2021 MERCEDES-BENZ B-CLASS HATCHBACK bonnet

R
Opens the bonnet →
338
S 0024 Electric parking brake →
219
T Light switch →
138 8
8
At
a glance – Cockpit

R
R
ectifying pr
ectifying pr oblems wit
oblems with t
h the sliding sunr
he sliding sunr oof
oof &
W
WARNING
ARNING Risk of becoming trapped or
fata l injuries when the sliding sunroof is
closed again
If th e sliding sunroof is closed again immedi-
ately aTer it has been bloc ked or reset, it will
close with increased forc e. #
Make sure that no parts of the body are
in the closing area. #
Release the button immediately if some-
body becomes trapped.
or #
Brie0y press the button in any direction
during the automatic closing process.
The closing process will be stopped. The sliding sunr
The sliding sunr
oof canno
oof cannot be closed and y
t be closed and y ou can-
ou can-
no
no t see t
t see t he cause.
he cause.
% The term "sliding sunroof" also refers to the
panorama sliding sunroof.
If th e sliding sunroof is obstructed during closing
and reopens again slightl y: #
Immediately aTer automatic reve rsing, pull
and hold the0057 button down again tothe
point of resis tance until the sliding sunroof is
closed.
The sliding sunroof will be closed with
increased forc e.
If th e sliding sunroof is obstructed again and
opens again slightl y: #
Repeat the pr evious step.
The sliding sunroof will be closed again with
increased forc e.
V V ehicles wit
ehicles wit h a panor
h a panorama sliding sunr
ama sliding sunr oof: t
oof: the slid-
he slid-
ing sunr
ing sunr oof or t
oof or the r
he roller sunblind is no
oller sunblind is no t oper
t operating
ating
smoot
smoot hly
hly.
. #
Reset the sliding sunroof and thero ller sun-
blind.
R
R ese
ese tting t
tting t he sliding sunr
he sliding sunr oof and t
oof and the r
he roller sun-
oller sun-
blind
blind #
Pull and hold the0057 button little bylittle
until the sliding sunroof is fully closed. #
Pull and hold the0057 button little bylittle
until thero ller sunblind is fully closed. #
Use automatic operation tofully open and
th en close the sliding sunroof. Anti-t
Anti-theT
heTprot
pr otection
ection F
F
unction of t
unction of t he immobiliser
he immobiliser The immobiliser pr
events your vehicle from being
star ted without the cor rect key.
The immobiliser is automatically activated when
th eve hicle is switched o., and deactivated when
th eve hicle is switched on. A A
T
TA
A (Anti-
(Anti- TheT
TheT Alar
Alarm syst
m syst em)
em) F
F
unction of t
unction of t heAT
he ATA systA syst em
em
If th eATA system is primed, a visual and audible
alarm is triggered in thefo llowing situations:
R when a door is opened
R when theta ilgate is opened
R when the bonnet is opened
R when interior pr otection is triggered
(/ page 104) 102
102
Opening and closing

#
Neverto uch damaged components of
th e high-voltage on-board electrical sys-
te m. #
ATer an accident, do not touch any com-
ponents of the high-voltage on-board
electrical system. #
ATer an accident, ha vetheve hicle trans-
por tedawa y. #
Have the components of the high-voltage
on-board electrical system checked at a
qu ali/ed specialist workshop and
re placed if necessar y.R
R
eq
eq uir
uir ements:
ements:
Only disconnect the high-voltage on-board electri-
cal system manually in thefo llowing situations:
R The 0075 restraint system warning lamp lights
up in the Instrument Displa y,e.g. aTer an
accident.
R The vehicle is badly damaged, e.g. aTer an
accident, and there straint system co mpo-
nents ha venot been triggered. T
T
o oper
o oper at
ate t
e t he high-v
he high-v olt
oltag
age disconnect de
e disconnect de vice
vice #
Switch o. theve hicle. #
ShiT the transmission toposition 005D. #
Apply the electric parking brake. #
Secure theve hicle against rolling away (see
th eve hicle Owner's Manual). #
Open the bonnet. #
Press release tab1 inthe direction of the
ar ro w and pull it out. #
Pull high- voltage disconnect device 2inthe
direction of the ar row until it engages.
The high- voltage on-board electrical system is
switched o..
All workon thehy brid drive system (including
aTer disconnecting the high-voltage on-board
electrical system manually) may only be car ried
out byaqu ali/ed specialist workshop. Switc
Switc
hing on t
hing on t he pow
he power suppl
er suppl y or t
y or the v
he vehicle
ehicle &
W
WARNING
ARNING Risk of accident and injury due
to leaving children unattended in theve hi-
cle
If ch ildren are leT unattended in theve hicle,
th ey could, in particular:
R open doors, thereby endangering other
persons or road users.
R get out and be struck byoncoming tra1c. 168
168
Driving and parking

