2017 MERCEDES-BENZ B-Class ECU

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 sol-
vents 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 pre-
vent water from draining away. This can lead
to corrosion damage and damage to elec-
tronic 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 graph- ite coating could be damaged. This could
cause wiper noise.
! Hold the wiper arm securely when folding
back. The windshield could be damaged if the wiper arm smacks against it suddenly. 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.
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 len- ses.
X Clean the plastic lenses of the exterior lights
with a wet sponge and a mild cleaning agent,
e.g. Mercedes-Benz car shampoo or cleaning
cloths.
Cleaning the mirror turn signals !
Only use cleaning agents or cleaning cloths
that are suitable for plastic lenses. Unsuitable
cleaning agents or cleaning cloths could
scratch or damage the plastic lenses of the
mirror turn signals.
X Clean the plastic lenses of the mirror turn sig-
nals in the exterior mirror housing using a wet sponge and mild cleaning agent, e.g.
Mercedes-Benz car shampoo or cleaning
cloths.
Cleaning the sensors !
If you clean the sensors with a power
washer, make sure that you keep 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. Care
237Maintenance and care Z

Where will I find...?
Vehicle tool kit
General notes Vehicles with a TIREFIT kit: the TIREFIT kit is
located in the stowage well under the cargo
compartment floor.
Vehicles with a tire-change tool kit: the tire-
change tool kit is in the stowage well under the
cargo compartment floor.
Apart from certain country-specific variations,
the vehicles are not equipped with a tire-change tool kit. Some tools for changing a wheel are
specific to the vehicle. For more information on
which tire changing tools are required and
approved to perform a wheel change on your
vehicle, consult a qualified specialist workshop.
Tools required for changing a wheel may
include, for example:
R Jack
R Wheel chock
R Lug wrench
R Alignment bolt
Vehicles with a TIREFIT kit 0043
Tire inflation compressor
0044 Tire sealant filler bottle
0087 Towing eye
X Open the tailgate.
X Lift the cargo compartment floor upwards
(Y page 214).
X Use the TIREFIT kit (Y page 243) or remove it.
Towing eye 0087is located under tire inflation
compressor 0043. Vehicles with a tire-change tool kit X
Open the tailgate.
X Lift the cargo compartment floor upwards
(Y page 214).
X Remove the tire-change tool kit.
The tire-change tool kit contains:
R Jack
R Lug wrench
R One pair of gloves
R Folding wheel chock Flat tire
Preparing the vehicle
Your vehicle may be equipped with:
R MOExtended tires (tires with run-flat proper-
ties) (Y page 242)
Vehicle preparation is not necessary on vehi-
cles with MOExtended tires
R a TIREFIT kit (Y page 241)
Vehicles equipped with MOExtended tires are
not equipped with a TIREFIT kit at the factory. It
is therefore recommended that you additionally
equip your vehicle with a TIREFIT kit if you mount tires that do not feature run-flat properties, e.g.
winter tires. A TIREFIT kit may be obtained from a qualified specialist workshop.
Information on changing and mounting wheels
(Y page 275).
X Stop the vehicle on solid, non-slippery and
level ground, as far away as possible from
traffic.
X Switch on the hazard warning lamps.
X Secure the vehicle against rolling away
(Y page 128).
X If possible, bring the front wheels into the
straight-ahead position.
X Switch off the drive system.
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.
X Make sure that the passengers are not endan-
gered as they do so. Make sure that no one is
near the danger area while a wheel is being Flat tire
241Breakdown assistance

