lock MERCEDES-BENZ B-CLASS HATCHBACK 2021 Repair Manual

Chec
Chec
king t
king t he coolant lev
he coolant lev el
el &
W
WARNING
ARNING Risk of burns from hot compo-
nent parts in the engine compartment
Cer tain component parts in the engine com-
partment can be very hot, e.g. the engine, the
cooler and parts of theex haust system. #
Allow the engine tocool down and only
to uch component parts described in the
fo llowing. &
W
WARNING
ARNING Risk of scalding from hot cool-
ant
If yo u open the cap, you could be scalded. #
Let the mo tor cool down before opening
th e cap. #
When opening the cap, wear pr otective
glo ves and saf ety glasses. #
Open the cap slo wlytorelease pressure. #
Park theve hicle on a le vel sur face. #
Check the coolant temp erature display in the
inst rument cluster.
The coolant temp erature must be below 70°C. #
Slowly turn cap 1anti-clockwise torelease
ove rpressure. #
Continue turning cap 1anti-clockwise and
re mo veit. The coolant le
vel is cor rect in thefo llowing cases:
R Ifth e engine is cold, the coolant is up to
mar ker bar 2.
R Ifth e engine is warm,th e coolant is up to
1.5 cm overth e mar ker bar 2. #
If necessar y,top up with coolant that has
been appr ovedfo r Mercedes-Benz.
% Further information on coolant (/ page 404) T
T
opping up t
opping up t he windscr
he windscreen w
een washer syst
asher syst em
em &
W
WARNING
ARNING Risk of burns from hot compo-
nent parts in the engine compartment
Cer tain component parts in the engine com-
partment can be very hot, e.g. the engine, the
cooler and parts of theex haust system. #
Allow the engine tocool down and only
to uch component parts described in the
fo llowing. 342
342
Maintenance and care

Se
Se
tting up t
tting up t he w
he war
arning tr
ning tr iangle
iangle #
Fold side re0ectors 1upwards toform a tri-
angle and attach at theto p using upper press-
stud 2. #
Fold legs 3down and out tothe side. F
F
irs
irst-aid kit t-aid kit (soT-sided)
(soT-sided) ov
over
erview
view Fi
rs t-aid kit (soT sided) 1is in the load compart-
ment in the leT-hand st owage net. R
R
emo
emo ving t
ving t he
he/re
/re e
extinguisher
xtinguisher &
W WARNING ARNING Risk of accident due toan
inco rrectly secured /re extinguisher in the
driver's foot we ll
A /re extinguisher may impede pedal tr avel or
block a depressed pedal. This jeopardises
the operating and road saf ety
of theve hicle.
The /re extinguisher can be 0ung around and
injure the driver or other vehicle occupants. #
Always store and secure the /re extin-
guisher in the brac ket. #
Do not remo vethe /re extinguisher while
driving. #
LeT-hand
LeT-hand dr
driv
ive v
e v ehicle:
ehicle: pulltab1 upwards. #
Right-hand dr
Right-hand dr iv
ive v
e v ehicle:
ehicle: pulltab1 down-
wa rds. #
Remo ve/re extinguisher 2. Breakdown assistance
353
353

#
Pull plug 7with the cable and /ller hose 3
out of the tyre in0ation compressor housing. #
Insert tyre sealant bottle 9in soc ket6 of
th e tyre in0ation compressor in such a way
th at there d ar row on tyre sealant bottle 9
matches there d ar row on the tyre in0ation
compressor. #
Turn tyre sealant bottle 9aqu arter turn
clockwise. #
Insert the plug of /ller hose 3in soc ket5
of tyre sealant bottle 9. #
Turn /ller hose 3aqu arter turn clockwise. #
Remo vetheva lve cap from valve A onthe
fa ulty tyre. #
Screw union nut 4of /ller hose 3onto
va lve A. #
Insert plug 7into a 12 V soc ket in your vehi-
cle. #
Turn theke yto position 0047inthe ignition loc k. #
Press on and o. switch 8onthe tyre in0a-
tion compressor.
The tyre in0ation compressor is switched on.
The tyre is in0ated. Firs t, tyre sealant is pum-
ped into the tyre. The pressure may brie0y rise
to appr oximately 500 kPa (5 bar/73 psi).
Do no Do no t switc
t switc h
ho.
o. t
the tyr
he tyr e
ein0ation
in0ation com
compr
pressor
essor
dur
dur ing t
ing t his phase!
his phase! #
Let the tyre in0ation compressor runfo r a
maximum of ten minutes.
The tyre should then ha veattained a tyre pres-
sure of at least 200 kPa (2.0 bar/29 psi).
If tyre sealant leaks out, make sure you clean the
a.ected area as quickly as possible. It is prefera-
ble touse clean water.
If yo uget tyre sealant on your clo thing, ha veit
cleaned as soon as possible with per chloroe thy-
lene.
If, If, aTer
aTer t
ten minut
en minut es, a tyr
es, a tyre pr
e pressur
essur e of 200 kPa
e of 200 kPa
(2.0 bar/29 psi) has no
(2.0 bar/29 psi) has no t been att
t been att ained:
ained: #
Switch o. the tyre in0ation compressor. 358
358
Breakdown assistance

