ECU MERCEDES-BENZ B-CLASS 2012 Service Manual

Stowage compartment in front of the
armrest (vehicles with automatic
transmission)
X
To open: press the marking on cover :.
i You can remove
the non-slip mat and the
insert for cleaning. When removing the
insert you will have to overcome some
slight resistance.
Stowage compartment under the armrest X
To open: on vehicles with moveable
armrests, make sure that the armrest is in
the rearmost position.
X Press button : and fold the armrest up.
i Depending on the vehicle's equipment, a
USB connection and

an AUX IN connection
or a Media Interface are installed in the
stowage compartment. A Media Interface
is a universal interface for mobile audio
equipment, e.g. for an iPod ®
or MP3 player
(see the separate COMAND Operating
Instructions). Stowage compartment under the driver's
seat and front-passenger seat G
WARNING
If you exceed the maximum load for the
stowage compartment, the cover may not be
able to restrain the items. Items may be
thrown out of the stowage compartment and
hit vehicle occupants.

There is a risk of injury,
particularly in the event of sudden braking or
a sudden change in direction.
Never exceed the maximum permissible load
for the stowage compartment. Stow and
secure heavy objects in the cargo
compartment.
The maximum permissible load of the
stowage compartment is 2.6 lbs (1.5 kg). X
To open: pull handle : up and fold
cover ; forwards.
Stowage space in the rear Stowage compartment in the rear center
console238
Stowage areas
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Depending on the angle of the backrest,
therefore, the right and left rear seats can
be pushed
back
varying distances until the
backrest is resting against the cargo
compartment cover.
If the backrest comes into contact with
surrounding parts of the cargo
compartment paneling, reduce the angle of
the backrest.
Adjusting the seat fore-and-aft position
! When moving the rear seats back, make
sure there are no objects in the footwell or
behind the seats. The rear seats and/or the
objects could otherwise be damaged. X
Lift the left or right release handle and slide
the corresponding seat forwards or
backwards.
X Let go of the release handle again.
Make sure that

you hear the seat engage in
position. Securing cargo
Cargo tie-down rings Observe the following notes on securing
loads:
R
Observe the loading guidelines
(Y page 236).
R Secure the load using the cargo tie-down
rings.
R Distribute the load on the cargo tie-down
rings evenly. R
Do not use
elastic straps or nets to secure
a load, as these are only intended as an
anti-slip protection for light loads.
R Do not route tie-downs across sharp edges
or corners.
R Pad sharp edges for protection.
There are four cargo tie-down rings in the
cargo compartment. :
Cargo tie-down rings
Bag hook G
WARNING
The bag hooks cannot restrain heavy objects
or items of luggage. Objects or items of
luggage could be

flung around and thereby hit
vehicle occupants when braking or abruptly
changing directions. There is a risk of injury.
Only hang light objects on the bag hooks.
Never hang hard, sharp-edged or fragile
objects on the bag hooks.
! The bag hook can bear a maximum load
of 6.6lbs (3kg) and should not be used to
secure a load.
There is one bag hook on either side of the
cargo compartment. Stowage areas
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:
Bag hook Cargo compartment cover
Important safety notes G
WARNING
On its own, the cargo compartment cover
cannot secure or restrain heavy objects,
items of luggage and heavy loads. You could
be hit by an unsecured load during sudden
changes in direction, braking or in the event
of an accident. There is an increased risk of
injury or even fatal injury.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping over, e.g. by
using tie downs, even if you are using the
cargo compartment cover.
! When loading the
vehicle, make sure that
you do not stack the load in the cargo
compartment higher than the lower edge of
the side windows. Do not place heavy
objects on top of the cargo compartment
cover.
! When removing and installing the cargo
compartment cover, ensure that its end
caps do not scrape the light-colored parts
of the vehicle.
The cargo compartment cover is located
behind the rear bench seat backrest. Extending/retracting the cargo
compartment cover
X
To extend: pull the cargo compartment
cover back by grab handle : and clip it
into retainers ; on the left and right.
X To retract: unhook the cargo compartment
cover from

