
front-end collision with a vehicle ahead or
reduce the effects of such a collision. If COL-
LISION PREVENTION ASSIST PLUS detects
that there is a risk of a collision, you will be
warned visually and acoustically. In critical
situations COLLISION PREVENTION ASSIST
PLUS also initiates automatic braking.
Function
XTo activate/deactivate: activate or deac-
tivate COLLISION PREVENTION ASSIST
PLUS in the on-board computer
( Y page 218).
If COLLISION PREVENTION ASSIST PLUS is
deactivated, the æ symbol appears in the
assistance graphics display.
If the driver's seat belt is fastened, COLLI-
SION PREVENTION ASSIST PLUS can brake
automatically within a speed range of
between 7 km/h and 200 km/h.
COLLISION PREVENTION ASSIST PLUS can
also react to stationary obstacles with auto-
matic braking within a speed range of
between 7 km/h and 30 km/h.
Vehicles with PRE-SAFE ®
: if the automatic
braking function of COLLISION PREVENTION
ASSIST PLUS intervenes powerfully, preven-
tive passenger protection measures (PRE-
SAFE ®
) are deployed simultaneously.
In particular, the detection of obstacles can
be impaired in the case of:
R dirt on the sensors or the sensors are
obscured
R snow or heavy rain
R interference by other radar sources
Driving safety systems67SafetyZProCarManuals.com

Replacing the battery
You require a CR 2025 3 V cell battery.
XTake the emergency key element out of the
key ( Y page 77).XPress emergency key element ; into the
opening in the key in the direction of the
arrow until battery tray cover : opens.
When doing so, do not hold cover : shut.XRemove battery tray cover :.XRepeatedly tap the key against your palm
until battery = falls out.XInsert the new battery with the positive ter-
minal facing upwards. Use a lint-free cloth
to do so.XMake sure that the surface of the battery is
free from lint, grease and all other forms of
contamination.XInsert the front tabs of battery tray
cover : and then press to close it.XInsert the emergency key element into the
key.XCheck the function of all key buttons on the
vehicle.Key79Opening and closingZProCarManuals.com

PARKTRONIC is only an aid. It is not a substi-
tute for your attention to the immediate sur-
roundings. The responsibility for safe
manoeuvring and parking remains with you.
Make sure that there are no persons, animals
or objects in range while manoeuvring and
parking.
! 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 the vehicle or
the objects.
The sensors may not detect snow and
objects which absorb ultrasonic sources.
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.
PARKTRONIC is activated automatically if
you:
R switch on the ignition
R shift to position D, R or N on vehicles with
automatic transmission
R release the electric parking brake
PARKTRONIC is deactivated at speeds above
18 km/h. It is reactivated at lower speeds.
Range of the sensors
General notes
PARKTRONIC does not take into account
obstacles located:
R below the detection range, e.g. persons,
animals or objects
R above the detection range, e.g. overhang-
ing loads, tail sections or loading ramps of
goods vehicles
:Example: sensors in the front bumper,
left-hand side
Side view
Top view
The sensors must be free of dirt, ice and
slush. Otherwise, they may not function cor-
rectly. Clean the sensors regularly, taking
care not to scratch or damage them
( Y page 291).
Front sensors
CentreApprox. 100 cmCornersApprox. 60 cmDriving systems183Driving and parkingZProCarManuals.com

When Standard is selected, no warning vibra-
tion occurs if:
R you have switched on the turn signals. In
this event, the warnings are suppressed for
a certain period of time.
R a driving safety system intervenes, such as
ABS, BAS or ESP ®
.
When Adaptive is selected, no warning vibra-
tion occurs if:
R you have switched on the turn signals. In
this case, the warnings are suppressed for
a certain period of time.
R a driving safety system intervenes, such as
ABS, BAS or ESP ®
.
R you accelerate hard, e.g. kickdown.
R you brake hard.
R you steer actively, e.g. swerve to avoid an
obstacle or change lane quickly.
R you cut the corner on a sharp bend.
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.
Towing a trailer
Notes on towing a trailer
Important safety notes
GWARNING
The braking system can overheat if you leave
your foot on the brake pedal while driving.
This increases the braking distance and could
even cause the braking system to fail. There
is a risk of an accident.
Never use the brake pedal as a footrest. Do
not simultaneously depress both the brake
pedal and the accelerator pedal while driving.GWARNING
You could lose control of the vehicle/trailer
combination if it begins to swerve. The vehi-
cle/trailer combination could even overturn.
There is a risk of an accident.
On no account should you attempt to
straighten out the vehicle/trailer combina-
tion by increasing speed. Decrease your
speed and do not countersteer. Brake if nec-
essary.
GWARNING
If you exceed the permissible noseweight
while carrying a load, the carrier system could
detach from the vehicle and fall on the road.
There is a risk of an accident and injury.
Always maintain the permissible noseweight
when carrying loads.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If you exceed the maximum permissible nose-
weight of the trailer drawbar on the ball cou-
pling, the following may become damaged:
R your vehicle
R the trailer
R the ball coupling
R trailer tow hitch
The vehicle/trailer combination could
become unstable.
If the noseweight used is lower than the min-
imum permissible noseweight, the vehicle/
trailer combination could also become unsta-
ble.
Towing a trailer201Driving and parkingZProCarManuals.com