+
ENVIR
ENVIR
ONMENT
ONMENT AL NO
AL NOTE
TE Environmen tal
pollution caused byenvironmentally ir re-
sponsible disposal Ty
re sealant contains pollu tants. #
Have the tyre sealant bottle disposed of
professionall y,e.g. at a Mercedes-Benz
Service Centre. #
Stow the tyre sealant bottle, the tyre in0ation
compressor and thewa rning triangle. #
Pull awa
Pull away immediat
y immediat ely.
el y. #
Stop driving aTer appr oximately ten minutes
and check the tyre pressure using the tyre
in0ation compressor.
The tyre pressure must now be at least
130 kPa (1.3 bar/19 psi). &
W WARNING
ARNING Risk of accident due tothe
speci/ed tyre pressure not being attained
If th e speci/ed tyre pressure is not reached,
th e tyre is too badly damaged. The tyre seal-
ant cannot repair the tyre in this instance. The braking and driving
characteristics may be
gr eatly impaired. #
Do not continue driving. #
Consult a quali/ed specialist workshop. Countr
Countr
ies t
ies that hav
hat hav e Mer
e Mercedes-Benz Ser
cedes-Benz Ser vice24h:
vice24h:
yo u will /nd a stic ker with thete lephone number,
e.g. on the B‑pillar on the driver's side. #
Correct the tyre pressure if it is still at least
130 kPa (1.3 bar/19 psi). See the tyre pres-
sure table on the fuel /ller 0ap forva lues.
Incr
Incr easing t
easing t he tyr
he tyre pr
e pressure
essure #
Switch on the tyre in0ation compressor.
Decr
Decr easing t
easing t he tyr
he tyre pr
e pressure
essure #
Remo vethe tyre sealant bottle from the tyre
in0ation compressor. #
Insert the /ller hose in the soc ket of the tyre
in0ation compressor and turn it a quarter turn
clockwise. #
Press pressure release button Cnext to
manome terB.
When t When t he tyr he tyre pr
e pressur
essur e is corr
e is corr ect
ect #
Unscr ewthe /lling hose from theva lve of the
sealed tyre. #
Screw theva lve cap onto theva lve of the
sealed tyre. #
Stow the tyre sealant bottle and the tyre in0a-
tion compressor. #
Drive tothe nearest quali/ed specialist work-
shop and ha vethe tyre, tyre sealant bottle and
/lling hose replaced there. 360
360
Breakdown assistance

