towing MERCEDES-BENZ B-CLASS HATCHBACK 2021 Owners Manual

Changing bulbs (only
forve hicles with hal-
ogen headlamps) ......................................... 147
Wi ndsc reen wipers and windscreen
wa sher system ............................................ 149
Mir rors ........................................................ 153 Climat
Climat
e contr
e control ol........................................... 157 157
Overview of climate control systems ............ 157
Operating the climate control system .......... 158 Dr
Dr
iving and par
iving and par king
king..................................... 166 166
Driving ........................................................1 66
DY NAMIC SELECT switch ........................... .182
Manual transmission ................................... 185
Au tomatic transmission .............................. .187
Fu nction of the 4MATIC ...............................1 91
Re fuelling .................................................... 191
Charging the high-voltage battery (plug-in
hy brid) ........................................................ 198
Pa rking .......................................................2 15
Driving and driving saf ety sy stems ............... 223
Tr ailer hitch ................................................ .273
Bicycle rack function ................................... 277
Ve hicle towing instructions .......................... 279 Ins
Ins
tr
trument displa
ument displa y and on-boar
y and on-boar d com-
d com-
put
put er
er........................................................... 280 280
No tes on the inst rument display and on-
board computer .......................................... 280
Overview of instrument display .................... 281
Overview of buttons on the steering wheel ... 282
Operating the on-board computer ................2 82
Fu nction of the po wer me ter (plug-in
hy brid) ........................................................ 284
Fu nction of the electric mo tor po wer
av ailability displ ay(plug-in hybrid) ................ 284
Displaying the po wer me ter (plug-in
hy brid) ........................................................ 285
Overview of displa ysinthe inst rument
display ........................................................ 285
Head-up display .......................................... 285 MBUX multimedia syst MBUX multimedia syst
em
em........................... .288
288
Overview and operation ............................... 288
System settings .......................................... 297
Plug-in hybrid settings ................................ .301
Na vigation .................................................. .302
Te lephone ................................................... 311
Mercedes me app ....................................... 314 Mercedes-Benz emer
gency call system ....... 323
Ra dio & media ............................................ .330
Sound settings ............................................ 335 Maint Maint
enance and car
enance and car e
e................................. 336 336
ASS YST PLUS service inter val display .......... 336
Engine compartment ................................... 337
Cleaning and care ....................................... 343 Br Br
eakdo
eakdo wn assist
wn assist ance
ance................................. 352 352
Emer gency .................................................. 352
Flat tyre ...................................................... 354
Battery (vehicle) .......................................... 361
To w- starting or towing away ........................ 365
Electrical fuses ............................................ 371 Wheels and tyr Wheels and tyr
es
es......................................... 374 374
No tes on noise or unusual handling char-
acteristics ................................................... 374
No tes on regula rly inspecting wheels and
tyres .......................................................... .374
No tes on snow chains ................................. 374
Ty re pressure .............................................. 375 Contents
3 3

1
Safetyve sts →
352
2 Fire extinguisher →
353
3 ; me button →
314
0053 SOS button →
314
4 002F Hazard warning light system →
141
5 Starting assis tance →
363
6 Tocheck and top up operating 0uids →
396
7 Tow- starting or towing away →
367
8 Flat tyre →
354
9 B-pillar with: QR code
for accessing there scue card →
41
A Tow- starting or towing away →
367
B Warning triangle →
352
C TIREFIT kit →
356
D Firs t-aid kit (soT sided) →
353
E Fuel /ller 0ap with:
information label on fuel type →
191
information label on tyre pressure →
376
QR code for accessing there scue card →
41 At
a glance – Emer gencies and breakdowns
21
21

