computer MERCEDES-BENZ C-Class SEDAN 2012 W204 Owner's Guide

XMake sure that the SmartKey is in position
1 or 2 in the ignition lock.XBriefly press button :.
Both exterior mirrors fold in or out.
i Make sure that the exterior mirrors are
always folded out fully while the vehicle is
in motion, as they may otherwise vibrate.
i If you are driving faster than
9 mph (15 km/h), you can no longer fold in
the exterior mirrors.
Setting the exterior mirrors
This function is only available in vehicles for
Canada.
If the battery has been disconnected or
completely discharged, the exterior mirrors
must be reset. The exterior mirrors will
otherwise not fold in when you select the
"Fold in mirrors when locking" function in the
on-board computer ( Y page 209).
XMake sure that the SmartKey is in
position 1 in the ignition lock.XBriefly press button :.
Folding the exterior mirrors in or out
automatically
This function is only available in vehicles for
Canada.
If the "Fold in mirrors when locking" function
is activated in the on-board computer
( Y page 209):
R the exterior mirrors fold in automatically as
soon as you lock the vehicle from the
outside.
R the exterior mirrors fold out again
automatically as soon as you unlock the
vehicle and then open the driver's or front-
passenger door.
i The mirrors do not fold out if they have
been folded in manually.
Exterior mirror out of position
If an exterior mirror has been pushed out of
position, proceed as follows:
XVehicles without electrically folding
exterior mirrors: move the exterior mirror
into the correct position manually.XVehicles with electronically folding
mirrors 6
: press the mirror-folding button
( Y page 101) repeatedly until you hear the
mirror engage in position.
The mirror housing is engaged again and
you can adjust the exterior mirrors as usual
( Y page 101).
Automatic anti-glare mirrors
GWARNING
If incident light from headlamps is prevented
from striking the sensor in the rear-view
mirror, for instance, by luggage piled too high
in the vehicle, the mirror's automatic anti-
glare function will not operate.
Incident light could then blind you. This may
distract you from the traffic conditions and,
as a result, you may cause an accident.
The rear-view mirror and the exterior mirror
on the driver's side automatically go into anti-
glare mode if the ignition is switched on and
incident light from headlamps strikes the
sensor in the rear-view mirror.
The mirrors do not go into anti-glare mode if
reverse gear is engaged or the interior lighting
is switched on.
Parking position for the exterior
mirror on the front-passenger side
Setting and storing the parking position
You can position the front-passenger side
exterior mirror in such a way that you can see
the rear wheel on that side as soon as you
6 Canada only102MirrorsSeats, steering wheel and mirrors

steering wheel): you can activate the
daytime running lamps function using the
on-board computer ( Y page 207).XTurn the light switch to c or à .
With the engine running: depending on the
ambient light, the daytime running lamps or
the low-beam headlamps are switched on.
When the low-beam headlamps are
switched on, the L indicator lamp in the
instrument cluster lights up.
It is only possible to activate the high-beam
headlamps if the brightness of the ambient
light is at a low level.
However, the high-beam flasher can always
be used.
If the engine is running and you turn the light
switch to T or L , the manual settings
take precedence over the daytime running
lamps.
Automatic headlamp mode
XTo switch on automatic headlamp
mode: turn the light switch to c or
à .
SmartKey in position 1 in the ignition lock:
the parking lamps are switched on or off
automatically depending on the brightness
of the ambient light.
With the engine running: depending on the
brightness of the ambient light, the daytime
running lamps 8
or the low-beam headlamps
are switched on or off automatically.
When the low-beam headlamps are
switched on, the L indicator lamp in the
instrument cluster lights up.GWARNING
If the light switch is set to c or à , the
low-beam headlamps will not come on
automatically if it is foggy. This could
endanger you and others. Therefore, turn the
light switch to L in fog.
The automatic headlamp feature is only an
aid. The driver is responsible for the vehicle's
lighting at all times.
Front fog lamps
Only vehicles with front fog lamps have the
fog lamps function.
GWARNING
If you suspect that driving conditions will be
foggy, turn the light switch to L before you
start your journey. Otherwise, your vehicle
may not be visible and you could endanger
yourself and others.
XTo switch on the front fog lamps: turn
the SmartKey in the ignition lock to position
2 or start the engine.XTurn the light switch to L or c or
à .XPress the N button.
The green N indicator lamp in the
instrument cluster lights up.XTo switch off the front fog lamps: press
the N button.
The green N indicator lamp in the
instrument cluster goes out.
Rear fog lamp
XTo switch on the rear fog lamp: turn the
SmartKey in the ignition lock to position 2
or start the engine.XTurn the light switch to L or c or
à .
If the light switch is set to c or à ,
the rear fog lamp only lights up if the low-
beam headlamps are on.8 Only if daytime running lamps have been activated via the on-board computer.108Exterior lightingLights and windshield wipers

