2012 MERCEDES-BENZ C-Class SEDAN brake

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

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.
Lane-correcting brake application
If you leave your lane under certain
circumstances the vehicle will brake briefly
on one side. This is meant to assist you in
bringing the vehicle back to the original lane.
This function is available in the range between
40 mph and 120 mph (60 km/h to
200 km/h).
A lane-correcting brake application can only
be made after driving over a solid,
recognizable lane marking. Before this, a
warning must be given by means of
intermittent vibration in the steering wheel.
In addition, a lane with lane markings on both
sides must be recognized. The brake
application also slightly reduces vehicle
speed.
If a lane-correcting brake application occurs,
the following, for example, appears in the
multifunction display:
i A further lane-correcting brake
application can only occur after your
vehicle has returned to the original lane.
GWARNING
Active Lane Keeping Assist does not keep
your vehicle in its lane. It is only an aid
designed to assist driving. It is not a substitute
for attentive driving. In some cases, the lane-
correcting brake application is not sufficient
to bring your vehicle back to the original lane.
In such cases, you must steer the vehicle
yourself to ensure that it does not leave the
lane.
Active Lane Keeping Assist does not detect
road and traffic conditions. Always make sure
that there is sufficient distance to the side for
other traffic or obstacles. In rare cases,
unclear markings or particular structures on
the roadway can be recognized as solid lane
markings. An inappropriate brake application,
e.g. after intentionally driving over a solid lane
marking, may be interrupted at any time by
steering slightly in the opposite direction.
Active Lane Keeping Assist cannot take
weather conditions into account.
You are responsible for the driving at
appropriate speeds, 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.
No lane-correcting brake application occurs
if:
R you clearly and actively steer, brake or
accelerate.
R you cut the corner on a sharp bend.
R you switch on the turn signals.
R a driving safety system intervenes, e.g.
ESP ®
, PRE-SAFE ®
Brake or Active Blind
Spot Assist.
R you have adopted a sporty driving style with
high cornering speeds or high rates of
acceleration.
R ESP ®
is switched off.
R the transmission is not in position D.
R a loss of tire pressure or a defective tire has
been detected and displayed.Driving systems191Driving and parkingZ

Active Lane Keeping Assist does not detect
traffic situations or road users. An
inappropriate brake application may be
interrupted at any time if you:
R steer slightly in the opposite direction.
R use a turn signal.
R clearly brake or accelerate.
A lane-correcting brake application is
interrupted automatically if:
R a driving safety system intervenes, e.g.
ESP ®
, PRE-SAFE ®
Brake or Active Blind
Spot Assist.
R lane markings can no longer be recognized.
Switching on Active Lane Keeping AssistXSwitch on Active 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. Active Lane
Keeping Assist is ready for use.192Driving systemsDriving and parking

XTo show menu bar ;: press the =
or ; button on the steering wheel.
The following messages may appear in the
multifunction display:
X j YParking Guidance ( Y page 178)_Adaptive Highbeam Assist
( Y page 110)ÀATTENTION ASSIST ( Y page 182)ÃLane Keeping Assist ( Y page 185) or
Active Lane Keeping Assist
( Y page 190)HOLDHOLD function ( Y page 172)ÄPRE-SAFE ®
Brake ( Y page 65)Displays and operation197On-board computer and displaysZ

Assistance menu
Introduction
In the DriveAssist. menu you can:
R show the distance display
R activate/deactivate ESP ®
R activate/deactivate PRE-SAFE ®
Brake
R activate/deactivate ATTENTION ASSIST
R activate/deactivate Blind Spot Assist or
Active Blind Spot Assist
R activate/deactivate Lane Keeping Assist or
Active Lane Keeping Assist
Showing the distance display
This function is only available with
DISTRONIC PLUS.
XPress the = or ; button on the
steering wheel to select the DriveAssist
menu.XPress the 9 or : button to select
Distance Display .XPress a.
The DISTRONIC PLUS distance display
( Y page 168) appears in the multifunction
display.Deactivating/activating ESP ®GWARNING
Under no circumstances should you
deactivate ESP ®
when the ÷ ESP®
warning lamp in the instrument cluster
flashes. Proceed as follows:
R when driving off, apply as little throttle as
possible.
R while driving, ease up on the accelerator
pedal.
R adapt your speed to suit the prevailing road
and weather conditions.
Failure to observe these guidelines could
cause the vehicle to skid. ESP ®
cannot
prevent accidents resulting from excessive
speed.
Activating/deactivating ESP ®
on AMG
vehicles ( Y page 62).
For further information about ESP ®
, see
( Y page 61).
XStart the engine.XPress = or ; on the steering wheel
to select the Assist. menu.XPress the 9 or : button to select
ESP .XPress the a button.XTo deactivate: press a again.
The å warning lamp in the instrument
cluster comes on.GWARNING
When the å ESP®
OFF warning lamp is lit,
ESP ®
is deactivated.
If the ÷ ESP®
warning lamp and the
å ESP®
OFF warning lamp remain lit,
ESP ®
is not available due to a malfunction.
When ESP ®
is deactivated or not operational,
vehicle stability in standard driving
maneuvers is reduced.
Adapt your speed and driving to the prevailing
road conditions and to the non-operating
status of the ESP ®
.
204Menus and submenusOn-board computer and displays