*
N
NO
OTE
TE Damage caused byobjects in the
fo ot we ll or behind the seat The automatic adjustment of
the seat position
may result in damage tothe seat and/or the
object. #
Stow objects in a suitable place. R
R
e
ev
ver
er sing t
sing t he PRE-S
he PRE-S AFE
AFE®
®
syst
syst em measur
em measur es
es If an accident did not occur,
the pre-em ptive
measures that we re ta ken are reve rsed.
Yo u will need toper form certain settings yourself. #
Ifth e seat belt pre-tensioning is not reduced,
mo vethe seat backrest back slightl y.
The locking mechanism releases. F
F
unction of PRE-S
unction of PRE-S AFE
AFE ®
®
PL
PL US (anticipat
US (anticipat or
ory occu-
y occu-
pant pr ot
pant pr otection plus)
ection plus) PRE-SAFE
®
PLUS can de tect cer tain impacts, par-
ticular lyan imminent rear impact, and take pre-
em ptive measures toprotect theve hicle occu- pants. These measures cann
otnecessarily pre-
ve nt an imminent impact.
PRE-SAFE ®
PLUS can implement thefo llowing
measures independently of each other:
R Tightening the seat belts on the driver's seat
and front passenger seat.
R Activating there ar hazard warning lights at a
higher 0ashing frequency.
R Increasing brake pressure when theve hicle is
stationar y.This brake application is cancelled
automatically when theve hicle pulls away.
If an accident did not occur, the pre-em ptive
measures that we re ta ken are reve rsed.
Syst
Syst em limits
em limits
The system will not initiate any action in thefo l-
lowing situations:
R when reve rsing
or
R when theve hicle is towing a trailer and there
is a risk of a rear impact The system will not initiate any braking application
in thefo llowing situations:
R whilst driving
or
R when entering or exiting a parking space while
using Active Parking Assist A A
ut
ut omatic measur
omatic measur es
esaTer
aTer an accident
an accident
Depending on the type and se verity of the acci-
dent, and depending on theve hicle's equipment,
th efo llowing measures can be implemented, for
ex ample:
R automatic braking (post-collision brake)
R activating the hazard warning lights
R triggering an automatic emer gency call
(/ page 325)
R switching o. the engine
To start theve hicle again, switch theve hicle
o. and on once more (/ page 169). Depend-
ing on the type and se verity of the accident,
yo u may no longer be able tostart theve hicle.
R switching o. the fuel supply 60
60
Occupant saf
ety

de
tected bythe system. The maximum permissi-
ble speed applying toave hicle with a trailer is not
de tected bythe system.
Ad just the speed in these situations. &
W
WARNING
ARNING Risk of accident due toActive
Speed Limit Assist ada pting theve hicle's
speed
The speed adop tedby Active Speed Limit
Assist may be too high or incor rect in some
individual cases, such as:
R at speed limits below 20 km/h
R inwe t conditions or in fog
R when towing a trailer #
Ensure that the driven speed complies
with tra1c regulations. #
Adjust the driving speed tosuit cur rent
tra1c and weather conditions. F F
unction of r
unction of r out
oute-based speed adapt
e-based speed adapt ation
ation
When Active Distance Assist DISTRONIC is acti va-
te d, theve hicle speed will be adap ted accordingly
to thero ute events ahead. Depending on the drive prog
ram selected, theve hicle neg otiates a route
ev ent ahead in an economical, comfor table or
dynamic manner. When thero ute event has been
passed, theve hicle accelerates again tothe
stored speed. The set distance totheve hicle in
front, vehicles de tected ahead and speed restric-
tions ahead are take n into account.
Yo u can activate and deactivate route-based
speed adap tation in the multimedia system
(/ page 241).
The following route events are take n into account:
R Bends
R T-junctions, roundabouts and toll stations
R Turns and exits
R Tra1c jams ahead (only with Live Tra1c Infor-
mation )
% When theto ll station is reached, Active Dis-
ta nce Assist DISTRONIC ado ptsth e speed as
th e stored speed.
Also, the speed is reduced if the turn signal indi-
cator tochange lanes is switched on and one of
th efo llowing situations is de tected:
R Turning o. at junctions R
Driving on slowing-down lanes
R Driving on lanes adjacent toslowing-down
lanes
The driver is responsible forch oosing theright
speed and observing other road users. This
applies in particular tojunctions, roundabouts and
tra1c lights, as route-based speed adap tation
does not brake theve hicle toa standstill.
When route guidance is active, the /rst speed
adjustment is car ried out automaticall y.Ifth e turn
signal indicator is switched on, the selected route
is con/rmed and fur ther speed adjustment is acti-
va ted.
Speed adap tation is cancelled in thefo llowing
cases:
R Ifth e turn signal indicator is switched o.
before thero ute event.
R Ifth e driver depresses the accelerator or
brake pedal during the process.
Syst Syst em limits
em limits
Ro ute-based speed adap tation does not take right
of wa yre gulations into account. The driver is 240
240
Driving and parking