The system automatically adapts the low-
beam headlamp range depending on the
distance to the other vehicle. Once the
system no longer detects any other vehicles,
it reactivates the high-beam headlamps.
The system's optical sensor is located behind
the windshield near the overhead control
panel.XTo activate: activate the Adaptive
Highbeam Assist function using the on-
board computer ( Y page 207).XTurn the light switch to c or à .XPress the combination switch beyond the
pressure point in the direction of arrow :
( Y page 109).
If it is dark and the light sensor activates
the low-beam headlamps, the _
indicator lamp in the instrument cluster
lights up.
If you drive faster than approximately
28 mph (45 km/h):
the headlamp range is set automatically
depending on the distance between the
vehicle and other road users.
If you drive faster than approximately
35 mph (55 km/h) and no other road users
are identified:
the high-beam headlamps are switched on
automatically. The K indicator lamp in
the instrument cluster also lights up.When you drive slower than approximately
30 mph (45 km/h) or if other road users
are identified or if the roads are sufficiently
illuminated:
the high-beam headlamps are switched off
automatically. The K indicator lamp in
the instrument cluster goes out. The _
indicator lamp in the instrument cluster
stays on.XTo deactivate: move the combination
switch back to its normal position.
The _ indicator lamp in the instrument
cluster goes out.GWARNING
The Adaptive Highbeam Assist is only an aid
intended to support you while driving. The
driver is and remains responsible for proper
vehicle lighting in accordance with the
prevailing light, sight and traffic conditions.
The system may be impaired or unavailable
when
R visibility is poor, e.g. due to snow, rain, fog,
or heavy spray
R the optical sensor area of the windshield is
dirty, fogged up, or covered by a sticker for
example
The system cannot recognize the following
road users:
R Road users without a lighting system of
their own, e.g. pedestrians
R Road users with dim lighting of their own,
e.g. cyclists
R Road users whose lighting is obstructed,
e.g. road users behind a guardrail
R In some seldom cases, even road users with
a lighting system of their own may be
recognized too late or not at all.
The automatic high-beam headlamps will then
not be deactivated or it will be activated in
spite of preceding or oncoming road users.
This could endanger you and/or others and
cause an accident. Always pay close attention
to the traffic situation and switch off the high
beam manually if necessary.
Exterior lighting111Lights and windshield wipersZ

Headlamps fogged up on the inside
The headlamps may fog up on the inside if
there is high atmospheric humidity.XDrive with the headlamps switched on.
The level of moisture diminishes,
depending on the length of the journey and
the weather conditions (humidity and
temperature).
If the level of moisture does not diminish:
XHave the headlamps checked at a qualified
specialist workshop.
Interior lighting
Overview of interior lighting
Front overhead control panel
:u Switches the rear interior lighting
on/off;| Switches the automatic interior
lighting control on/off=p Switches the right-hand front
reading lamp on/off?c Switches the front interior lighting
on/offAp Switches the left-hand front reading
lamp on/off
Rear-compartment overhead control panel
:p Switches the right-hand reading
lamp on/off;p Switches the left-hand reading lamp
on/off
Interior lighting control
Important notes
In order to prevent the vehicle's battery from
discharging, the interior lighting functions are
automatically deactivated after some time
except for when the SmartKey is in position
2 in the ignition lock.
Automatic interior lighting control
XTo switch on/off: press the | button.
When the automatic interior lighting
control is activated, the button is flush with
the overhead control panel.
The interior lighting automatically switches
on if you:
R unlock the vehicle
R open a door
R remove the SmartKey from the ignition lock
The interior light is activated for a short while
when the SmartKey is removed from the
ignition lock. You can activate this delayed
switch-off using the on-board computer
( Y page 208).
112Interior lightingLights and windshield wipers

Setting the specified minimum distance
You can set the specified minimum distance
for DISTRONIC PLUS by varying the time span
between one and two seconds. With this
function, you can set the minimum distance
that DISTRONIC PLUS keeps to the vehicle in
front, dependent on vehicle speed. You can
see this distance in the multifunction display
( Y page 168).
GWARNING
It is up to the driver to exercise discretion to
select the appropriate setting given road
conditions, traffic, driver's preferred driving
style and applicable laws and driving
recommendations for safe following distance.
XTo increase: turn control ; in direction
= .
DISTRONIC PLUS then maintains a greater
distance between your vehicle and the
vehicle in front.XTo decrease: turn control ; in
direction :.
DISTRONIC PLUS then maintains a shorter
distance between your vehicle and the
vehicle in front.
i Make sure that you maintain a sufficient
and safe distance from the vehicle in front.
Adjust the distance to the vehicle in front if
necessary.
DISTRONIC PLUS displays in the
speedometer
When DISTRONIC PLUS is activated, one or
two segments ; in the set speed range light
up.
i For design reasons, the speed displayed
in the speedometer may differ slightly from
the speed set for DISTRONIC PLUS.
If DISTRONIC PLUS detects a vehicle in front,
segments ; between speed of the vehicle in
front : and stored speed = light up.
DISTRONIC PLUS displays in the
multifunction display
General notes
You can select the distance display in the
Assistance menu ( Y page 204) of the on-
board computer.
Display when DISTRONIC PLUS is
deactivated
XSelect the Distance Display function
using the on-board computer
( Y page 204).
When DISTRONIC PLUS is deactivated, you
will see the following in the multifunction
display:
168Driving systemsDriving and parking

