ECU MERCEDES-BENZ B-CLASS HATCHBACK 2021 Workshop Manual

R
Type Combo 2 forch arging with alternating
cur rent (mode 2/3) and charging with direct
cur rent (mode 4) Combo 1
vehicle soc ket Combo 2
vehicle soc ket
1 Type 1 or type 2 connection forch arging with
alternating cur rent
2 Socketex tension forch arging with direct cur-
re nt
% When using a CCS (Combined Cha rging Sys-
te m) charging cable tocharge with direct cur-
re nt at a combo vehicle soc ket, bo thvehicle soc
ket connections 1and 2are used for
ch arging.
Charging options forth e high-voltage battery
(mode 2, 3 or 4):
R Charging through recuperation while theve hi-
cle is in motion
R Charging with alternating cur rent when sta-
tiona ry:
- at a mains soc ket (mode 2)
- at a wallbox or charging station (mode 3)
R Charging with direct cur rent when stationary
(vehicles with combo vehicle soc kets):
- at a fast charging station (mode 4)
Depending on the count ry-speci/c vehicle equip-
ment and your vehicle's charging cable, single
phase ACcharging is also possible.
Obser vethe di.erent grid requ irements of your
cur rent location when charging. Only use charging
cables which conform tothegr id requi rements.
Consult a quali/ed elect rician or your local grid
operator if you ha veany questions. Driving and parking
199
199

It is
recommended that youch arge the high-volt-
age battery at a wallbox or charging station due to
th e impr ovedch arging per form ance and better
ch arging e1ciency o.ered.
S
S t
to
o wing t
wing t he c
he char
harging cable
ging cable
Alw ays st owtheve hicle charging cable in the
ch arging cable bag pr ovided and secure it in the
boot or load compartment of your vehicle.
Otherwise, thech arging cable is not su1ciently
secured.
Syst
Syst em limits em limits
The po wer output of the high-voltage battery may
be impaired bythefo llowing:
R High or low outside temp eratures
R Electrical auxiliary consumers in theve hicle
being switched on, e.g. operating the air con-
ditioning system
R Extended periods without charging
The charging time of the high-voltage battery may
be increased bythefo llowing:
R High or low outside temp eratures
R Extended periods without charging R
The maximum available charge cur rent of the
ch arging facility
R The charging cur rent set (mode 2) in the multi-
media system (/ page 301) N
No
ot
tes on c
es on c har
harging t
ging t he high-v
he high-v olt
oltag
age batt
e batt er
ery at t
y at t he
he
mains soc ke
mains soc ket (mode 2)
t (mode 2) &
D
DAN
AN GER
GER Risk of fatal injury from incor-
re ctly ins talled component parts
Connecting thech arging cable toa mains
soc ket using incor rectly ins talled component
parts could cause a /re or an electric shoc k,
fo rex ample. #
Only connect thech arging cable to a
mains soc ketth at:
R Has been proper lyinstalled and
R Has been inspected byaqu ali/ed elect ri-
cian #
For saf etyre asons, only use thech arging
cable supplied with theve hicle or an
original Mercedes-Benz charging cable. #
Purchase these parts at a Mercedes-
Benz Service Centre and obtain advice
th ere.
Mercedes-Benz thoroughly tests these original
ch arging cables forth eir suitability for high-
vo ltage charging of your vehicle. #
Never use a damaged charging cable. #
Do not use:
R Extension cables
R Extension reels
R Multiple soc kets #
Never use soc ket ada pters toconnect
th ech arging cable tothe mains soc ket.
The only exception being if the adap ter
has been tested and appro vedby the
manufacturer forch arging the high-volt-
age battery of an electric vehicle. #
Obser vethe saf ety no tes in the operat-
ing inst ructions forth e soc ket ada pter. Only
thefo llowing charging cables may be used:
R The charging cable supplied with theve hicle. 200 200
Driving and parking

