2012 MERCEDES-BENZ C-Class SEDAN change time

passenger door or one of the rear doors is
open.
R the vehicle has skidded.
If DISTRONIC PLUS is deactivated, you will
hear a warning tone. The DISTRONIC PLUS
Off message is shown in the multifunction
display for approximately five seconds.
If the vehicle has been stopped by DISTRONIC
PLUS and a malfunction occurs in the system,
the Brake Immediately message appears in
the multifunction display. Depress the brake
pedal immediately so that the vehicle does
not roll away. DISTRONIC PLUS is then
deactivated, and the message disappears.GWARNING
The DISTRONIC PLUS switches off and
releases the brakes when the vehicle
decelerates below the minimum speed of
20 mph (30 km/h) by operation of the system
unless the DISTRONIC PLUS detects a vehicle
directly ahead of you. At that time the driver
must apply the brakes in order to reduce
vehicle speed further or bring it to a stop.
Tips for driving with DISTRONIC PLUS
Important safety notes
The following contains descriptions of certain
road and traffic conditions in which you must
be particularly attentive. In such situations,
brake if necessary. DISTRONIC PLUS is then
deactivated.
GWARNING
The DISTRONIC PLUS works to maintain the
speed selected by the driver unless a moving
obstacle proceeding directly ahead of it in the
same travel direction is detected (e.g.
following another vehicle ahead of you at your
set distance).
This means that:
R Your vehicle can pass another vehicle after
you have changed lanes.
R While in a sharp turn or if the preceding
vehicle is in a sharp turn, the DISTRONIC
PLUS could lose sight of the preceding
vehicle. Your vehicle could then accelerate
to the previously selected speed.
The DISTRONIC PLUS regulates only the
distance between your vehicle and those
directly ahead of it. It may not register
stationary objects in the road, e.g.:
R a stopped vehicle in a traffic jam
R a disabled vehicle
R an oncoming vehicle
The driver must always be alert, observe all
traffic and intercede as required by means of
steering or braking the vehicle.GWARNING
The DISTRONIC PLUS should not be used in
snowy or icy road conditions.
Cornering, going into and coming out of a
bend
The ability of DISTRONIC PLUS to detect
vehicles when cornering is limited. Your
vehicle may brake unexpectedly or late.
Vehicles traveling on a different line
170Driving systemsDriving and parking

You are responsible for safety at all times and
must continue to pay attention to the
immediate surroundings when parking and
maneuvering. This includes the area behind,
in front of, and beside the vehicle. Otherwise
you could endanger yourself and/or others.GWARNING
The rear view camera will not function or will
not fully function if:
R the trunk lid is open
R it is raining or snowing strongly or if it is
foggy
R it is night or if you are parking/
maneuvering your vehicle in a very dark
area
R a very bright white light is affecting the
camera
R the immediate vicinity is illuminated with
fluorescent light (the display of the
COMAND system can flicker)
R temperature changes abruptly, for example
if you drive out of the cold into a heated
garage (condensation on the lens)
R the camera lens is dirty or covered
R the rear of your vehicle is damaged
In this case, have the position and the
setting of the camera checked at a
specialist workshop. Mercedes-Benz
recommends that you consult a Mercedes-
Benz Center for this purpose.
Do not use the rear view camera in these
situations. You could otherwise injure
yourself and other people and/or cause
damage - including damage to your vehicle -
while parking/maneuvering.
Activating the rear view camera
XMake sure that the SmartKey is in position
2 in the ignition lock.XMake sure that the "rear view camera"
function is selected in COMAND (see theseparate operating instructions for
COMAND).XEngage reverse gear.
The area behind the vehicle is shown in the
COMAND display.
ATTENTION ASSIST
Important safety notes
ATTENTION ASSIST helps you during long,
monotonous journeys such as on freeways
and interstate highways. It is active in the
range between 50 mph (80 km/h) and
112 mph (180 km/h).
If ATTENTION ASSIST detects typical
indicators of fatigue or increasing lapses in
concentration on the part of the driver, it
suggests you take a break.
GWARNING
ATTENTION ASSIST is only an aid and may
detect your tiredness or lapses in
concentration too late or not at all. It is not a
substitute for a well-rested and attentive
driver.
Fatigue may cause you to recognize
hazardous situations too late, misjudge a
situation or react more slowly. For this
reason, make sure you feel rested before you
begin driving and during your journey. Make
sure that you take regular breaks in time,
particularly on long journeys. Otherwise, you
may fail to recognize dangers in time, cause
an accident and injure yourself and others.
ATTENTION ASSIST assesses your level of
fatigue or lapses in concentration by taking
the following criteria into account:
R your personal driving style, e.g. steering
characteristics
R driving conditions, e.g. time, driving time
182Driving 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

the miles display unit is selected, the
assistance range begins at 40 mph.GWARNING
Lane Keeping Assist does not keep your
vehicle in its lane. It is only an aid and may
detect the lane markings on the road
incorrectly or not at all.
The system may be impaired or may not
function if:
R there is poor visibility, e.g. due to
insufficient 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.
R the windshield is dirty, fogged up or
covered, for instance by a sticker, in the
vicinity of the camera.
R several or no lane markings for a single lane
are present.
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 on the road are unclear,
e.g. near roadworks.
R the lane markings change quickly, e.g.
lanes branch off, cross one another or
merge.
R the road is narrow and winding.
Lane Keeping 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.
A warning can be given when a front wheel
passes over a lane marking. It will warn you
by means of intermittent vibration in the
steering wheel for up to 1.5 seconds.
In order that you are warned only when
necessary and in good time if you cross the
lane marking, the system recognizes certain
conditions 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
freeway.
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.
No warning vibration occurs if:
R you clearly and actively steer, brake or
accelerate.
R you cut the corner on a sharp bend.
R a driving safety system intervenes, e.g.
ABS, BAS or ESP ®
.
R you switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
Switching on Lane Keeping AssistXActivate Lane Keeping Assist using the on-
board computer ( Y page 205).
Symbol : appears in the multifunction
display.
If your speed exceeds 40 mph (60 km/h)
and lane markings are detected,
symbol : is shown in green. Lane Keeping
Assist is ready for use.186Driving 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