retainers ; on the left and right
and guide it forwards by grab handle :
until it is fully retracted.
Installing/removing the cargo
compartment cover X
To remove: make sure that the cargo
compartment cover is rolled up.
X Push in the end cap of cargo compartment
cover : in the direction of the arrow on
the right or left side using grip =.
X Push cargo compartment cover : into
opposite anchorage ;.
X Remove cargo compartment cover :
upwards. 244
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X
To install: set cargo compartment
cover : on the right or left-hand side in
anchorage ;.
X Push in the opposite end cap of cargo
compartment cover : in the direction of
the arrow and insert cargo compartment
cover : into opposite anchorage ;. Cargo net
Important safety notes G
WARNING
On its own, the cargo net cannot secure or
restrain heavy objects, items of luggage and
heavy loads. You
could be hit by an unsecured
load during sudden changes in direction,
braking or in the event of an accident. There
is an increased risk of injury or even fatal
injury.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping over, e.g. by
using tie downs, even if you are using the
cargo net.
It is important to use a cargo net if you load
the vehicle with small objects above the seat
backrests. For safety reasons, always use a
cargo net when transporting loads.
The cargo net is located in the stowage space
under the cargo compartment floor
(Y page 245).
X Open both Velcro fasteners and remove the
cargo net.
X Unroll and unfold the cargo net.
The joints on

the upper and lower guide rod
should engage audibly.
The corresponding cargo tie down rings for
tightening the cargo net are in the cargo
compartment (Y

page 243). Attaching and tightening the cargo net
X
To attach and tighten: insert guide
rod : into bracket ;.
X Attach belt hook ? to the cargo tie-down
ring and pull down on the loose end of the
lashing strap until the cargo net is taut.
X After driving a short distance, check the
tension of the cargo net and retighten it if
necessary.
X To loosen and detach: pull belt clamp
= up to reduce the tension in the lashing
strap.
X Unhook belt hook ? from the cargo tie-
down ring.
X Detach guide rod : from bracket ;.
X To stow: press the red
button on the upper
and lower guide rod.
X Fold the cargo net and roll it up.
X Close the two Velcro fasteners on the cargo
net holder. Stowage well under the cargo
compartment floor
Important safety notes G
WARNING
If you drive when the cargo compartment floor
is open, objects could be flung around, thus
striking vehicle occupants. There is a risk of
injury, particularly in the event of sudden
braking or a sudden change in direction. Stowage areas
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X
To raise: using handle :, lift up cargo
compartment floor ; in the direction of
arrow = and pull it upwards.
X Lower cargo compartment floor ; again.
To do
this,
push the trunk floor away so that
it engages in the guide on the upper level.
Cargo compartment floor ; engages in
the upper position.
i Carry out this step using both hands.
X To lower: raise cargo compartment
floor ; slightly
using

handle : and pull it
towards you.
X Lower cargo compartment floor ; again
slowly. Whilst doing so, press the trunk
floor into the lower level.
Cargo compartment floor ; engages in
the lower position. Roof carrier
Important safety notes G
WARNING
When you load the roof, the center of gravity
of the vehicle rises and the driving
characteristics change. If you exceed the
maximum roof load, the driving
characteristics, as well as steering and
braking, will be greatly impaired. There is a
risk of an accident.
Never exceed the maximum roof load and
adjust your driving style.
! Mercedes-Benz recommends that you
only use roof

carriers that have been tested
and approved for Mercedes-Benz vehicles.
This helps to prevent damage to the
vehicle.
Position the load on the roof rack in such a
way that the vehicle will not sustain
damage even when it is in motion.
Ensure that, depending on the vehicle's
equipment, you can raise the panorama
roof with power tilt/sliding panel fully and open the tailgate fully when the roof carrier
is installed.
The maximum roof load is 165 lbs((75 kg).
An incorrectly secured roof carrier or roof
load may

become detached from the vehicle.
You must therefore ensure that you observe
the roof carrier manufacturer's installation
instructions.
Attaching the roof carrier X
Open covers : carefully in
the direction of
the arrow.
X Fold covers : upwards.
X Only secure the roof carrier to the
anchorage points under covers :.
X Observe the manufacturer's installation
instructions. Features
Cup holder
Important safety notes G
WARNING
The cup holder cannot hold a container secure
whilst traveling. If