find further information in the separate operat-
ing instructions. Charging the 12‑volt battery
G
WARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open 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 skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten- tion. 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-
starting connection point.
The jump-starting connection point is in the
engine compartment (Y page 249).
X Open the hood.
X Connect the battery charger to the positive
terminal and ground point in the same order
as when connecting the donor battery in the
jump-starting procedure (Y page 249).
If the indicator/warning lamps do not light up in
the instrument cluster at low temperatures, it is very likely that the discharged battery has fro-
zen. In this case you may neither jump-start the vehicle nor charge the battery. The service life of
a thawed-out battery may be shorter. The start-ing characteristics can be impaired, particularly at low temperatures. Have the thawed-out bat-
tery checked at a qualified specialist workshop.
Only charge the installed battery with a battery
charger which has been tested and approved byMercedes-Benz. A battery charger unit specially
adapted for Mercedes-Benz vehicles and tested
and approved by Mercedes-Benz is available as an accessory. It permits the charging of the bat-tery in its installed position. Contact an author-
ized Mercedes-Benz Center for further informa- tion and availability. Read the battery charger's
operating instructions before charging the bat-
tery. 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.
Following an accident, do not touch any high- voltage components and never modify the
vehicle'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 can exceed a
critical value. In this case flammable gas
escapes through a ventilation valve on the
underbody. The gas can ignite. There is a risk of injury.
Leave the danger zone immediately. Secure
the danger area at a suitable distance, whilst
observing legal requirements. 248
BatteriesBreakdown assistance

!
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

X
Vehicles with KEYLESS-GO: use the Smart-
Key instead of the Start/Stop button
(Y page 110).
X Make sure that the vehicle is stationary.
X Turn the SmartKey to position 2in the ignition
lock.
X When the vehicle is stationary, depress the
brake pedal and keep it depressed.
X Shift the transmission to position P.
X Release the brake pedal.
X Release the electric parking brake.
X Switch off the automatic locking
(Y page 166).
X Switch on the hazard warning lamps
(Y page 89).
X Turn the SmartKey in the ignition lock to posi-
tion 0and leave the SmartKey in the ignition
lock. Towing the vehicle with the rear axle
raised
When towing your vehicle with the rear axle
raised, it is important that you observe the
safety instructions (Y page 251).
! The ignition must be switched off if you are
towing the vehicle with the rear axle raised.
Intervention by ESP ®
could otherwise dam-
age the brake system.
The transmission automatically shifts to posi-
tion Pwhen you open the driver's or front-
passenger door or when you remove the Smart-
Key from the ignition lock. In order to ensure
that the transmission stays in position Nwhen
towing the vehicle, you must observe the fol-
lowing points:
X Vehicles with KEYLESS-GO: use the Smart-
Key instead of the Start/Stop button
(Y page 110).
X Make sure that the vehicle is stationary.
X Turn the SmartKey to position 2in the ignition
lock.
X Depress and hold the brake pedal.
X Shift the transmission to position N.
X Release the brake pedal.
X Apply the electric parking brake.
X Switch off the automatic locking
(Y page 166). X
Bring the front wheels into the straight-ahead
position.
X Switch on the hazard warning lamps
(Y page 89).
X Turn the SmartKey in the ignition lock to posi-
tion 0and leave the SmartKey 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 SmartKey to position 2in the ignition
lock (Y page 109).
X Shift the transmission to position N.
As soon as the vehicle has been loaded: X Prevent the vehicle from rolling away by
applying the electric parking brake.
X Shift the transmission to position P.
X Turn the SmartKey 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 transporting pur- poses. Fuses
Important safety notes
G
WARNING
If you manipulate or bridge a faulty fuse or if
you replace it with a fuse with a higher amper- age, the electric cables could be overloaded.
This could result in a fire. There is a risk of an
accident and injury.
Always replace faulty fuses with the specified
new fuses having the correct amperage.
! 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". Other- 254
FusesBreakdown 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

