2012 MERCEDES-BENZ C-Class SEDAN Sensors

The multifunction display shows the RACE
START active message.
RACE START is deactivated when a speed of
approximately 30 mph (Canada: 50 km/h) is
reached. Drive program S+ is activated.
SPORT handling mode remains activated.
RACE START is deactivated immediately if
you release the accelerator pedal during
RACE START or if any of the activation
conditions are no longer fulfilled. The
multifunction display shows the RACE START
not possible See Operator's Manual
message.
i If RACE START is used repeatedly within
a short period of time, it is only available
again after the vehicle has been driven a
certain distance.
4MATIC (permanent four-wheel drive)
4MATIC ensures that all four wheels are
permanently driven. Together with ESP ®
, it
improves the traction of your vehicle
whenever a drive wheel spins due to
insufficient grip.
GWARNING
If a drive wheel is spinning due to insufficient
traction:
R While driving off, apply as little throttle as
possible.
R While driving, ease up on the accelerator
pedal.
R Adapt your speed and driving style to the
prevailing road conditions.
Failure to observe these guidelines could
cause the vehicle to skid.
The 4MATIC cannot prevent accidents
resulting from excessive speed.
! 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 Limited 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 tires ( M+S tires), with snow
chains if necessary.
PARKTRONIC
Important safety notes
i PARKTRONIC is only available in Canada.
GWARNING
The PARKTRONIC is a supplemental system.
It is not intended to, nor does it replace, the
need for extreme care. The responsibility
during parking and other critical maneuvers
always remains with the driver.
GWARNING
Make sure no persons or animals are in or
near the area in which you are parking/
maneuvering. Otherwise, they could be
injured.
PARKTRONIC is an electronic parking aid with
ultrasonic sensors. It indicates visually and
audibly the distance between your vehicle
and an object.
PARKTRONIC is activated automatically when
you:
R switch on the ignition
R shift the transmission to position D, R or N
R release the parking brake
PARKTRONIC is deactivated at speeds above
11 mph (18 km/h). It is reactivated at lower
speeds.
PARKTRONIC monitors the area around your
vehicle using six sensors in the front bumper
and four sensors in the rear bumper.
Driving systems175Driving and parkingZ

:Sensors in the front bumper, left-hand
side (example)
Range of the sensors
General notes
The sensors must be free of dirt, ice and
slush; otherwise they may not function
correctly. Clean the sensors regularly, taking
care not to scratch or damage them
( Y page 287).
Side view
Top view
Front sensorsCenterApproximately 40 in
(approximately 100 cm)CornersApproximately 24 in
(approximately 60 cm)
Rear sensors
CenterApproximately 48 in
(approximately 120 cm)CornersApproximately 32 in
(approximately 80 cm)
! 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 other
objects that absorb ultrasonic waves.
Ultrasonic sources such as an automatic
car wash, the compressed-air brakes on a
truck or a pneumatic drill could cause
PARKTRONIC to malfunction.
PARKTRONIC may not function correctly on
uneven terrain.
Minimum distance
CenterApproximately 8 in
(approximately 20 cm)CornersApproximately 6 in
(approximately 15 cm)
If there is an obstacle within this range, the
relevant warning displays light up and a
warning tone sounds. If the distance falls
below the minimum, the distance may no
longer be shown.
176Driving systemsDriving and parking

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 center air vents.
The warning display for the rear area is
located on the headliner in the rear
compartment.
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
vehicle is divided into five yellow and two red
segments. PARKTRONIC is operational if
yellow segments showing operational
readiness = light up.
The selected transmission position
determines which warning display is active
when the engine is running.
Transmission
positionWarning displayDFront area activatedR , N or the vehicle
is rolling
backwardsRear and front areas
activatedPNo areas activatedOne or more segments light up as the vehicle
approaches an obstacle, depending on the
vehicle's distance from the obstacle.
From the:
R sixth segment onwards, you will hear an
intermittent warning tone for
approximately two seconds.
R seventh segment onwards, you will hear a
warning tone for approximately two
seconds. This indicates that you have now
reached the minimum distance.
Deactivating/activating PARKTRONIC:Indicator lamp;To deactivate/activate PARKTRONIC
If indicator lamp : lights up, PARKTRONIC is
deactivated. Parking Guidance is also
deactivated.
i PARKTRONIC is automatically activated
when you turn the SmartKey to position 2
in the ignition lock.
Driving systems177Driving and parkingZ