you use a cup holder whilst
traveling, the container may be flung around
and liquid may be spilled. The vehicle
occupants may come into contact with the
liquid and if it is hot, they may be scalded. You
may be distracted from the traffic conditions
and you could lose control of the vehicle.
There is a risk of an accident and injury. Features
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Only use the cup holder when the vehicle is
stationary. Only use the cup holder for
containers of the right size. Always close the
container, particularly if the liquid is hot.
G
WARNING
If objects in the passenger compartment are
stowed incorrectly, they can slide or be
thrown around and hit vehicle occupants.
There is a risk of injury, particularly in the
event of sudden braking or a sudden change
in direction.
R Always stow objects
so that they cannot be
thrown around in such situations.
R Always make sure that objects do not
protrude from stowage spaces, parcel nets
or stowage nets.
R Close the lockable stowage spaces while
driving.
R Stow and secure objects that are heavy,
hard, pointy, sharp-edged, fragile or too
large in the cargo compartment.
! Only use the cup holders for containers of
the right size and which have lids. The
drinks could otherwise spill.
The stowage compartments in the doors
provide space for bottles:
R front: capacity up to 51 fl. oz. (1.5 l)
R rear: capacity up to 17 fl. oz. (0.5 l)
Cup holder in the front-compartment
center console The cup holder and the rubber mat
underneath can be removed for cleaning.
Clean them
with

clean, lukewarm water only. X
To remove: carefully pull in upper sections
of cup holder : on the driver's and front-
passenger sides until they release.
X Lift the cup holder upwards ;

until it can
be removed. X
To install: insert the cup holder into lateral
curved sections ;

in the stowage
compartment. Insert the cup holder so that
the wedge of the upper section of cup
holder : faces forwards.
X Press the cup holder downwards until it
engages on the right and left-hand sides.
Cup holder in the rear seat armrest !
Do not sit

on or support your body weight
on the rear seat armrest when it is folded
down, as you could otherwise damage it.
! Close the cup holder before folding the
rear seat armrest up. Otherwise, the cup
holder could be damaged. 248
Features
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Emergency call
Important safety notes
!
You must have a license agreement to
activate the mbrace service. Make sure
that your system
is activated and ready for
use. To register, press the ï MB Info call
button. If any of the steps mentioned are
not carried out, the system may not be
activated.
If you have questions about the activation,
contact one of the following telephone
hotlines:
R USA: Mercedes-Benz Customer
Assistance Center at
1-800-FOR-MERCedes
(1-800-367-6372) or 1-866-990-9007
R Canada: Customer Service at
1-888-923-8367
General notes
An emergency call is dialed automatically if
an air bag or Emergency Tensioning Device is
triggered.
i You cannot end an automatically
triggered emergency call yourself.
An emergency call can also be initiated
manually.
As soon as the emergency call has been
initiated, the indicator lamp in the SOS button
flashes. The Connecting Call message
appears in the multifunction display.
The audio output is muted.
Once the connection has been made, the
Call Connected message appears in the
multifunction display.
All important information on the emergency
is transmitted, for example:
R Current location of the vehicle (as
determined by the GPS system)
R Vehicle identification number
R Information on the severity of the accident
Shortly after the emergency call has been
initiated, a voice connection is automatically
established between the Mercedes-Benz Customer Assistance Center and the vehicle
occupants.
R
If the vehicle occupants respond, the
Mercedes-Benz Customer Assistance
Center attempts to get more information
on the emergency.
R If there is no response from the vehicle
occupants, an ambulance is immediately
sent to the vehicle.
The mbrace system has not been able to
initiate an emergency call if no voice
connection to the

Response Center has been
established. This can occur, for example, if
the relevant mobile phone network is not
available. The indicator lamp in the SOS
button flashes continuously.
The Call Failed message appears in the
multifunction display and must be confirmed.
In this case, seek assistance by other means.
Making an emergency call G
WARNING
It can be dangerous to remain in the vehicle,
even if you

