wheel MERCEDES-BENZ B-CLASS 2012 Workshop Manual

i
On long journeys
at a constant speed, e.g.
on the highway, only the bar for Constant
will change.
i The ECO display summaries the driving
characteristics from the start of the journey
to its completion. For this reason, the bars
change dynamically at the beginning of the
journey. On longer journeys, there are
fewer changes. For more dynamic changes,
carry out a manual reset.
Further information on the ECO display
(Y page 190). Brakes
Important safety notes G
WARNING
If you shift down on a slippery road surface in
an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
There is an increased danger of skidding and
accidents.
Do not shift down for additional engine
braking on a slippery road surface.
Downhill gradients !
On long and steep gradients, you must
reduce the load

on the brakes by shifting to
a lower gear in good time. This allows you
to take advantage of the engine's braking
effect. For this, you need to have selected
manual drive program M. This helps you to
avoid overheating the brakes and wearing
them out excessively.
When you take advantage of the engine's
braking effect, a drive wheel may not turn
for some time, e.g. on a slippery road
surface. This could cause damage to the
drive train. This type of damage is not
covered by the Mercedes-Benz warranty.
i Briefly depressing the accelerator pedal
on downhill gradients while the manual
drive program M is temporarily activated:
the automatic transmission may switch to the last active automatic drive program
E
or S. The automatic

transmission may shift
to a higher gear. This can reduce the
engine's braking effect.
Heavy and light loads G
WARNING
If you rest your foot on the brake pedal while
driving, the braking

system can overheat. This
increases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately.
Drive on for a short while. This allows the
airflow to cool the brakes more quickly.
Wet roads If you have driven for a long time in heavy rain
without braking, there may be a delayed
reaction from
the

brakes when braking for the
first time. This may also occur after the
vehicle has been washed or driven through
deep water.
You have to depress the brake pedal more
firmly. Maintain a greater distance from the
vehicle in front.
After driving on a wet road or having the
vehicle washed, brake firmly while paying
attention to the traffic conditions. This will
warm up the brake discs, thereby drying them
more quickly and protecting them against
corrosion.
Limited braking performance on salt-
treated roads If you drive on salted roads, a layer of salt
residue may form on the brake discs and154
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Driving and parking
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Front wheel
Rear wheel
X
Bring the vehicle and wheels into a suitable
position so that you can attach test gauge
A.
X Secure the vehicle against rolling away
(Y page 149).
X Move the selector lever to position P.
X Switch off the engine.
X Place test gauge A between the wheel's
spokes on brake pad/lining =. X
Hold test gauge A vertically on brake
disc : and slide measuring pin ; onto
brake disc :.
X Check which color field ? the arrow on
measuring pin ; is pointing to.
Green: the brake pad/lining thickness is
sufficient.
Red: the brake pad/lining thickness is not
sufficient. Have the brake pads/lining
checked at
a
qualified specialist workshop.
i To avoid an inaccurate measurement:
R make sure you position the wheels
suitably
R do not
put

the measuring pin on a recess
in the brake disc Driving on wet roads
Hydroplaning If water has accumulated to a certain depth
on the road surface, there is a danger of
hydroplaning occurring, even if:
R
you drive at low speeds.
R the tires have adequate tread depth.
For this reason, in the event of heavy rain or
in conditions in which hydroplaning may
occur, you must drive in the following
manner:
R lower your speed.
R avoid ruts.
R brake carefully.
Driving on flooded roads !
Do not drive through flooded areas.
Check the depth

of any water before driving
through it. Drive slowly through standing
water. Otherwise, water may enter the
vehicle interior or the engine compartment.
This can damage the electronic
components in the engine or the automatic
transmission. Water can also be drawn in
by the engine's air suction nozzles and this
can cause engine damage. 156
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Winter driving
General notes G
WARNING
If you shift down on a slippery road surface in
an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
There is an increased danger of skidding and
accidents.
Do not shift down for additional engine
braking on a slippery road surface. G
DANGER
If the exhaust pipe is blocked or adequate
ventilation is not possible, poisonous gases
such as carbon
monoxide (CO) may enter the
vehicle. This is the case, e.g. if the vehicle
becomes trapped in snow. There is a risk of
fatal injury.
If you leave the engine or the auxiliary heating
running, make sure the exhaust pipe and area
around the vehicle are clear of snow. To
ensure an adequate supply of fresh air, open
a window on the side of the vehicle that is not
facing into the wind.
Have your vehicle winterproofed at a qualified
specialist workshop at the onset of winter.
Observe the notes in the "Winter operation"
section ( Y page 300).
Driving with summer tires Observe the notes in the "Winter operation"
section (
Y page 300).
Slippery road surfaces G
WARNING
If you shift down on a slippery road surface in
an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
There is an increased danger of skidding and
accidents.
Do not shift down for additional engine
braking on a slippery road surface. If the vehicle threatens to skid or cannot be
stopped when moving at low speed:
X
Shift the transmission to position N.
Drive particularly carefully on slippery road
surfaces. Avoid sudden

