2014 MERCEDES-BENZ C-CLASS SALOON brake sensor

override the laws of physics. 4MATIC cannot
take account of road, weather and traffic con-
ditions. 4MATIC 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.
If a drive wheel spins due to insufficient grip:
R when pulling away, only depress the accel-
erator pedal as far as is necessary
R accelerate less when driving
! Never tow the vehicle with one axle
raised. This may damage the transfer case. Damage of this sort is not covered by the
Mercedes-Benz implied warranty. All
wheels must remain either on the ground or
be fully raised. Observe the instructions for towing the vehicle with all wheels in full
contact with the ground.
i In wintry driving conditions, the maximum
effect of 4MATIC can only be achieved if
you use winter tyres (M+S tyres), with snow
chains if necessary. 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.
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.
PARKTRONIC 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
PARKTRONIC to malfunction.
PARKTRONIC may not function correctly on uneven terrain.
! Fold in the ball coupling if the trailer tow
hitch is not required. PARKTRONIC meas-
ures the minimum detection range to an
obstacle from the bumper, not the ball cou-
pling.
PARKTRONIC is activated automatically if
you: R switch on the ignition
R shift the transmission to position D,Ror N
PARKTRONIC is deactivated at speeds above
18 km/h. It is reactivated at lower speeds.
PARKTRONIC is deactivated for the rear area when you establish an electrical connection
between your vehicle and a trailer.
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 236
Driving systemsDriving and parking

Problems with PARKTRONIC
Problem
Possible causes/consequences and
M
MSolutions Only the red segments
in the PARKTRONIC
warning displays are lit.
You also hear a warning
tone for approximately
two seconds.
PARKTRONIC is then
deactivated and the
indicator lamp on the
PARKTRONIC button
lights up. PARKTRONIC has malfunctioned and has been deactivated.
X If problems persist, have PARKTRONIC checked at a qualified
specialist workshop. Only the red segments
in the PARKTRONIC
warning displays are lit.
PARKTRONIC is then
deactivated. The PARKTRONIC sensors are dirty or there is interference.
X Clean the PARKTRONIC sensors (Y page 401).
X Switch the ignition back on. The problem may be caused by an external source of radio or
ultrasound waves.
X See if PARKTRONIC functions in a different location. Active Parking Assist
General notes Active Parking Assist is an electronic parking
aid with ultrasound. It measures the road on
both sides of the vehicle. A parking symbol
indicates a suitable parking space. Active
steering intervention and brake application
can assist you during parking and when exit-
ing a parking space. You may also use
PARKTRONIC (Y page 236).
Important safety notes Active Parking Assist is only an aid. It is not a
substitute for your attention to the immediate
surroundings. The responsibility for safe
manoeuvring and parking remains with you.
Make sure that no persons, animals or
objects are in the manoeuvring range.
When PARKTRONIC is switched off, Active
Parking Assist is also unavailable. For vehicles with the trailer tow hitch folded
out, the minimum length for parking spaces is
slightly longer.
If you have attached a trailer to your vehicle,
you should not use Active Parking Assist.
Once the electrical connection is established
between your vehicle and the trailer, Active
Parking Assist is no longer available.
PARKTRONIC is deactivated for the rear area. G
WARNING
While parking or pulling out of a parking
space, the vehicle swings out and can drive
onto areas of the oncoming lane. This could
cause you to collide with other road users.
There is a risk of an accident.
Pay attention to other road users. Stop the
vehicle if necessary or cancel the Active Park- ing Assist parking procedure.
! If unavoidable, you should drive over
obstacles such as kerbs slowly and not at a Driving systems
239Driving and parking Z

