2014 MERCEDES-BENZ B-CLASS HATCHBACK ECU

manner. Take discharged
batteries to a qualified spe-
cialist workshop or to a col-
lection point for used batter-
ies.
! Have the battery checked regularly at a
qualified specialist workshop.
Observe the service intervals in the Service
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
necessary for you to disconnect the battery yourself, make sure that:
R you switch off the engine and remove the
key. On vehicles with KEYLESS-GO,
ensure that the ignition is switched off.
Check that all the indicator lamps in the
instrument cluster are off. Otherwise,
electronic components, such as the
alternator, may be damaged.
R you first remove the negative terminal
clamp and then the positive terminal
clamp. Never swap the terminal clamps.
Otherwise, the vehicle's electronic sys-
tem may be damaged.
R in vehicles with automatic transmission,
the transmission is locked in position P
after disconnecting the battery. The vehi-
cle is secured against rolling away. You
can then no longer move the vehicle.
The battery and the cover of the positive
terminal clamp must be fitted securely dur- ing operation.
Comply with safety precautions and take pro-
tective measures when handling batteries. WARNING
Fire, naked flames and smoking
are prohibited when handling the
battery. Avoid creating sparks. Battery acid is caustic. Avoid con-
tact with the skin, eyes or clothing.
Wear suitable protective clothing,
in particular gloves, an apron and a
face mask.
Immediately rinse acid splashes
off with clean water. Consult a doc-
tor if necessary. Wear eye protection.
Keep children away.
Observe this Owner's Manual.
For safety reasons, Mercedes-Benz recom-
mends that you only use batteries which have been tested and approved for your vehicle by
Mercedes-Benz. These batteries provide
increased impact protection to prevent vehi-
cle occupants from suffering acid burns
should the battery be damaged in the event of
an accident.
In order for the battery to achieve the maxi-
mum possible service life, it must always be
sufficiently charged.
Like other batteries, the vehicle battery may
discharge over time if you do not use the
vehicle. In such cases, have the battery dis-
connected at a qualified specialist workshop. You can also charge the battery with a
charger recommended by Mercedes-Benz.
For more information, please contact a quali-
fied specialist workshop.
Have the battery charge checked more fre-
quently if you use the vehicle mainly for short
trips or if you leave it standing idle for a
lengthy period. Consult a qualified specialist
workshop if you wish to leave your vehicle
parked up for a long period of time.
i When you park the vehicle, remove the
key if you do not require any electrical con- 340
Battery (vehicle)Breakdown assistance

Do not use a rapid charging device to start the vehicle. If your vehicle's battery is discharged,
the engine can be jump-started from another vehicle or from a second battery using jump
leads. Observe the following points:
R The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible,
jump-start the vehicle using a second battery or a jump-starting device.
R Vehicles with a petrol engine: only jump-start the vehicle when the engine and exhaust
system are cold.
R Do not start the engine if the battery is frozen. Let the battery thaw first.
R Jump-starting may only be performed using batteries with a nominal voltage of 12 V.
R Only use jump leads that are not damaged and have a sufficient cross-section and insulated
terminal clamps.
R Make sure that the two vehicles do not touch.
Make sure that:
R the jump leads are not damaged.
R non-insulated parts of the terminal clamps do not come into contact with other metal parts
while the jump leads are connected to the battery.
R the jump leads cannot come into contact with parts which can move when the engine is
running, such as the V-belt pulley or the fan.
X Secure the vehicle by applying the electric parking brake.
X Manual transmission: depress the clutch pedal fully and shift to neutral.
X Automatic transmission: shift the transmission to position P.
X Turn the key to position 0in the ignition lock and remove it.
X Switch off all electrical consumers, e.g. rear window heating, lighting etc.
X Open the bonnet. Jump-starting
343Breakdown assistance Z

