2012 MERCEDES-BENZ B-CLASS length

X
To activate: activate the Adaptive
Highbeam Assist function using the on-
board computer ( Y page 197).
X Turn the light switch to Ã.
X Press the combination switch beyond the
pressure point in
the direction of arrow :
(Y page 100).
The _ indicator lamp in the
multifunction display lights up if it is dark
and the light sensor activates the low-beam
headlamps.
If you are driving at speeds above
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 are driving at speeds above
approximately 35 mph (55 km/h) and no
other road users have been detected:
The high-beam headlamps are switched on
automatically. The K indicator lamp in
the instrument cluster also lights up.
If you are driving at speeds below
approximately 30 mph (45 km/h) or other
road users have been detected or the roads
are adequately lit: The high-beam headlamps are switched off
automatically. The
K indicator lamp in
the instrument cluster goes out. The _
indicator lamp in the multifunction display
remains lit.
X To deactivate: move the combination
switch back to its normal position.
The _ indicator lamp in the
multifunction display goes out. Headlamps fogged up on the inside
The headlamps may fog up on the inside if
there is high atmospheric humidity.
X Switch on the lights and drive off.
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:
X Have the headlamps checked at a qualified
specialist workshop. Interior lighting
Overview of interior lighting
Front overhead control panel
:
p To switch the left-hand front reading
lamp on/off
; c To switch the front interior lighting
on
= v

To switch the on/off Interior lighting
103
Lights and windshield wipers Z
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X
Attach the bulb holder and press firmly.
The retaining lugs on the bulb holder
engage audibly.
X Close the side trim panel ( Y page 109).
Backup lamp and rear fog lamp
Due to their location, have the bulbs in the
backup lamp and
rear fog lamp in the tailgate
changed at a qualified specialist workshop.
X Switch off the lights.
X Open the tailgate. X
In recess ? on the inside of the closing
handle, pry off and remove the upper
section of handle =

with a flat and smooth
object, e.g. a screwdriver.
X Pull the lower section of handle : using a
sharp, sudden
movement

to remove it from
the trim and then place it to one side. X
Reach under the right-hand side of trim
B and apply

a gentle jolting force along the
entire length of the trim in order to unclip
it. X
Pull out connector C of the surround
lighting by releasing the latches.
X Place trim B to one side. X
On the side where the bulb is to be
changed, unclip the remaining part of trim
D from the assembly using a sudden,
sharp movements, until bulb holder E is
accessible. X
Remove bulb holder E
using both

sides of
lever F. 110
Replacing bulbs
Lights and windshield wipers
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engine is switched off. The sounds that can
be heard
while
this is occurring are normal.
Applying/releasing manually Applying
X
Push handle :.
When the electric parking brake is
engaged, the !

red indicator lamp lights
up in the instrument cluster.
i The electric parking brake can also be
applied when the SmartKey is removed.
Releasing
X Pull handle :.
The red ! indicator lamp in the
instrument cluster goes out.
i You can only release the electric parking
brake when the key is in position 1 or 2 in
the ignition lock.
Applying automatically The electric parking brake is applied
automatically:
R
if DISTRONIC PLUS brings the vehicle to a
standstill or
R if the HOLD

function is keeping the vehicle
stationary
In addition, at least one of the following
conditions must be fulfilled:
R the engine is switched off.
R the driver's door is open and the seat belt
is not fastened.
R there is a system malfunction.
R the power supply is insufficient.
R the vehicle is stationary for a lengthy
period.
The red ! indicator lamp in the instrument
cluster lights up.
i The electric parking brake is not
automatically engaged if the engine is
switched off by the ECO start/stop
function. Releasing automatically Your vehicle's electric parking brake is
automatically released if all of the following
conditions are met:
R
the engine is running.
R the transmission is in position D or R.
R the seat belt has been fastened.
R you depress the accelerator pedal.
If the transmission