Active Lane Keeping Assist
Important safety notes
Active Lane Keeping Assist monitors the area
in front of your vehicle by means of a camera
at the top of the windshield. Active Lane
Keeping Assist detects lane markings on the
road and warns 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.
:Active Lane Keeping Assist camera
If you have selected the Display Unit
Speed-/Odometer (Y page 206) function in
the on-board computer and select km as the
unit of measurement, Active Lane Keeping
Assist is active from speeds of 60 km/h. If
the miles display unit is selected, the
assistance range begins at 40 mph.
GWARNING
Active Lane Keeping Assist does not keep
your vehicle in its lane. It is only an aid and
may detect the lane markings on the road
incorrectly or not at all.
The system may be impaired or may not
function if:
R several or no lane markings for a single lane
are present.
R there is poor visibility, e.g. due to
insufficient 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.
R the windshield is dirty, fogged up or
covered, for instance by a sticker, in the
vicinity of the camera.
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 on the road are unclear,
e.g. near roadworks.
R the lane markings change quickly, e.g.
lanes branch off, cross one another or
merge.
R the road is narrow and winding.
Active Lane Keeping 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.
Warning vibration in the steering wheel
A warning can be given when a front wheel
passes over a lane marking. You will be
warned by means of intermittent vibration in
the steering wheel for up to 1.5 seconds.
In order that you are warned only when
necessary and in good time if you cross the
lane marking, the system recognizes certain
conditions 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
freeway.
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.190Driving systemsDriving and parking

Display messagesPossible causes/consequences and M Solutionsb
Check Front Left
Parking
Lamp or Check Front
Right Parking LampThe front left or front right parking or standing lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 113).
or
XVisit a qualified specialist workshop.b
Backup LightThe backup lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 113).
or
XVisit a qualified specialist workshop.b
Check Front Left
Sidemarker
Lamp or Check Front
Right Sidemarker
LampThe left or right front side marker lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 113).
or
XVisit a qualified specialist workshop.b
Check Rear Left
Sidemarker
Lamp or Check Rear
Right Sidemarker
LampThe rear left or right side marker lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 113).
or
XVisit a qualified specialist workshop.b
Check Left Daytime
Running
Light or Check
Right Daytime
Running LightThe left or right-hand daytime running lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 113).
or
XVisit a qualified specialist workshop.b
Active Headlamps
InoperativeThe active light function is defective.XVisit a qualified specialist workshop.b
Malfunction See
Operator's ManualThe exterior lighting is defective.XVisit a qualified specialist workshop.224Display messagesOn-board computer and displays

TiresProblemPossible causes/consequences and M Solutionsh
USA only:
The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) is lit.
Canada only:
The yellow tire pressure
monitor warning lamp
(pressure loss) is lit.GRisk of accident
The tire pressure monitor has detected a loss of pressure in at
least one of the tires.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XObserve the additional display messages in the multifunction
display.XCheck the tire pressure. If necessary, correct the tire pressure
( Y page 319).XIf necessary, change a wheel ( Y page 334).h
USA only:
The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) flashes for
60 seconds and then
remains lit.The tire pressure monitor is faulty.XObserve the additional display messages in the multifunction
display.XVisit a qualified specialist workshop.GWARNING
Each tire, including the spare (if provided), should be checked at least every two weeks when
cold and inflated to the pressure recommended by the vehicle manufacturer on the Tire and
Loading Information placard on the driver's door B-pillar or, if available, the tire pressure label
on the inside of the fuel filler flap. If your vehicle has tires of a different size than the size indicated
on the Tire and Loading Information placard or the tire pressure label, you should determine the
proper tire pressure for those tires.
As an added safety feature, your vehicle has been equipped with a tire pressure monitoring
system (TPMS) that illuminates a low tire pressure telltale when one or more of your tires are
significantly underinflated. Accordingly, when the low tire pressure telltale illuminates, you should
stop and check your tires as soon as possible, and inflate them to the proper pressure. Driving
on a significantly underinflated tire causes the tire to overheat and can lead to tire failure.
Underinflation also reduces fuel efficiency and tire tread life, and may affect the vehicle's handling
and stopping ability. Please note that the TPMS is not a substitute for proper tire maintenance,
and it is the driver's responsibility to maintain correct tire pressure, even if underinflation has
not reached the level to trigger illumination of the TPMS low tire pressure telltale.
USA only:
Your vehicle has also been equipped with a TPMS malfunction indicator to indicate when the
system is not operating properly. The TPMS malfunction indicator is combined with the low tire
pressure telltale. When the system detects a malfunction, the telltale will flash for approximately
1 minute and then remain continuously illuminated. This sequence will be repeated every time
250Warning and indicator lamps in the instrument clusterOn-board computer and displays