Safety systemsDisplay messagesPossible causes/consequences and M Solutions!÷
currently unavail‐
able See Owner's
ManualABS (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 unavail-
able.
The adaptive brake lights and COLLISION PREVENTION ASSIST/
COLLISION PREVENTION ASSIST PLUS may also have failed.
In addition, the ÷, å and ! warning lamps light up in
the instrument cluster.
ATTENTION ASSIST is deactivated.
Possible causes:
R self-diagnosis is not yet complete.
R the on-board voltage may be insufficient.GWARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
The steerability and braking characteristics may be severely affec-
ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
XCarefully 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:
XDrive on carefully.XVisit a qualified specialist workshop.!÷
inoperative See
Owner's ManualABS, ESP ®
, BAS, PRE-SAFE ®
, the HOLD function, hill start assist
and ESP ®
trailer stabilisation are unavailable due to a malfunction.
The adaptive brake lights and COLLISION PREVENTION ASSIST/
COLLISION PREVENTION ASSIST PLUS may also have failed.
In addition, the J, ÷ , å and ! warning lamps light
up in the instrument cluster.
ATTENTION ASSIST is deactivated.GWARNINGDisplay messages227On-board computer and displaysZProCarManuals.com

Display messagesPossible causes/consequences and M Solutions÷
inoperative See
Owner's ManualESP ®
, BAS, PRE-SAFE ®
, the HOLD function, hill start assist and
ESP ®
trailer stabilisation are not available due to a malfunction.
The adaptive brake lights and COLLISION PREVENTION ASSIST/
COLLISION PREVENTION ASSIST PLUS may also have failed.
In addition, the ÷ and å warning lamps light up in the
instrument cluster.
ATTENTION ASSIST is deactivated.GWARNING
The brake system continues to function normally, but without the
functions listed above.
The braking distance may thus increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
XDrive on carefully.XVisit a qualified specialist workshop.T !
÷
inoperative See
Owner's ManualEBD (electronic brake force distribution), ABS, ESP ®
, BAS, PRE-
SAFE ®
, the HOLD function, hill start assist and ESP ®
trailer stabi-
lisation are unavailable due to a malfunction.
The adaptive brake lights and COLLISION PREVENTION ASSIST/
COLLISION PREVENTION ASSIST PLUS may also have failed.
In addition, the ÷, å and ! warning lamps light up in
the instrument cluster and a warning tone sounds.
ATTENTION ASSIST is deactivated.GWARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock, for example, if you brake hard.
The steerability and braking characteristics may be severely affec-
ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
XDrive on carefully.XVisit a qualified specialist workshop immediately.Display messages229On-board computer and displaysZProCarManuals.com

Safety systemsProblemPossible causes/consequences and M SolutionsJ
The red brake system
warning lamp is lit while
the engine is running. A
warning tone also
sounds.There is insufficient brake fluid in the brake fluid reservoir.GWARNING
The braking efficiency may be impaired.
There is a risk of an accident.
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.XSecure the vehicle against rolling away ( Y page 162).XDo not top up the brake fluid. Topping up will not rectify the
fault.XConsult a qualified specialist workshop.XObserve the additional display messages in the multifunction
display.!
The yellow ABS warning
lamp is lit while the
engine is running.ABS (Anti-lock Brake System) has been deactivated due to a fault.
Therefore, BAS (Brake Assist), COLLISION PREVENTION ASSIST,
COLLISION PREVENTION ASSIST PLUS, ESP ®
(Electronic Stability
Program), PRE-SAFE ®
, the HOLD function, hill start assist, the
adaptive brake lights and ESP ®
trailer stabilisation, for example,
are also deactivated.
ATTENTION ASSIST is deactivated.GWARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
The steerability and braking characteristics may be severely affec-
ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
XObserve the additional display messages in the multifunction
display.XDrive on carefully.XVisit a qualified specialist workshop.
If the ABS control unit is faulty, there is also a possibility that other
systems, such as the navigation system or the automatic trans-
mission, will be unavailable.
256Warning and indicator lamps in the instrument clusterOn-board computer and displays
ProCarManuals.com

ProblemPossible causes/consequences and M Solutions!
The yellow ABS warning
lamp is lit while the
engine is running.ABS is temporarily unavailable. Therefore, BAS, COLLISION PRE-
VENTION ASSIST, COLLISION PREVENTION ASSIST PLUS, ESP ®
,
EBD (electronic brake force distribution), PRE-SAFE ®
, the HOLD
function, hill start assist, the adaptive brake lights and ESP ®
trailer
stabilisation, for example, are also deactivated.
Possible causes:
R self-diagnosis is not yet complete.
R the on-board voltage may be insufficient.
ATTENTION ASSIST is deactivated.GWARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock, for example, if you brake hard.
The steerability and braking characteristics may be severely affec-
ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is a risk of an accident.
XCarefully drive on a suitable stretch of road, making slight steer-
ing movements at a speed above 20 km/h.
The functions mentioned above are available again when the
warning lamp goes out.
If the warning lamp is still on:
XObserve the additional display messages in the multifunction
display.XDrive on carefully.XVisit a qualified specialist workshop.Warning and indicator lamps in the instrument cluster257On-board computer and displaysZProCarManuals.com