engine MERCEDES-BENZ B-Class 2017 W246 Service Manual

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 0043.
X Connect positive terminal 0044on the vehicle with the flat battery to positive terminal 0087of the
donor vehicle using the red jumper cable. Begin with the flat battery.
X Connect negative terminal 0085of the donor vehicle to negative terminal 0083of the vehicle with the
flat battery using the black jumper cable, beginning with donor vehicle's battery 0084.
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 Jumper cables and further information regarding jump-starting can be obtained at any qualified
specialist workshop. Towing
Important safety notes
G
WARNING
Functions relevant to safety are restricted or
no longer available if:
R the ignition is switched off
R the brake system or the power steering is
malfunctioning
R there is a malfunction in the power supply
or the vehicle's electrical system
If your vehicle is being towed, much more
force may be necessary to steer or brake.
There is a risk of an accident.
In such cases, use a tow bar. Before towing,
make sure that the steering moves freely. G
WARNING
You can no longer steer the vehicle if the
steering wheel lock has been engaged. There is a risk of an accident.
Always switch off the ignition when towing the
vehicle with a tow cable or a tow bar. G
WARNING
When towing or tow-starting another vehicle
and its weight is greater than the permissible gross weight of your vehicle, the:
R the towing eye could detach itself
R the vehicle/trailer combination could roll-
over.
There is a risk of an accident.
When towing or tow-starting another vehicle,
its weight should not be greater than the per- missible gross weight of your vehicle.
Details on the permissible gross vehicle weight
of your vehicle can be found on the vehicle iden-
tification plate (Y page 282).
! When Active Brake Assist or the HOLD func-
tion is activated, the vehicle brakes automat- ically in certain situations. To avoid damage to the vehicle, deactivate these systems in the
following or similar situations:
R when towing the vehicle
R in the car wash
! Make sure that the electric parking brake is
released. If the electric parking brake is faulty,
visit a qualified specialist workshop.
Mercedes-Benz recommends that you use an authorized Mercedes-Benz Center for this
purpose. Towing
251Breakdown assistance Z

!
Only secure the tow rope or tow bar at the
towing eyes. Otherwise, the vehicle could be
damaged.
! Observe the following points when towing
with a tow rope:
R Secure the tow rope on the same side on
both vehicles.
R Ensure that the tow cable is not longer than
legally permitted. Mark the tow cable in the
middle, e.g. with a white cloth (30 x 30 cm). This will make other road users aware that
the vehicle is being towed.
R Only secure the tow cable to the towing
eye.
R Observe the brake lamps of the towing
vehicle while driving. Always maintain a dis-
tance so that the tow rope does not sag.
R Do not use steel cables or chains to tow
your vehicle. You could otherwise damage
the vehicle.
! Do not use the towing eyes for recovery pur-
poses as this could damage the vehicle. If in
doubt, recover the vehicle with a crane.
! When towing, pull away slowly and
smoothly. If the tractive power is too high, the vehicles could be damaged.
! The vehicle can be towed a maximum of
30 miles (50km). The towing speed of 30 mph
(50km/h) must not be exceeded.
If the vehicle has to be towed more than
30 miles (50km), the front axle must be raised
or the entire vehicle raised and transported.
! Do not tow with sling-type equipment. This
could damage the vehicle.
! To tow vehicles with KEYLESS-GO, use the
SmartKey instead of the Start/Stop button.
The transmission may otherwise shift to posi- tion Pwhen you open the driver's or front-
passenger door, which could damage the
transmission.
Observe the legal requirements for the relevant countries when towing away.
Make sure that no charging cable is plugged in.
The parking lock cannot be released if a charg-
ing cable is plugged in.
It is better to have the vehicle transported than
to have it towed away. 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
- Service Required Do Not Shift Service Required Do Not Shift
Gears Visit Dealer Gears Visit Dealer
R you have to tow the vehicle over a longer dis-
tance than 30 miles (50 km).
The battery must be connected and charged.
Otherwise, you:
R cannot turn the SmartKey to position 2in the
ignition 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 the electric parking brake may not be applied
in certain circumstances, or
R the transmission may not be shifted to P
Switch off non-essential consumers, e.g. the
radio.
Disarm the automatic locking feature before the
vehicle is towed (Y page 166). You could other-
wise be locked out when pushing or towing the
vehicle. 252
TowingBreakdown assistance

wise, components or systems could be dam-
aged.
! 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 seep-
ing in or dirt could otherwise impair the oper- ation of the fuses.
The fuses in your vehicle serve to close down
faulty circuits. If a fuse blows, all the compo-
nents on the circuit and their functions stop
operating.
Blown fuses must be replaced with fuses of the same rating, which you can recognize by the
color and value. The fuse ratings are listed in the
fuse allocation chart.
The fuse allocation chart is in the fuse box in the front-passenger footwell (Y page 256).
If a newly inserted fuse also blows, have the
cause traced and rectified at a qualified special- ist workshop, e.g. an authorized Mercedes-Benz
Center. Before changing a fuse
X Secure the vehicle against rolling away
(Y page 128).
X Switch off all electrical consumers.
X Vehicles without KEYLESS-GO: remove the
SmartKey from the ignition lock.
X Vehicles with KEYLESS-GO: open the driv-
er's door.
The vehicle electronics now have status 0.
This is the same as the SmartKey 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 256). Fuse box in the engine compartment
G
WARNING
When the hood is open and the windshield
wipers are set in motion, you can be injured by the wiper linkage. There is a risk of injury.
Always switch off the windshield wipers and
the ignition before opening the hood. X
Open the hood.
X Use a dry cloth to remove any moisture from
the fuse box.
X To open: unclip hood release cable 0085from
bracket 0087.
X Open retaining clamps 0044.
X Fold cover 0043up in the direction of the arrow
and remove it. X
To close: check whether the seal is seated
correctly in cover 0043.
X Insert cover 0043at the back into openings 0083
on the fuse box.
X Slide hood release cable 0085to the side and
hold if necessary.
X Fold down cover 0043.
X Clip hood release cable 0085into bracket 0087. Fuses
255Breakdown assistance Z