acceleration, steering
and braking maneuvers. Do not use the cruise
control or DISTRONIC PLUS.
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Changes in the outside temperature are
displayed after a short delay.
Indicated temperatures just above the
freezing point do not guarantee that the road
surface is free of ice. The road may still be icy,
especially in wooded areas or on bridges. You
should pay special attention to road
conditions when temperatures are around
freezing point.
i For more information on driving with
snow chains, see ( Y page 301). Driving systems
Cruise control
Important safety notes If you fail to adapt your driving style, cruise
control can neither reduce the risk of an
accident nor override the laws of physics.
Cruise control cannot take into account the
road, traffic and weather conditions. Cruise
control is only

an aid. You are responsible for
the distance to the vehicle in front, for vehicle
speed, for braking in good time and for
staying in your lane.
Do not use cruise control:
R in road and traffic conditions which do not
allow you to maintain a constant speed e.g.
in heavy traffic or on winding roads
R on slippery road surfaces. Braking or
accelerating could cause the drive wheels Driving systems
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In such cases, DISTRONIC PLUS may:
R
give an unnecessary warning and then
brake the vehicle
R neither give a warning nor intervene
R accelerate unexpectedly
There is a risk of an accident.
Continue to drive carefully and be ready to
brake, in particular when warned to do so by
DISTRONIC PLUS. G
WARNING
DISTRONIC PLUS brakes your vehicle with up
to 40% of the maximum braking force. If this
braking force is
insufficient, DISTRONIC PLUS
warns you visually and audibly. There is a risk
of an accident.
In such cases, apply the brakes yourself and
try to take evasive action.
! If DISTRONIC PLUS or the HOLD function
is activated, the vehicle brakes
automatically in certain situations. To
prevent damage to the vehicle, deactivate
DISTRONIC PLUS and the HOLD function in
the following or other similar situations:
R when towing the vehicle
R in the car wash
If you fail to adapt your driving style,
DISTRONIC PLUS can neither reduce the risk
of accident nor override the laws of physics.
DISTRONIC PLUS cannot take into account
the road, traffic and weather conditions.
DISTRONIC PLUS is only an aid. You are
responsible for the distance to the vehicle in
front, for vehicle speed, for braking in good
time and for staying in your lane.
Do not use DISTRONIC PLUS:
R in road and traffic conditions which do not
allow you to maintain a constant speed e.g.
in heavy traffic or on winding roads
R on slippery road surfaces. Braking or
accelerating could cause the drive wheels to lose traction and the vehicle could then
skid
R when there is

poor visibility, e.g. due to fog,
heavy rain or snow
DISTRONIC PLUS may not detect narrow
vehicles driving in front, e.g. motorcycles, or
vehicles driving on a different line.
In particular, the detection of obstacles can
be impaired if:
R dirt on the sensors or anything else
covering the sensors
R snow or heavy rain
R interference by other radar sources
R strong radar reflections, for example, in
parking garages
If DISTRONIC PLUS no longer detects a
vehicle in front, DISTRONIC PLUS may
unexpectedly accelerate the vehicle to the
stored speed.
This speed may:
R be too high if you are driving in a filter lane
or an exit lane
R be so high when driving in the right-hand
lane that you overtake vehicles in the left-
hand lane
R be so high when driving in the left-hand lane
that you overtake vehicles in the right-hand
lane
If there is a change of drivers, advise the new
driver of the speed stored.
General notes DISTRONIC PLUS regulates the speed and
automatically helps you maintain the
distance to the vehicle detected in front.
DISTRONIC PLUS brakes automatically so
that the set speed is not exceeded.
On long and steep downhill gradients,
especially if the vehicle is laden, you must
select a low gear in good time. For this, you
will need to have selected manual drive
program
M(Y page 154).