a
ch arging capacity of 10 kW or highe r,th eva lue
in thech arge leve l display is rounded o. and
shown without a decimal place.
% The value in item 3varies depending on the
setting of thech arging process. It displ aysthe
ch arging prediction, e.g. the time at which the
selected charge leve l will be reached or the
ch arge leve l at the pre-selected departure
time. P P
ar
ar king
king P
P
ar
ar king t
king t he v
he vehicle
ehicle &
W
W ARNING
ARNING Risk of accident and injury
caused byan insu1ciently secured vehi-
cle rolling away
If th eve hicle is not securely par ked su1-
cient ly,it can rollawa y in an uncontrolled way
eve n at a slight downhill gradient. #
On uphill or downhill gradients, turn the
front wheels so that theve hicle rolls
to wa rdsth eke rb if it starts moving. #
apply the parking brake. #
Vehicles with automatic transmission:
shiT the transmission toposition 005D. #
Vehicles with manual transmission:
engage /r st0047 orreve rsege ar 005E. &
W
WARNING
ARNING Risk of /re caused byhot
ex haust system parts
Flammable materials such as lea ves, grass or
twigs may ignite. #
Park theve hicle so that no 0ammable
material can come into contact with hot
ve hicle components. #
In particular, do not park on dry grass-
land or har vested grain /elds. &
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.
R operate vehicle equipment and become
trapped, forex ample.
In addition, thech ildren could also set the
ve hicle in motion by,fo rex ample:
R releasing the parking brake.
R changing the transmission position.
R starting theve hicle. #
Never lea vechildren unattended in the
ve hicle. #
When leaving theve hicle, alw aysta ke the
ke y with you and lock theve hicle. #
Keep theve hicle key out of there ach of
ch ildren. Driving and parking
215
215

*
N
NO
OTE
TE Damage totheve hicle due toitro ll-
ing away #
Always secure theve hicle against rolling
awa y. #
Bring theve hicle toa standstill bypressing the
brake pedal. #
Ongradients, turn the front wheels so that the
ve hicle will rollto wa rdsth eke rb if it starts
moving. #
Apply the electric parking brake. #
V
Vehicles wit
ehicles wit h manual tr
h manual tr ansmission:
ansmission: Engage
/rst 0047orreve rsege ar 005E. #
V
Vehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: Engage
transmission position 005Din a stationary vehi-
cle with the brake pedal applied
(/ page 188). #
Switch o. theve hicle bypressing the1 but-
to n. #
Release the service brake slo wly. #
Get out of theve hicle and lock it.
% When you park theve hicle, you can still oper-
ate the side windo wsand the panoramic slid-
ing sunroof for appr oximately four minutes if
th e driver's door is closed. Gar
Gar
ag
age door opener
e door opener Pr
Pr
ogr
ogr amming butt
amming butt ons f
ons for t
or the g
he g ar
arag
ag e door opener
e door opener &
D
DAN
AN GER
GER Risk of fatal injuries caused by
ex haust gases
Combustion engines emit poisonous exhaust
ga ses such as carbon monoxide. Inhaling
th ese exhaust gases is hazardous tohealth
and leads topoisoning. #
Never lea vetheve hicle or, if present, the
stationa ryheater running in an enclosed
space without su1cient ventilation. &
W
WARNI NG
ARNI NGRisk of injury bybecoming
trapped when opening and closing a
ga rage door
When you operate or prog ram a garage door
with an integ ratedga rage door opener, per-
sons can become trapped or struck bythe
ga rage door if they stand wi thin its range of
mo vement. 216 216
Driving and parking

Appl
Appl
ying/r
ying/r eleasing t
eleasing t he electr
he electric par
ic parking br
king br ake
ake
manual ly
manually
Appl Appl ying
ying #
Push handle 1.
The red0024 indicator lamp lights up in the
inst rument clus ter. %
The electric parking brake is only securely
applied if there d0024 indicator lamp is lit
continuousl y.
R R eleasing
eleasing #
Switch on theve hicle. #
Pull handle 1.
The red0024 indicator lamp in the inst rument
cluster goes out.
Emerg Emerg ency br
ency br aking
aking #
Press and hold handle 1.
As long as theve hicle is in motion, the
Release parking brake message is displayed
and there d0024 indicator lamp 0ashes.
When theve hicle has been braked toa stand-
still, the electric parking brake is applied. The
re d0024 indicator lamp lights up in the inst ru-
ment cluster. Inf
Inf
or
ormation on collision det
mation on collision det ection on a park
ection on a parked
ed
v
v ehicle
ehicle If a collision is de
tected when theto w- awa y pro-
te ction is primed on a loc kedve hicle, you will re
ceive a noti/cation in the multimedia system
when you switch theve hicle on.
Yo u will receive information about thefo llowing
points:
R The area of theve hicle that may ha vebeen
damaged.
R The forc e of the impact.
The following situation can lead toinadver tent
activation:
R The par kedve hicle is mo ved, forex ample, in a
two-s tore yga rage.
% Deactivate tow- awa y protection in order to
pr ev ent inadver tent activation. If you deacti-
va te to w-awa y protection, collision de tection
will also be deactivated.
Syst
Syst em limits em limits
De tection may be restric ted in thefo llowing situa-
tions:
R theve hicle is damaged without impact, for
ex ample, if an outside mir ror is torn o. or the
paint is damaged byakey
R an impact occurs at low speed Driving and parking
221 221

