2012 MERCEDES-BENZ B-CLASS battery

Vehicle
Display messages Possible causes/consequences and
M SolutionsShift to 'P' or 'N'
to Start Engine You have attempted to start the engine with the transmission in
position R or D.
X
Shift the transmission to position P or N.Auxiliary Battery
Malfunction The auxiliary battery for the automatic transmission is no longer
being charged.
X
Visit a qualified specialist workshop at the next opportunity.
X Until then, set the automatic transmission to position P before
you switch off the engine.
X Before leaving the vehicle, apply the electric parking brake. Depress Brake to
Start Engine You have attempted to start the engine with the transmission in
position N without depressing the brake pedal.
X
Depress the brake pedal. To Deselect P or N,
Depress Brake and
Start Engine You have attempted to shift the transmission to position
R or D
without starting the engine.
X Start the engine.
X Depress the brake pedal.
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, you can move the DIRECT SELECT lever but the
parking lock remains engaged.
i At transmission fluid temperatures below Ò4 ‡ (Ò20 †) you
can only shift out of position P into another transmission
position when the engine is running. Apply Brake to
Shift from 'P' You have attempted to move the transmission selector lever to
position R, N or D without depressing the brake pedal.
X
Depress the brake pedal. Transmission Not
in P
Risk of Vehicle
Rolling Away The driver's door is open and the transmission is in position
R, N
or D.
A warning tone also sounds.
X Shift the transmission to position P.
X Secure the vehicle against rolling away ( Y page 149).220
Display messagesOn-board computer and displays
ProCarManuals.com

i
If you remove the ashtray insert, you can
use the resulting compartment for
stowage.
Rear-compartment ashtray X
To open: pull cover = out by its top edge.
X To remove: pull insert ; by recess : in
the direction of arrow ? until it audibly
releases.
X Lift insert ; up and out.
X To install the insert: place
insert ;
from
above into the holder and press down until
it engages. Cigarette lighter
G
WARNING
You can burn yourself if you touch the hot
heating element or

the socket of the cigarette
lighter.
In addition, flammable materials can ignite if:
R the hot cigarette lighter falls
R a child holds the hot cigarette lighter to
objects, for example
There is a risk of fire and injury.
Always hold the cigarette lighter by the knob.
Always make sure that the cigarette lighter is
out of reach of children. Never leave children
unsupervised in the vehicle.
Your attention must always be focused on the
traffic conditions. Only use the cigarette lighter when road and traffic conditions
permit.
Example: vehicles with a cover over the stowage
compartment
X
Turn the SmartKey to position 2 in the
ignition lock (Y page 135).
X To open: push the lower section of
cover :.
The stowage compartment opens.
X Press in cigarette lighter ;.
Cigarette lighter ; will pop out
automatically when the heating element is
red-hot. 12 V sockets
Points to observe before use X
Turn the SmartKey to position 1 in the
ignition lock (Y page 135).
The sockets can be used for accessories with
a maximum draw of 180 W (15 A).
Accessories include such items as lamps or
chargers for mobile phones.
If you use the sockets for long periods when
the engine is switched off, the battery may
discharge.
i An emergency cut-out ensures that the
on-board voltage does not drop too low. If
the on-board voltage is too low, the power
to the sockets is automatically cut. This
ensures that there is sufficient power to
start the engine. 250
Features
Stowage and features
ProCarManuals.com

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
Shortly after
successfully registering with the
mbrace service (Canada: TELEAID), a user ID
and password will be sent to you by post. USA
only: you can use this password to log onto
the mbrace area under "Owners Online" at
http://www.mbusa.com .
The mbrace system is available if:
R it has been activated and is operational
R the corresponding mobile phone network
is available for transmitting data to the
Customer Center
R a service subscription is available
R the starter battery is sufficiently charged
i Determining the location of the vehicle on
a map is only possible if:
R GPS reception is available.
R the vehicle position can be forwarded to
the Customer Assistance Center.
The mbrace system To adjust the volume during an mbrace call,
proceed as follows:
X
Press the W or X button on the
multifunction steering wheel.
or
X Use the volume controller of the audio
system/COMAND.
The mbrace system provides various
services, e.g.:
R automatic and manual emergency call
R Roadside Assistance call
R MB Info call USA only: you can find information and a
description of all available features under
"Owners
Online" at
http://www.mbusa.com.
System self-test After you have switched on the ignition, the
system carries out a self-diagnosis.
A malfunction in the system has been
detected if one of the following occurs:
R
The indicator lamp

in the SOS button does
not come on during the system self-test.
R The indicator lamp in the F Roadside
Assistance button does not light up during
self-diagnosis of the system.
R The indicator lamp in the ï MB Info call
button does not light up during self-
diagnosis of the system.
R The indicator lamp in one or more of the
following buttons continues to light up red
after the system self-diagnosis:
-SOS button
- the F Roadside Assistance call
button
- the ï MB Info call button
R The mbrace Inoperative or mbrace
Service Not Activated message
appears in the multifunction display after
the system self-diagnosis.
If a malfunction is indicated as outlined
above, the system may not operate as
expected. In the event of an emergency, help
will have to be summoned by other means.
Have the system checked at the nearest
authorized Mercedes-Benz Center or contact
the following service 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 252
Features
Stowage and features
ProCarManuals.com