re
sponsible for complying with road tra1c regula-
tions and driving at a suitable speed.
The speed ada ptation made bythe system may
not alw ays be suitable, particular lyin thefo llowing
situations:
R thero ad's course not clear lyvisible
R road nar rowing
R varying maximum permissible speeds in indi-
vidual lanes, forex ample at toll stations
R wetro ad sur faces, snow or ice
R when towing a trailer
In these situations the driver must inter vene
accordingl y. &
W WARNI NG
ARNI NGRisk of accident in spi teof
ro ute-based speed adap tation
Ro ute-based speed adap tation can malfunc-
tion or be temp orarily una vailable in thefo l-
lowing situations:
R Ifth e driver does not follow the calculated
ro ute R
If map data is not up-to-date or available
R Intheev ent of roadwor ks
R In bad weather or road conditions
R Ifth e accelerator pedal is depressed
R Intheeve nt of electronically displa yed
speed limi tations #
Adapt the speed tothe tra1c situation. Se
Se
tting r
tting r out
oute-based speed adapt
e-based speed adapt ation
ation
R
R eq
eq uir
uir ements:
ements:
R Active Distance Assist DISTRONIC is acti va-
te d.
R ECO Assist is active.
Multimedia system: 4 © 5
Settings 5
Assistance
5 Route-based speed adapt. #
Activate or deactivate the function.
When the function is active, theve hicle speed
is adjusted depending on thero ute events
ahead. %
Further information on the route-based speed
adap tation (/ page 240). A
A
ctiv
ctiv eSt
e St eer
eer ing Assist
ing Assist F
F
unction of A
unction of A ctiv
ctiveSt
e St eer
eer ing Assist
ing Assist
Ac tive Steering Assist is only available up to a
speed of 210 km/h. The system helps youto stay
in the centre of the lane bymeans of moderate
steering inter ventions. Depending on the speed
driven, Active Steering Assist uses theve hicles
ahead and lane markings as a refere nce.
% Depending on the countr y,in the lo wer speed
ra nge Active Steering Assist can use the sur-
ro unding tra1c as a refere nce. If necessar y,
Ac tive Steering Assist can then also pr ovide
assistance when driving outside the centre of
th e lane, forex ample, toform are scue lane.
If th e de tection of lane markings and vehicles
ahead is impaired, Active Steering Assist switches
to passive mode. The system pr ovides no support
in this case. Driving and parking
241
241

R
The windsc reen is dirty, misted up, damaged
or co vered in the vicinity of the camera, e.g.
by a stic ker.
R No, or se veral, unclear lane markings are pres-
ent for one lane, or the markings change
qu ickl y,forex ample, in a construction area or
junctions.
R The lane markings are wornawa y,dark or co v-
ered up, e.g. bydirt or sno w.
R Ifth e distance totheve hicle in front is too
short and thus the lane markings cannot be
de tected.
R The road is na rrow and winding.
R There are obs tacles on the lane or projecting
out into the lane, such as object mar kers.
The system does not pr ovide assistance in thefo l-
lowing conditions:
R On tight bends and when turning.
R When crossing junctions.
R Atroundabouts or toll stations.
R When towing a trailer.
R When the tyre pressure is too lo w. &
W
WARNI NG
ARNI NGRisk of accident if Active Steer-
ing Assist unexpectedly stops functioning
If th e system limits of Active Steering Assist
are reached there is no guarantee that the
system will remain active or will keep theve hi-
cle in lane. #
Alwayske ep your hands on the steering
wheel and obser vethe tra1c carefull y. #
Always steer theve hicle paying attention
to tra1c conditions. &
W
WARNI NG
ARNI NGRisk of accident if Active Steer-
ing Assist unexpectedly inter venes
The de tection of lane markings and objects
may malfunction and cause unexpected steer-
ing inter ventions. #
Steer according totra1c conditions. A A
ctiv
ctiv ating/deactiv
ating/deactiv ating A
ating Activ
ctiveSt
e St eer
eer ing Assist
ing Assist
R
R eq
eq uir
uir ements:
ements:
R ESP ®
is activated, but is not inter vening. R
Active Distance Assist DISTRONIC is acti va-
te d.
Multimedia system: 4 © 5
Settings 5
Quick access #
Select 004FAct. Steer. Asst . F
F
unction of A
unction of A ctiv
ctive Emerg
e Emerg encySt
ency Stop Assist
op Assist If
th e system de tects that the driver has not
steered theve hicle for a considerable period of
time or has remo vedth eir hands from the steering
wheel, display 1appears in the Instrument Dis-
pla y.Ifth e driver still does not steer theve hicle,
or gives no con/rmation tothe system, a warning Driving and parking
243
243