Mercedes-Benz
recommends that you ha vethe
12 V battery replaced at a quali/ed specialist
wo rkshop, e.g. at a Mercedes-Benz Se rvice
Centre.
Obser vethefo llowing no tes if youwa nttoreplace
th e battery yourself:
R Alwaysre place a faulty battery with a battery
which meets the speci/c vehicle requ ire-
ments.
The vehicle is equipped with a 0eece batter y.
Fu llve hicle functionality is only guaranteed
with a 0eece batter y.Fo r saf etyre asons,
Mercedes-Benz recommends that you only
use batteries which ha vebeen tested and
appro vedfo ryo ur vehicle byMercedes-Benz.
R Use de tach able parts such as vent hoses,
elbow /ttings or term inal co vers from the bat-
te ry which is tobe replaced.
R Make sure that theve nt hose is alw ays con-
nected tothe original opening on the side of
th e batter y.
Fi t any existing or supplied cell caps.
Otherwise, gases or battery acid could
escape. R
Make sure that de tach able parts are recon-
nected in the same way. T T
o
o w
w -st
-st ar
arting or to
ting or towing away
wing away P
P
er
er mitt
mitt edto
ed towing met
wing met hods (non plug-in h
hods (non plug-in h ybr
ybrid)
id) P
P
er
er mitt
mitt edto
ed towing met
wing met hods
hods
Mercedes-Benz recommends transporting your
ve hicle in the case of a breakdown, rather than
to wing it away.
Fo rto wing, use a tow rope or tow bar with bo th
axles on thegr ound. Do not use tow bar systems. &
W
WARNING
ARNING Risk of accident when towing
with steering wheel lock
If th e steering wheel lock is engaged, you will
not be able tosteer theve hicle. #
When towing with a tow rope or tow bar,
alw ays switch on theve hicle. *
N
NOOTE
TE Damage totheve hicle due to tow-
ing awa y incor rectly #
Obser vethe inst ructions and no tes on
to wing away. V
V
ehicles wit
ehicles wit h manual tr
h manual tr ansmission
ansmission
Bo th axles on
th egr ound Ye
s, maximum 50 km at
50 km/h
Fr ont axle
ra ised Ye
s, maximum 50 km at
50 km/h
Re ar axle
ra ised Ye
s, maximum 50 km at
50 km/h V
V
ehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission
ansmission
Bo th axles on
th egr ound Ye
s, maximum 50 km at
50 km/h
Fr ont axle
ra ised Ye
s, maximum 50 km at
50 km/h
Re ar axle
ra ised Ye
s, maximum 50 km at
50 km/h Breakdown assis
tance
365
365

#
Information on the permissible gross mass of
th eve hicle can be found on theve hicle identi-
/cation plate (/ page 394).#
V
Vehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: do not
open the driver's door or front passenger
door; the transmission otherwise automati-
cally shiTs toposition 005D. #
Fitth eto wing eye (/ page 370). #
Fasten theto wing device.
* N
NOOTE
TE Damage due toincor rect connec-
tion of theto w bar #
Only connect theto w rope or tow bar to
th eto wing eyes. #
Deactivate the automatic locking mechanism
(/ page 87). #
Do not activate the HOLD function. #
Deactivate tow- awa y protection
(/ page 104). #
Deactivate Active Brake Assist (/ page 248).#
V
Vehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: shiTto
position 005C. #
V
Vehicles wit
ehicles wit h manual tr
h manual tr ansmission:
ansmission: shiTto
neutral 005C. #
Release the electric parking brake. &
W
WARNING
ARNING Risk of accident due tolimited
saf ety-re lated functions during theto wing
process
Saf ety-re lated functions are limited or no lon-
ge rav ailable in thefo llowing situations:
R theve hicle is switched o..
R the brake system or po wer steering system
is malfunctioning.
R the energy supply or the on-board electri-
cal system is malfunctioning.
When your vehicle is towe daw ay, signi/cantly
more e.ort may be requ ired tosteer and
brake than is normally requ ired. #
Use a tow bar. #
Make sure that the steering wheel can
mo vefreely be fore towing theve hicle
awa y. *
N
NO
O TE
TE Damage due toexcessive tractive
po wer If
yo u pull away sharpl y,the tractive po wer
may be too high and theve hicles could be
damaged. #
Pull away slo wlyand smoo thly. Loading t
Loading t
he v
he v ehicle f
ehicle f or tr
or transport
anspo rt Hybr
Hybr
id v
id vehicles:
ehicles: transpor tation of vehicles should
only be car ried out byprofessional reco very com-
panies. #
Obser vethe no tes on towing away
( / page 367). #
Connect theto wing device totheto wing eye
in order toload theve hicle.
% You can also attach theto w bar tothe trailer
hitch. #
V
Vehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: shiTthe
automatic transmission toposition 005C. 368
368
Breakdown assistance

