2012 MERCEDES-BENZ B-CLASS catalytic converter

Maintenance
The Service and Warranty Booklet describes
all the necessary maintenance work which
should be done at regular intervals.
Always have the Service and Warranty
Booklet with you when you bring the vehicle
to an authorized Mercedes-Benz Center. The
service advisor will record every service for
you in the Service and Warranty Booklet. Roadside Assistance
The Mercedes-Benz Roadside Assistance
Program offers technical help in the event of
a breakdown. Calls to the toll-free Roadside
Assistance Hotline are answered by our
agents 24 hours a day, 365 days a year.
1-800-FOR-MERCedes(1-800-367-6372)
(USA)
1-800-387-0100
(Canada)
For additional information, refer to the
Mercedes-Benz Roadside Assistance
Program brochure (USA) or the "Roadside
Assistance" section in the Service and
Warranty booklet (Canada). You will find both
in your vehicle literature portfolio. Change of address or change of
ownership
In the event of a change of address, please
send us the

"Notification of Address Change"
in the Service and Guarantee booklet or
simply call the Mercedes-Benz Customer
Assistance Center (USA) at the hotline
number
1-800-FOR-MERCedes(1-800-367-6372) or
Customer Service Center (Canada) at
1-800-387-0100. This will assist us in
contacting you in a timely manner should the
need arise.
If you sell your Mercedes, please leave the
entire literature in the vehicle so that it is
available to the next owner. If you have purchased a used car, please send
us the
"Notification

of Used Car Purchase" in
the Service and Guarantee booklet or simply
call the Mercedes-Benz Customer Assistance
Center (USA) at the hotline number
1-800-FOR-MERCedes(1-800-367-6372) or
Customer Service (Canada) at
1-800-387-0100. Vehicle operation outside Canada
If you plan to operate your vehicle in foreign
countries, please be aware that:
R service facilities or

replacement parts may
not be readily available.
R unleaded fuel for vehicles with a catalytic
converter may not be available. Leaded fuel
may cause damage to the catalytic
converter.
R the fuel may have a considerably lower
octane rating. Unsuitable fuel can cause
engine damage.
Some Mercedes-Benz models are available
for delivery in Europe through our European
Delivery Program. For details, consult an
authorized Mercedes-Benz Center or write to
one of the following addresses.
In the USA
Mercedes-Benz USA, LLC
European Delivery Department
One Mercedes Drive
Montvale, NJ 07645-0350
In Canada
Mercedes-Benz Canada, Inc.
European Delivery Department
98 Vanderhoof Avenue
Toronto, Ontario M4G 4C9 22
Introduction
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Do not switch off the ignition while driving.
G
WARNING
If the parking brake has not been fully
released when driving,
the parking brake can:
R overheat and cause a fire
R lose its hold function.
There is a risk of fire and an accident. Release
the parking brake fully before driving off.
! Warm up the engine quickly. Do not use
the engine's full performance until it has
reached operating temperature.
Only shift the automatic transmission to
the desired drive position when the vehicle
is stationary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery
roads. You could otherwise damage the
drive train. Key positions
g
To remove the SmartKey
(shift the transmission to position P)
1 Power supply for some consumers, such
as the windshield wipers
2 Ignition (power supply for all consumers)
and drive position
3 To start the engine
i The SmartKey can be turned in the
ignition lock even if it is not the correct
SmartKey for the

vehicle. The ignition is not
switched on. The engine cannot be started. Starting the engine
Important safety notes G
WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Inhaling
these exhaust gases

leads to poisoning. There
is a risk of fatal injury. Therefore never leave
the engine running in enclosed spaces
without sufficient ventilation. G
WARNING
Flammable materials introduced through
environmental influence or by animals can
ignite if in

contact with the exhaust system or
parts of the engine that heat up. There is a risk
of fire.
Carry out regular checks to make sure that
there are no flammable foreign materials in
the engine compartment or in the exhaust
system.
! Do not depress the accelerator pedal
when starting the engine.
i During a cold start, the engine runs at
higher speeds to enable the catalytic
converter to reach its operating
temperature. The sound of the engine may
change during this time.
Automatic transmission X
Shift the transmission to position P.
Transmission position display
P

is shown in
the multifunction display.
i When the transmission is in position N,
you can also

start the engine with the brake
pedal depressed.
Starting procedure X
Turn the SmartKey to position 3 in the
ignition lock (

Y page 135) and release it as
soon as the engine is running. Driving
135
Driving and parking Z
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Pulling away
Automatic transmission i
It is only
possible to shift the transmission
from position P to the desired position if
you depress the brake pedal. Only then can
the parking lock be deactivated. If you do
not depress the brake pedal, the DIRECT
SELECT lever can still be moved but the
parking lock remains engaged.
i If the transmission oil temperature is
below Ò4 ‡ (Ò20 † ), you can only shift from
position P when the engine is running.
X Depress the brake pedal and keep it
depressed.
X Shift the transmission to position D or R.
X Release the brake pedal.
X Carefully depress the accelerator pedal.
The electric parking brake (Y page 150) is
automatically released.
The red ! indicator lamp in the
instrument cluster goes out.
i The vehicle locks

centrally once you have
pulled away. The locking knobs in the doors
drop down.
You can open the doors from the inside at
any time.
You can also deactivate the automatic
locking feature (Y page 198).
i Upshifts take place at higher engine
speeds after a cold start. This helps the
catalytic converter to reach its operating
temperature more quickly.
Hill start assist G
WARNING
After a short time, hill start assist will no
longer brake your vehicle and it could roll
away. There is

