light MERCEDES-BENZ B-CLASS 2012 Service Manual

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please note
that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Read the information on qualified
specialist workshops: ( Y page 24).Correct driver's seat position
Observe the safety guidelines on seat
adjustment (
Y page 87).
X Make sure that seat = is adjusted
properly.
Manual seat adjustment ( Y page 88)
Electrical seat adjustment ( Y page 88)
When adjusting the seat, make sure that:
R you are as far away from the driver's air
bag as possible.
R you are sitting in a normal upright
position.
R you can fasten the seat belt properly. R
you have moved the backrest to an
almost vertical position.
R you have set the seat cushion angle so
that your thighs are gently supported.
R you can depress the pedals properly.
X Check whether the head restraint is
adjusted properly ( Y page 89).
When doing so, make sure that you have
adjusted

the head restraint so that the back
of your head is supported at eye level by
the center of the head restraint.
Observe the safety guidelines on steering
wheel adjustment ( Y page 91).
X Make sure that steering wheel : is
adjusted properly.
Adjusting the steering wheel
(Y page 91)
When adjusting the steering wheel, make
sure that:
R you can hold

the steering wheel with your
arms slightly bent.
R you can move your legs freely.
R you can see all the displays in the
instrument cluster clearly.
Observe the safety guidelines for seat belts
(Y page 45).
X Check whether you have fastened seat
belt ; properly ( Y page 47).
The seat belt should:
R fit snugly across your body
R be routed across the middle of your
shoulder
R be routed in your pelvic area across the
hip joints
X Before starting off, adjust the rear-view
mirror and the exterior mirrors
(

Y page 92) in such a way that you have
a good view of road and traffic conditions.
X Vehicles with a memory function: save
the seat and exterior mirror settings
(Y page 95). 86
Correct driver's seat position
Seats, steering wheel and mirrors
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heating should also not be used to dry
the seats.
R clean the seat covers as recommended;
see the "Interior care" section.
R do not transport heavy loads on the
seats. Do not
place sharp objects on the
seat cushions, e.g. knives, nails or tools.
The seats should only be occupied by
passengers, if possible.
R when the seat heating is in operation, do
not cover the seats with insulating
materials, e.g. blankets, coats, bags,
seat covers, child seats or booster seats.
! Make sure that there are no objects in the
footwell or behind the seats when resetting
the seats. There is a risk that the seats
and/or the objects could be damaged.
i The head restraints in the front and rear
seats can be removed. 1
For more information, contact a qualified
specialist workshop.
i Further related subjects:
R Luggage compartment enlargement
(folding down the rear seats)
(Y page 240) Adjusting the seats manually Seat fore-and-aft adjustment
X
Lift handle : and slide the seat forwards
or backwards.
X Release lever : again.
Make sure
that

you hear the seat engage in
position.
Backrest angle X
Relieve the pressure on the backrest.
X Turn handwheel ? forwards or
backwards.
Seat height X
Pull handle = upwards or push it down
repeatedly until the seat has reached the
desired height.
Seat cushion angle Adjust the angle so that your thighs are lightly
supported.
X
Turn handwheel ; forwards or
backwards. Adjusting the seats electrically
:
Head restraint height 2
; Seat cushion angle
= Seat height
? Seat fore-and-aft adjustment
A Backrest angle
1 Not on vehicles with sports seats.
2 Not available on vehicles with sports seats.88
Seats
Seats, steering wheel and mirrors
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Rear seat head restraints
Adjusting the rear seat head restraint
height
X
To raise: pull the head restraint up to the
desired position.
X To lower: press release catch : and push
the head restraint down until it is in the
desired position.
Removing and installing the rear seat
head restraints G
WARNING
If head restraints are not installed and
adjusted correctly, they cannot provide
protection as intended.