XTo activate: press a again.
The å warning lamp in the instrument
cluster goes out.
Activating/deactivating PRE-SAFE ®
Brake
PRE-SAFE ®
Brake is only available in vehicles
with DISTRONIC PLUS.
XPress the = or ; button on the
steering wheel to select the DriveAssist
menu.XPress 9 or : to select PRE-SAFE
Brake .XPress a.
The current selection is displayed.XTo activate/deactivate: press a
again.
When PRE-SAFE ®
Brake ( Y page 65) is
activated, the multifunction display shows
the Ä symbol as long as the HOLD
function is not activated ( Y page 172).
Vehicles with Parking Guidance: if
PARKTRONIC is activated and you are driving
at a speed under 22 mph (35 km/h) the j
symbol for Parking Guidance is displayed
instead of the Ä symbol.
Activating/deactivating ATTENTION
ASSIST
XPress the = or ; button on the
steering wheel to select the DriveAssist
menu.XPress the 9 or : button to select
Attention Asst. .XPress a.
The current selection is displayed.XTo activate/deactivate: press a
again.
When ATTENTION ASSIST ( Y page 182) is
activated, the À symbol appears in the
multifunction display when the ignition is on.
Activating/deactivating Blind Spot
Assist
You can use the Blind Spot Asst. function
to activate or deactivate Blind Spot Assist
( Y page 183) or Active Blind Spot Assist
( Y page 187).
XPress = or ; on the steering wheel
to select the DriveAssist menu.XPress 9 or : to select Blind Spot
Asst. .XPress a.
If the function is activated, the monitored
areas are shown in red in the multifunction
display.XTo activate/deactivate: press a
again.
Activating/deactivating Lane Keeping
Assist
You can use the Lane Keep. Asst. function
to activate/deactivate Lane Keeping Assist
( Y page 185) or Active Lane Keeping Assist
( Y page 190).
XPress the = or ; button on the
steering wheel to select the DriveAssist
menu.XPress the 9 or : button to select
Lane Keep. Asst. .XPress a.
If the function is activated, the road
markings are shown in red in the
multifunction display.XTo activate/deactivate: press a
again.
If Lane Keeping Assist or Active Lane keeping
Assist is activated, the multifunction display
shows the à symbol when the ignition is
switched on.
Menus and submenus205On-board computer and displaysZ

Deactivating delayed switch-off of the
exterior lighting temporarily:XBefore leaving the vehicle, turn the
SmartKey to position 0 in the ignition lock.XTurn the SmartKey to position 2 in the
ignition lock and back to position 0.
The exterior lighting delayed switch-off is
deactivated.
Delayed switch-off of the exterior lighting is
reactivated the next time you start the
engine.
Activating/deactivating the interior
lighting delayed switch-off
If you activate the Light. delay function,
the interior lighting remains on for 20
seconds after you remove the SmartKey from
the ignition lock.
XPress the = or ; button on the
steering wheel to select the Settings
menu.XPress the : or 9 button to select the
Lights submenu.XPress the a button to confirm.XPress the : or 9 button to select the
Light. Delay function.
When the Light. Delay function is
activated, the vehicle interior is displayed
in red in the multifunction display.XPress the a button to save the setting.
Vehicle
Activating/deactivating the automatic
door locking feature
If you select the Auto. Door Locks
function, the vehicle is centrally locked above
a speed of around 9 mph (15 km/h).
i For further information on the automatic
locking feature, see ( Y page 78).
XPress the = or ; button on the
steering wheel to select the Settings
menu.XPress the : or 9 button to select the
Vehicle submenu.XPress the a button to confirm.XPress the : or 9 button to select the
Auto. Door Locks function.
When the Auto. Door Locks function is
activated, the vehicle doors are displayed
in red in the multifunction display.XPress the a button to save the setting.
Activating/deactivating the acoustic
locking verification signal
If you activate the Acoustic Lock function,
an audible signal sounds depending on the
vehicle's date of manufacture:
R when locking
or
R once when unlocking and three times when
locking
XPress the = or ; button on the
steering wheel to select the Settings
menu.XPress the : or 9 button to select the
Vehicle submenu.XPress the a button to confirm.XPress the : or 9 button to select the
Acoustic Lock function.
If the Acoustic Lock function is activated,
the & symbol in the multifunction
display lights up red.XPress the a button to save the setting.
Activating/deactivating the radar sensor
system
The following systems are switched off when
the radar sensor system is deactivated:
R DISTRONIC PLUS ( Y page 161)
R BAS PLUS ( Y page 60)
R PRE-SAFE ®
Brake ( Y page 65)
208Menus and submenusOn-board computer and displays

Safety systemsDisplay messagesPossible causes/consequences and M Solutions!÷
Currently
Unavailable See
Operator's ManualGRisk of accident
ABS (Anti-lock Braking System), ESP ®
(Electronic Stability
Program), BAS (Brake Assist), the HOLD function and hill start
assist are temporarily unavailable.
BAS PLUS and PRE-SAFE ®
Brake may also have failed.
In addition, the ÷, å and ! warning lamps light up in
the instrument cluster.
The self-diagnosis function might not be complete, for example.
ATTENTION ASSIST is deactivated.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
XCarefully drive a suitable distance making slight steering
movements at a speed above 12 mph (20 km/h).
If the display message disappears, the functions mentioned
above are available again.
If the display message continues to be displayed:
XDrive on carefully.XVisit a qualified specialist workshop.GRisk of accident
ABS, ESP ®
, BAS, the HOLD function and hill start assist are
temporarily unavailable.
BAS PLUS and PRE-SAFE ®
Brake may also have failed.
In addition, the ÷, å and ! warning lamps light up in
the instrument cluster.
For example, the on-board voltage may be insufficient.
ATTENTION ASSIST is deactivated.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
XDrive on carefully.
If the display message disappears, the functions mentioned
above are available again.
If the display message continues to be displayed:
XDrive on carefully.XVisit a qualified specialist workshop.214Display messagesOn-board computer and displays