engine MERCEDES-BENZ B-CLASS 2012 Workshop Manual

selected and engaged is shown in the
multifunction display.
Manual drive program
M differs from drive
programs E and S
with regard to spontaneity,
responsiveness and smoothness of gear
changes. Gear Driving situations
=
You can use the engine's braking
effect
5
To use the braking effect of the
engine on downhill gradients and
for driving:
R
on steep mountain roads
R in mountainous terrain
R in arduous conditions 4
To use the braking effect of the
engine on
extremely

steep downhill
gradients and on long downhill
stretches Switching on the manual drive program
Activating permanently
X
Press the program selector button
(Y page 143)

repeatedly until M appears in
the multifunction display.
Manual drive program M remains active
until drive program E or S is engaged.
Activating temporarily
X Pull the right or left steering wheel paddle
shifter (Y page 144).
M is shown in the multifunction display.
Manual drive program M is temporarily
active. Depending on which paddle shifter
is pulled, the automatic transmission
immediately shifts into

the next gear down
or up.
i When manual drive program M is
activated via the steering wheel paddle
shifters, the temporarily active manual
drive program M will be deactivated
automatically after a limited time, if the
driving situation permits. In this case, the automatic transmission shifts into the
automatic drive program that was last
engaged, i.e.
E or S. When driving on
downhill gradients, the temporarily active
manual drive program M will only be
deactivated if the accelerator pedal is
depressed while the vehicle is rolling
downhill.
Upshifting X
Pull the right-hand steering wheel paddle
shifter (Y page 144).
The automatic transmission

shifts up to the
next gear.
X Shift up a gear when the ^ upshift symbol
appears in the display instead of M.
i To prevent engine damage the automatic
transmission shifts up automatically:
R if the maximum engine speed on the
currently engaged gear is reached and
R you continue to accelerate.
Downshifting X
Pull the left-hand steering wheel paddle
shifter (Y page 144).
The automatic transmission

shifts down to
the next gear.
i If you slow down or stop without shifting
down, the automatic transmission
automatically shifts down.
i For maximum acceleration, pull the left-
hand steering wheel

paddle shifter until the
transmission selects the optimum gear for
the current speed.
i If the engine exceeds the maximum
engine speed when shifting down, the
automatic transmission protects against
engine damage by not shifting down. Automatic transmission
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Kickdown
You can also use kickdown for maximum
acceleration in manual drive program
M.
X Depress the accelerator pedal beyond the
pressure point.
The transmission shifts to a lower gear
depending on the engine speed.
X Shift back up once the desired speed is
reached.
i During kickdown, you
cannot change gear
using the steering wheel paddle shifters.
i If you apply full throttle, the automatic
transmission shifts up to the next gear
when the maximum engine speed is
reached. This prevents the engine from
overrevving.
Switching off the manual drive program X
Press the program selector button
(Y page 143) repeatedly until E or S
appears in the multifunction display.
Deactivating the temporary manual drive
program
X Pull and hold the right-hand steering wheel
paddle shifter until the automatic
transmission shifts into the last active
automatic drive program: E or S.
i If manual drive

program M is deactivated,
the automatic transmission in automatic
drive program E or S may shift from the
current gear into a higher or lower gear.
This is dependent on the position of the
accelerator pedal, speed and load. 146
Automatic transmission
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Problems with the transmission
Problem Possible causes/consequences and
M SolutionsThe transmission has
problems shifting gear. The transmission is losing oil.
X
Have the transmission checked at a qualified specialist
workshop immediately. The acceleration ability
is deteriorating.
The transmission no
longer shifts into all of
the gears.
Reverse gear can no
longer be engaged. The transmission is in emergency mode.
X
Stop the vehicle.
X Shift the transmission to position P.
X Switch off the engine.
X Wait at least 10 seconds before restarting the engine.
X Shift the transmission to position D.
X Have the transmission checked at a qualified specialist
workshop immediately. Refueling
Important safety notes
G
WARNING
Fuel is highly flammable. If you handle fuel
incorrectly, there is a risk of fire and
explosion.
You must avoid fire, open flames, creating
sparks and smoking. Switch off the engine
and, if applicable,
the auxiliary heating before
refueling. G
WARNING
Fuel is poisonous and hazardous to health.
There is a risk of injury.
You must make

sure that fuel does not come
into contact with your skin, eyes or clothing
and that it is not swallowed. Do not inhale fuel
vapors. Keep fuel away from children.
If you or others come into contact with fuel,
observe the following:
R Wash away fuel from skin immediately
using soap and water.
R If fuel comes into contact with your eyes,
immediately rinse them thoroughly with clean water. Seek medical assistance
without delay.
R If fuel is swallowed, seek medical
assistance without delay. Do not induce
vomiting.
R Immediately change out of clothing which
has come into contact with fuel. G
WARNING
Electrostatic buildup can create sparks and
ignite fuel vapors. There is a risk of fire and
explosion.
Always touch the