There is an increased
risk of injury in the head and neck area, e.g.
in the event of an accident or when braking.
Always drive with the head restraints
installed. Before driving off, make sure for
every vehicle occupant that the center of the
head restraint supports the back of the head
at about eye level.
The rear head restraints on the outer seats
can be removed and re-installed. X
Fold the seat backrest slightly forwards in
order to remove the head restraint
(Y page 240).
X To remove: pull the head restraint up to
the stop.
X Press release catch : and pull the head
restraint out of the guides.
X To re-install: insert the head restraint so
that the notches on the bar are on the left
when viewed in the direction of travel.
X Push the head restraint down until you hear
it engage in position. Adjusting the 4-way lumbar support
You can adjust the contour of the front seat
backrests individually to provide optimum
support for your back. :
To raise the backrest contour
; To soften the backrest contour
= To lower the backrest contour
? To harden the backrest contour90
Seats
Seats, steering wheel and mirrors
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Switching the seat heating on/off
Activating/deactivating G
WARNING
Repeatedly switching on the seat heating can
cause the seat cushion and backrest pads to
become very hot. The health of persons with
limited temperature sensitivity or a limited
ability to react to excessively high
temperatures may be affected or they may
even suffer burn-like injuries. There is a risk
of injury.
Therefore, do not switch the seat heating on
repeatedly. The three red indicator lamps in the button
indicate the heating level you have selected.
The system automatically switches down
from level 3 to level 2 after approximately
eight minutes.
The system automatically switches down
from level
2
to level 1 after approximately ten
minutes.
The system automatically switches off
approximately 20 minutes after it is set to
level 1.
X Make sure that the SmartKey is in position
1 or 2 in the ignition lock.
X To switch on: press button : repeatedly
until the desired heating level is set.
X To switch off: press button : repeatedly
until all the indicator lamps go out.
i If the battery voltage is too low, the seat
heating may switch off. Problems with the seat heating The seat heating has switched off
prematurely or cannot be switched on. The
vehicle's electrical system voltage is too low
because too many electrical consumers are
switched on.
X
Switch off electrical consumers that you do
not need, such as the rear window
defroster or interior lighting. Steering wheel
Important safety notes
G
WARNING
You could lose control of your vehicle if you
do the following while driving:
R adjust the driver's seat, head restraint,
steering wheel or mirrors
R fasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint,
steering wheel and mirror and fasten your
seat belt before starting the engine. G
WARNING
Children could injure themselves if they
adjust the steering wheel. There is a risk of
injury.
When leaving the vehicle, always take the
SmartKey with you

and lock the vehicle. Never
leave children unsupervised in the vehicle. Adjusting the steering wheel
G
WARNING
If the steering wheel is unlocked while the
vehicle is in motion, it could change position
unexpectedly. This could cause you to lose
control of the vehicle. There is a risk of an
accident.
Before starting off, make sure the steering
wheel is locked. Never unlock the steering
wheel while the vehicle is in motion. Steering wheel
91
Seats, steering wheel and mirrors Z
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:
Release lever
; To adjust the steering wheel height
= To adjust the steering wheel position
(fore-and-aft adjustment)
X Push release lever : down completely.
The steering column is unlocked.
X Adjust the steering wheel to the desired
position.
X Push release lever : up completely.
The steering column is locked.
X Check if the steering column is locked.
When doing so, try to push the steering
wheel up or down or try to move it in the
fore-and-aft direction. Mirrors
Rear-view mirror
X
Anti-glare mode: flick anti-glare lever :
forwards or back. Exterior mirrors
Adjusting the exterior mirrors G
WARNING
The exterior mirror on the front-passenger
side reduces the size of the image. Visible
objects are actually closer than they appear.
This means that you could misjudge the
distance from road users traveling behind,
e.g. when changing
lane. There is a risk of an
accident.
For this reason, always make sure of the
actual distance from the road users traveling
behind by glancing over your shoulder. X
Make sure that the SmartKey is in position
1 or 2 in the ignition lock.
X Press button : for the left-hand exterior
mirror or button ; for the right-hand
exterior mirror.
The indicator lamp in the corresponding
button lights up in red.
The indicator lamp goes out again after
some time. You can adjust the selected
mirror using adjustment button = as long
as the indicator lamp is lit.
X Press adjustment button = up, down, or
to the left or right until you have adjusted
the exterior mirror to the correct position.
You should have a good overview of traffic
conditions.
The convex exterior mirrors provide a larger
field of vision.
The exterior
mirrors

