radar sensor MERCEDES-BENZ C-Class SEDAN 2015 W205 User Guide

Change into a lower gear in good time on long
and steep downhill gradients. This is espe-
cially important if the vehicle is laden. 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. DISTRONIC PLUS cannot pre-
vent a collision without your intervention. An
intermittent warning tone will then sound and the distance warning lamp will light up in the
instrument cluster. Brake immediately in
order to increase the distance to the vehicle
in front or take evasive action provided it is
safe to do so.
DISTRONIC PLUS operates in range between 0 mph (0 km/h) and 120 mph (200 km/h).
Do not use DISTRONIC PLUS while driving onroads with steep gradients.
As DISTRONIC PLUS transmits radar waves, it
can resemble the radar detectors of the
responsible authorities. You can refer to the
relevant chapter in the Operator's Manual if
questions are asked about this.
i USA only: This device has been approved
by the FCC as a "Vehicular Radar System".
The radar sensor is intended for use in an
automotive radar system only. Removal,
tampering, or altering of the device will void
any warranties, and is not permitted by the
FCC. Do not tamper with, alter, or use in
any non-approved way.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
i Canada only: This device complies with
RSS-210 of Industry Canada. Operation is
subject to the following two conditions:
1. This device may not cause harmful inter-
ference, and
2. this device must accept any interference received, including interference that may
cause undesired operation of the device. Removal, tampering, or altering of the
device will void any warranties, and is not
permitted. Do not tamper with, alter, or use
in any non-approved way.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
Important safety notes G
WARNING
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. G
WARNING
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 or brake 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. G
WARNING
DISTRONIC PLUS brakes your vehicle with up to 50 %of the maximum possible deceleration.
If this braking force is insufficient, DISTRONIC
PLUS warns you visually and audibly. There is a risk of an accident.
In such cases, apply the brakes yourself and
try to take evasive action. 186
Driving systemsDriving and parking

!
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,
DISTRONIC PLUS can neither reduce the risk
of accident nor override the laws of physics.
DISTRONIC PLUS cannot take into account
the road, traffic and weather conditions.
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 your 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 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
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 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
example, in parking garages
If DISTRONIC PLUS no longer detects a vehi- cle in front, DISTRONIC PLUS may unexpect-
edly accelerate the vehicle to the stored
speed. This speed may:
R be too high if you are driving in a filter lane
or an exit lane
R be so high in the right lane that you pass
vehicles driving on the left (left-hand drive
countries)
R be so high in the left lane that you pass
vehicles driving on the right (right-hand
drive countries)
If there is a change of drivers, advise the new driver of the speed stored.
Cruise control lever 0043
To activate or increase speed
0044 To activate or reduce speed
0087 To deactivate DISTRONIC PLUS
0085 To activate at the current speed/last
stored speed
0083 To set the specified minimum distance
Selecting DISTRONIC PLUS X
Check whether LIM indicator lamp 0043is off. Driving systems
187Driving and parking Z

i
USA only:
This device has been approved by the FCC as a "Vehicular Radar System". The radar
sensor is intended for use in an automotive radar system only. Removing, tampering
with, or altering the device will void any
warranties, and is not permitted by the
FCC. Do not tamper with, alter, or use in
any non-approved way.
Any unauthorized modification to this
device could void the user’s authority to
operate the equipment.
Radar sensors
The radar sensors for Blind Spot Assist are
integrated into the rear bumper. Make sure
that the bumpers are free from dirt, ice or
slush. The sensors must not be covered, for
example by cycle 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 spe-
cialist workshop. Blind Spot Assist may no
longer work properly.
Monitoring area
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 poor visibility, e.g. due to fog, heavy
rain, snow or spray
R there are narrow vehicles, e.g. motorcycles
or bicycles
R the road has very wide lanes
R the road has narrow lanes
R you are not driving in the middle of the lane
R there are barriers or similar lane borders
Vehicles in the monitoring range are then not indicated. Blind Spot Assist monitors the area up to 10 ft
(3 m) behind your vehicle and directly next to your vehicle, as shown in the diagram.
If the lanes are narrow, vehicles driving in the
lane beyond the lane next to your vehicle may
be indicated, especially if the vehicles are not
driving in the middle of their lane. This may be the case if there are vehicles driving at the
inner edge of their lanes.
Due to the nature of the system:
R warnings may be issued in error when driv-
ing close to crash barriers or similar solid
lane borders.
R the warning is canceled when driving for an
extended period next to long vehicles, such
as trucks.
The two radar sensors for Blind Spot Assist
are integrated into the sides of the rear
bumper. Make sure that the bumper is free of dirt, ice or slush in the vicinity of the sensors.
The sensors must not be covered, for exam-
ple by cycle racks or overhanging loads. Fol-
lowing a severe impact or in the event of dam- age to the bumpers, have the function of the
sensors checked at a qualified specialist
workshop. Blind Spot Assist may otherwise
not work properly. 218
Driving systemsDriving and parking