R
If an incor rect transmission position is
engaged.
Drive Away Assist is active under thefo llowing
conditions:
R IfPa rking Assist PARKTRONIC is activated.
R Ifyo u shiT the transmission position to005E or
005B when theve hicle is stationar y.
R Ifth e de tected obs tacle is less than appr ox.
1.0 m away.
R Ifth e manoeuvring assistance function is acti-
va ted in the multimedia system.
Syst
Syst em limits
em limits
The per form ance of Drive AwayAssist is limited
on inclines.
When driving with a trailer, Drive AwayAssist is
not available.
% Also obser vethe system limits of Parking
Assist PARKTRONIC (/ page 264).
F
F unction of Cr unction of Cr oss
ossTr
Tr a1c
a1c Alert
Alert
% Cross Tra1c Ale rtis only available forve hicles
with Blind Spot Assist or Active Blind Spot
Assist. Cross
Tra1c Ale rtcan warndrivers of any cross-
ing tra1c when reve rsing and manoeuvring out of
a parking space. The radar sensors in the bumper
also monitor the area adjacent totheve hicle. If a
critical situation is de tected, theL symbol
appears in the media display and theve hicle can
be braked automaticall y.
If th era dar sensors are obstructed byvehicles or
ot her objects, de tection is not possible.
Cross Tra1c Ale rtis active under thefo llowing
conditions:
R ifth eve hicle is reve rsing at a walking pace.
R manoeuvring assista nce is activated
(/ page 273).
% Also obser vethe inst ructions on Blind Spot
Assist and Active Blind Spot Assist
(/ page 252).
Syst
Syst em limits
em limits
Cross Tra1c Ale rtis not available on inclines.
Cross Tra1c Ale rtis not available when driving
with a trailer. A
A ctiv
ctiv ating/deactiv
ating/deactiv ating manoeuvr
ating manoeuvr ing assist
ing assistant
ant
Multimedia system:
4 © 5
Settings 5
Assistance
5 Camera & parking #
Activate/deactivate Manoeuvring assistance.
% Manoeuvring assistant must be acti veforthe
function of Drive AwayAssist (/ page 272)
and Cross Tra1c Ale rt (/ page 273). T
T
r
railer hitch
ailer hitch N
No
ot
tes on tr
es on tr ailer oper
ailer oper ation
ation Obser
vethefo llowing no tes on theto ngue weight:
R Do not use a tongue weight that exceeds or
fa lls below the permissible tongue weight
R Use a tongue weight as close as possible to
th e maximum tongue weight
Do not exceed thefo llowing values:
R Perm issible towing capacity
R Perm issible rear axle load of theto wing vehi-
cle
R Perm issible gross weight of theto wing vehicle Driving and parking
273
273

2
Horizontal distance between centre of grav ity
and ball head
3 The centre of grav ity is on theve hicle's cent re
axis
Obser vethefo llowing information when you are
loading the bicycle rack with up tothre e bicycles:
Loading t
Loading t he bicy
he bicycle r
cle rack
ack T
T
o
o t
tal w
al w eight
eight
of bicy
of bicy cle
cle
r
r ac
ac k and load
k and load Max. dist
Max. dist
ance
ance
1
1 Max. dist
Max. dist
ance
ance
2
2
Up to75 kg 420 mm 300 mm V
V
ehicle to
ehicle towing ins
wing ins tr
tructions
uctions
The vehicle is not suitable forth e use of tow bar
systems that are used for 0at towing or dinghy
to wing, forex ample. Attach ing and using tow bar
systems can result in damage totheve hicle.
When you are towing a vehicle with tow bar sys-
te ms, safe driving characteristics cann otbe guar-
anteed forth eto wing vehicle or theto we dve hicle.
The vehicle-trailer combination may swer vefrom
side toside. Obser
vethefo llowing information:
R Perm itted towing me thods (/ page 365)
R Plug-in h
Plug-in h ybr
ybrid:
id:permitted towing me thods
(/ page 366)
R The no tes on towing theve hicle with bo th
axles on thegr ound (/ page 367) Driving and parking
279
279

