2013 MERCEDES-BENZ CLA brake sensor

Useful information
i This Owner's Manual describes all mod-
els, series and optional equipment for your
vehicle that were available at the time of
going to press. National variations are pos-
sible. Note that your vehicle may not be
equipped with all of the functions descri-
bed. This is also the case for systems and
functions relevant to safety.
i Read the information on qualified special-
ist workshops: ( Y page 24).
Key
Important safety notes
GWARNING
If children are left unsupervised in the vehicle,
they could:
R open the doors, thus endangering other
people or road users.
R get out and disrupt traffic.
R operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
R release the parking brake.
R shift the automatic transmission out of
parking position P.
R shift the manual transmission into neutral.
R start the engine.
There is a risk of an accident and injury.
When leaving the vehicle, always take the key
with you and lock the vehicle. Never leave
children or animals unattended in the vehicle.
Always keep the key out of reach of children.
GWARNING
If persons (particularly children) are exposed
to heat or cold for a prolonged period, there
is a risk of serious or even fatal injuries. Never
leave persons (particularly children) unatten-
ded in the vehicle.
GWARNING
If you attach heavy or large objects to the key,
the key could be unintentionally turned in the
ignition lock. This could cause the engine to
be switched off. There is a risk of an accident.
Do not attach any heavy or large objects to
the key. Remove any bulky keyrings before
inserting the key into the ignition lock.
! Keep the key away from strong magnetic
fields. Otherwise, the remote control func-
tion could be affected.
Strong magnetic fields can occur in the
vicinity of powerful electrical installations.
Do not keep the key:
R with electronic devices, e.g. a mobile
phone or another key
R with metallic objects, e.g. coins or metal
film
R inside metallic objects, e.g. a metal case
United Kingdom only:
GWARNING
When the double locks are activated, the
doors can no longer be opened from the
inside. People in the vehicle can no longer get
out, e.g. in hazardous situations. There is a
risk of injury.
Therefore, do not leave any people unsuper-
vised in the vehicle, particularly children, eld-
erly people or people in need of special assis-
tance. Do not activate the double lock when
people are in the vehicle.
If the vehicle has been locked with the key,
then the double lock function is activated as
standard. It is then not possible to open the
doors from inside the vehicle. You can deac-
tivate the double lock function by deactivat-
ing the interior motion sensor ( Y page 72).
The doors can then be opened from the inside
after the vehicle has been locked from the
outside. You can open the rear doors from
inside the vehicle if they are not secured by
the child-proof locks ( Y page 63). The anti-
theft alarm system is triggered if the door is
76KeyOpening and closing

Rdrive slower than the stored speed without
kickdown
R set a new speed or
R call up the last speed stored again
The SPEEDTRONIC passive message in the
multifunction display disappears.
Permanent SPEEDTRONIC
You can use the on-board computer to limit
the speed permanently to a value between
160 km/h (e.g. for driving on winter tyres) and
the maximum speed ( Y page 223).
Shortly before the stored speed is reached, it
appears in the multifunction display.
Permanent SPEEDTRONIC remains active,
even if variable SPEEDTRONIC is deactivated.
You cannot exceed the stored limit speed,
even if you depress the accelerator pedal
beyond the pressure point (kickdown).
DISTRONIC PLUS
General notes
DISTRONIC PLUS regulates the speed and
automatically helps you maintain the dis-
tance to the vehicle detected in front. Vehi-
cles are detected with the aid of the radar
sensor system. DISTRONIC PLUS brakes
automatically so that the set speed is not
exceeded.
Change into a lower gear in good time on long
and steep downhill gradients. Take particular
note of this when driving a laden vehicle. By
doing so, you will make use of the braking
effect of the engine. This relieves the load on
the brake system and prevents the brakes
from overheating and wearing too quickly.
If DISTRONIC PLUS detects that there is a risk
of a collision, you will be warned visually and
acoustically. Without your intervention, DIS-
TRONIC PLUS cannot prevent a collision. An
intermittent warning tone will then sound and
the distance warning lamp will light up in the
instrument cluster. Brake immediately to
increase the distance to the vehicle driving in
front, or take evasive action, provided it is
safe to do so.
DISTRONIC PLUS operates in the range
between 0 km/h and 200 km/h.
Do not use DISTRONIC PLUS while driving on
roads with steep gradients.
Important safety notesGWARNING
DISTRONIC PLUS does not react to:
R people or animals
R stationary obstacles on the road, e.g. stop-
ped or parked vehicles
R oncoming and crossing traffic
As a result, DISTRONIC PLUS may neither give
warnings nor intervene in such situations.
There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake.
GWARNING
DISTRONIC PLUS cannot always clearly iden-
tify other road users and complex traffic sit-
uations.
In such cases, DISTRONIC PLUS may:
R give an unnecessary warning and then
brake the vehicle
R neither give a warning nor intervene
R accelerate unexpectedly
There is a risk of an accident.
Continue to drive carefully and be ready to
brake, in particular when warned to do so by
DISTRONIC PLUS.
GWARNING
DISTRONIC PLUS brakes your vehicle with up
to 50% of the maximum possible deceleration.
If this deceleration is not sufficient, DIS-
TRONIC PLUS alerts you with a visual and
acoustic warning. There is a risk of an acci-
dent.
Driving systems173Driving and parkingZ