vehicle body before opening
the fuel filler flap or touching the fuel pump
nozzle. Any existing electrostatic buildup is
thereby discharged.
! Do not use diesel to refuel vehicles with a
gasoline engine. Do not switch on the
ignition if you accidentally refuel with the
wrong fuel. Otherwise, the fuel will enter
the fuel system. Even small amounts of the
wrong fuel could result in damage to the
fuel system and the engine. The repair
costs are high. Notify a qualified specialist
workshop and have the fuel tank and fuel
lines drained completely. Refueling
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!
Overfilling the fuel
tank could damage the
fuel system.
! Take care not to spill any fuel on painted
surfaces. You could otherwise damage the
paintwork.
! Use a filter when refueling from a fuel can.
Otherwise, the fuel lines and/or injection
system could be blocked by particles from
the fuel can.
Do not get into the vehicle again during the
refueling process. Otherwise, electrostatic
charge could build up again.
If you overfill the fuel tank, fuel could spray
out when the fuel pump nozzle is removed.
For further information on fuel and fuel quality
(Y page 330). Refueling
Opening/closing the fuel filler flap :
To open the fuel filler flap
; Tire pressure table
= To insert the fuel filler cap
? Fuel type to be used
The fuel filler flap is unlocked or locked
automatically when you open or close the
vehicle with the SmartKey.
The position of the fuel filler cap is displayed
æ in
the

instrument cluster. The arrow on
the filling pump indicates the side of the
vehicle. Opening X
Switch the engine off.
X Remove the SmartKey from the ignition
lock.
X Press the fuel filler flap in the direction of
arrow :.
The fuel filler flap swings up.
X Turn the fuel filler flap counter-clockwise
and remove it.
X Insert the fuel filler cap into holder on the
inside of fuel filler flap =.
X Completely insert the filler neck of the fuel
pump nozzle into the tank, hook in place
and refuel.
X Only fill the tank until the pump nozzle
switches off.
i Do not add any more fuel after the pump
stops filling for the first time. Otherwise,
fuel may leak out.
Closing X
Replace the cap on the filler neck and turn
clockwise until it engages audibly.
X Close the fuel filler flap.
i Close the fuel

filler flap before locking the
vehicle.
i If you are driving with the fuel filler cap
open, the 8 reserve fuel warning lamp
flashes. A message appears in the
multifunction display ( Y page 214).
In addition, the ; Check Engine warning
lamp may light up ( Y page 231).
For further information on warning and
indicator lamps in the instrument cluster,
see ( Y page 231).148
Refueling
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Problems with fuel and the fuel tank
Problem Possible causes/consequences and
M SolutionsFuel is leaking from the
vehicle. The fuel line or the fuel tank is faulty.
G WARNING
Risk of explosion or fire.
X Turn the SmartKey to position 0
in the
ignition lock immediately
and remove it (Y page 135).
X Do not restart the engine under any circumstances.
X Consult a qualified specialist workshop. The fuel filler flap
cannot be opened. The fuel filler flap is not unlocked.
or
The SmartKey battery is discharged.
X
Unlock the vehicle (Y page 68).
or
X Unlock the vehicle using the mechanical key ( Y page 69).The fuel filler flap is unlocked, but the opening mechanism is
jammed.
X
Consult a qualified specialist workshop. Parking
Important safety notes
G
WARNING
If flammable materials such as leaves, grass
or twigs are

exposed to prolonged contact to
parts of the exhaust system that heat up, they
could ignite. There is a risk of fire.
Park the vehicle so that no flammable
materials come into contact with parts of the
vehicle which are hot. Take particular care not
to park on dry grassland or harvested grain
fields. G
WARNING
If you leave children unsupervised in the
vehicle, they could set it in motion by, for
example:
R releasing the parking brake
R shifting the automatic transmission out of
the parking position P
R starting the engine.
They could also operate the vehicle's
equipment. There is

a risk of an accident and
injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children unsupervised in the vehicle.
! Always secure the vehicle correctly
against rolling away. Otherwise, the vehicle
or its drivetrain could be damaged. Parking
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To ensure that the vehicle is secured against
rolling away unintentionally:
R
the electric parking
brake must be applied.
R the transmission must be in position P and
the transmission position display must
show P.
R the SmartKey must be removed from the
ignition lock.
R on uphill or downhill gradients, the front
wheels must be turned towards the curb. Switching off the engine
Important safety notes G
WARNING
The automatic transmission switches to
neutral position N when you switch off the
engine. The vehicle may roll away. There is a
risk of an accident.
After switching off the engine, always switch
to parking position P. Prevent the parked
vehicle from rolling away by applying the
parking brake.
Vehicles with automatic transmission X
Apply the electric parking brake.
X Shift the transmission to position P.
X Turn the SmartKey to position 0 in the
ignition lock and remove it.
The immobilizer is activated.
i If you switch the engine off with the
transmission in position R or D, the
automatic transmission shifts to N
automatically.
If you then open one of the front doors or
remove the SmartKey

from the ignition, the
automatic transmission shifts to P.
If you shift the automatic transmission to
N before switching off the engine, the
automatic transmission remains in N even
if a door is opened. i
The automatic transmission shifts to P
automatically if you:
R switch off the