Syst
Syst
em limits
em limits
ST EER CONTROL may be impaired or may not
function in thefo llowing situations:
R ESP ®
is deactivated.
R ESP ®
is malfunctioning.
R The steering is malfunctioning.
If ESP ®
is malfunctioning, you will be assisted fur-
th er by the electric po wer steering. HOLD function
HOLD function
HOLD function
HOLD function
The HOLD function holds
theve hicle at a stand-
still without requ iring youto depress the brake
pedal, e.g. while waiting in tra1c.
The HOLD function is only an aid. The responsibil-
ity forth eve hicle safely standing still remains with
th e driver.
Syst Syst em limits em limits
The HOLD function is only intended toprov ide
assistance when driving and is not a su1cient
means of safeguarding theve hicle against rolling
awa y when stationa ry. R
The incline must not be greater than 30%.
A
A ctiv ctiv ating/deactiv
ating/deactiv ating t
ating t he HOLD function
he HOLD function &
W
WARNING
ARNING Risk of an accident due tothe
HOLD function being active when you
lea vetheve hicle
If th eve hicle is only braked with the HOLD
function it could, in thefo llowing situations,
ro llawa y:
R Ifth ere is a malfunction in the system or in
th e po wer suppl y.
R Ifth e HOLD function is deactivated by
depressing the accelerator pedal or brake
pedal, e.g. byave hicle occupant. #
Always secure theve hicle against rolling
awa y before you lea veit. R
R
eq
eq uir
uir ements:
ements:
R The vehicle is stationar y.
R The driver's door is closed or the seat belt on
th e driver's side is fastened. R
The vehicle has been star ted or has been
automatically switched o. bythe ECO start/
stop function.
R The vehicle has been star ted.
R The electric parking brake is released.
R Active Distance Assist DISTRONIC is deactiva-
te d.
R V
V ehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: the
transmission is in position 005B,005Eor005C.
A
A ctiv
ctiv ating t
ating t he HOLD function
he HOLD function #
Depress the brake pedal, and aTer a short
time quickly depress fur ther until the00D9
display appears in the Instrument Displa y. #
Release the brake pedal.
Deactiv
Deactiv ating t
ating the HOLD function
he HOLD function #
Depress the accelerator pedal topull away.
or #
Depress the brake pedal until the00D9 display
disappears from the Instrument Displa y.228
228
Driving and parking

The HOLD function is deactivated in
thefo llowing
situations:
R Active Distance Assist DISTRONIC is acti va-
te d.
R V
Vehicles wit
ehicles wit h aut
h aut omatic tr
omatic tr ansmission:
ansmission: the
transmission is shiTed toposition 005D.
R The vehicle is secured with the electric par k-
ing brake.
In thefo llowing situations, theve hicle is held by
transmission position 005Dand/or bythe electric
parking brake:
R The seat belt is unfastened and the driver's
door is opened.
R The vehicle is switched o..
R There is a system malfunction.
R The po wer supply is insu1cient.
V
V ehicles wit
ehicles wit h manual tr
h manual tr ansmission
ansmission
The Brake immediately message may also appear
in the Instrument Displa y:#
Immediately depress the brake pedal /rmly
until thewa rning message disappears.
The HOLD function is deactivated. A horn sounds at
regular inter vals if, despite the
Brake immediately message,you switch o. the
ve hicle, remo veyour seat belt and open the driv-
er's door. If you attem pttolock theve hicle, the
horn tone becomes louder. The vehicle cann otbe
loc ked until you ha vedeactivated the HOLD func-
tion.
% Once you ha veswitched o. theve hicle, you
cannot restart it until you ha vedeactivated
th e HOLD function. F
F
unction of Hill St
unction of Hill Star
art Assist
t Assist Hill
Start Assist holds theve hicle for a short time
when pulling away on a hill under thefo llowing
conditions:
R V
V ehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: the
transmission is in position 005Bor005E.
R The electric parking brake is released.
This gives you enough time tomo veyour foot
from the brake pedal tothe accelerator pedal and
depress it before theve hicle begins torollaw ay. &
W
WARNI NG
ARNI NGRisk of accident and injury due
to theve hicle rolling away
ATer a sho rttime, Hill Start Assist no lon ger
holds theve hicle. #
SwiTly mo veyour foot from the brake
pedal tothe accelerator pedal. Do not
lea vetheve hicle when it is being held by
Hill Start Assist. F
F
unction of A
unction of A dap
daptiv
tive Br
e Br ak
ake Lights
e Lights Ad
aptive Brake Lights warnfollowing tra1c in an
emer gency braking situation with thefo llowing
actions:
R By 0ashing the brake lamps
R By activating the hazard warning lights
If th eve hicle is braked sharply from speeds abo ve
50 km/h, the brake lamps 0ash rapidl y.This pro-
vides tra1c tr avelling behind you with an even
more noticeable warning.
If th eve hicle is tr avelling at speeds of more than
70 km/h at the beginning of the brake applica-
tion, the hazard warning lights switch on once the Driving and parking
229
229