By doing so, you will
make use of the braking effect of the engine.
This relieves the load on the brake system and 160
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Problems with PARKTRONIC
Problem Possible causes/consequences and
M SolutionsOnly the red segments
in the PARKTRONIC
warning displays
are
lit.
You also hear a warning
tone for approximately
two seconds.
PARKTRONIC is
deactivated after
approximately
20 seconds, and the
indicator lamp in the
PARKTRONIC button
lights up. PARKTRONIC has malfunctioned and has switched off.
X
If problems persist, have PARKTRONIC checked at a qualified
specialist workshop. Only the red segments
in the PARKTRONIC
warning displays
are

lit.
PARKTRONIC is
deactivated after
approximately
20seconds. The PARKTRONIC sensors are dirty or there is interference.
X
Clean the PARKTRONIC sensors ( Y page 275).
X Switch the ignition back on. The problem may be caused by an external source of radio or
ultrasound waves.
X
See if PARKTRONIC functions in a different location. Active Parking Assist
Important safety notes Active Parking Assist is merely an aid. It is not
a replacement for your attention to your
immediate surroundings. You are always
responsible for safe maneuvering, parking
and exiting a parking space. When
maneuvering, parking or pulling out of a
parking space, make sure that there are no
persons, animals or objects in the area in
which you are maneuvering.
G
WARNING
The vehicle swings out when parking and in
doing so could cross into the opposite lane.
This could result in a collision with another
road user. There is a risk of an accident.
Pay attention to other road users when
parking. Stop the vehicle if necessary or cancel the Active Parking Assist parking
procedure.
! If unavoidable, you should drive over
obstacles such as curbs slowly and not at
a sharp angle.

Otherwise, you may damage
the wheels or tires.
Active Parking Assist may possibly indicate
parking spaces which are not suitable for
parking, for example:
R where parking or stopping is prohibited
R in front of driveways or entrances and exits
R on unsuitable surfaces
Parking tips:
R On narrow roads, drive as close to the
parking space as possible.
R Parking spaces that are littered, overgrown
or partially occupied by trailer drawbars
might be identified incorrectly or not at all.172
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R
Snowfall or heavy
rain may lead to a parking
space being measured inaccurately.
R Pay attention to the PARKTRONIC
(Y page 170) warning messages during the
parking procedure.
R You can intervene in the steering procedure
to correct it at any time. Active Parking
Assist will then be canceled.
R When transporting a load which protrudes
from your vehicle, you should not use
Active Parking Assist.
R Never use Active Parking Assist when snow
chains are installed.
R Make sure that the tire pressures are
always correct. This has a direct influence
on the parking characteristics of the
vehicle.
General notes Active Parking Assist is an electronic parking
aid with ultrasound. Ultrasound is used to
measure the
road

on both sides of the vehicle.
A suitable parking space is indicated by the
parking symbol. Active steering intervention
can assist you during parking.
You may also use PARKTRONIC
(Y page 169). When PARKTRONIC is switched
off, Active Parking Assist is also unavailable.
Use Active Parking Assist for parking spaces:
R that are parallel to the direction of travel
R that are on straight roads, not bends
R that are on the same level as the road, e.g.
not on the pavement
Detecting parking spaces Objects located above the height range of
Active Parking Assist will not be detected
when the parking space is measured. These
are not taken into account when the parking
procedure is calculated, e.g. overhanging
loads,
tail
sections

or loading ramps of goods
vehicles. In some circumstances, Active
Parking Assist may therefore guide you into
the parking space too early. G
WARNING
If there are objects above the detection range,
Active Parking Assist may turn prematurely.
You may cause