Details on the permissible gross vehicle
weight of your vehicle can be found on the
vehicle identification plate (Y page 386).
! When COLLISION PREVENTION ASSIST
PLUS, DISTRONIC PLUS or the HOLD func- tion is activated, the vehicle brakes auto-
matically in certain situations. To avoid
damage to the vehicle, deactivate these
systems in the following or similar situa-
tions:
R when towing away
R in a car wash
! Make sure that the electric parking brake
is released. If the electric parking brake is
faulty, visit a qualified specialist workshop.
! Only secure the tow cable or tow bar to
the towing eyes or, if available, to the trailer
tow hitch. You could otherwise damage the
vehicle.
! Observe the following points when towing
with a tow rope:
R Secure the tow rope on the same side on
both vehicles.
R Make sure that the tow rope is not longer
than legally permitted. Mark the tow rope
in the middle, e.g. with a white cloth
(30 x 30 cm). This will make other road
users aware that a vehicle is being
towed.
R Only secure the tow cable to the towing
eyes or, if available, to the trailer tow
hitch.
R Observe the brake lamps of the towing
vehicle while driving. Always maintain a
distance a distance so that the tow rope does not sag.
R Do not use steel cables or chains to tow
your vehicle. You could otherwise dam-
age the vehicle.
! Do not use the towing eyes for recovery
purposes as this could damage the vehicle.
If in doubt, recover the vehicle with a crane. !
Pull away smoothly when towing away or
tow-starting a vehicle. If the tractive power
is too high, the vehicles could be damaged.
! You may tow the vehicle for a maximum of
50km. A towing speed of 50 km/h must not be exceeded.
For towing distances over 50 km, the frontaxle or the entire vehicle must be raised
and transported.
! To tow vehicles with KEYLESS-GO, use
the key instead of the Start/Stop button.
The automatic transmission may otherwise switch to position Pwhen you open the
driver's or front-passenger door which
could damage the transmission.
! Vehicles with automatic transmission
must not be tow-started. The transmission
may otherwise be damaged.
Observe the legal requirements for the rele-
vant countries when towing and tow-starting.
It is better to have the vehicle transported
than to have it towed.
If the vehicle can no longer be driven because
of an accident or breakdown, you have the
following options:
R Transporting the vehicle.
As a rule, you should have the vehicle trans-
ported.
R Towing the vehicle with a tow rope or tow
bar.
Only tow the vehicle in exceptional cases.
Vehicles with automatic transmission:
when towing a vehicle, the transmission must be in position N.
The battery must be connected and charged.
Otherwise, you:
R cannot turn the key to position 2in the
ignition lock
R cannot release the electric parking brake
R cannot shift the transmission to position N
on vehicles with automatic transmis-
sion Towing away and tow-starting
345Breakdown assistance Z

i
The function of the electric parking brake
and the parking lock is dependent on the
on-board voltage.
If the on-board voltage is low or if there is a system malfunction:
R it may not be possible to apply the
released parking brake or
R it may not be possible to shift the trans-
mission to position P
i Switch off non-essential consumers, such
as the radio.
i Deactivate the automatic locking feature
before the vehicle is towed away
(Y page 247). You could otherwise be
locked out when pushing or towing the
vehicle.
Deactivate tow-away protection before the vehicle is towed away . Fitting/removing the towing eye
Fitting the towing eye Example: covers for towing eye mountings
X Remove the towing eye from the stowage
space.
The towing eye is located with the vehicle
tool kit under the luggage compartment
floor (Y page 333). Vehicles with a TIREFIT kit: the towing eye
is located under the tyre inflation compres-
sor.
X Press the mark on cover :inwards in the
direction of the arrow.
X Remove cover :from the opening.
X Screw in the towing eye clockwise to the
stop.
Vehicles with a trailer tow hitch only have a
bracket at the front for the screw-in towing
eye. If you intend to use the vehicle for tow-
ing, fold out the ball coupling (Y page 226)
and secure the towbar to it.
Removing the towing eye X
Loosen the towing eye and unscrew it.
X Attach cover :to the bumper and press
until it engages.
X Place the towing eye in the stowage well
(Y page 333) under the luggage compart-
ment floor.
X Vehicles with a TIREFIT kit: replace the tyre
inflation compressor. Towing the vehicle with the front axle
raised
When towing your vehicle away with the rear axle raised, it is important that you observe
the safety instructions (Y page 344).
Only vehicles without 4MATIC can be
towed with the front axle raised.
! Vehicles with 4MATIC must not be towed
with the front or rear axle raised; otherwise, the transmission may be damaged.
Vehicles with 4MATIC may either be towed
away with both axles on the ground or be loa-
ded up and transported.
! The ignition must be switched off if you
are towing the vehicle with the front axle
raised. Intervention by ESP ®
could other-
wise damage the brake system. 346
Towing away and tow-startingBreakdown assistance