ve
hicle is stationar y.When you pull away again,
th e hazard warning lights will switch o. automati-
cally at appr oximately 10 km/h. You can also
switch o. the hazard warning lights using the haz-
ard warning button. S
S
t
tar
ar t-o.
t-o. assist
assist F
F
unction of t
unction of t he
hest
star
ar t-o.
t-o. assist
assist
The start-o. assist enables optimal vehicle accel-
eration from a standstill. Forth is, a suitably high-
gr ip road sur face is requ ired, the tyres and vehicle
must also be in good condition.
Do not activate the start-o. assist on public
ro ads.
Be sure toobser vethe saf ety no tes and informa-
tion on ESP ®
(/ page 225).
A
A ctiv
ctiv ating t
ating t he
hest
starar t-o.
t-o. assist
assist &
W
WARNING
ARNING Risk of skidding and having an
accident from wheels spinning
When you use start-o. assist, individual
wheels could spin and you could lose control
of theve hicle. If ESP
®
is deactivated, there is a risk of skid-
ding and accident! #
Make sure that no persons or obs tacles
are in the close vicinity of your vehicle. #
Deactivating ESP ®
(/ page 227). #
Movethe steering wheel tothe straight-ahead
position. #
Depress the brake pedal /rmly with your leT
fo ot and keep it depressed. #
Engage the005B drive position (/ page 189). #
Select the sportiest available drive prog ram
B orC(/ page 183). #
Rapidly depress the accelerator pedal full y. #
Take your foot o. the brake, but keep the
accelerator pedal depressed.
The vehicle pulls away at maximum accelera-
tion. #
Switch on ESP ®
once the acceleration proce-
dure is comple te. ESP ®
will otherwise not be
able tostabilise theve hicle if theve hicle
starts toskid or a wheel starts tospin. Cancelling t Cancelling t
he
hest
star
ar t-o.
t-o. assist
assist #
Remo veyour foot from the accelerator pedal. #
Reactivate the ESP ®
. A A
TTENTION ASSIST TTENTION ASSIST F
F
unction of A
unction of A TTENTION ASSIST
TTENTION ASSIST
AT TENTION ASSIST assists you on long, mono to-
nous journe ys, e.g. on mo torw ays and trunk
ro ads. If ATTENTION ASSIST de tects indicators of
fa tigue or increasing lapses in concentration on
th e part of the driver, it suggests taking a break.
AT TENTION ASSIST is only an aid. It cannot
alw ays de tect fatigue or lapses in concentration in
time. The system is not a substitute for a well-res-
te d and attentive driver. On long journe ys,ta ke
re gular breaks in good time that allow for ade-
qu ate recuperation.
Yo u can choose between two settings:
R St Standar andar d:
d:normal system sensitivity.
R Sensitiv Sensitiv e: e:higher system sensitivity. The driver
is wa rned earlier and the attention le vel de tec-
te dby ATTENTION ASSIST is ada pted accord-
ingl y. 230
230
Driving and parking