engine using the SmartKey
and remove the SmartKey from the
ignition lock or
R switch off the engine using the SmartKey
and open a front door.
If you attempt to turn off the engine when the
selector lever is not in position P:
R a message appears in the multifunction
display
R a warning signal sounds Electric parking brake
General notes G
WARNING
If you leave children unsupervised in the
vehicle, they could set it in motion by, for
example:
R releasing the parking brake
R shifting the automatic transmission out of
the parking position P
R starting the engine.
They could also operate the vehicle's
equipment. There is

a risk of an accident and
injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children unsupervised in the vehicle. i
The electric parking brake performs a
function test at regular intervals while the 150
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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
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Parking the vehicle for a long period
If you leave
the vehicle parked for longer than
four weeks, the battery may be damaged by
exhaustive discharging.
If you leave the vehicle parked for longer than
six weeks, the vehicle may suffer damage as
a result of lack of use.
X Visit a qualified specialist workshop and
seek advice.
i You can obtain information about trickle
chargers from a qualified specialist
workshop. Driving tips
General notes
Important safety notes G
WARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with limitations, or

not at all. This could affect,
for example, the power steering and the brake
boosting effect. You will require considerably
more effort to steer and brake. There is a risk
of an accident.
Do not switch off the ignition while driving. G
WARNING
If you operate mobile communication
equipment while driving, you will be
distracted from traffic conditions. You could
also lose control

of the vehicle. There is a risk
of an accident.
Only operate this equipment when the vehicle
is stationary.
Observe the legal requirements for the
country in which you are driving. Some
jurisdictions prohibit the driver from using a
mobile phone while driving a vehicle.
If you make a call while driving, always use
hands-free mode. Only operate the telephone
when the traffic situation permits. If you are unsure, pull over to a safe location and stop
before operating the telephone.
Bear in mind that at a speed of only 30 mph
(approximately
50 km/h), the vehicle covers
a distance of 44 feet (approximately

14 m)
per second.
Drive sensibly – save fuel Observe the following tips to save fuel:
R
The tires should always be inflated to the
recommended tire pressure.
R Remove unnecessary loads.
R Remove roof racks when they are not
needed.
R Warm up the

engine at low engine speeds.
R Avoid frequent acceleration or braking.
R Have all maintenance work carried out as
indicated by the service intervals in the
Maintenance Booklet or by the service
interval display.
Fuel consumption also increases when
driving in cold weather, in stop-start traffic
and in hilly terrain.
Drinking and driving G
WARNING
Drinking and driving and/or taking drugs and
driving are very dangerous combinations.
Even a small amount of alcohol or drugs can
affect your reflexes, perceptions and
judgment.
The possibility of a serious or even fatal
accident are greatly

increased when you drink
or take drugs and drive.
Do not drink or take drugs and drive or allow
anyone to drive who has been drinking or
taking drugs.
Emission control G
WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Inhaling
these exhaust gases

leads to poisoning. There152
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is a risk of fatal injury. Therefore never leave
the engine running in enclosed spaces
without sufficient ventilation.
Certain engine systems
are designed to keep
the level of poisonous components in exhaust
fumes within legal limits.
These systems only work at peak efficiency if
they are serviced exactly in accordance with
the manufacturer's specifications. For this
reason, only have work on the engine carried
out by qualified and authorized Mercedes-
Benz technicians.
The engine settings must not be changed
under any circumstances. Furthermore, all
specific service work must be carried out at
regular intervals and in accordance with the
Mercedes-Benz service requirements. Details
can be found in the Maintenance Booklet. ECO display
The ECO display

gives you information on how
economical your driving style is. The ECO
display assists you in achieving the optimum
driving style in terms of consumption, taking
the actual and selected conditions into
consideration. Your driving style can
significantly influence the vehicle's
consumption. Example: ECO display
The ECO display consists of three bars:
R
Acceleration
R Constant
R Coasting
The percent value

is the average value of the
three bars. The three bars and the mean value
begin at the value of 50%. A higher percentage indicates a more economical
driving style.
The ECO display

does not indicate the actual
fuel consumption and a fixed percentage
count in the ECO display does not indicate a
fixed consumption figure.
Apart from driving style, consumption is
dependent on many factors such as, e.g.:
R Load
R Tire pressure
R Cold start
R Choice of route
R Electrical consumers switched on
These factors are not taken into
consideration by the ECO display.
The evaluation of your driving style is carried
out using the following three categories:
R Acceleration (evaluation of all
acceleration processes)
-The bar fills up: moderate acceleration,
especially at higher speeds
- The bar empties: sporty acceleration
R Constant (assessment of driving behavior
at all times)
-The bar fills up: constant speed and
avoidance of unnecessary acceleration
and deceleration
- The bar empties: fluctuations in speed
R Coasting (assessment of all deceleration
processes)
-The bar fills up: anticipatory driving,
keeping your distance and early release
of the accelerator. The vehicle can coast
without use of the brakes.
- The bar empties: frequent braking
i An economical driving style specially
requires driving at moderate engine
speeds.
To achieve a higher value in the categories
Acceleration and Constant:
R observe the gearshift recommendations.
R drive in drive program E. Driving tips
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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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