T
T
o
o wing ey
wing eye st
e st or
orag
ag e location
e location The
towing eye is under the load compartment
0oor. F
F
itting and r
itting and r emo
emo ving t
ving t heto
he towing eye
wing eye #
Press the mark on co ver1 inwa rds and
re mo ve. #
Screw intheto wing eye clockwise as far as it
will go and tighten.
V
V ehicles wit
ehicles wit h a tr
h a trailer hitc
ailer hitc h:
h:vehicles with a trailer
hitch do not ha veare ar brac ketfo rth eto wing
ey e. Fasten theto w bar tothe trailer hitch. #
Make sure that co ver1 engages in the
bumper when youre mo vetheto wing eye.
* N
NOOTE
TE Damage totheve hicle due toincor-
re ct use of theto wing eye or trailer hitch When a
towing eye or trailer hitch is used to
re co ver a vehicle, theve hicle may be damaged
in the process. #
Only use theto wing eye or trailer hitch to
to w awa y or tow start theve hicle. #
Do not use theto wing eye or trailer hitch
to to wtheve hicle during reco very. T
T
o
o w
w -st
-st ar
arting t
ting t he v
he vehicle
ehicle V V
ehicles wit ehicles wit h aut
h automatic tr
omatic tr ansmission
ansmission
* NO
NOTE
TE Damage tothe automatic transmis-
sion due to tow-starting The au
tomatic transmission may be damaged
in the process of tow- starting vehicles with
automatic transmission. #
Vehicles with automatic transmission
must not be tow- star ted. #
Vehicles with an automatic transmission must
not be tow- star ted.
V V ehicles wit ehicles wit h manual tr
h manual tr ansmission
ansmission #
Obser vethe no tes on towing away
( / page 367). #
If necessar y,allow the engine and exhaust
system tocool down. #
Swit chon the ignition. #
Engage second gear. #
Release the electric parking brake. 370
370
Breakdown assistance

R
The vehicle is on solid, non-slippery and le vel
gr ound.
R The requ ired tyre-change tool kit is available.
% Ifyo ur vehicle is not equipped with the tyre-
ch ange tool kit, consult a quali/ed specialist
wo rkshop to/nd out about sui table tools. #
Apply the electric parking brake manuall y.#
Movethe front wheels tothe straight-ahead
position. #
V
Vehicles wit
ehicles wit h manual tr
h manual tr ansmission:
ansmission: engage
/rst or reve rsege ar. #
V
Vehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: shiTto
position 005D. #
Switch o. theve hicle. #
Make sure that theve hicle cann otbe star ted. #
Place choc ks orother suitable items under the
front and rear of the wheel that is diagonal ly
opposite the wheel you wish tochange. #
If necessar y,remo vethe wheel trim/hub caps
(/ page 384). #
Raise theve hicle (/ page 384). R
R
emo
emo ving and
ving and /tting
/ttingt
the wheel tr
he wheel tr im/hub caps
im/hub caps R
R
eq
eq uir
uir ements:
ements:
R The vehicle is prepared for a wheel change
(/ page 383).
Wheel tr
Wheel tr im
im
The wheel trim co vers the wheel bolts on vehicles
with steel wheels. Before unscr ewing the wheel
bolts, remo vethe wheel trim. #
T
T o r
o r emov
emov e:
e: using bo thhands, carefully reach
into two wheel trim openings and remo vethe
wheel trim. Plas Plas
tic hub cap tic hub cap #
T
To r
o r emov
emov e:
e:turn the centre co ver of the hub
cap anti-clockwise and remo vethe hub cap. #
T
To
o /t:
/t: make sure that the centre co ver of the
hub cap is turned anti-clockwise. #
Position the hub cap and turn the centre co ver
clockwise until the hub cap engages ph ysically
and audibl y. R
R
aising t
aising t he v
he vehicle when c
ehicle when c hanging a wheel
hanging a wheel R R
eq eq uir
uir ements:
ements:
R There are no persons in theve hicle.
R The vehicle has been prepared for a wheel
ch ange (/ page 383).
R The wheel trims and hub caps ha vebeen
re mo ved (/ page 384).
Impor tant no tes on using the jack:
R Use only a vehicle-speci/c jack that has been
appr ovedby Mercedes-Benz toraise theve hi-
cle.
R The jack is only designed forra ising and hold-
ing theve hicle for a short time while a wheel 384
384
Wheels and tyres