are automatically heated
after starting the vehicle if the rear window 92
Mirrors
Seats, steering wheel and mirrors
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defroster is switched on and the outside
temperature is
low.
Mirror heating lasts up to
10 minutes.
i You can also heat up the exterior mirrors
manually by switching on the rear window
defroster.
Folding the exterior mirrors in or out
electrically X
Make sure that the SmartKey is in position
1 or 2 in the ignition lock.
X Briefly press button :.
Both exterior mirrors fold in or out.
i Make sure that the exterior mirrors are
always folded out fully while driving. They
could otherwise vibrate.
i If you are driving faster than
30 mph (47 km/h ), you can no longer fold
in the exterior mirrors.
Setting the exterior mirrors 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 199).
X Make sure that the SmartKey is in
position 1 in the ignition lock.
X Briefly press button :. Folding the exterior mirrors in or out
automatically If the "Fold in mirrors when locking" function
is activated in the on-board computer
(Y page 199):
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 If the exterior mirrors have been folded in
manually, they do not fold out.
Exterior mirror pushed out of position If an exterior mirror has been pushed out of
position, proceed as follows:
X
Vehicles without electrically folding
exterior mirrors:
move

the exterior mirror
into the correct position manually.
X Vehicles with electrically folding
exterior mirrors: press and hold mirror-
folding button ( Y page

93) until you hear a
click and then the mirrors engage in
position.
The mirror housing is engaged again and
you can adjust the exterior mirrors as usual
(Y page 92). Automatic anti-glare mirrors
The "Automatic anti-glare

mirrors" function is
only available if the vehicle is equipped with
the "Mirrors package".
The rear-view mirror and the exterior mirror
on the driver's side automatically go into anti-
glare mode if:
R the ignition is switched on and
R 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. Mirrors
93
Seats, steering wheel and mirrors Z
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Useful information ..............................
98
Exterior lighting .................................. 98
Interior lighting ................................. 103
Replacing bulbs ................................. 104
Windshield wipers ............................111 97Lights and windshield wipers
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Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please note
that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Read the information on qualified
specialist workshops: ( Y page 24).Exterior lighting
General notes
For reasons of safety, Mercedes-Benz
recommends that you drive with the lights
switched on even

during the daytime. In some
countries, operation of the headlamps varies
due to legal requirements and self-imposed
obligations. Driving abroad
Conversion to symmetrical low beam Switch the headlamps to symmetrical low
beam in countries in which traffic drives on
the opposite
side

of the road from the country
where the vehicle is registered. This prevents
glare to oncoming traffic. When using
symmetrical lights, the edge of the road is not
lit as widely and as far ahead as normal.
Have the headlamps converted at a qualified
specialist workshop as close to the border as
possible before driving in these countries.
Conversion to asymmetrical low beam
after returning Have the headlamps converted back to
asymmetrical low-beam headlamps at a
qualified specialist workshop as soon as
possible after crossing the border again. Setting the exterior lighting
Setting options Exterior lighting can be set using:
R
the light switch
R the combination switch ( Y page 100)
R the on-board computer (Y page 197)
Light switch Operation
1W
Left-hand standing lamps
2X Right-hand standing lamps
3T Parking lamps, license plate and
instrument cluster lighting
4Ã Automatic headlamp mode,
controlled by the light sensor
5L Low-beam/high-beam headlamps
BR Rear fog lamp
CN Fog lamp (only vehicles with front fog
lamps)
If you hear a warning tone when you leave the
vehicle, the lights may still be switched on.
X Turn the light switch to Ã.
The exterior lighting (except the parking/
standing lamps) switches off automatically if
you:
R remove the
SmartKey

from the ignition lock
R open the driver's door with the SmartKey
in position 0.98
Exterior lighting
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Automatic headlamp mode
G
WARNING
When the light switch is set to Ã,
the low-
beam headlamps may not be switched on
automatically if there is fog, snow or other
causes of poor visibility due to the weather
conditions
such as spray. There is a risk of an
accident.
In such situations, turn the light switch to
L.
The automatic headlamp feature is only an
aid. The driver is responsible for the vehicle's
lighting at all times.
à is the favored light switch setting. The
light setting is automatically selected
according to the brightness of the ambient
light (exception: poor visibility due to weather
conditions such as fog, snow or spray):
R 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.
R With the engine running: if you have
activated the daytime running lamps
function via the on-board computer, the
daytime running lamps or the low-beam
headlamps and parking lamps are switched
on or off automatically depending on the
brightness of the ambient light.
X To switch on automatic headlamp
mode: turn the light switch to Ã.
The daytime running lamps improve the
visibility of your vehicle during the day. The
daytime running lamps