Problems with PARKTRONICProblemPossible causes/consequences and M SolutionsOnly the red segments
in the PARKTRONIC
warning displays are lit.
You also hear a warning
tone for approximately
two seconds.
PARKTRONIC is
deactivated after
approximately
20 seconds, and the
indicator lamp in the
PARKTRONIC button
lights up.PARKTRONIC has malfunctioned and has switched off.XIf problems persist, have PARKTRONIC checked at a qualified
specialist workshop.Only the red segments
in the PARKTRONIC
warning displays are lit.
PARKTRONIC is
deactivated after
approximately 20
seconds.The PARKTRONIC sensors are dirty or there is interference.XClean the PARKTRONIC sensors ( Y page 287).XSwitch the ignition back on.The problem may be caused by an external source of radio or
ultrasound waves.XSee if PARKTRONIC functions in a different location.Parking Guidance
Important safety notes
i Parking Guidance is only available in
Canada.
Parking Guidance is an electronic parking aid
with ultrasound. Ultrasound is used to
measure the road on both sides of the vehicle.
A suitable parking space is indicated by the
parking symbol. You receive steering
instructions when parking. You may also use
PARKTRONIC ( Y page 175).
GWARNING
Parking Guidance is merely an aid and may
display parking spaces that are not suitable
for parking, for example:
R no-parking areas
R parking spaces with unsuitable surfaces
(road surface)
R driveways
R entrances and exits
Parking Guidance detects and measures
potential parking spaces while driving past.
Changes to the parking space after this point
are not taken into account, for example if the
vehicle in front of or behind the parking space
changes position or objects in the parking
space are moved.
Even when using Parking Guidance, you are
still responsible for driving carefully. If you
rely on Parking Guidance alone, you could
178Driving systemsDriving and parking

The functionality of ATTENTION ASSIST is
restricted and warnings may be delayed or
not occur at all:
R if the road condition is poor, e.g. if the
surface is uneven or if there are potholes
R if there is a strong side wind
R if you have adopted a sporty driving style
with high cornering speeds or high rates of
acceleration
R if you predominantly drive at speeds under
50 mph (80 km/h) or over 112 mph
(180 km/h)
R if you are currently using COMAND or
making a telephone call with it
R if the time has been set incorrectly
R in active driving situations, such as when
you change lanes or change your speed
Warning and display messages in the
multifunction displayXActivate ATTENTION ASSIST using the on-
board computer ( Y page 205).
Symbol : appears in the multifunction
display.
If ATTENTION ASSIST is active, you will be
warned no sooner than 20 minutes after your
journey has begun. You will then hear an
intermittent warning tone twice, and the
Attention Assist: Drowsiness
Detected message appears in the
multifunction display.
XIf necessary, take a break.XPress a to confirm the message.
On long journeys, take regular breaks in good
time to allow yourself to rest properly. If you
do not take a break and ATTENTION ASSIST
still detects typical indicators of fatigue or
increasing lapses in concentration, you will be
warned again after 15 minutes at the earliest.
ATTENTION ASSIST is reset when you
continue your journey and starts assessing
your tiredness again if:
R you switch off the engine.
R you take off your seat belt and open the
driver's door, e.g. for a change of drivers or
to take a break.
Lane Tracking package
General notes
The Lane Tracking package consists of Blind
Spot Assist ( Y page 183) and Lane Keeping
Assist ( Y page 185).
Blind Spot Assist
Important safety notes
Blind Spot Assist uses a radar sensor system
to monitor the areas on both sides of your
vehicle. It supports you from speeds of
approximately 20 mph (30 km/h). A warning
display in the exterior mirrors draws your
attention to vehicles detected in the
monitored area. If you then switch on the
corresponding turn signal to change lane, you
will also receive an optical and audible
collision warning. Blind Spot Assist uses
sensors in the rear bumper for monitoring
purposes.
GWARNING
Blind Spot Assist is only an aid designed to
assist driving. It may fail to detect some
vehicles and is no substitute for attentive
driving.
Blind Spot Assist cannot detect road and
traffic conditions. It may fail to detect narrow
vehicles, such as motorcycles or bicycles, or
may only detect them too late.
Monitoring may be affected by dirty sensors,
strong spray or poor visibility caused by snow,
Driving systems183Driving and parkingZ