The washer fluid reservoir is used for both the
windshield washer
system
and the headlamp
cleaning system.
The recommended minimum amount when
topping up is 1 liter. If the water level drops
below this, a message appears in the
multifunction display prompting you to refill
the washer fluid ( Y page 223).
Further information on windshield washer
fluid/antifreeze ( Y page 334).Maintenance
ASSYST PLUS
Service messages The ASSYST PLUS service interval display
informs you of the next service due date.
Information on
the

type of service and service
intervals (see the separate Maintenance
Booklet).
You can obtain further information from an
authorized Mercedes-Benz Center or at
http://www.mbusa.com (USA only).
i The ASSYST PLUS service interval display
does not show any information on the
engine oil level. Observe the notes on the
engine oil level ( Y page 267).
The multifunction display shows a service
message for several seconds, e.g.:
R Next Service A in .. Days
R Service A Due
R Service A Exceeded by .. Days
Depending on the operating conditions of the
vehicle, the remaining time or distance until
the next service due date is displayed.
The letter A or B, possibly in connection with
a number or another letter, shows the type of
service. A stands for a minor service and B for
a major service.
You can obtain further information from an
authorized Mercedes-Benz Center.
The ASSYST PLUS service interval display
does not take into account any periods of time during which the battery is
disconnected.
Maintaining the time-dependent service
schedule:
X
Note down the service due date displayed
in the multifunction display before
disconnecting the battery.
or
X After reconnecting the battery, subtract
the battery
disconnection

periods from the
service date shown on the display.
Hiding a service message X
Press % or a.
Displaying service messages X
Switch on the ignition.
X Using = or ;, select the Serv.
menu.
X Press 9 or : to select the ASSYST
PLUS submenu and

press a to confirm.
The service due date appears in the
multifunction display.
Information about Service Resetting the ASSYST PLUS service
interval display
!
If the ASSYST PLUS service interval
display has been inadvertently reset, this
setting can be corrected at a qualified
specialist workshop.
Have service work

carried out as described
in the Maintenance Booklet. This may
otherwise lead to increased wear and
damage to the major assemblies or the
vehicle.
A qualified specialist workshop, e.g. an
authorized Mercedes-Benz Center, will reset
the ASSYST PLUS service interval display
after the service work has been carried out.
You can also obtain further information on
maintenance work, for example. 270
Maintenance
Maintenance and care
ProCarManuals.com

!
Make sure that the automatic
transmission is in
position N when washing
your vehicle in a tow-through car wash. The
vehicle could be damaged if the
transmission is in another position.
! Make sure that:
R the side windows and the sliding sunroof
are fully closed.
R the ventilation/heating is switched off
(the OFF button has been pressed/the
airflow control is set to position 0).
R the windshield wiper switch is in position
0.
Otherwise, the vehicle might be damaged.
You can wash the vehicle in an automatic car
wash from the very start.
If the vehicle is very dirty, pre-wash it before
cleaning it in an automatic car wash.
After using an automatic car wash, wipe off
wax from the windshield and the wiper
blades. This will prevent smears and reduce
wiping noises caused by residue on the
windshield.
Washing by hand In some countries, washing by hand is only
allowed at wash bays that are specially
designed for this purpose. Observe the legal
requirements in all countries concerned.
X
Do not use hot water and do not wash the
vehicle in direct sunlight.
X Use a soft sponge to clean.
X Use a mild cleaning agent, such as a car
shampoo approved by Mercedes-Benz.
X Thoroughly hose down the vehicle with a
gentle jet of water.
X Do not point the water jet directly towards
the air inlet.
X Use plenty of water and rinse out the
sponge frequently. X
Rinse the vehicle with clean water and dry
thoroughly with a chamois.
X Do not let the cleaning agent dry on the
paintwork.
When using the vehicle in winter, remove all
traces of road salt deposits carefully and as
soon as possible.
Power washers G
WARNING
The water jet from a circular jet nozzle (dirt
blasters) can cause