(Y
page 243) are shown in green. Lane
Keeping Assist is ready for use.
X To switch off: press button0044.
Indicator lamp 0043goes out. Lane Keeping
Assist is deactivated. The Lane Keeping
Lane Keeping
Assist Off
Assist Off message appears in the mul-
tifunction display.
Selecting Standard or Adaptive setting
X In the DriveAssist
DriveAssist menu on the on-board
computer, select the Lane Keeping
Lane Keeping
Assist
Assist function (Y page 246).
X Select Standard
Standard orAdaptive
Adaptive.
Standard
When Standard Standard is selected, no warning vibra-
tion occurs if:
R you switch 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 ®
.
Adaptive
When Adaptive
Adaptive is selected, no warning vibra-
tion occurs if:
R you switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
R a driving safety system intervenes, e.g.
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 lanes 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 recognizes 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 high-
way.
R the system recognizes 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 185),
Active Blind Spot Assist (Y page 221) and
Active Lane Keeping Assist (Y page 224).
Active Blind Spot Assist General notes
Active Blind Spot Assist uses a radar sensor
system, pointed toward the rear of the vehi-
cle, to monitor the area to the sides of the
vehicle which the driver is unable to see. A
warning display in the exterior mirrors draws
your attention to vehicles detected in the
monitored area. If you then switch on the cor-
responding turn signal to change lane, you
will also receive an optical and audible warn- ing. If a risk of lateral collision is detected,
corrective braking may help you avoid a col-
lision. Active Blind Spot Assist evaluates the
free space in the direction of travel and to the
side before making a course-correcting brake application. For this, Active Blind Spot Assist
uses radar sensors which are pointed in the
direction of travel.
Active Blind Spot Assist supports you from a
speed of approximately 20 mph (30 km/ h).
Important safety notes
Active Blind Spot Assist is only an aid and is
not a substitute for attentive driving. Driving systems
221Driving and parking Z

G
WARNING
Active Blind Spot Assist does not react to:
R vehicles overtaken too closely on the side,
placing them in the blind spot area
R vehicles which approach with a large speed
differential and overtake your vehicle
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 observe the traffic conditions care-
fully, and maintain a safe lateral distance.
i USA only: This device has been approved
by the FCC as a "Vehicular Radar System". The radar sensor is intended for use in an
automotive radar system only. Removal,
tampering, or altering of the device will void
any warranties, and is not permitted by the
FCC. Do not tamper with, alter, or use in
any non-approved way.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
i Canada only: This device complies with
RSS-210 of Industry Canada. Operation is
subject to the following two conditions:
1. This device may not cause harmful inter- ference, and
2. This device must accept any interference
received, including interference that may
cause undesired operation of the device.
Removal, tampering, or altering of the
device will void any warranties, and is not
permitted. Do not tamper with, alter, or use
in any non-approved way.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
Radar sensors
The Active Blind Spot Assist radar sensors are integrated into the front and rear bumpers
and behind a cover in the radiator grill. Make
sure that the bumpers and the cover in the
radiator grill 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 work properly.
Monitoring area G
WARNING
Active Blind Spot Assist does not detect all
traffic situations and road users. There is a
risk of an accident.
Always make sure that there is sufficient dis-
tance on the side for other traffic or obstacles. Active Blind Spot Assist monitors the area up
to 10 ft (3.0 m) behind your vehicle and
directly next to your vehicle, as shown in the
diagram.
The detection of obstacles can be impaired in the case of:
R there is dirt on the sensors or anything else
covering the sensors
R poor visibility, e.g. due to rain, snow or
spray
Vehicles in the monitoring range are then not
indicated. 222
Driving systemsDriving and parking

cation. Always maintain a safe distance at the
sides. If a course-correcting brake application
occurs, red warning lamp 0043flashes in the
exterior mirror and a dual warning tone
sounds. In addition, display 0044underlining
the danger of a side collision appears in the
multifunction display.
In very rare cases, the system may make an
inappropriate brake application. A course-
correcting brake application may be interrup-
ted at any time if you steer slightly in the
opposite direction or accelerate.
The course-correcting brake application is
available in the speed range between 20 mph (30 km/h) and 120 mph (200 km/h).
Either no braking application, or a course-
correcting brake application adapted to the
driving situation occurs if:
R there are vehicles or obstacles, e.g. crash
barriers, located on both sides of your vehi-
cle.
R a vehicle approaches you too closely at the
side.
R you have adopted a sporty driving style with
high cornering speeds.
R you clearly brake or accelerate.
R a driving safety system intervenes, e.g.
ESP ®
or PRE-SAFE ®
Brake.
R ESP ®
is switched off.
R a loss of tire pressure or a defective tire is
detected. Switching on Active Blind Spot Assist
X Make sure that Active Blind Spot Assist is
activated in the on-board computer
(Y page 246).
X Turn the SmartKey to position 2in the igni-
tion lock.
Warning lamps 0043in the exterior mirrors
light up red for approximately 1.5 seconds. Gray radar waves propagating backwards
appear next to the vehicle in the assistance
display 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 0043at the top of the windshield. Vari-
ous different areas to the front, rear and side of your vehicle are also monitored with the aid
of the radar sensor system. Active Lane Keep-
ing Assist detects lane markings on the road
and can warn you before you leave your lane
unintentionally. 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 kmin the Display Unit
Display Unit
Speed-/Odometer:
Speed-/Odometer: function on the on-board
computer (Y page 248), Active Lane Keeping
Assist is activated starting at a speed of
60 km/h. If the miles
miles display unit is selected,
the assistance range begins at 40 mph. 224
Driving systemsDriving and parking

