2015 MERCEDES-BENZ B-CLASS HATCHBACK engine

X
If necessary, top up with coolant that has
been tested and approved by Mercedes-Benz.
X Replace cap :and turn it clockwise as far as
it will go.
For further information on coolant, see
(Y page 283).
Topping up the windscreen washer sys-
tem/headlamp cleaning system G
WARNING
Certain components in the engine compart-
ment may be very hot, e.g. the drive system
and radiator. When carrying out work in the
engine compartment there is a risk of injury.
If possible, let the drive system cool down and only touch the components described in the
following. G
WARNING
Windscreen washer concentrate is highly
flammable. If it comes into contact with hot
components in the front compartment, it may ignite. There is a risk of fire and injury.
Make sure that windscreen washer concen-
trate is not spilled next to the filler neck. X
To open: pull cap:upwards by the tab.
X Top up with the premixed washer fluid.
X To close: press cap :onto the filler neck
until it engages.
The washer fluid reservoir is used for both the
windscreen washer system and the headlamp
cleaning system.
On vehicles with the headlamp cleaning system,
the recommended minimum washer fluid level is 3.5 litres. On vehicles not equipped with the headlamp
cleaning system, the recommended minimum
washer fluid level is 1 litre.
If the washer fluid level drops below 1 litre, a
message appears in the multifunction display
prompting you to top up the washer fluid
(Y page 212).
Further information on windscreen washer
fluid/antifreeze (Y page 284). ASSYST PLUS
Service message
The ASSYST PLUS service interval display
informs you of the next service due date.
You can find information on the type of service
and service intervals in the Service Booklet.
You can obtain further information from a
Mercedes-Benz Service Centre.
The multifunction display shows a service mes-
sage for a few seconds, e.g.:
R Service A in .. days
Service A in .. days
R Service A due Service A due
R Service A overdue by .. days
Service A overdue 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 indicates which service is due. A A
stands for a minor service and B
Bfor a major ser-
vice. A number or another letter may be dis-
played after the letter.
Only for certain countries: the position after the
letter A
A or B Bindicates any necessary additional
maintenance work. If you notify a qualified spe-
cialist workshop of this display, you will receive
a statement on the associated costs.
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 sched-
ule:
X Note down the service due date displayed in
the multifunction display before disconnect-
ing the battery.
or
X After reconnecting the battery, subtract the
battery disconnection periods from the ser-
vice date shown on the display. ASSYST PLUS
241Maintenance and care Z

X
Drive to the nearest qualified specialist work-
shop and have the tyre changed there.
X Have the tyre sealant bottle and the filler hose
replaced as soon as possible at a qualified
specialist workshop.
X Have the tyre sealant bottle replaced every
four years at a qualified specialist workshop. Batteries
12 V battery - important safety notes
Work on the batteries, e.g. removing or fitting,
requires specialist knowledge and the use of
special tools. For this reason, always have work on the batteries carried out at a qualified spe-
cialist workshop. G
WARNING
The battery terminal clamps can remain under voltage even after being disconnected. If work
on the battery is carried out incorrectly, a
short-circuit may result. There is a risk of fire.
Always have work on the batteries carried out
at a qualified specialist workshop. Never dis-
connect a battery yourself. G
WARNING
Work carried out incorrectly on the battery
can lead, for example, to a short circuit and
thus damage the vehicle electronics. This can lead to function restrictions applying to
safety-relevant systems, e.g the lighting sys-
tem, the ABS (anti-lock braking system) or the
ESP ®
(Electronic Stability Program). The oper-
ating safety of your vehicle may be restricted.
You could lose control of the vehicle, for
example:
R when braking
R in the event of abrupt steering manoeuvres
and/or when the vehicle's speed is not
adapted to the road conditions
There is a risk of an accident.
In the event of a short circuit or a similar inci- dent, contact a qualified specialist workshop
immediately. Do not drive any further. Always have work on the battery carried out at a
qualified specialist workshop.
Further information about ABS (Y page 61) and
ESP ®
(Y page 65). G
WARNING
Electrostatic build-up can lead to the creation of sparks, which could ignite the highly explo-
sive 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 is created
while the battery is charging and when jump-
starting.
Always make sure that neither you nor the bat-
tery is electrostatically charged. Electrostatic
charge is created, for example: R by wearing synthetic fibre clothing
R by friction between clothing and the seat
R when you pull or push the battery across car-
pet or other synthetic materials
R when you rub the battery with a cloth G
WARNING
During the charging process, a battery produ- ces 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 con-
tact with vehicle parts.
R Never place metal objects or tools on a bat-
tery.
R It is important that you observe the descri-
bed 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 dis-
connecting the jump leads.
R Never connect or disconnect the battery
terminals while the engine is running. 254
BatteriesBreakdown assistance