Apply the brakes yourself in these situations
and try to take evasive action.
! If DISTRONIC PLUS or the HOLD function
is activated, the vehicle brakes automati-
cally in certain situations. To prevent dam-
age to the vehicle, deactivate DISTRONIC
PLUS and the HOLD function in the follow-
ing or other similar situations:
R when towing the vehicle
R in the car wash
If you fail to adapt your driving style, DIS-
TRONIC PLUS can neither reduce the risk of
an accident nor override the laws of physics.
DISTRONIC PLUS cannot take road and
weather conditions or traffic conditions into
account. DISTRONIC PLUS 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 the lane.
Do not use DISTRONIC PLUS:
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 smooth or slippery roads. Braking or
accelerating can 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.
DISTRONIC PLUS may not detect narrow
vehicles driving in front, e.g. motorcycles, or
vehicles driving on a different line.
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
R the possibility of strong radar reflections,
for example, in multi-storey car parks
If DISTRONIC PLUS no longer detects a vehi-
cle in front, it may unexpectedly accelerate to
the speed stored.This speed can:
R be too high for a filter lane or a slip road
R be so high in the right lane that you pass
vehicles driving on the left
R be so high in the left lane that you pass
vehicles driving on the right
If there is a change of drivers, advise the new
driver of the speed stored
Cruise control lever
With the cruise control lever, you can operate
DISTRONIC PLUS and variable SPEED-
TRONIC.
The LIM indicator lamp on the cruise control
lever indicates which system you have selec-
ted:
R LIM indicator lamp off: DISTRONIC PLUS
is selected.
R LIM indicator lamp on: variable SPEED-
TRONIC is selected.
:To store the current speed or a higher
speed;To set the specified minimum distance=LIM indicator lamp?To store the current speed and calling up
the last stored speedATo store the current speed or a lower
speedBTo switch between DISTRONIC PLUS and
variable SPEEDTRONICCTo deactivate DISTRONIC PLUS174Driving systemsDriving and parking

Activating the HOLD functionXMake sure that the activation conditions
are met.XDepress the brake pedal.XQuickly depress the brake pedal further
until : appears in the multifunction dis-
play.
The HOLD function is activated. You can
release the brake pedal.
i If depressing the brake pedal the first
time does not activate the HOLD function,
wait briefly and then try again.
Deactivating the HOLD function
The HOLD function is deactivated automati-
cally if:
R you accelerate. On vehicles with automatic
transmission: only when the transmission
is in position D or R.
R the transmission is in position P on vehicles
with automatic transmission.
R you depress the brake pedal again with a
certain amount of pressure until : disap-
pears from the multifunction display.
R you secure the vehicle using the electric
parking brake.
R you activate DISTRONIC PLUS.
i After a time, the electric parking brake
secures the vehicle and relieves the service
brake.
The electric parking brake secures the vehicle
automatically if the HOLD function is activa-
ted and:
R the driver's door is open and the driver's
seat belt is unfastened
R the engine is switched off, unless it is auto-
matically switched off by the ECO start/
stop function
R a system fault occurs
R the power supply is not sufficient
Vehicles with automatic transmission
If a fault occurs, then the transmission may
be shifted into position P automatically.
Vehicles with manual transmission
The Brake immediately message can also
appear in the multifunction display.XImmediately depress the brake pedal firmly
until the warning message in the multifunc-
tion display goes out.
The HOLD function is deactivated.
A horn will sound at regular intervals if you
turn off the engine, take off your seat belt or
open the driver's door when the HOLD func-
tion is activated. The horn alerts you to the
fact that the HOLD function is still activated.
If you attempt to lock the vehicle, the tone
becomes louder. The vehicle cannot be
locked until you have deactivated the HOLD
function.
i Once you have switched off the engine,
you cannot restart it until you have deacti-
vated the HOLD function.
PARKTRONIC
Important safety notes
PARKTRONIC is an electronic parking aid with
ultrasonic sensors. It monitors the area
around your vehicle using six sensors in the
front bumper and six sensors in the rear
bumper. PARKTRONIC indicates visually and
audibly the distance between your vehicle
and an object.
182Driving systemsDriving and parking