a collision as a result. There is
a risk of an accident.
If there are objects above the detection range,
stop and deactivate Active Parking Assist.
Active Parking Assist is automatically
activated when driving forwards. The system
is operational at speeds of up to
approximately 22 mph (35 km/h). While in
operation, the system independently locates
and measures parking spaces on both sides
of the vehicle. When driving at speeds below
19 mph (30 km/h), you will see the parking
symbol as a status indicator in the instrument
cluster. By default, Active Parking Assist only
displays parking spaces on the front-
passenger side. Parking spaces on the
driver's side are displayed as soon as the turn
signal on the driver's side is activated. To park
on the driver's side, you must leave the
driver's side turn signal switched on. This
must remain switched on until you
acknowledge the use of Active Parking Assist
by pressing the a button on the
multifunction steering wheel.
When a parking space has been detected, an
arrow towards the right or the left also
appears. Example: detected parking space for a vehicle with
automatic transmission
:
Detected parking space on the left
; Parking symbol
= Detected parking space on the right Driving systems
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Active Parking Assist will only detect parking
spaces:
R
that are parallel to the direction of travel
R that are at least 59 in (1.5 m) wide
R that are at least 51 in (1.3 m) longer than
your vehicle
A parking space is displayed while you are
driving past it, and until you are
approximately 50 ft (15 m) away from it.
Parking G
WARNING
Active Parking Assist merely aids you by
intervening actively in the steering. If you do
not brake there is a risk of an accident.
Always apply the brakes yourself when
maneuvering and parking.
i When PARKTRONIC detects obstacles,
Active Parking Assist brakes automatically
during the parking process. You are
responsible for braking in good time.
Active Parking Assist does not support you
with parking spaces parallel to the direction
of travel if:
R the parking space is on a curb
R the parking space is apparently blocked,
for example by foliage or grass paving
blocks
R the range of movement is too small
R the parking space is bordered by an
obstacle which is not clearly defined such
as a tree or a trailer
X Stop the vehicle when the parking space
symbol shows the
desired parking space in
the instrument cluster.
X Shift the transmission to position R.
The Start Park Assist? Yes: OK No:
% message appears

in the multifunction
display. X
To cancel the procedure: press the
% button on the multifunction steering
wheel or pull away.
or
X To park using Active Parking Assist:
press the a

button on the multifunction
steering wheel.
The Park Assist Active Accelerate
and Brake Observe Surroundings
message appears in the multifunction
display.
X Let go of the multifunction steering wheel.
X Back up the vehicle, being ready to brake
at all times. Do not exceed a maximum
speed of approximately 5 mph (10 km/h )
when

backing up. Otherwise Active Parking
Assist will be canceled.
i In tight parking spaces, you will achieve
the best parking results by backing up as
far as possible. When doing so, also
observe the PARKTRONIC messages.
X Stop as soon as PARKTRONIC sounds the
continuous warning tone, if not before.
Maneuvering may be required in tight
parking spaces.
The Park Assist Active Select D
Observe Surroundings

message appears in
the multifunction display.
X Shift the transmission to position D while
the vehicle is stationary.
Active Parking Assist

immediately steers in
the other direction.
The Park Assist Active Accelerate
and Brake Observe Surroundings
message appears in the multifunction
display.
i You will achieve the best results by
waiting for the steering procedure to
complete before pulling away.
X Drive forwards and be ready to brake at all
times.
X Stop as soon as PARKTRONIC sounds the
continuous warning tone, if not before.174
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The Park Assist Active Select R
Observe Surroundings

message appears in
the multifunction display.
X Further transmission shifts may be
necessary.
As soon as the parking procedure is
complete, the Park Assist Finished
message appears in the multifunction
display.
Active Parking Assist is then deactivated.
PARKTRONIC is still available.
X Maneuver if necessary.
X Always observe the warning messages
displayed by PARKTRONIC (
Y page 170).
Parking tips:
R The way your vehicle is positioned in the
parking space after parking is dependent
on various factors. These include the
position and shape of the vehicles parked
in

front and
behind it and the conditions of
the location. It may be the case that Active
Parking Assist guides you too far into a
parking space, or not far enough into it. In
some cases, it may also lead you across or
onto the curb. If necessary, you should
cancel the parking procedure with Active
Parking Assist.
R You can also engage forward gear
prematurely. The vehicle redirects and
does not drive as far into the parking space.
Should a gear be changed too early, the
parking procedure will be canceled. A
sensible parking position can no longer be
achieved from this position.
Exiting a parking space In order that Active Parking Assist can
support you
when

you exit the parking space:
R the border of the parking space must not
be too low.
R the border of the parking space must not
be too wide. The system maneuvers the
vehicle into a position at a maximum of 45° to the starting position in the parking
space.
R a maneuvering distance of at least 24 in
(0.60 m) must be available.
Active Parking Assist

can only assist you with
exiting a parking space if you have parked the
vehicle using Active Parking Assist.
X Start the engine.
X Switch on the turn signal on the side facing
the street.
X Shift the transmission to position D or R.
The Start Park Assist? Yes: OK No:
% message appears

in the multifunction
display.
X To cancel the procedure: press the
% button on the multifunction steering
wheel or pull away.
or
X To exit a parking space using Active
Parking Assist: press the a button on
the multifunction steering wheel.
The Park Assist Active Accelerate
and Brake Observe Surroundings
message appears in the multifunction
display.
X Let go of the multifunction steering wheel.
X Reverse the vehicle or drive forwards, being
ready to brake at all times. Do not exceed
a maximum speed of approximately
6 mph (10 km/h) when exiting a parking
space. Otherwise