rain or mist, for example. In this case, vehicles
are detected late or not at all.
Always pay attention to traffic conditions and
your surroundings. Otherwise, you may fail to
recognize dangers in time, cause an accident
and injure yourself and others.
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.
For Blind Spot Assist to assist you when
driving, the radar sensor system must be
activated ( Y page 208) and operational.
Monitoring range of the sensors
Blind Spot Assist monitors the area shown in
the figure up to 10 ft (3 m) behind and
immediately adjacent to your vehicle.GWARNING
Blind Spot Assist monitors certain areas in the
immediate vicinity of your vehicle. Vehicles
that approach and drive past at high speeds
are not detected. There is no display and no
warning.
If the lanes are very wide, it may not be
possible to monitor the complete width of the
neighboring lane. For this reason, vehicles in
the next lane may not be detected, especially
if they are driving in a staggered formation.
This may be the case if vehicles are driving at
that edge of their lane which is furthest away
from your vehicle.
Always pay attention to traffic conditions and
your surroundings. Otherwise, you may fail to
recognize dangers in time, cause an accident
and injure yourself and others.
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 the vehicles are driving on the
inner side of their lane.
Due to the nature of the system:
R warnings may be issued in error when
driving close to crash barriers or similar
solid lane borders.
R warnings may be interrupted when driving
alongside long vehicles, such as trucks, for
a prolonged time.
The two sensors for Blind Spot Assist are
integrated into the sides of the rear bumper.
Make sure that the bumper is free from dirt,
ice or slush around the sensors. The rear
sensors must not be covered, for example 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, e.g. an authorized Mercedes-Benz
Center. Blind Spot Assist may otherwise not
work properly.184Driving systemsDriving and parking

Active Driving Assistance package
General notes
The Active Driving Assistance package
consists of DISTRONIC PLUS ( Y page 161),
Active Blind Spot Assist ( Y page 187) and
Active Lane Keeping Assist ( Y page 190).
Active Blind Spot Assist
Important safety notes
Active Blind Spot Assist uses a radar sensor
system to monitor the side areas of your
vehicle which are in back of the driver. A
warning display in the exterior mirrors draws
your attention to vehicles detected in the
monitored area. If you then switch on the
corresponding turn signal to change lane, you
will also receive an optical and audible
collision warning. If a risk of lateral collision
is detected, 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 system. Active Blind Spot Assist
supports you from speeds of approximately
20 mph (30 km/h).
GWARNING
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
function 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
narrow vehicles, such as motorcycles or
bicycles, or may only detect them too late. It
cannot detect vehicles that are overtaken at
a small distance 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
style to suit the prevailing road and weather
conditions. Always pay attention to traffic
conditions and your surroundings. Otherwise,
you may fail to recognize dangers in time,
cause an accident and injure yourself and
others.
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.
For Active Blind Spot Assist to assist you
when driving, the radar sensor system must
be activated ( Y page 208) and operational.
Monitoring area
Active Blind Spot Assist monitors the area
shown in the figure up to 10 ft (3 m) behind
and immediately adjacent to your vehicle. For
this purpose, Active Blind Spot Assist uses
radar sensors in the rear bumper.Driving systems187Driving and parkingZ

GWARNING
Active Blind Spot Assist monitors certain
areas in the immediate vicinity of your vehicle.
Vehicles that approach and drive past at high
speeds are not detected. No visual nor
audible warnings are emitted and the system
does not brake the vehicle to correct your
course.
If the lanes are very wide, it may not be
possible to monitor the complete width of the
neighboring lane. For this reason, vehicles in
the next lane may not be detected, especially
if they are driving in a staggered formation.
This may be the case if vehicles are driving at
that edge of their lane which is furthest away
from your vehicle.
Always pay attention to traffic conditions and
your surroundings. Otherwise, you may fail to
recognize dangers in time, cause an accident
and injure yourself and others.
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
driving close to crash barriers or similar
solid lane borders.
R warnings may be interrupted when driving
alongside long vehicles, such as trucks, for
a prolonged time.
Two Active Blind Spot Assist radar sensors
are integrated into the front and rear bumpers
respectively. An additional radar sensor is
located behind the cover in the radiator grill.
Make sure that the sensor areas on the
bumpers and the sensor cover in the radiator
grill are free of dirt, ice and slush. The rear
sensors must not be covered, for example by
cycle racks or overhanging cargo. 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. Blind Spot Assist may otherwise
not work properly.
Indicator and warning display:Yellow indicator lamp/red warning lamp
When Active Blind Spot Assist is activated,
indicator lamp : lights up yellow in the
exterior mirrors up to a vehicle speed of
20 mph (30 km/h). When the vehicle speed
exceeds 20 mph (30 km/h), the indicator
lamp goes out and Active Blind Spot Assist is
ready for use.
When your speed exceeds approximately
20 mph (30 km/h), warning lamp : lights up
red on the corresponding side whenever a
vehicle is detected in the blind spot
monitoring range. This warning is always
given when a vehicle enters the blind spot
monitoring range from behind or from the
side. When you are passing another vehicle,
the warning is emitted only if the difference
in speed is less than 7 mph (12 km/h).
The yellow indicator lamp goes out if reverse
gear is engaged. In this event, Active Blind
Spot Assist is no longer active.
The brightness of the indicator/warning
lamps is adjusted automatically according to
the ambient light.
GWARNING
Active Blind Spot Assist is not active at speeds
lower than 20 mph (30 km/h). The indicator
lamps in the exterior mirrors are yellow.
Vehicles in the monitoring range are then not
indicated.
188Driving systemsDriving and parking