invisible exterior damage
to the tires or chassis components.
Components damaged in this way may fail
unexpectedly. There is a risk of an accident.
Do not use power washers with circular jet
nozzles to clean the vehicle. Have damaged
tires or chassis components replaced
immediately.
! Always maintain a distance of at least
11.8 in (30 cm) between the vehicle and the
power washer nozzle. Information about
the correct distance is available from the
equipment manufacturer.
Move the power washer nozzle around
when cleaning your vehicle.
Do not aim directly at any of the following:
R tires
R door gaps, roof gaps, joints, etc.
R electrical components
R battery
R connectors
R lights
R seals
R trim
R ventilation slots
Damaged seals or electrical components
can lead to leaks or failures. 272
Care
Maintenance and care
ProCarManuals.com

Useful information ............................
280
Where will I find...? ........................... 280
Flat tire .............................................. 281
Battery (vehicle) ................................ 285
Jump-starting .................................... 289
Towing and tow-starting .................. 291
Fuses .................................................. 294 279Breakdown assistance
ProCarManuals.com

X
Stop after driving for approximately ten
minutes and check the tire pressure with
the tire inflation compressor.
The tire pressure must now be at least
130 kPa (1.3 bar/19 psi). G
WARNING
If the required tire pressure is not reached
after driving for a short period, the tire is too
badly damaged. The
tire sealant cannot repair
the tire in this instance. Damaged tires and a
tire pressure that is too low can significantly
impair the vehicle's braking and driving
characteristics. There is a risk of accident.
Do not continue driving. Contact a qualified
specialist workshop.
X Correct the tire pressure if it is still at least
130 kPa (1.3 bar/19 psi) (for the values,
see the Tire and Loading Information
placard on the driver's side B-pillar or tire
pressure table on the fuel filler flap).
X To increase the tire pressure: switch on
the tire inflation compressor. X
To reduce the tire pressure: depress
pressure release button : next to
pressure gauge ;. X
To remove the tire sealant bottle from the
tire inflation compressor, press together
the locking tabs on the yellow cap.
X Pull the tire sealant bottle out of the tire
inflation compressor.
The filler hose

remains attached to the tire
sealant bottle.
X Stow the tire sealant bottle and the tire
inflation compressor.
X Drive to the nearest qualified specialist
workshop and have

the tire changed there.
X Have the tire sealant bottle and the filler
hose replaced as soon as possible at a
qualified specialist workshop.
X Have the tire sealant bottle replaced every
four years at a qualified specialist
workshop. Battery (vehicle)
Important safety notes
Special tools and expert knowledge are
required when working on the battery, e.g.
removal and installing. You should therefore
have all work

involving the battery carried out
at a qualified specialist workshop. G
WARNING
Work carried out incorrectly on the battery
can, for example, lead to a short circuit and
damage your vehicle's

electronic system. This
can disrupt driving safety systems such as
ABS (anti-lock braking system) or ESP ®
(Electronic Stability Program). Battery (vehicle)
285
Breakdown assistance
ZProCarManuals.com

R
If ABS malfunctions, the wheels can lock
during braking. This limits the steerability
of the vehicle
when braking and the braking
distance may increase. There is a risk of
accident.
R If ESP ®
malfunctions, the vehicle will not be
stabilized if it starts to skid or a wheel starts
to spin. There is a risk of accident.
You should therefore have all work involving
the battery carried out at a qualified specialist
workshop. G
WARNING
Electrostatic build-up can lead to the creation
of sparks, which could ignite the highly
explosive gases of

a battery. There is a risk of
an explosion.
Before handling the battery, touch the vehicle
body to remove any existing electrostatic
build-up.
The highly flammable gas mixture forms when
charging the battery as well as when jump-
starting.
Always make sure that neither you nor the
battery is electrostatically charged. There is
a build-up of electrostatic charge, e.g.:
R by wearing clothing made from synthetic
fibers
R due to friction between clothing and seats
R if you push or pull the battery across the
carpet or other synthetic materials
R if you wipe the battery with a cloth. 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
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. H
Environmental note Batteries contain dangerous
substances. It is against the
law to dispose of them with
the household rubbish. They
must be
collected

separately
and recycled to protect the
environment. Dispose of batteries in an
environmentally friendly
manner. Take discharged
batteries to a qualified
specialist workshop or a
special collection point for
used batteries.
! Have the battery checked regularly at a
qualified specialist workshop.
Observe the service intervals in the
Maintenance Booklet or

contact a qualified
specialist workshop for more information.
! You should have all work involving the
battery carried out at a qualified specialist
workshop. In the exceptional case that it is 286
Battery (vehicle)
Breakdown assistance
ProCarManuals.com