&
W
W ARNI NG
ARNI NGRisk of an accident due to
Ac tive Distance Assist DISTRONIC being
acti vewhen you lea vethe driver's seat
If yo u lea vethe driver's seat while theve hicle
is being braked byActive Distance Assist
DISTRONIC onl y,theve hicle can rollaw ay. #
Always deacti vate Ac tive Distance Assist
DISTRONIC and secure theve hicle to
pr ev ent it from rolling away before you
lea vethe driver's seat. #
Select Owiththe leT rock er switch.
% Ifyo u brake, deactivate ESP ®
or if ESP ®
inter-
ve nes, Active Distance Assist DISTRONIC is
deactivated.
Incr
Incr easing/decr
easing/decr easing t
easing the st
he stor
ored speed
ed speed #
1 km/h: press roc ker switch 1upM or
down Ntothe pressure point, or press and
hold (increments of 1 km/h).
or #
10 km/h: press rock er switch 1upM or
down Nbeyond the pressure point, or
press and hold (increments of 10 km/h).
or #
Accelerate theve hicle tothe desired speed
and press rock er switch 1upM.
Changing t
Changing t he
hespeci/ed
speci/ed dist
distance t
ance t o t
o the v
he v ehicle in
ehicle in
fr
fr ont
ont #
T
To r
o r educe t
educe t he
hespeci/ed
speci/ed dist
distance:
ance: pressthe
ri ght rock er switch up ( Ñ). #
T To incr o incr ease t
ease t he
hespeci/ed
speci/ed dist
distance:
ance: pressthe
ri ght rock er switch down ( Ò).
F
F unction of A
unction of A ctiv
ctive Speed Limit Assist
e Speed Limit Assist
If a change in the speed limit of 20 km/h or more
is de tected and automatic adoption of speed lim-
its is activated, the new speed limit is automati-
cally adop ted as the stored speed (/ page 252).
The driven speed is adjusted when theve hicle is
le ve l with the tra1c sign at the latest. In the case
of signs indicating entry into an urban area, the
speed is adap ted according tothe speed permit-
te d within the urban area. The speed limit display in
the Instrument Display is alw ays updated when
th eve hicle is le vel with the tra1c sign.
If th ere is no speed restriction on an unlimited
str etch ofroad (e.g. on a mo torw ay),th ere com-
mended speed is automatical lyadop ted as the
stored speed. The system uses the speed stored
on an unlimited str etch ofroad as there commen-
ded speed. If you do not alter the stored speed on
an unlimited str etch ofroad, there commended
speed is 130 km/h.
If Ac tive Distance Assist DISTRONIC has been put
into passive mode bypressing the accelerator
pedal, only speed limits which are higher than the
set speed are adop ted.
Obser vethe no tes on driving systems and your
re sponsibility; you may otherwise failto recognise
dangers (/ page 223).
Syst
Syst em limits em limits
The system limits of Tra1c Sign Assist apply to
th e de tection of tra1c signs (/ page 250).
Speed limits below 20 km/h are not automatical ly
adop tedby the system as the stored speed. Tem-
porary speed restrictions (e.g. for a cer tain time
or due towe ather conditions) cann otbe proper ly Driving and parking
239
239

to
ne sounds in addition tothe visual warning mes-
sage.
If th e driver still does not respond tothewa rning,
th eBeginning emergency stop message appears
in the Instrument Displa y.Ifth e driver still does
not respond, Active Distance Assist DISTRONIC
re duces the speed. The vehicle is decelerated in
stages toa standstill.
Depending on the countr y,at speeds below
60 km/h the hazard warning lights switch on
automaticall y.
When theve hicle is stationar y,thefo llowing
actions are car ried out:
R The vehicle is secured with the electric par k-
ing brake.
R Active Distance Assist DISTRONIC is ended.
R The vehicle is unloc ked.
R If possible, an emer gency call is placed tothe
Mercedes-Benz eme rgency call centre.
The driver can cancel the deceleration at any time
by per form ing one of thefo llowing actions:
R Steering R
Braking or accelerating
R Deactivating Active Distance Assist
DISTRONIC A A
ctiv
ctiv e Br
e Br ak
ake Assist
e Assist F
F
unction of A
unction of A ctiv
ctive Br
e Br ak
ake Assist
e Assist
Ac tive Brake Assist consists of thefo llowing func-
tions:
R Distance warning function
R Autonomous braking function
R Situation-dependent braking assistance
R V
Vehicles wit
ehicles wit h Dr
h Driving Assist
iving Assist ance P
ance Pack
ackag
age:
e: Eva-
sive Steering Assist and cornering function
Ac tive Brake Assist can help youto minimise the
ri sk of a collision with vehicles, cyclists or pedes-
trians or toreduce the e.ects of such a collision.
If Ac tive Brake Assist has de tected a risk of colli-
sion, a warning tone sounds and theL dis-
ta nce warning lamp lights up in the inst rument
cluster. V V
ehicles wit ehicles wit h PRE-S
h PRE-SAFE
AFE®
®
:
:depending on the coun-
tr y, an additional haptic warning occurs in the
fo rm of slight, repeated tensioning of the seat
belt.
If yo u do not react tothewa rning, autonomous
braking can be initiated in critical situations.
In especially critical situations, Active Brake Assist
can initiate autonomous braking directl y.In this
case, thewa rning lamp and warning tone occur
simultaneously with the braking application.
If yo u apply the brake yourself in a critical situa-
tion or apply the brake during autonomous brak-
ing, situation-dependent braking assistance
occurs. The brake pressure increases up tomaxi-
mum full-s top braking if necessar y.
Obser vethe no tes on driving systems and your
re sponsibility; you may otherwise failto recognise
dangers (/ page 223). 244 244
Driving and parking