Active Parking Assist will
be canceled.
X Stop when PARKTRONIC sounds the
continuous warning tone, if not before.
X Shift the transmission to position D or R
as
required while the vehicle is stationary.
Active Parking Assist immediately steers in
the other direction. The Park Assist
Active Accelerate and Brake
Observe Surroundings message appears
in the multifunction display.
i You will achieve the best results by
waiting for the steering procedure to
complete before pulling away. Driving systems
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If you back up after activation, the steering
wheel is moved to the straight-ahead
position.
X Drive forwards or back up the vehicle, being
ready to brake at all times.
X Stop as soon as PARKTRONIC sounds the
continuous warning tone, if not before.
X Drive forwards and reverse as prompted by
the PARKTRONIC warning
displays, several
times if necessary.
Once you have exited the parking space
completely, the steering wheel is moved to
the straight-ahead position. You hear a tone
and the Park Assist Finished message
appears in the

multifunction display. You will
then have to steer and merge into traffic on
your own. PARKTRONIC is still available.
Canceling Active Parking Assist You can cancel Active Parking Assist at any
time.
X
Stop the movement of the multifunction
steering wheel or steer yourself.
Active Parking Assist will be canceled at
once. The Park Assist Canceled
message appears in the multifunction
display.
or
X Press the PARKTRONIC button on the
center console (
Y

page 171).
PARKTRONIC is switched off and Active
Parking Assist is immediately canceled.
The Park Assist Canceled message
appears in the multifunction display.
Active Parking Assist is canceled
automatically if:
R you engage the electric parking brake.
R parking using Active Parking Assist is no
longer possible.
R you are driving faster than 6 mph
(10 km/h).
R a wheel

spins, ESP®
intervenes or fails. The
÷ warning lamp lights up in the
instrument cluster. A warning tone sounds. The parking space
symbol disappears and the multifunction
display shows the
Park Assist Canceled
message.
If Active
Parking

Assist is canceled, you must
steer again yourself.
If a system malfunction occurs, the vehicle is
braked to a standstill. To drive on, depress the
accelerator again. Rear view camera
Important safety notes The rear view camera is only an aid. It is not
a replacement for your attention to your
immediate surroundings. You are always
responsible for safe maneuvering and
parking.
When
maneuvering

or parking, make
sure that there are no persons, animals or
objects in the area in which you are
maneuvering.
Under the following circumstances, the rear
view camera will not function, or will function
in a limited manner:
R the tailgate is open
R in heavy rain, snow or fog
R at night or in very dark places
R if the camera is exposed to very bright light
R if the area is lit by fluorescent light or LED
lighting (the display may flicker)
R if there is a sudden change in temperature,
e.g. when driving into a heated garage in
winter
R if the camera lens is dirty or obstructed
R if the rear of your vehicle is damaged. In
this event, have the camera position and
setting checked at a qualified specialist
workshop.176
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Lanes
:
White guide line without turning the
steering wheel, vehicle width including
the exterior mirrors (static)
; Yellow lane marking tires at current
steering wheel angle,
vehicle width to the
outer side of the wheels (dynamic)
= Red guide line for the vehicle width
including the exterior mirrors, for current
steering wheel angle (dynamic)
? Bumper Guide lines
?
Bumper
A Red guide line at a distance of
approximately 10 in (0.25 m
) from the
rear of the vehicle
B Yellow guide line at a distance of
approximately

13 ft (
4.0 m) from the rear
of the vehicle
C Vehicle center axle (marker assistance)
D Yellow guide line at a distance of
approximately 3 ft (1.0 m ) from the rear
of the vehicle The lanes and guide lines are only displayed
if you have engaged reverse gear.
The distance specifications only apply to
objects that are at ground level.
Additional displays on vehicles with PARKTRONIC
and COMAND
:
Front warning display
; Additional PARKTRONIC measurement
operational readiness indicator
= Rear warning display
Vehicles with PARKTRONIC and
COMAND: if PARKTRONIC is operational
(Y page 169), an additional operational
readiness indicator will appear in COMAND
display ;.If the PARKTRONIC warning
displays are active or light up, warning
displays : and
=


are also active or light up
correspondingly in the COMAND display.
Reverse parking function X
Make sure that the rear view camera is
activated and the "Reverse parking"
function is selected; see the separate
operating instructions for the audio
system/COMAND.
The lane and the guide lines are shown.178
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