is in position R, the tailgate
must be closed.
If your seat belt is not fastened, the following
conditions must be fulfilled to automatically
release the electric parking brake:
R the driver's door is closed.
R you have shifted out of transmission
position P or you have previously driven
faster than 2 mph (3 km/h).
Emergency braking The vehicle can also be braked during an
emergency by using the electric parking
brake.
X
While driving, push handle : of the
electric
parking brake ( Y page 150).
i The vehicle is braked for as long as
handle : of the electric parking brake is
pressed. The longer electric parking brake
handle : is depressed, the greater the
braking force.
During braking:
R a warning tone sounds
R the Release Park. Brake message
appears
R the red ! indicator lamp in the
instrument cluster flashes
When the vehicle has been braked to a
standstill, the electric parking brake is
engaged. Parking
151
Driving and parking Z
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Driving to the final position
:
White lane at current steering wheel angle
; Parking space marking
X Turn the steering wheel to the center
position while the vehicle is stationary. :
Red guide line at a distance of
approximately 10 in (0.25 m
) from the
rear of the vehicle
; White lane with steering wheel straight
= End of parking space
X Back up carefully until you have reached
the final position.
Red guide line :
is
then

at end of parking
space =. The vehicle is almost parallel in
the parking space. ATTENTION ASSIST
General notes ATTENTION ASSIST helps you during long,
monotonous journeys, such as on 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.
Important safety notes
ATTENTION ASSIST is only an aid to the
driver. It might not always recognize fatigue
or increasing
inattentiveness

in time or fail to
recognize them at all. The system is not a
substitute for a well-rested and attentive
driver.
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 journey details, e.g. time of day and length
of journey
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 are predominantly driving slower
than 50 mph (80 km/h) or faster than
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 speed180
Driving systems
Driving and parking
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Folding the rear seat backrest back
X
Move the driver's or front-passenger seat
forward if necessary.
! Make sure that the seat belt does not
become trapped when
folding the rear seat
backrest back. Otherwise, it could be
damaged.
X Swing backrest : back.
X Adjust the backrest to the desired angle by
pulling the loop ( Y page 242).
X Adjust the head restraints if necessary
(

Y page 90).
X Move the driver's or front-passenger seat
back if necessary.
Notes on using the cargo compartment Load position Making the best use of your cargo
compartment:
R
Load capacity is increased when
backrest : is set

to the load position (90°)
(Y page 242).
R Vehicles with a height-adjustable trunk
floor: a level load surface can be obtained
by moving the trunk floor to the upper
position (Y page 246).
R A larger load area can be obtained by
moving the rear bench seat as far forward
as possible ( Y page 243).
R The load area can be lengthened by folding
forward the folding backrest of the front-
passenger seat ( Y page 239) and the
corresponding backrest in the rear.
Adjusting the angle of the rear seat
backrests
You can set the angle of the seat backrests
to one of 13 detent positions. X
Pull right or left release loop ; forwards in
the direction of the arrow.
Corresponding seat backrest

: is
released.
X Pull backrest : forward
in
the direction of
the arrow, or push it back and let it engage.
X To ensure that the backrest has engaged,
lean firmly against backrest :.
i The angle and

fore/aft position of the left
and right rear seats can be separately
adjusted for each seat in order to make
better use of the cargo compartment. 242
Stowage areas
Stowage and features
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necessary for you to disconnect the battery
yourself, make sure that:
R
you switch off
the engine and remove the
SmartKey. Check that all the indicator
lamps in the instrument cluster are off.
Otherwise, electronic components, such
as the alternator, may be damaged.
R you first remove the negative terminal
clamp and then the positive terminal
clamp. Never swap the terminal clamps.
Otherwise, the vehicle's electronic
system may be damaged.
R on vehicles with automatic transmission,
the transmission is locked in position P
after disconnecting the battery. The
vehicle is secured against rolling away.
You can then no longer move the vehicle.
The battery and the cover of the positive
terminal clamp must be installed securely
during operation.
Comply with safety precautions and take
protective measures when handling
batteries. WARNING
Fire, open flames and smoking are
prohibited when handling the
battery. Avoid creating sparks.
Battery acid is caustic. Avoid
contact with the skin, eyes or
clothing.
Wear suitable protective clothing,
in particular gloves, an apron and
a face mask.
Immediately rinse acid splashes
off with clean water. Consult a
doctor if necessary.
Wear eye protection. Keep children away.
Observe this Operator's Manual.
For safety reasons, Mercedes-Benz
recommends that you only use batteries
which have been tested and approved for
your vehicle by Mercedes-Benz. These
batteries provide increased impact
protection to prevent