Charging the 12‑
volt batteryG
WARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, naked flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery. G
WARNING
Battery acid is caustic. There is a risk of injury. Avoid contact with the skin, eyes or clothing.
Do not breathe in any battery gases. Do not
lean over the battery. Keep the batteries out
of the reach of children. Immediately rinse off
battery acid thoroughly with plenty of clean
water and seek medical attention at once. G
WARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing 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.
! Only use battery chargers with a maximum
charging voltage of 14.8 V.
! Only charge the battery using the jump-start
connection point.
The jump-starting connection point is in the
engine compartment (Y page 258).
X Open the bonnet.
X Connect the battery charger to the positive
terminal and earth point in the same order as
when connecting the donor battery in the
jump-starting procedure (Y page 258).
If the indicator/warning lamps do not light up at
low temperatures, it is very likely that the dis-
charged battery has frozen. In this case you may neither jump-start the vehicle nor charge the
battery. The service life of a battery that has
been thawed may be reduced. The starting char-
acteristics may be impaired, especially at low temperatures. Have the thawed battery
checked at a qualified specialist workshop.
Only charge the installed battery with a battery
charger which has been tested and approved by
Mercedes-Benz. A battery charger unit specially
adapted for Mercedes-Benz vehicles and tested
and approved by Mercedes-Benz is available as an accessory. This device permits charging of
the battery in position. Contact a Mercedes-
Benz Service Centre for information and availa-
bility. Read the battery charger's operating
instructions before charging the battery. High-voltage battery - important
safety notes
G
DANGER
The vehicle's high voltage electrical system is under high voltage. If you modify components
in the vehicle's high-voltage electrical system or touch damaged components, you may be
electrocuted. The components in the vehi-
cle's high-voltage electrical system may be
damaged in an accident, although the damage
is not visible. There is a risk of fatal injury.
Do not touch any high-voltage components
after an accident and never modify the vehi-
cle's high-voltage electrical system. Have the vehicle towed away after an accident and the vehicle's high-voltage electrical system
checked by a qualified specialist workshop. G
WARNING
In the event of a vehicle fire, the internal pres- sure of the high-voltage battery could exceeda critical value. In this case, flammable gas
escapes through a vent valve in the vehicle's
underbody. The gas can ignite. There is a risk
of injury.
Leave the danger area immediately. Secure
the danger area at a suitable distance, whilst
observing legal requirements. 256
BatteriesBreakdown assistance

The vehicle's high-voltage electrical system is
under high voltage.
R Do not handle high-voltage components or
the orange cables of the vehicle's high-volt-
age electrical system.
R Do not touch high-voltage components or the
orange cables of the high-voltage electrical
system when a vehicle has been involved in a
crash.
R Do not touch any damaged components or
the damaged orange cables of the vehicle's
high-voltage electrical system.
R Do not remove the covers of the high-voltage
electrical system components that are
marked with a warning sticker.
Do not leave the vehicle parked for longer than
14 days with a high-voltage battery charge sta-
tus below 20%.
You can check the charge status in the charge
level display (Y page 174).
If you park the vehicle and leave it stationary for
longer periods, connect it to a power supply.
If you leave the vehicle parked up for longer than
four weeks, the battery may be damaged by
exhaustive discharging.
If you leave the vehicle parked up for longer than
six weeks, it may suffer from lack of use.
X Visit a qualified specialist workshop and seek
advice.
i You can obtain information about trickle
chargers from a qualified specialist work-
shop.
i Very low or very high outside temperatures
can impair the function of the high-voltage
battery (Y page 136). This can also occur
when the vehicle engine is switched off
(Y page 136). Batteries
257Breakdown assistance Z

Jump-starting
For the jump-starting procedure, use only the jump-starting connection point, consisting of a pos- itive 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 breathe in any battery gases. Do not lean over the battery. Keep the batteries out of the reach of children. Immediately rinse off battery acid
thoroughly with plenty of clean water and seek medical attention at once. G
WARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, naked 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 jump leads.
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.
! Avoid repeated and lengthy starting attempts.
Do not use a rapid-charging device to start the engine.
If the indicator/warning lamps do not light up at low temperatures, it is very likely that the dis-
charged battery has frozen. In this case you may neither jump-start the vehicle nor charge the
battery. The service life of a battery that has been thawed may be reduced. Have the thawed battery checked at a qualified specialist workshop.
If the 12 V battery is discharged, or after the vehicle has been jump-started, the Without chang‐ Without chang‐
ing
ing gear,
gear, consult
consult workshop
workshop message appears. There is a malfunction in the on-board voltage.
Visit a qualified specialist workshop immediately.
The drive system cannot be started if the 12 V battery is discharged. This is not dependant on
whether the high-voltage battery is charged or not. The vehicle cannot be jump-started if the high-
voltage battery is discharged. The high-voltage battery must first be charged. 258
Jump-startingBreakdown assistance