X
On vehicles with KEYLESS-GO or the
KEYLESS-GO start function: you must
use the key instead of the Start/Stop but-
ton (Y page 160).
X Make sure that the vehicle is stationary.
X Turn the key to position 2in the ignition
lock.
X When the vehicle is stationary, depress the
brake pedal and keep it depressed.
X Vehicles with automatic transmission:
shift the automatic transmission to posi-
tion P.
or
X Vehicles with manual transmission:
depress the clutch pedal fully and engage
neutral.
X Release the brake pedal.
X Release the electric parking brake.
X Deactivate tow-away protection
(Y page 81).
X Deactivate automatic locking (Y page 247).
X Switch on the hazard warning lamps
(Y page 125).
X Turn the key in the ignition lock to position
0 and leave the key in the ignition lock. Towing the vehicle with both axles on
the ground
It is important that you observe the safety
instructions when towing away your vehicle
(Y page 344).
X On vehicles with KEYLESS-GO or the
KEYLESS-GO start function: you must
use the key instead of the Start/Stop but-
ton (Y page 160). Vehicles with automatic transmission:
the
automatic transmission automatically shifts
to position Pwhen you open the driver's or
front-passenger door or when you remove the
key from the ignition lock. In order to ensure that the automatic transmission stays in posi- tion Nwhen towing away the vehicle, you
must observe the following points:
X Make sure that the vehicle is stationary.
X Turn the key to position 2in the ignition
lock.
X Depress the brake pedal and keep it
depressed.
X Shift the automatic transmission to posi-
tion N.
Vehicles with manual transmission: X Turn the key to position 2in the ignition
lock.
X When the vehicle is stationary, depress the
brake pedal and keep it depressed.
X Depress the clutch pedal fully and shift to
neutral.
All vehicles:
X Leave the key in position 2in the ignition
lock.
X Release the brake pedal.
X Release the electric parking brake.
X Switch on the hazard warning lamps
(Y page 125).
i In order to signal a change of direction
when towing the vehicle with the hazard
warning lamps switched on, use the com-
bination switch as usual. In this case, only
the turn signals for the desired direction
flash. When you reset the combination
switch, the hazard warning lamps start
flashing again. Transporting the vehicle
! You may only secure the vehicle by the
wheels, not by parts of the vehicle such as Towing away and tow-starting
347Breakdown assistance Z

axle or steering components. Otherwise,
the vehicle could be damaged.
X Vehicles with manual transmission:
depress the clutch pedal fully and engage
neutral.
X Turn the key to position 2in the ignition
lock (Y page 159).
X Vehicles with automatic transmission:
turn the key to position 2in the ignition lock
(Y page 159).
X Shift the transmission to position N.
As soon as the vehicle is loaded: X Prevent the vehicle from rolling away by
applying the electric parking brake.
X Vehicles with manual transmission:
depress the clutch pedal fully and engage
first or reverse gear.
X Vehicles with automatic transmission:
shift the transmission to position P.
X Turn the key to position 0in the ignition
lock and remove it.
X Secure the vehicle.
The towing eyes or trailer tow hitch can be
used to pull the vehicle onto a trailer or trans- porter if you wish to transport it. Notes for 4MATIC vehicles
! Vehicles with 4MATIC must not be towed
with the front or rear axle raised; otherwise, the transmission may be damaged.
Vehicles with 4MATIC may only be either
towed away with both axles on the ground or be loaded up and transported.
If the vehicle has transmission damage or
damage to the front or rear axle, have it trans-
ported on a transporter or trailer.
In the event of damage to the electrical
system:
If the battery is defective, the automatic
transmission will be locked in position P. To
shift the automatic transmission to position
N, you must provide power to the vehicle's electrical system in the same way as when
jump-starting (Y
page 342).
Have the vehicle transported on a transporter
or trailer. Tow-starting (emergency engine
starting)
! Do not tow-start vehicles with automatic
transmission. You could otherwise damage the automatic transmission.
i You can find information on "Jump-start-
ing" under (Y page 342).
Before tow-starting, the following conditions
must be fulfilled: R the battery is connected
R the engine has cooled down
R the exhaust system has cooled down
When tow-starting, it is important that you
observe the safety notes (Y page 344) and the
legal requirements in each respective coun-
try.
X Switch on the hazard warning lamps
(Y page 125).
X Fit the towing eye (Y page 346).
X Secure the rigid towing bar or the towing
rope.
X When the vehicle is stationary, depress the
brake pedal and keep it depressed.
X Turn the key to position 2in the ignition
lock (Y page 159).
X Depress the clutch pedal fully, engage sec-
ond gear and continue to keep the clutch
pedal fully depressed.
X Release the brake pedal.
X Tow-start the vehicle.
X Release the clutch pedal slowly, do not
depress the accelerator pedal while doing
so.
X When the engine has been started, imme-
diately depress the clutch pedal fully and
shift to neutral. 348
Towing away and tow-startingBreakdown assistance