a risk of an accident and injury.
Therefore, quickly move your foot from the
brake pedal to the accelerator pedal. Never
leave the vehicle when it is held by hill start
assist. Hill start assist helps you when pulling away
forwards or in reverse on an uphill gradient.
It holds the vehicle for a short time after you
have removed
your

foot from the brake pedal.
This gives you enough time to move your foot
from the brake pedal to the accelerator pedal
and to depress it before the vehicle begins to
roll.
X Remove your foot from the brake pedal.
The vehicle is

then held for about a second.
X Pull away.
Hill start assist will not function if:
R you are pulling away on a level road or on
a downhill gradient.
R the transmission is in position N.
R the electric parking brake is applied.
R ESP ®
is malfunctioning.
Further information on holding the vehicle
stationary on uphill gradients ( Y page 143). ECO start/stop function
Important safety notes G
WARNING
If the engine is switched off automatically and
you exit the vehicle, the engine is restarted
automatically. The vehicle

may begin moving.
There is a risk of accident and injury.
If you wish to exit the vehicle, always turn off
the ignition and secure the vehicle against
rolling away.
General notes If the
¤ symbol is shown in the
multifunction display, the ECO start/stop
function switches the engine off
automatically when the vehicle stops.
The engine starts automatically when the
driver wants to pull away again. The ECO
start/stop function thereby helps you to
reduce the fuel consumption and emissions
of your vehicle. 136
Driving
Driving and parking
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Problem Possible causes/consequences and
M SolutionsThe engine is not
running smoothly and
is misfiring. There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
X
Only depress the accelerator pedal slightly.
X Have the cause rectified immediately at a qualified specialist
workshop.
Otherwise, non-combusted fuel may get into the catalytic
converter and damage it. The coolant
temperature display is
showing more than
248 ‡
(120 †). The
coolant warning lamp
may also be lit and a
warning tone may
sound. The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.
X
Stop as soon as possible and allow the engine and the coolant
to cool down.
X Check the coolant level (Y page 269). Observe the warning
notes as you do so and add coolant if necessary. Automatic transmission
Important safety notes
G
WARNING
If the engine speed is above the idling speed
and you engage transmission position D or
R, the vehicle
could pull away suddenly. There
is a risk of an accident.
When engaging transmission position D or R,
always firmly depress the brake pedal and do
not simultaneously accelerate. 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. DIRECT SELECT lever
Overview of transmission positions The DIRECT SELECT lever is on the right of the
steering column.
j
Park position with parking lock
k Reverse gear
i Neutral
h Drive
i The DIRECT SELECT lever always returns
to its original position. The current
transmission position
P, R

, N or D appears
in the transmission position display
(Y page 141) in the multifunction display. 140
Automatic transmission
Driving and parking
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Checking the oil level using the oil
dipstick
Example
X
Pull oil dipstick : out of the dipstick guide
tube.
X Wipe off oil dipstick :.
X Slowly slide oil dipstick : into the guide
tube to the stop, and take it out again.
If the level is between MIN mark = and
MAX mark ;, the oil level is correct.
X If the oil level has dropped to MIN mark
= or below, add 1.1 US qt
(1.0 liter) of
engine oil.
Adding engine oil G
WARNING
If engine oil comes into contact with hot
components in the engine compartment, it
may ignite. There is a risk of fire and injury.
Make sure that engine oil is not spilled next
to the filler neck. Let the engine cool down
and thoroughly clean the engine oil off the
components before starting the engine. H
Environmental note
When adding oil, take care not to spill any. If
oil enters the soil or waterways, it is harmful
to the environment.
! Only use engine oils and oil filters that
have been approved for vehicles with a
service system. You

can obtain a list of the
engine oils and oil filters tested and
approved in accordance with the Mercedes-Benz Specifications for Service
Products at any Mercedes-Benz Service
center.
Damage to
the

engine or exhaust system is
caused by the following:
R using engine oils and oil filters that have
not been specifically approved for the
service system
R replacing engine oil and oil filters after
the interval for replacement specified by
the service system has been exceeded
R using engine oil additives.
! Do not add too much oil. adding too much
engine oil can result in damage to the
engine or to the catalytic converter. Have
excess engine oil siphoned off. Example: engine oil cap
X
Turn cap : counter-clockwise and remove
it.
X Add engine oil.
If the oil level is at or below the MIN mark
on the oil

dipstick, add 1.1 US qt (1.0 liter)
of engine oil.
X Replace cap : on the filler neck and turn
clockwise.
Ensure that the cap locks into place
securely.
X Check the oil level again with the oil
dipstick (Y page 268).
Further information on engine oil
(Y page 332). 268
Engine compartment
Maintenance and care
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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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Fuel
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.
Tank capacity Model Total
capacity B 250 BlueEFFICIENCY
13.2 US gal
(50.0 l) Model Of which
reserve B 250 BlueEFFICIENCY
Approx.
1.6 US gal (6.0 l) Gasoline
Fuel grade
!
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.
! You should only refuel with unleaded
premium-grade gasoline as this avoids
damaging the catalytic converter.
If engine running problems are apparent,
have the cause checked immediately and
repaired. Excess unburned fuel can
otherwise enter the catalytic converter,
leading to overheating and possibly
causing a fire.
! To ensure the longevity and full
performance of the engine, only premium-
grade unleaded gasoline may be used.
If there is no premium-grade unleaded
gasoline available and regular unleaded
gasoline must be used, please observe the
following precautions:
R only fill the fuel tank to half full with
regular unleaded gasoline and fill the rest
with premium-grade unleaded gasoline
as soon as possible.
R do not drive at the maximum speed.
R avoid sudden acceleration.330
Service products and filling capacities
Technical data
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