:Symbol for activated PRE-SAFE®
Brake;Vehicle in front, if detected=Distance indicator, current distance to
the vehicle in front?Specified minimum distance to the
vehicle in front; adjustableAOwn vehicle
Display when DISTRONIC PLUS is
activated
XSelect the Distance Display function
using the on-board computer
( Y page 204).
You will see the stored speed for about five
seconds when you activate DISTRONIC PLUS.
After this time, you will see the following in
the multifunction display while DISTRONIC
PLUS is activated:
:DISTRONIC PLUS activated;Own vehicle=Specified minimum distance to the
vehicle in front; adjustable?Vehicle in front, if detectedDeactivating DISTRONIC PLUS
There are several ways to deactivate
DISTRONIC PLUS:
XBriefly press the cruise control lever
forwards :.
or
XBrake, unless the vehicle is stationary.
When you deactivate DISTRONIC PLUS, the
DISTRONIC PLUS Off message is shown in
the multifunction display for approximately
five seconds.
i The last speed stored remains stored until
you switch off the engine.
i DISTRONIC PLUS is not deactivated if you
depress the accelerator pedal. If you
accelerate to overtake, DISTRONIC PLUS
adjusts the vehicle's speed to the last
speed stored after you have finished
overtaking.
DISTRONIC PLUS is automatically
deactivated if:
R you apply the parking brake.
R you are driving slower than
15 mph (25 km/h) and there is no vehicle
in front, or if the vehicle in front is no longer
detected.
R ESP ®
intervenes or you deactivate ESP ®
.
R the transmission is in the P, R or N position.
R you switch off the radar sensor system
( Y page 208).
R you pull the cruise control lever towards
you in order to pull away and the front-
Driving systems169Driving and parkingZ

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

Indicator and warning display:Yellow indicator lamp/red warning lamp
When 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 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, Blind Spot
Assist is no longer active.
The brightness of the indicator/warning
lamps is adjusted automatically according to
the ambient light.
GWARNING
Blind Spot Assist is not active at speeds under
approximately 20 mph (30 km/h). The
indicator lamps in the exterior mirrors are
yellow. Vehicles in the monitoring range are
then not indicated.
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.
Collision warning
If a vehicle is detected in the monitoring range
of Blind Spot Assist and you switch on the turn
signal, a double warning tone sounds. Red
warning lamp : flashes. If the turn signal
remains on, detected vehicles are indicated
by the flashing of red warning lamp :. There
are no further warning tones.
Switching on Blind Spot AssistXMake sure that the radar sensor system
( Y page 208) and Blind Spot Assist
( Y page 205) are activated in the on-board
computer.XTurn the SmartKey to position 2 in the
ignition lock.
Warning lamps : light up red in the
exterior mirrors for approximately 1.5
seconds and then turn yellow.
Lane Keeping Assist
Important safety notes
Lane Keeping Assist monitors the area in
front of your vehicle by means of a camera at
the top of the windshield. Lane Keeping Assist
detects lane markings on the road and warns
you before you leave your lane
unintentionally.
:Lane Keeping Assist camera
If you have chosen 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
Driving systems185Driving 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

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.
Visual and audible collision warnings
If you switch on the appropriate turn signals
and a vehicle is detected in the side
monitoring range, you will receive a visual and
acoustic collision warning. You will hear a
double warning tone and red warning
lamp : flashes. If the turn signal remains on,
vehicles detected are indicated by the
flashing of red warning lamp :. There are no
further warning tones.
Course-correcting brake application
If Active Blind Spot Assist detects a risk of a
lateral collision in the monitoring range, a
course-correcting brake application is carried
out. This is meant to assist you in avoiding a
collision.
The course-correcting brake application is
available in the range between 20 mph
(30 km/h) and 120 mph (200 km/h).
If a course-correcting brake application
occurs, red warning lamp : flashes in the
exterior mirror and the following is shown in
the multifunction display, for example:GWARNING
Active Blind Spot Assist is only an aid
designed to assist driving. It is not a substitute
for attentive driving. In some cases, the
course-correcting brake application is not
sufficient to avoid a collision. In such a case,
you must steer, brake or accelerate.
In very rare cases, the system may
erroneously detect a danger of collision in the
area of crash barriers or similar lane borders
and apply the brakes. Active Blind Spot Assist
does not detect all traffic situations and road
users. Always make sure that there is
sufficient distance on the side for other traffic
or obstacles. An inappropriate brake
application may be interrupted at any time if
you steer slightly in the opposite direction or
accelerate.
You are responsible for 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.
There will be either no or only a weak course-
correcting brake application if:
R there are vehicles or obstacles, e.g. crash
barriers, located on both sides of your
vehicle.
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 AssistXMake sure that the radar sensor system
( Y page 208) and Active Blind Spot Assist
( Y page 205) are activated in the on-board
computer.XTurn the SmartKey to position 2 in the
ignition lock.
Warning lamps : light up red in the
exterior mirrors for approximately 1.5
seconds and then turn yellow.Driving systems189Driving and parkingZ