X
Pull over at a suitable place and stop the
vehicle safely, paying attention to road and
traffic conditions.
X Use the electric parking brake to secure the
vehicle and prevent it from rolling away.
X Remove the rigid towing bar or towing rope.
X Remove the towing eye (Y page 346).
X Switch off the hazard warning lamps. Electrical fuses
Important safety notes
G
WARNING
If you manipulate, bridge or replace a faulty
fuse with a fuse of a higher amperage, the
electric cables could be overloaded. This may result in a fire. There is a risk of an accident
and injury.
Always replace faulty fuses with specified new fuses of the correct amperage.
Blown fuses must be replaced with fuses of
the same rating, which you can recognise by
the colour and fuse rating. The fuse ratings
are listed in the fuse allocation chart.
If the newly inserted fuse also blows, have the
cause traced and rectified at a qualified spe-
cialist workshop, e.g. a Mercedes-Benz Ser-
vice Centre.
! Only use fuses that have been approved
for Mercedes-Benz vehicles and which
have the correct fuse rating for the system concerned. Only use fuses marked with an
"S". Components or systems could other-
wise be damaged.
The fuses in your vehicle disconnect faulty
circuits. If a fuse blows, all the components on the circuit and their functions will fail.
Blown fuses must be replaced with fuses of
the same rating, which you can recognise by
the colour and fuse rating. The fuse ratings
are listed in the fuse allocation chart.
If the newly inserted fuse also blows, have the
cause traced and rectified at a qualified spe- cialist workshop, e.g. a Mercedes-Benz Ser-
vice Centre. Before replacing a fuse
X Secure the vehicle against rolling away
(Y page 181).
X Switch off all electrical consumers.
X Vehicles without KEYLESS-GO: remove
the key from the ignition lock.
X Vehicles with KEYLESS-GO start-func-
tion or KEYLESS-GO: open the driver's
door.
The on-board electronics now have status
0. This is the same as the key having been removed.
The fuses are located in various fuse boxes:
R fuse box in the engine compartment on the
left-hand side of the vehicle, when viewed
in the direction of travel
R fuse box in the front-passenger footwell
The fuse allocation chart is on the fuse box in
the front-passenger footwell (Y page 350). Fuse box in the engine compartment
G
WARNING
When the bonnet is open, and the windscreen wipers are set in motion, you can be injured by
the wiper linkage. There is a risk of injury.
Always switch off the windscreen wipers and
the ignition before opening the bonnet.
! Make sure that no moisture can enter the
fuse box when the cover is open.
! When closing the cover, make sure that it
is lying correctly on the fuse box. Moisture
seeping in or dirt could otherwise impair
the operation of the fuses. Electrical fuses
349Breakdown assistance Z

Securing the vehicle against rolling
away
If your vehicle is equipped with a wheel chock,
it can be found in the tyre-change tool kit
(Y page 333).
The folding wheel chock is an additional
securing measure to prevent the vehicle from
rolling away, for example when changing a
wheel.
X Fold both plates upwards :.
X Fold out lower plate ;.
X Guide the lugs on the lower plate fully into
the openings in base plate =.Securing the vehicle on level ground
X On level ground: place chocks or other
suitable items under the front and rear of
the wheel that is diagonally opposite the
wheel you wish to change. Securing the vehicle on slight downhill gradients
X On slight downhill gradients: place
chocks or other suitable items in front of
the wheels of the front and rear axle.
Raising the vehicle G
WARNING
If you do not position the jack correctly at the appropriate jacking point of the vehicle, the
jack could tip over with the vehicle raised.
There is a risk of injury.
Only position the jack at the appropriate jack-
ing point of the vehicle. The base of the jack
must be positioned vertically, directly under
the jacking point of the vehicle.
Observe the following when raising the
vehicle: R to raise the vehicle, only use the vehicle-
specific jack that has been tested and
approved by Mercedes-Benz. If the jack is
used incorrectly, it could tip over while the vehicle is raised.
R the jack is designed only to raise and hold
the vehicle for a short time while a wheel
is being changed. It is not suitable for per-
forming maintenance work under the vehi- cle.
R avoid changing the wheel on uphill and
downhill slopes.
R before raising the vehicle, safeguard it from
rolling away by applying the parking brake
and positioning wheel chocks. Do not Changing a wheel
363Wheels and tyres Z