th
e emer gency call and faster transfer of the
accident data.
Measu resfo rre scue, reco very or towing away
can then be initiated in quickl y.
R With a Mercedes-Benz emer gency call, the
accident data is only transfer redto the public
coordination centre with the appr oval of the
cus tomer.
In theev ent of an automatically triggered
emer gency call in which there is no voice con-
ta ct, the accident data is transmitted immedi-
ately tothe public emer gency call centre.
R Should the Mercedes-Benz emer gency call
centre not be available, the 112 emer gency
call is ca rried out automaticall y.Ov Ov
er
ervie
vie w of emerg
w of emerg ency call syst
ency call syst ems
ems Bo
th th e Mercedes-Benz emer gency call system
as well as the 112 emer gency call system (EU
eCall) can help toreduce the time between an
accident and the ar riva l of emer gency services at
th e site of the accident. They help locate an acci-
dent site in places that are di1cult toaccess. Bo
th emer gency call systems can initia tean emer-
ge ncy call automatically (/ page 325) or man-
ual ly ( / page 326).
Only make emer gency calls if you or others are in
need of rescue. Do not make an emer gency call in
th eev ent of a breakdown or a similar situation.
Messag
Messag es on t
es on the display
he display
The following message s appear inthe display of
bo th emer gency call systems:
R SOS NOT READY: theve hicle is not switched
on or the emer gency call system is malfunc-
tioning. This does not necessarily indicate
comple tefailure of the emer gency call system.
Eme rgency calls call still be transmitted.
The display only refers to theve hicle and does
not take account of theav ailability of mobile
phone networ ksand the Mercedes-Benz emer-
ge ncy call centre.
The functional readiness of the emer gency call
system on theve hicle can be seen when the
SOS NOT READY displaydisappears once the
ve hicle is switched on. R
0053: The icon appears in the display during
an active emer gency call.
% Ifth ere is a malfunction in the emer gency call
system (e.g. a fault with the speaker, micro-
phone, airbag, SOS button), a cor responding
message appears on the inst rument displa y. T T
r
r igg
igg er
ering an aut
ing an aut omatic emerg
omatic emerg ency call
ency call R
R
eq
eq uir
uir ements:
ements:
R The vehicle is switched on.
R The star ter battery is su1ciently charge d.
Bo th th e Mercedes-Benz emer gency call system
as well as the 112 emer gency call system (EU
eCall) automatically initia tean emer gency call
aTer:
R Activation of there straint systems su chas air-
bags or seat belt tensioners aTer an accident
The eme rgency call has been made:
R Avo ice connection is established with the
emer gency call centre. MBUX multimedia system
325
325

*
N
NO
OTE
TE Damage from automatic braking If one of
thefo llowing functions is switched
on, theve hicle brakes automatically in cer tain
situations:
R Active Brake Assist
R Active Distance Assist DISTRONIC
R HOLD function
R Active Parking Assist
To avoid damage totheve hicle, deactivate
th ese systems in thefo llowing or similar situa-
tions: #
during towing #
in a car wash *
N
NOOTE
TE Damage due tounsuitable car wash #
Before driving into a car wash make sure
th at the car wash is suitable forth eve hi-
cle dimensions. #
Ensu rethere is su1cient ground clear-
ance between the underbody and the
guide rails of the car wash. #
Ensure that the clearance width of the
car wash, in particular the width of the
guide rails, is su1cient. To
avo id damage toyour vehicle when using a car
wa sh, ensu rethefo llowing beforehand:
R Active Distance Assist DISTRONIC is deactiva-
te d.
R The HOLD function is switched o..
R The side windo wsand sliding sunroof are com-
ple tely closed.
R The blo werfo rth eve ntilation/heating is
switched o..
R The windsc reen wiper switch is in position 005A.
R The key is at a minimum dis tance of 3 m away
from theve hicle. Otherwise theta ilgate could
open unintentionall y.
R In automatic car washes with con veyo r sys-
te ms:
- Neutral 005Cis engaged. -
V Vehicles wit ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: If
yo uwo uld like tolea vetheve hicle while it
is being washed, make sure theke y is
located in theve hicle. The park position
005D isotherwise automatically engaged.
% If, aTer the car wash, youre mo vethewax
from the windscreen and wiper rubbers, this
will pr event smearing and reduce wiper noise.
A
A ut
ut omatic car w
omatic car w ash mode
ash mode
In car wash mode, theve hicle is prepared for driv-
ing into the automatic car wash. Car wash mode
can be activated at a speed of up to20 km/h
Ac tivate (/ page 345).
The following settings are made when car wash
mode is activated:
R The outside mir rors are folded in.
R Topreve ntthe windscreen washer system
from starting up automaticall y,thera in sensor
is deactivated.
R The rear wind owwiper is deacti vated.
R The windo wsand the sliding sunroof are
closed. 344
344
Maintenance and care