have pressed the SOS button in an
emergency if:
R you see smoke inside or outside of the
vehicle, e.g. if there is a fire after an
accident
R the vehicle is on a dangerous section of
road
R the vehicle is not visible or cannot easily be
seen by other road users, particularly when
dark or in poor visibility conditions
There is a risk of an accident and injury.
Leave the vehicle immediately in this or
similar situations as soon as it is safe to do
so. Move to a safe location along with other
vehicle occupants. In such situations, secure
the vehicle in accordance with national
regulations, e. g. with a warning triangle. Features
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X
Push a round pen into opening
=(Y page 263) for approximately three
seconds.
The zone currently selected appears in
compass display ;(Y page 263).
X To select the zone: push
a round pen into
opening =(Y page 263) until the desired
zone is selected.
If, after a few seconds, the display in
compass display ;(Y page 263) changes
direction, the zone has been selected.
Calibrating the compass X
Make sure that there is sufficient space for
you to drive in a circle without impeding
traffic.
In order to calibrate the compass correctly,
do the following:
R calibrate the compass in the open and not
in the vicinity of steel structures or high-
voltage transmission lines.
R switch off electrical

consumers such as the
climate control, windshield wipers or rear
window defroster.
R close all doors and the tailgate.
X Switch on the ignition.
X Push a round pen into opening
=(Y page 263) for approximately six
seconds, until symbol C is shown in
compass display ;(Y page 263).
X Drive your vehicle in a full circle at
approximately 3 mph (5 km/h) to 6 mph
(10 km/h

).
When the calibration has successfully been
completed, the current direction is shown
in compass display ;(Y page 263).Floormat on the driver's side
G
WARNING
Objects in the driver's footwell can restrict the
pedal travel or obstruct a depressed pedal. The operating and road safety of the vehicle
is jeopardized. There is a risk of an accident.
Make sure that all objects in the vehicle are
stowed correctly, and that they cannot enter
the driver's footwell. Install the floormats
securely and as specified in order to ensure
sufficient clearance
for

the pedals. Do not use
loose floormats. X
Slide the seat backwards.
X To install: place the floormat in the
footwell.
X Press safety catch knobs : onto
retainers ;.
X To remove: pull the floormat off
retainers ;.
X Remove the floormat.264
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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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These notes also apply to light alloy wheels
with a clear matte finish.
i
The vehicle should preferably be washed
by hand using a soft sponge, car shampoo
and plenty of water.
i Use only insect
remover and car shampoo
from the range of recommended and
approved Mercedes-Benz care products.
Cleaning the windows G
WARNING
You could become trapped by the windshield
wipers if they

start moving while cleaning the
windshield or wiper blades. There is a risk of
injury.
Always switch off the windshield wipers and
the ignition before cleaning the windshield or
wiper blades.
! Only fold the windshield wipers away from
the windshield when vertical. Otherwise,
you will damage the hood.
! Do not use dry cloths, abrasive products,
solvents or cleaning agents containing
solvents to clean the inside of the windows.
Do not touch the insides of the windows
with hard objects, e.g. an ice scraper or
ring. There is otherwise a risk of damaging
the windows.
! Clean the water drainage channels of the
windshield and the rear window at regular
intervals. Deposits such as leaves, petals
and pollen may under certain
circumstances prevent water from draining
away. This can lead to corrosion damage
and damage to electronic components.
X Clean the inside and outside of the
windows with a damp cloth and a cleaning
product that is recommended and
approved by Mercedes-Benz. Cleaning wiper blades G
WARNING
You could become trapped by the windshield
wipers if they

start moving while cleaning the
windshield or wiper blades. There is a risk of
injury.
Always switch off the windshield wipers and
the ignition before cleaning the windshield or
wiper blades.
! Only fold the windshield wipers away from
the windshield when vertical. Otherwise,
you will damage the hood.
! Do not pull the wiper blade. Otherwise,
the wiper blade could be damaged.
! Do not clean wiper blades too often and
do not rub them too hard. Otherwise, the
graphite coating could be damaged. This
could cause wiper noise.
X Fold the windshield wiper arms away from
the windshield.
X Carefully clean the wiper blades with a
damp cloth.
X Fold the windshield wiper arms back again
before switching on the ignition.
! Hold the wiper

arm securely when folding
back. The windshield could be damaged if
the wiper arm smacks against it suddenly.
Cleaning the exterior lighting !
Only use cleaning agents or cleaning
cloths which are suitable for plastic light
lenses. Unsuitable cleaning agents or
cleaning cloths could scratch or damage
the plastic light lenses.
X Clean the plastic lenses of the exterior
lighting using a wet sponge and a mild
cleaning agent, e.g. Mercedes-Benz car
shampoo or cleaning cloths.274
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