vehicle occupants from
suffering acid burns should the battery be
damaged in the event of an accident.
In order for the battery to achieve the
maximum possible service life, it must always
be sufficiently charged.
Like other batteries, the vehicle battery may
discharge over time if you do not use the
vehicle. In this case, have the battery
disconnected at a qualified specialist
workshop. You can also charge the battery
with a charger recommended by Mercedes-
Benz. Contact a qualified specialist workshop
for further information.
Have the battery charge level checked more
frequently if you use the vehicle mainly for
short trips or if you leave it standing idle for
a lengthy period. Consult a qualified specialist
workshop if you wish to leave your vehicle
parked for a long period of time.
Only replace a battery with a battery that has
been recommended by Mercedes-Benz.
i Remove the SmartKey if you park the
vehicle and do not require any electrical
consumers. The vehicle will then use very
little energy, thus conserving battery
power. Battery (vehicle)
287
Breakdown assistance Z
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Jump-starting
For the jump-starting
procedure, use only the jump-starting connection point, consisting of a
positive terminal and an earth point, in the engine compartment. G
WARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with the skin, eyes or clothing. Do not inhale any battery gases. Do not lean over
the battery. Keep children away from batteries. Wash battery acid immediately with water and
seek medical attention. G
WARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk
of an explosion.
Particularly avoid fire, open flames, creating sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting. Do not lean over a battery. G
WARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or sparks
are created, the hydrogen gas can ignite. There is a risk of an explosion.
R Make sure that the positive terminal of a connected battery does not come into contact with
vehicle parts.
R Never place metal objects or tools on a battery.
R It is important

that you observe the described order of the battery terminals when connecting
and disconnecting a battery.
R When jump-starting, make sure that the battery poles with identical polarity are connected.
R It is particularly important to observe the described order when connecting and disconnecting
the jumper cables.
R Never connect or disconnect the battery terminals while the engine is running. G
WARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting the
vehicle or charging

the battery, gases can escape from the battery. There is a risk of an explosion.
Allow the frozen battery to thaw out before charging it or jump-starting. G
WARNING
Non-combusted fuel can collect in the exhaust system and ignite. There is a risk of fire. Avoid
repeated and lengthy starting attempts.
! Avoid repeated and

lengthy starting attempts. Otherwise, the catalytic converter could be
damaged by the non-combusted fuel.
If, at low temperatures, the indicator lamps/warning lamps in the instrument cluster do not
light up, it is highly likely that the discharged battery has frozen. In this case you may neither
jump-start the vehicle nor charge the battery. The service life of a thawed-out battery may be Jump-starting
289
Breakdown assistance Z
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Refrigerant instruction label
Example: refrigerant instruction label
:
Warning symbol
; Refrigerant filling capacity
= Applicable SAE standards
? PAG oil part number
A Type of refrigerant
Warning symbols : indicate:
R possible dangers
R that it is necessary to have maintenance
work carried out at a qualified specialist
workshop
Filling capacities All models Capacity
Refrigerant
650 ± 10 g
(22.9 ± 0.4 oz) PAG oil
120 g
(4.2 oz) Vehicle data
General notes
Please note that for the specified vehicle
data:
R the heights specified may vary as a result
of:
-tires
- load
- condition of the suspension
- optional equipment
Dimensions and weights Model :
Maximum
headroom ;
Opening height B 250
BlueEFFICIEN
CY
73.8 in
(1874 mm) 78.0 in
(1981 mm) B 250 BlueEFFICIENCY
Vehicle length
171.6 in
(4359 mm) Vehicle width
including exterior
mirrors
79.1 in
(2010 mm) Vehicle height
61.3 in
(1558 mm) Wheelbase
106.3 in
(2699 mm) Vehicle data
335Technical data Z
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