Adaptive
When
Adaptive 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. Driving Assistance PLUS package
General notes The Active Driving Assistance PLUS package
consists of DISTRONIC PLUS (Y
page 222),
Active Blind Spot Assist (Y page 263) and
Active Lane Keeping Assist (Y page 266).
Active Blind Spot Assist General notes
Active Blind Spot Assist monitors the areas
on either side of the vehicle that are not visi-
ble to the driver with two lateral, rear-facing
radar sensors. A warning display in the exte-
rior mirrors draws your attention to vehicles detected in the monitored area. If you then
switch on the corresponding turn signal to
change lanes, you will also receive a visual
and audible collision warning. If a risk of side
impact is detected, corrective braking may
help you avoid a collision. Active Blind Spot
Assist evaluates the free space in the direc-
tion of travel and to the side before making a course-correcting brake application. For this,Active Blind Spot Assist uses the forward-
facing radar sensors.
Active Blind Spot Assist supports you from a
speed of approximately 30 km/h.
Important safety notes
Active Blind Spot Assist is only an aid and is
not a substitute for attentive driving. G
WARNING
Active Blind Spot Assist does not react to
vehicles:
R overtaking too closely on the side, placing
them in the blind spot area
R if the difference in the speed of approach
and overtaking is too great
As a result, Active Blind Spot Assist may nei-
ther give warnings nor intervene in such sit-
uations. There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and maintain a safe distance at the side of the vehicle.
Radar sensors
The Active Blind Spot Assist radar sensors are
integrated into the front and rear bumpers
and behind a cover in the radiator grille. Make sure that the bumpers and the cover in the
radiator grille are free of dirt, ice or slush. The
rear sensors must not be covered, e.g. by
bicycle racks or overhanging loads. Following
a severe impact or in the event of damage to the bumpers, have the function of the radar
sensors checked at a qualified specialist
workshop. Active Blind Spot Assist may oth-
erwise no longer function properly. Driving systems
263Driving and parking Z

Activating Active Blind Spot Assist
X Make sure that Active Blind Spot Assist is
activated in the on-board computer
(Y page 309).
X Turn the key to position 2in the ignition
lock.
Warning lamps :in the exterior mirrors
light up red for approximately 1.5 seconds. Grey radar waves propagating backwards
appear next to the vehicle in the assistance
display in the multifunction display.
Towing a trailer
If you couple up a trailer, make sure that you have correctly established the electrical con-
nection. This can be accomplished by check- ing the trailer lighting. Active Blind Spot Assist
is then deactivated. The radar waves next to
the vehicle are hidden in the assistance dis-
play. The Active
Active Blind BlindSpot
SpotAssist
Assist not
not
available
available when
whentowing
towing a
atrailer
trailer See
See
Owner's Manual
Owner's Manual message appears in the
multifunction display.
Active Lane Keeping Assist General notes
Active Lane Keeping Assist monitors the area
in front of your vehicle by means of camera
system :at the top of the windscreen. Var-
ious areas to the front, rear and side of your
vehicle are also monitored with the aid of the
radar sensor system. Active Lane Keeping
Assist detects lane markings on the road and
can warn you before you leave your lane unin-
tentionally. If you do not react to the warning, a lane-correcting application of the brakes
can bring the vehicle back into the original
lane.
If you select km
km in the Display unit Display unit
Speed-/odometer:
Speed-/odometer: function on the on-board
computer (Y page 312), Active Lane Keeping
Assist is activated starting at a speed of
60 km/h. If the miles milesdisplay unit is selected,
the assistance range begins at 40 mph.
Important safety notes
If you fail to adapt your driving style, Active
Lane Keeping Assist can neither reduce the
risk of an accident nor override the laws of
physics. Active Lane Keeping Assist cannot
take account of road and weather conditions. It may not recognise traffic situations. Active Lane Keeping Assist 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 lane.
Active Lane Keeping Assist cannot continu-
ously keep your vehicle in its lane. G
WARNING
Active Lane Keeping Assist cannot always
clearly detect lane markings.
In such cases, Active Lane Keeping Assist
can:
R give an unnecessary warning and then
make a course-correcting brake application
to the vehicle
R neither give a warning nor intervene
There is a risk of an accident.
Always pay particular attention to the traffic
situation and keep within the lane, especially
if Active Lane Keeping Assist alerts you. Ter-
minate the intervention in a non-critical driv-
ing situation. 266
Driving systemsDriving and pa
rking