Overinflated tires may:
R
increase the braking distance
R adversely affect handling
R wear excessively and/or unevenly
R have an adverse effect on ride comfort
R be more susceptible to damage
Maximum tire pressures 0043
Example: maximum permissible tire pres-
sure
Never exceed the maximum permissible tire
inflation pressure. Always observe the recom-
mended tire pressure for your vehicle when
adjusting the tire pressure (Y page 260).
i The actual values for tires are vehicle-spe-
cific and may deviate from the values in the
illustration. Checking the tire pressures
Important safety notes Observe the notes on tire pressure
(Y
page 260).
Information on air pressure for the tires on your vehicle can be found:
R on the vehicle's Tire and Loading Information
placard on the B-pillar
R in the tire pressure table in the charge socket
flap (Y page 124)
R in the "Tire pressure" section Checking tire pressures manually To determine and set the correct tire pressure,
proceed as follows:
X Remove the valve cap of the tire that is to be
checked.
X Press the tire pressure gauge securely onto
the valve.
X Read the tire pressure and compare it to the
recommended value on the Tire and Loading
Information placard or the tire pressure table
(Y page 260).
X If the tire pressure is too low, increase the tire
pressure to the recommended value.
X If the tire pressure is too high, release air. To
do so, press down the metal pin in the valve,
using the tip of a pen for example. Then check the tire pressure again using the tire pressure
checker.
X Screw the valve cap onto the valve.
X Repeat these steps for the other tires. Tire pressure monitor
General notes If a tire pressure monitor is installed, the vehi-
cle's wheels have sensors that monitor the tire
pressures in all four tires. The tire pressure mon-
itor warns you if the pressure drops in one or
more of the tires. The tire pressure monitor only functions if the corresponding sensors are
installed in all wheels.
Information on tire pressures is displayed in the
multifunction display. After a few minutes of
driving, the current tire pressure of each tire is
shown in the Serv. Serv.menu of the multifunction
display, see illustration (example). For information on the message display, refer to
the "Checking the tire pressure electronically"
section (Y page 265). Tire pressure
263Wheels and tires Z

PSI (pounds per square inch)
A standard unit of measure for tire pressure.
Aspect ratio
Relationship between tire height and tire width
in percent.
Tire pressure
This is pressure inside the tire applying an out-
ward force to each square inch of the tire's sur-
face. The tire pressure is specified in pounds per
square inch (psi), in kilopascal (kPa) or in bar.
The tire pressure should only be corrected when
the tires are cold.
Cold tire pressure
The tires are cold:
R if the vehicle has been parked with the tires
out of direct sunlight for at least three hours
and
R if the vehicle has not been driven further than
1 mile (1.6 km)
Tread
The part of the tire that comes into contact with
the road.
BeadThe tire bead ensures that the tire sits securely
on the wheel. There are several steel wires in the
bead to prevent the tire from coming loose from the wheel rim.
Sidewall
The part of the tire between the tread and the
bead.
Weight of optional extras The combined weight of those optional extras
that weigh more than the replaced standard
parts and more than 2.3 kg (5 lbs). These
optional extras, such as high-performance
brakes, level control, a roof rack or a high-per-
formance battery, are not included in the curb
weight and the weight of the accessories.
TIN (Tire Identification Number) This is a unique identifier which can be used by
a tire manufacturer to identify tires, for example for a product recall, and thus identify the pur-
chasers. The TIN is made up of the manufactur-
er's identity code, tire size, tire type code and
the manufacturing date. Load bearing index
The load bearing index (also load index) is a code that contains the maximum load bearing capa-
city of a tire.
Traction
Traction is the result of friction between the tires and the road surface.
Treadwear indicatorsNarrow bars (tread wear bars) that are distrib-
uted over the tire tread. If the tire tread is level
with the bars, the wear limit of 00CDin (1.6 mm)
has been reached.
Occupant distribution The distribution of occupants in a vehicle at theirdesignated seating positions.
Total load limit Nominal load and luggage load plus 68 kg
(150 lbs) multiplied by the number of seats in
the vehicle. Changing a wheel
Flat tire
The "Breakdown assistance" section
(Y page 241) contains information and notes on
how to deal with a flat tire. Information on driv-
ing with MOExtended tires in the event of a flat
tire can be found under "MOExtended tires (tires with run-flat characteristics" (Y page 242). Rotating the wheels
G
WARNING
Interchanging the front and rear wheels may
severely impair the driving characteristics if
the wheels or tires have different dimensions. The wheel brakes or suspension components
may also be damaged. There is a risk of acci-
dent.
Rotate front and rear wheels only if the wheels and tires are of the same dimensions.
! On vehicles equipped with a tire pressure
monitor, electronic components are located
in the wheel. Changing a wheel
275Wheels and tires Z