The drive system can be started using another vehicle.
R Only use batteries with an equal nominal voltage (12 volts).
R Make sure that the battery of the donor vehicle does not have a significantly lower capacity than
the discharged battery.
R Use jump leads with a sufficient cross-section and insulated terminal clamps from a qualified
specialist workshop, e.g. a Mercedes-Benz Service Centre.
R Make sure that the two vehicles do not touch.
R Route the jump leads so that they cannot be caught by rotating components in the engine com-
partment.
R Do not disconnect the discharged battery from the vehicle's electrical system. X
Switch off the engine of both vehicles.
X Shift the transmission to position P.
X Switch off all electrical consumers.
X Remove battery cover :.
X Connect positive terminal ;on the vehicle with the flat battery to positive terminal =of the
donor vehicle using the red jump lead. Begin with the flat battery.
X Connect negative terminal ?of the donor vehicle to negative terminal Aof the vehicle with the
flat battery using the black jump lead. Begin with donor vehicle's battery B.
X Start the engine of the donor vehicle and run it at idling speed.
X Switch on the ignition in the vehicle with the flat battery.
X If the drive system cannot be activated immediately, wait for approximately 60 seconds between
starting attempts.
If the drive system does not start, call a breakdown service.
i Jump-starting cables and further information regarding jump starting can be obtained at any
qualified specialist workshop. Jump-starting
259Breakdown assistance Z

passenger door, which could damage the
transmission.
Observe the legal requirements for the relevant countries when towing.
Make sure that no charging cables are connec-
ted. The parking lock cannot be released if a
charging cable is connected.
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 follow- ing 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.
Observe the following notes.
The vehicle may not be towed and must always be transported if:
R the multifunction display is not working
R one of more of the following warning lamps is
lit up:
- Drive system
- 12 V battery
R one or both of the following display messages
have appeared:
- Stop Switch engine off
Stop Switch engine off
- Without changing gear, consult Without changing gear, consult
workshop
workshop
R you have to tow the vehicle over a longer dis-
tance than 50 km.
The battery must be connected and charged.
Otherwise, you:
R cannot turn the key to position 2in the igni-
tion lock
R cannot release the electric parking brake
R cannot move the transmission to position N
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 sys- tem malfunction:
R it may not be possible to apply the released
parking brake or
R it may not be possible to shift the transmis-
sion to position P Switch off non-essential consumers, e.g. the
radio.
Deactivate the automatic locking feature before
towing the vehicle (Y page 187). You could oth-
erwise be locked out when pushing or towing
the vehicle.
Deactivate tow-away protection before towing
away the vehicle (Y page 68). Fitting/removing the towing eye
Fitting the towing eye The mountings for the removable towing eyes
are located in the bumpers. They are at the rear
and at the front, under covers :.
X Remove the towing eye from the stowage
space.
The towing eye is located under the luggage
compartment floor.
Vehicles with a TIREFIT kit: the towing eye is
located under the tyre inflation compressor.
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. Recovery
261Breakdown assistance Z

The transmission automatically shifts to posi-
tion 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
transmission stays in position Nwhen towing
the vehicle, you must observe the following
points:
X On vehicles with KEYLESS-GO or the KEY-
LESS-GO start function: you must use the
key instead of the Start/Stop button
(Y page 127).
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 transmission to position N.
X Release the brake pedal.
X Apply the electric parking brake.
X Deactivate tow-away protection (Y page 68).
X Deactivate automatic locking (Y page 187).
X Move the front wheels to the straight-ahead
position.
X Switch on the hazard warning lamps
(Y page 100).
X Turn the key in the ignition lock to position 0
and leave the key in the ignition lock. Transporting the vehicle
All vehicles !
You may only secure the vehicle by the
wheels, not by parts of the vehicle such as
axle or steering components. Otherwise, the
vehicle could be damaged.
X Turn the key to position 2in the ignition lock
(Y page 126).
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 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 eye can be used to pull the vehicle
onto a trailer or transporter for transportation. 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 newfuses 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 special- ist workshop, e.g. a Mercedes-Benz Service
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". Compo-
nents or systems could otherwise be dam-
aged.
The fuses in your vehicle disconnect faulty cir-
cuits. If a fuse blows, all the components on the circuit and their functions will fail. Before replacing a fuse
X Safeguard the vehicle against rolling away
(Y page 145).
X Switch off all electrical consumers.
X Vehicles without KEYLESS-GO: remove the
key from the ignition lock.
X Vehicles with KEYLESS-GO start-function
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 Electrical fuses
263Breakdown assistance Z