The system may be impaired or may not func-
tion if:
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
(e.g. if the road surface is wet)
R the windscreen is dirty, misted up, dam-
aged or covered, for instance by a sticker,
in the vicinity of the camera
R if the radar sensors in the front or rear
bumpers or the radiator grille are dirty, e.g. obscured by snow
R no, or several, unclear lane markings are
present for one lane, e.g. in a construction
area
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 change quickly, e.g.
lanes branch off, cross one another or
merge
R the road is narrow and winding
R there are highly variable shade conditions
on the road
If no vehicle is detected in the adjacent lane
and broken lane markings are detected, no
lane-correcting brake application is made.
Warning vibration through the steering
wheel
A warning may be given if a front wheel
passes over a lane marking. It will warn you by means of intermittent vibration in the steer-
ing wheel for up to 1.5 seconds.
Lane-correcting brake application
If you leave your lane under certain circum-
stances, the vehicle will brake briefly on one
side. This is intended to help you return the
vehicle to the original lane. G
WARNING
A lane-correcting brake application cannot
always bring the vehicle back into the original lane. There is a risk of an accident.
Always steer, brake or accelerate yourself,
especially if Active Lane Keeping Assist warns
you or makes a lane-correcting brake appli-
cation. If a lane-correcting brake application occurs,
display :appears in the multifunction dis-
play. The brake application also slightly
reduces driving speed.
This function is available in the range between
60 km/h and 200 km/h.
A lane-correcting brake application can be
made after driving over a lane marking rec-
ognised as being solid or broken. Before this,
a warning must have been issued by means of
intermittent vibration through the steering
wheel. In addition, a lane with lane markings
on both sides must be recognised.
In the case of a broken lane marking being
detected, a lane-correcting brake application can only be made if a vehicle has been detec-
ted in the adjacent lane. Oncoming vehicles,
overtaking vehicles and vehicles in adjacent
lanes can be detected.
i A further lane-correcting brake applica-
tion can only occur after your vehicle has
returned to the original lane. Driving systems
267Driving and parking Z

Display messages
Possible causes/consequences and
M
MSolutions !
Turn on the igni‐ Turn on the igni‐
tion to release tion to release
the parking brake the parking brake The red
!indicator lamp lights up.
You attempted to release the electric parking brake while the igni-
tion was switched off.
X Switch the ignition on. J
Check brake fluid Check brake fluid
level level There is insufficient brake fluid in the brake fluid reservoir.
In addition, the red Jwarning lamp lights up in the instrument
cluster and a warning tone sounds.
G WARNING
Braking efficiency may be impaired.
There is a risk of an accident. X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 207).
X Consult a qualified specialist workshop.
X Do not top up the brake fluid. This does not correct the fault. #
Check brake pad Check brake pad
wear wear The brake pads/linings have reached their wear limit.
X Visit a qualified specialist workshop. Collision Preven‐
Collision Preven‐
tion Assist Plus tion Assist Plus
currently unavail‐ currently unavail‐
able See Owner's able See Owner's
Manual Manual COLLISION PREVENTION ASSIST PLUS is temporarily inoperative.
Possible causes:
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:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 207).
X Restart the engine. 322
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions Collision Preven‐
Collision Preven‐
tion Assist Plus tion Assist Plus
inoperative inoperative COLLISION PREVENTION ASSIST PLUS is temporarily inoperative
due to a malfunction. Adaptive Brake Assist may also have failed.
X Visit a qualified specialist workshop. PRE-SAFE inopera‐
PRE-SAFE inopera‐
tive See Owner's tive See Owner's
Manual Manual
Important functions of PRE-SAFE
®
have failed. All other occupant
safety systems, e.g. airbags, remain available.
X Visit a qualified specialist workshop immediately. PRE-SAFE
PRE-SAFE
Functions
Functions
currently limited
currently limited
See Owner's Manual See Owner's Manual PRE
‑SAFE ®
PLUS or PRE ‑SAFE®
Brake is temporarily inoperative.
Possible causes:
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.
PRE ‑SAFE ®
PLUS and PRE ‑SAFE®
Brake are operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 207).
X Restart the engine. PRE-SAFE PRE-SAFE
Functions
Functions
limited See Own‐
limited See Own‐
er's Manual er's Manual PRE
‑SAFE ®
PLUS or PRE‑ SAFE®
Brake is unavailable due to a mal-
function. BAS PLUS might also be deactivated.
X Visit a qualified specialist workshop. Display
messages
323On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions Radar sensors
Radar sensors
dirty See Owner's dirty See Owner's
Manual Manual At least one of the following driving systems or driving safety sys-
tems is temporarily restricted or inoperative:
R PRE-SAFE ®
PLUS
R PRE-SAFE ®
Brake
R COLLISION PREVENTION ASSIST PLUS
R Active Lane Keeping Assist
R Active Blind Spot Assist
R DISTRONIC PLUS
Possible causes:
R the sensors in the radiator trim and/or in the bumpers are dirty
R the function of the driving system and/or driving safety system
is impaired due to heavy rain or snow
A warning tone also sounds.
Once the causes listed above no longer apply, the display message
goes out. All driving systems/driving safety systems are operative again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 207).
X Switch off the engine.
X Clean the sensors (Y page 401) in the following locations:
R in the radiator trim
R in the front bumper
R in the rear bumper, particularly in the middle of the rear
bumper
X Restart the engine.
The display message disappears. ü ü If this 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 50). 324
Display
messagesOn-board computer and displays