R
The bonnet is closed.
R The doo rsare closed and loc ked.
R The windo wsand sliding sunroof are closed. #
Start theve hicle using the smartphone.
ATer every engine start, the engine runs for
te n minutes.
Yo u can car ryout a maximum of two consecutive
starting attem pts. You must start the engine with
th eke y before trying tostart theve hicle again
with the smartphone.
Yo u can switch o. theve hicle at any time as fol-
lo ws:
R Viath e Smartphone App
R By pressing theÜ orß button on the
key
% Further information can be found in the
smartphone app.
Secur
Secur ing t
ing the v
he v ehicle ag
ehicle ag ains
ainst st
t star
arting bef
ting bef or
ore car ry-
e car ry-
ing out maint
ing out maint enance or r
enance or repair w
epair wor
ork:
k: #
Switch on the hazard warning light system.
or #
Unlock the doors.
or #
Open a side window or the sliding sunroof. R
R
unning-in not
unning-in not es
es To
preser vethe engine during the /rst 1,500 km:
R Drive at varying road speeds and engine
speeds.
R Do not drive at speeds greater than
140 km/h.
R Drive theve hicle in drive prog ram A
or ;.
R ShiT tothe next highest gear at theve ry latest
when the needle reaches the last third before
th ere d area in there v counter.
R Do not shiT down manual lyin order tobrake.
R Avoid overstraining theve hicle, e.g. driving at
full thro ttle.
R V
V ehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: do not
depress the accelerator pedal be yond the
pressure point (kickdown). R
Only increase the engine speed gradually and
accelerate theve hicle tofull speed aTer
1,500 km.
This also applies when the engine or parts of the
driv etra in ha vebeen replaced.
Please also obser vethefo llowing running-in
no tes:
R In cer tain driving and driving saf ety sy stems,
th e sensors adjust automatically while a cer-
ta in distance is being driven aTer theve hicle
has been deli vered or aTer repairs. Full sys-
te m e.ectiveness is not reached until the end
of this teach-in process.
R Brakepads, brake disks and tyres that are
either new or ha vebeen replaced only achie ve
optimum braking e.ect and grip aTer se veral
hund red kilometres of driving. Compensate for
th ere duced braking e.ect byapplying greater
fo rc eto the brake pedal. 172
172
Driving and parking

R
Frequent operation in mountainous terrain or
on poor road sur faces
R When the engine is oTen leT idling for long
periods
R Operation in particular lydusty conditions
and/or if air-recirculation mode is frequently
used
In these or similar operating conditions, ha vethe
interior air /lter, air /lter, engine oil and oil /lter,
fo rex ample, changed more frequentl y.The tyres
must be checked more frequently if theve hicle is
operated under increased loads. Further informa-
tion can be obtained at a quali/ed specialist work-
shop. Batt Batt
er
ery disconnection per
y disconnection per iods
iodsThe AS
SYST PLUS service inter val display can cal-
culate the service due date only when the battery
is connected. #
Display and no tedown the service due date
on the inst rument display before disconnect-
ing the battery (/ page 336). Engine com
Engine com
par
partment
tment A
A
ctiv
ctiv e bonne
e bonne t (pedes
t (pedestr trian pr ot
ian pr otection)
ection) Oper
Oper
ation of t
ation of t he activ
he active bonne
e bonne t (pedes
t (pedestr trian pr ot
ian pr otec-
ec-
tion)
tion)
In cer tain accident situations, the actuation of the
active bonnet reduces therisk of injury topedes-
trians. The rear area of the bonnet is raised by
appr oximately 70 mm.
Fo rth e drive tothewo rkshop, reset the actuated
active bonnet yourself (/ page 337).
ATer the active bonnet has been actuated, pedes-
trian pr otection may be limited.
Ha ve the full functionality of the active bonnet
re stored in a quali/ed specialist workshop.
R
R ese ese tting t
tting t he activ
he activ e bonnet
e bonnet &
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. #
With your hand 0at, push down active bonnet
1 inthe area around the hinges on bo th
sides (ar rows ).
In doing so, the actuator is depressurised and
yo u may hear a hissing sound.
The engine bonnet must engage in position. #
Ifth e active bonnet can be raised slightly at
th ere ar in the area of the hinges, repeat the
step until it engages co rrectl y. Maintenance and ca
re
337
337