Other identifications, for example:
R 0 W-30
R 5 W-30
R 5 W-40 Brake fluid
G
WARNING
The brake fluid constantly absorbs moisture
from the air. This lowers the boiling point of
the brake fluid. If the boiling point of the brake fluid is too low, vapor pockets may form in the brake system when the brakes are applied
hard. This would impair braking efficiency.
There is a risk of an accident.
You should have the brake fluid renewed at
the specified intervals.
When handling brake fluid, observe the impor-
tant safety notes on service products
(Y page 283).
The brake fluid change intervals can be found in the Maintenance Booklet.
Only use brake fluid approved by Mercedes-
Benz in accordance with MB-Freigabe or MB-
Approval 331.0.
Information about approved brake fluid can be
obtained at any qualified specialist workshop or
on the Internet at
http://bevo.mercedes-benz.com.
i Have the brake fluid regularly replaced at a
qualified specialist workshop and the replace- ment confirmed in the Maintenance Booklet. Coolant
Important safety notes G
WARNING
If antifreeze comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Let the engine cool down before you add anti-
freeze. Make sure that antifreeze is not spilled
next to the filler neck. Thoroughly clean the antifreeze from components before starting
the engine.
! Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise damage the engine.
Further information on coolants can be found in the Mercedes-Benz Specifications for Ser-
vice Products, MB BeVo 310.1, e.g. on the
Internet at http://bevo.mercedes-benz.com. Or contact a qualified specialist workshop.
! Always use a suitable coolant mixture, even
in countries where high temperatures prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
i Have the coolant regularly replaced at a
qualified specialist workshop and the replace- ment confirmed in the Maintenance Booklet.
Comply with the important safety precautions
for service products when handling coolant
(Y page 283).
The coolant is a mixture of water and corrosion
inhibitor/antifreeze concentrate. It performs
the following tasks:
R Anti-corrosion protection
R Antifreeze protection
R Raising the boiling point
If the coolant has antifreeze protection down to -35 ‡ (-37 †), the boiling point of the coolant
during operation is approximately 266 ‡
(130 †).
The antifreeze concentrate/corrosion inhibitor
concentration in the engine cooling system
should:
R be at least 50%. This will protect the engine
cooling system against freezing down to
approximately -35 ‡ (-37 †)
R not exceed 55% (antifreeze protection down
to -49 ‡ [-45 †]). Otherwise, heat will not be
dissipated as effectively
Mercedes-Benz recommends a coolant or cor-
rosion inhibitor/antifreeze concentrate in
accordance with
MB Specifications for Service Products 310.1.
i When the vehicle is first delivered, it is filled
with a coolant mixture that ensures adequate
antifreeze and anti-corrosion protection. 284
Service products and filling capacitiesTechnical data

i
The coolant is checked with every mainte-
nance interval at a qualified specialist work-
shop.
Filling capacities Missing values were not available at time of
going to print. Model Capacity
All models
Windshield washer system
Important safety notes G
WARNING
Windshield washer concentrate could ignite if it comes into contact with hot engine compo-
nents or the exhaust system. There is a risk of
fire and injury.
Make sure that no windshield washer con-
centrate is spilled next to the filler neck.
! Only MB SummerFit and MB WinterFit
washer fluid should be mixed together. The
spray nozzles may otherwise become
blocked.
Do not use distilled or de-ionized water. Other-
wise, the level sensor may give a false reading.
When handling washer fluid, observe the impor- tant safety notes on service products
(Y page 283).
At temperatures above freezing:
X Fill the washer fluid reservoir with a mixture of
water and windshield washer fluid, e.g. MB
SummerFit.
Add 1 part MB SummerFit to 100 parts water.
At temperatures below freezing:
X Fill the washer fluid reservoir with a mixture of
water and washer fluid, e.g. MB WinterFit.
For the correct mixing ratio refer to the infor- mation on the antifreeze reservoir.
i Add windshield washer fluid, e.g. MB Sum-
merFit or MB WinterFit, to the washer fluid all
year round. Climate control system refrigerant
Important safety notes The climate control system of your vehicle is fil-
led with refrigerant R‑ 134a.
The instruction label regarding the refrigerant
type used can be found on the left, on the under-
side of the hood.
! Only the refrigerant R‑134a and the PAG oil
approved by Mercedes-Benz may be used.
The approved PAG oil may not be mixed with
any other PAG oil that is not approved for
R-134a refrigerant. Otherwise, the climate
control system may be damaged.
Service work, such as refilling with refrigerant or replacing component parts, may only be carriedout by a qualified specialist workshop. All appli-
cable regulations, as well as SAE standard J639, must be adhered to.
Always have work on the climate control system
carried out at a qualified specialist workshop.
Refrigerant instruction label Example: refrigerant instruction label
0043 Warning symbol
0044 Refrigerant filling capacity
0087 Applicable standards
0085 PAG oil part number
0083 Type of refrigerant
Warning symbol 0043advises you about:
R Possible dangers
R Having service work carried out at a qualified
specialist workshop Service products and filling capacities
285Technical data Z