Important safety notes
If you fail to adapt your driving style, Active
Lane Keeping Assist can neither reduce the
risk of accident nor override the laws of phys- ics. Active Lane Keeping Assist cannot take
account of road and weather conditions. It
may not recognize 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 your 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 not give a warning or 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.
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 reflections (e.g. when the road
surface is wet)
R the windshield is dirty, fogged up, damaged
or covered, for instance by a sticker, in the
vicinity of the camera
R the radar sensors in the front or rear bump-
ers or the radiator grill are dirty, e.g.
obscured by snow R
there are no, several or unclear lane mark-
ings for a lane, e.g. in areas with road con-
struction work
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 strong shadows cast on the road
If no vehicle is detected in the adjacent lane
and there are broken lane markings detected,
no lane-correcting brake application is made.
Warning vibration in 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 meant to assist you in bringing
the vehicle back 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. Driving systems
225Driving and parking Z

Display messages
Possible causes/consequences and
0050
0050Solutions 0027(USA
only)004D
(Canada
only)
Check Brake Fluid Check Brake Fluid
Level Level There is not enough brake fluid in the brake fluid reservoir.
In addition, the
0027(USA only)/ 004D(Canada only) warning
lamp lights up in the instrument cluster and a warning tone
sounds.
G WARNING
The braking effect 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 174).
X Consult a qualified specialist workshop.
X Do not add brake fluid. This does not correct the malfunction. 0026
Check Brake Pad Check Brake Pad
Wear Wear The brake pads/linings have reached their wear limit.
USA only: the red
0027brake system warning lamp also lights up
while the engine is running.
X Visit a qualified specialist workshop. 0053
Inoperative Inoperative One or more main features of the mbrace system are malfunc-
tioning.
X Have the mbrace system checked immediately at a qualified
specialist workshop. Collision Preven‐ Collision Preven‐
tion Assist Plus tion Assist Plus
Currently Unavail‐ Currently Unavail‐
able See Opera‐ able See Opera‐
tor's Manual tor's Manual COLLISION PREVENTION ASSIST PLUS is temporarily not opera-
tional. Possible causes are:
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.
When the causes stated above no longer apply, the display mes-
sage disappears.
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 174).
X Restart the engine. 258
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
0050
0050Solutions 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 Opera‐ tive See Opera‐
tor's Manual tor's Manual
Important functions of PRE-SAFE
®
have failed. All other occupant
safety systems, e.g. air bags, remain available.
X Visit a qualified specialist workshop immediately. PRE-SAFE
PRE-SAFE
Functions
Functions
Currently Limited
Currently Limited
See See Operator's
Operator's Man‐
Man‐
ual
ual PRE
‑SAFE ®
PLUS or PRE ‑SAFE®
Brake is temporarily inoperative.
Possible causes are:
R 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.
When the causes stated above no longer apply, the display mes-
sage disappears.
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 174).
X Restart the engine. PRE-SAFE PRE-SAFE
Functions
Functions
Limited See Opera‐
Limited See Opera‐
tor's Manual tor's Manual PRE
‑SAFE ®
PLUS or PRE‑ SAFE®
Brake is unavailable due to a mal-
function. BAS PLUS may also have failed.
X Visit a qualified specialist workshop. Display
messages
259On-board computer and displays Z

Display messages
Possible causes/consequences and
0050
0050Solutions Radar Sensors
Radar Sensors
Dirty See Opera‐ Dirty See Opera‐
tor's Manual tor's 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 are:
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.
When the causes stated above no longer apply, the display mes-
sage disappears. 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 174).
X Switch off the engine.
X Clean the sensors in the following locations (Y page 334):
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. 0075
SRS Malfunction SRS Malfunction
Service Required Service Required The restraint system is faulty. The
0075warning lamp also lights
up in the instrument cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be trig- gered unintentionally or, in the event of an accident, may not be
triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop.
For further information about the restraint system, see
(Y page 42). 260
Display
messagesOn-board computer and displays