Opening and closing t
Opening and closing t
he bonnet
he bonnet&
W
WARNING
ARNING Risk of accident due todriving
with the bonnet unloc ked
The bonnet may open and blo ckyour vie w. #
Neverre lease the bonnet when driving. #
Before every trip, ensure that the engine
bonnet is loc ked. &
W
WARNING
ARNING Risk of accident and inju ry
when opening and closing the bonnet
The bonnet may suddenly drop into the end
position.
There is a risk of injury for an yone in the
engine bonnet's range of mo vement. #
Do not open or close the bonnet if there
is a person in the bonnet's range of
mo vement. &
W WARNING
ARNING Risk of burns when opening the
bonnet
If yo u open the bonnet in theev ent of an over-
heated engine or /re in the engine compart-
ment, thefo llowing situations may occur:
R You may come into contact with hot gases.
R You may come into contact with other
escaping hot operating 0uids. #
Before opening the bonnet, allow the
engine tocool down. #
Intheev ent of a /re in the engine com-
partment, keep the bonnet closed and
call the /re service. &
W
WARNING
ARNING Risk of injury due tomoving
parts
Components in the engine compartment may
continue torun or start unexpectedly even
when the drive system is switched o..
Obser vethefo llowing if you must open the
bonnet: #
Switch o. theve hicle. #
Neverto uch the danger zones sur round-
ing moving components, e.g. thero tation
area of thefa n. #
Remo vejewe llery and watches. #
Keep items of clo thing and hair away
from moving pa rts. &
W
WARNING
ARNING Risk of injury from touching
components under voltage
The ignition system and the fuel injection sys-
te m operate at high voltage. You could receive
an elect ric shoc k. #
Neverto uch ignition system or fuel injec-
tion system components when theve hi-
cle is switched on. The live components include
thefo llowing, for
ex ample:
R Ignition coils
R Fuel injectors 338
338
Maintenance and care

R
Electric lines tothe ignition coils and the fuel
injectors &
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
W ARNING
ARNING Risk of injury from using the
windscreen wipers when the bonnet is
open
If th e windscreen wipers start moving when
th e bonnet is open, you could be trapped by
th e wiper linkage. #
Always switch o. the windscreen wipers
and theve hicle /r stifyo u need toopen
th e bonnet. Opening t
Opening t
he bonnet
he bonnet #
Torelease the bonnet, pull on handle 1. #
Push yellow handle 1onthe bonnet catch to
th e leT as far as it will go (palm down wards).
LiT the bonnet until it is automatically raised
by the pneumatic spring.
Closing t
Closing t he bonnet
he bonnet #
Lowe rth e bonnet and let it drop from a height
of appr oximately 20 cm. Maintenance and care
339
339

#
Ifth e bonnet can still be liTed slightl y,open
th e bonnet again and close it with a little force
until it engages cor rectl y. Engine oil
Engine oil
Chec
Chec
king t
king t he engine oil lev
he engine oil lev el using t
el using the on-board
he on-board
com
com put
puter
er
R
R eq
eq uir
uir ements:
ements:
R The engine has been warmed up.
R The vehicle is par ked on a le vel sur face.
R The engine is running at idle speed.
R The bonnet is closed.
The engine oil le vel is de term ined during driving.
De term ining the engine oil le vel can take up to
30 minutes with a normal driving style and even
longer with an active driving style. On-board computer:
4 Service 5
Engine oil level
One of thefo llowing message s will appear onthe
inst rument displa y:
R Engine oil level Measuring now: measu rement
of the oil le vel is not yet possible. #
Repeat there qu est aTer a maximum of
30 minutes' driving.
R Engine oil level OK andthe bar display for
indicating the oil le vel on the inst rument dis-
play is green and is between "min" and "max":
th e oil le vel is cor rect.
R Engine oil level Add 1,0 l andthe bar display
fo r indicating the oil le vel on the inst rument
display is orange and is below "min": #
Add 1 l of engine oil.
R Reduce engine oil level andthe bar display for
indicating the oil le vel on the inst rument dis-
play is orange and is abo ve"max": #
Drain o. any excess engine oil that has been
added. Todo so, consult a quali/ed specialist
wo rkshop.
R For engine oil level turn on ignition #
Switch on theve hicle tocheck the engine oil
le ve l.
R Engine oil level System inoperative: The oil
leve l sensor is defective or not connected. #
Consult a quali/ed specialist workshop.
R Engine oil level System currently unavail. #
Close the bonnet.
T T opping up engine oil
opping up engine oil &
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. 340
340
Maintenance and care