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 parkingZ

Display messagesPossible causes/consequences and M SolutionsJ
Check brake fluid
levelThere is insufficient brake fluid in the brake fluid reservoir.
In addition, the red J warning lamp lights up in the instrument
cluster and a warning tone sounds.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).XConsult a qualified specialist workshop.XDo not top up the brake fluid. This does not correct the fault.#
Check brake pad
wearThe brake pads/linings have reached their wear limit.XVisit a qualified specialist workshop.PRE-SAFE
inoperative See
Owner's ManualImportant functions of PRE-SAFE ®
have failed. All other occupant
safety systems, e.g. airbags, remain available.XVisit a qualified specialist workshop immediately.Collision Preven‐
tion Assist Plus
currently unavail‐
able See Owner's
ManualCOLLISION PREVENTION ASSIST PLUS is temporarily inoperative.
Possible causes:
R the radar sensor cover in the radiator trim is dirty.
R the function is impaired due to heavy rain or snow.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
Once the causes listed above no longer apply, the display message
goes out.
COLLISION PREVENTION ASSIST PLUS is operational again.
If the display message does not disappear:XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XSecure the vehicle against rolling away ( Y page 162).XClean the radar sensor cover in the radiator grille
( Y page 291).XRestart the engine.Display messages233On-board computer and displaysZ

Display messagesPossible causes/consequences and M SolutionsCollision Preven‐
tion Assist Plus
inoperativeCOLLISION PREVENTION ASSIST PLUS is malfunctioning. The dis-
tance warning signal may also have failed.XVisit a qualified specialist workshop.PRE-SAFE
Function currently
limited See Own‐
er's ManualAdaptive Brake Assist is temporarily inoperative. Possible causes:
R the front bumper is dirty.
R the function is impaired due to heavy rain or snow.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
Once the causes listed above no longer apply, the display message
goes out.
Adaptive Brake Assist is operational again.
If the display message does not disappear:XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XSecure the vehicle against rolling away ( Y page 162).XClean the front bumper ( Y page 291).XRestart the engine.PRE-SAFE
Function limited
See Owner's ManualAdaptive Brake Assist is faulty. The distance warning signal may
also have failed.XVisit a qualified specialist workshop.üIf the symbol appears in the multifunction display, a seat belt
tongue has been inserted into a rear seat belt buckle.
Further information on the status indicator for the rear seat belts
( Y page 49).234Display messagesOn-board computer and displays

Display messagesPossible causes/consequences and M SolutionsSpeed Limit Assist
currently unavail‐
able See Owner's
ManualSpeed Limit Assist is deactivated and temporarily inoperative.
Possible causes:
R the windscreen is dirty in the camera's field of vision.
R visibility is impaired due to heavy rain, snow or fog.XClean the windscreen.
If the system detects that the camera is fully operational, the dis-
play message disappears.
Speed Limit Assist is operational again.
Speed Limit Assist:
Unavailable in
this countrySpeed Limit Assist is only available in certain countries.XDrive on.
Speed Limit Assist is available again as soon as you drive into a
country in which its use is approved.Speed Limit Assist
inoperativeSpeed Limit Assist is faulty.XVisit a qualified specialist workshop.ë
OffThe HOLD function is deactivated. The vehicle is skidding.
A warning tone also sounds.XReactivate the HOLD function later ( Y page 181).The HOLD function is deactivated. When the brake pedal is firmly
depressed, an activation condition is not fulfilled.
A warning tone also sounds.XCheck the activation conditions for the HOLD function
( Y page 181).Radar sensor deac‐
tivated See Own‐
er's ManualThe radar sensor system is deactivated.XSwitch on the radar sensor system ( Y page 223).Display messages243On-board computer and displaysZ