#
Turn ratchet 3clockwise until support 2
sits comple tely on jack support point 1and
th e base of the jack lies evenly on thegr ound. #
Turn ratchet 3until the tyre is raised a maxi-
mum of 3 cm from thegr ound. #
Loosen and remo vethe wheel (/ page 387). R
R
emo
emo ving a wheel
ving a wheel R
R
eq
eq uir
uir ements:
ements:
R The vehicle is raised (/ page 384).
When changing a wheel, avoid applying any force
to the brake disks, as this could impair the le vel of
comfort when braking.
* NO
NOTE
TEDamage tothre ading from dirt on
wheel bolts #
Do not place wheel bolts in sand or on a
dirty sur face. #
Unscr ewthe uppermost wheel bolt com-
ple tely. #
Screw cent ring pin 1into theth re ad ins tead
of the wheel bolt. #
Unscr ewthere maining wheel bolts com-
ple tely. #
Remo vethe wheel and, if necessar y,store it in
th e load compartment. #
Notes on removing an emer gency spa rewheel
(/ page 389). F
F
itting a ne
itting a ne w wheel
w wheel R R
eq
eq uir
uir ements:
ements:
R The wheel tobe changed is remo ved and the
cent ring pin is sc rewe d in (/ page 387). &
W WARNING
ARNING Risk of accident from losing a
wheel
Oiled, greased or damaged wheel bolt/wheel
nut thre ads or wheel hub/wheel mounting
bolt thre ads can cause the wheel bolts/wheel
nuts tocome loose.
As a result, you could lose a wheel while driv-
ing. #
Never oil or grease theth re ads. #
Intheev ent of damage totheth re ads,
contact a quali/ed specialist workshop
immediatel y. #
Have the damaged wheel bolts or dam-
aged hub thre ads replaced. #
Do not continue driving. #
Obser vethe information on thech oice of tyres
(/ page 379).
Fo r tyres with a speci/ed direction of rotation, an
ar ro w on the side wall of the tyre indicates the
cor rect direction of rotation. Obser vethe direc-
tion of rotation when /tting. Wheels and tyres
387
387

#
Slide the wheel tobe mounted onto the cen-
tring pin and push it on. #
Obser vethe no tes on /tting an emer gency
spa rewheel (/ page 389). &
W
WARNING
ARNING Risk of injury from tightening
wheel bolts and nuts
If yo u tighten the wheel bolts or wheel nuts
when theve hicle is raised, the jack could tip. #
Only tighten wheel bolts or wheel nuts
when theve hicle is on thegr ound. #
Obser vethe inst ructions and saf ety no tes on
"Changing a wheel" (/ page 379).#
For saf etyre asons, only use wheel bolts which
ha ve been appr oved byMercedes-Benz and
fo rth e wheel in question. #
Tighten the wheel bolts evenly in a diagonal
pattern in the order indicated until they are
/nger-tight. #
Unscr ewand remo vethe centring pin. #
Tighten the last wheel bolt until it is /n ger-
tight. #
Lowe rth eve hicle (/ page 388). Low Low
er
ering t
ing t he v
he vehicle
ehicle aTer
aTera wheel c
a wheel c hange
hange R
R
eq
eq uir
uir ements:
ements:
R The new wheel has been /tted (/ page 387). #
T
To low
o low er t
er the v
he v ehicle:
ehicle: placethera tchet onto
th e he xagon nut of the jack so that the letters
"AB" are visible and turn anti-clockwise. #
Tighten the wheel bolts evenly in a diagonal
pattern in the order indicated 1to5 with
an initial maximum forc e of 80 Nm. #
Tighten the wheel bolts evenly in a diagonal
pattern in the order indicated 1to5 with
th e speci/ed tightening torque of 130 Nm. &
W
WARNING
ARNING Risk of accident due toincor-
re ct tightening torque
The wheels could come loose if the wheel
bolts or wheel nuts are not tightened tothe
prescribed torque. #
Ensure that the wheel bolts or wheel
nuts are tightened tothe prescribed
tightening torque. #
Ifyo u are not sure, do not mo vetheve hi-
cle. Con tact a quali/ed specialist work-
shop and ha vethe tightening torque
ch ecked immediatel y. #
Check the tyre pressure of the ne wly/tted
wheel and adjust it if necessar y.
% The following does not apply if the new wheel
is an emer gency spa rewheel. 388
388
Wheels and tyres