function is required by
law in Canada.
When the engine is running and the vehicle is
stationary: if you move the selector lever from
a drive position to P, the daytime running
lamps/low-beam headlamps go out after
three minutes.
When the engine is running, the vehicle is
stationary and in high ambient light: if you
turn the light switch to T, you turn on the
daytime running lamps and parking lamps. If the engine is running and you turn the light
switch to L, the manual settings take
precedence over the daytime running lamps.
Low-beam headlamps
Even if the light sensor does not detect that
it is dark, the parking lamps and low-beam
headlamps switch on when the ignition is
switched
on and

the light switch is set to the
L position. This is a particularly useful
function in the event of rain and fog.
X To switch on the low-beam headlamps:
turn the SmartKey in the ignition lock to
position 2 or start the engine.
X Turn the light switch to L.
The green L indicator lamp in the
instrument cluster lights up.
Front fog lamps
In conditions where visibility is poor due to
fog, snow or rain, the fog lamps improve
visibility as well as making it easier for other
road users to see you. They can be operated
together with the parking lamps or together
with the parking lamps and low-beam
headlamps.
X To switch on the front fog lamps: turn
the SmartKey in

the ignition lock to position
2 or start the engine.
X Turn the light switch to L or Ã.
X Press the N button.
The green N indicator lamp in the
instrument cluster lights up.
X To switch off the front fog lamps: press
the N button.
The green N indicator lamp in the
instrument cluster goes out.
Only vehicles with front fog lamps are
equipped with the "fog lamp" function;
information on the fog lamp function for
vehicles with Intelligent Light System
(Y page 102). Exterior lighting
99Lights and windshield wipers Z
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Rear fog lamp
The rear fog lamp improves visibility of your
vehicle for the traffic behind in the event of
thick fog. Please take note of the country-
specific regulations for the use of rear fog
lamps.
X
To switch on the rear fog lamps: turn the
SmartKey in the ignition lock to position 2
or start the engine.
X Turn the light switch to
L or Ã.
X Press the R button.
The yellow R indicator lamp in the
instrument cluster lights up.
X To switch off the rear fog lamp: press the
R
button.
The yellow R indicator lamp in the
instrument cluster goes out.
Parking lamps
! If the battery has been excessively
discharged, the parking lamps or standing
lamps are automatically switched off to
enable the next engine start. Always park
your vehicle safely and sufficiently lit
according to legal standards. Avoid the
continuous use of the T parking lamps
for several hours.

If possible, switch on the
X right or the W left standing lamp.
X To switch on: turn the light switch to
T.
The green T indicator lamp in the
instrument cluster lights up.
Standing lamps
Switching on the

standing lamps ensures the
corresponding side of the vehicle is
illuminated.
X To switch on the standing lamps: the
SmartKey is not in the ignition lock or it is
in position 0.
X Turn the light switch to W (left-hand side
of the vehicle) or
X (right-hand side of
the vehicle). Combination switch
Turn signal :
High-beam headlamps
; Turn signal, right
= High-beam flasher
? Turn signal, left
X To indicate briefly: press the
combination
switch briefly to the pressure point in the
direction of arrow

; or ?.
The corresponding turn signal flashes three
times.
X To indicate: press the combination
switch
beyond the pressure point in the direction
of arrow ; or ?.
High-beam headlamps X
To switch on the high-beam headlamps:
turn the SmartKey in the ignition lock to
position 2 or start the engine.
X Turn the light switch to L or Ã.
X Press the combination switch beyond the
pressure point in the direction of
arrow :.
In the à position, the high-beam
headlamps are only switched on when it is
dark and the engine is running. 100
Exterior lighting
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