2021 MERCEDES-BENZ B-CLASS HATCHBACK key battery

K
K
e
ey
y Ov
Ov
er
ervie
vie w of ke
w of key functions
y functions &
W
W ARNING
ARNING Risk of accident and inju rydue
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. *
N
NOOTE
TE Damage totheke y caused bymag-
netic /elds #
Keep theke yaw ay from strong magnetic
/elds. Ve
hicle key
1 Locks
2 Indicator lamp 3
Unloc ks
4 Opens/closes theta ilgate
% If indicator lamp 2does not light up aTer
pressing theÜ orß button, the battery
is we ak or possibly dischar ged. Re place the
battery as soon as possible.
Re place theke y battery (/ page 83).
The key loc ksand unloc ksthefo llowing compo-
nents:
R Doors
R Fuel /ller 0ap
R Soc ket 0ap (plug-in hybrid)
R Tailgate
If th eve hicle is not opened within appr oximately
40 seconds aTer unlocking, it loc ksagain. Anti-
th eT pr otection is primed again.
Do not keep theke yto get her with elect ronic devi-
ces or me tal objects. This can a.ect theke y's
functionalit y. Opening and closing
81 81

R
R
emo
emo ving/inser
ving/inser ting t
ting the emerg
he emerg encykey
ency key R R
emo emo ving t
ving t he emerg
he emerg encykey
ency key #
Press release button 1.
Emer gency key2 is pushed out slightl y.#
Pull out eme rgency key2 until it en gage s in
th e intermediate position. #
Press release button 1again and fully
re mo veemer gency key2.
Inser
Inser ting t
ting t he emerg
he emerg encykey
ency key #
Press release button 1. #
Insert emer gency key2 tothe intermediate
position or fully until it engages. %
You can use the intermediate position of
emer gency key2 toattach theke yto akey
ri ng. R
R
eplacing t
eplacing t heke
he key batt
y batt ery
ery &
D
DAN
AN GER
GER Risk of fatal injuries due toswal-
lowing batteries
Bat teries contain toxic and cor rosive subs tan-
ces. Swall owing batteries may cause se vere
internal burns tooccur within two hours.
There is a risk of fatal injur y. #
Keep batteries out of there ach of chil-
dren. #
Ifth e cap and/or the battery compart-
ment does not close securel y,do not use
th eke y any lon ger and keep it out of the
re ach of children. #
If batteries are swallo wed, seek medical
attention immediatel y. +
ENVIR
ENVIR ONMENT
ONMENT AL NO
AL NOTE
TEEnvironmen tal
damage due toimproper disposal of bat-
te ries Batteries contain pollutants. It is
illegal todispose of them with the household
ru bbish. #
Dispose of batteries in an
environmentally responsible manner.
Ta ke dischar ged batteries toaqu ali/ed
specialist workshop or toa collection
point for used batteries. R
R
eq
eq uir
uir ements:
ements:
R Youre qu ire a CR 2032 3 V cell batter y.
Mercedes-Benz recommends that you ha vethe
battery replaced at a quali/ed specialist work-
shop. #
Remo vethe emer gency key (/ page 83). Opening and closing
83
83

#
Press release knob 2down fully and slide
co ver1 inthe direction of the ar row. #
Fold out co ver1 inthe direction of the ar row
and remo ve. #
Remo vebattery compartment 3and take
out the dischar ged batter y. #
Insert the new battery into battery compart-
ment 3. Obser vethe positive pole marking in
th e battery compartment and on the battery
when doing this. #
Push in battery compartment 3.#
Re-attach co ver1 and push it until it
engages. Pr
Pr
oblems wit
oblems wit h t
h the key
he key , tr
, troubleshoo
oubleshoo ting
ting Y Y
ou can no long ou can no long er loc
er lock or unloc
k or unloc k t
k the v
he v ehicle
ehicle
Po ssible causes:
R The key battery is weak or dischar ged. #
Check the battery using the indicator lamp
(/ page 81). #
Replace theke y batter y,if necessary
(/ page 83). #
Use there placement key. #
Use the emer gency keyto lock or unlock
(/ page 88). #
Have theke ych ecked at a quali/ed specialist
wo rkshop.
Ther
Ther e is int
e is int erf
erfer
erence fr
ence fr om a pow
om a pow er
erful r
ful r adio signal
adio signal
sour sour ce ce
Po ssible causes if the function of theke y is
impaired:
R high voltage po wer lines
R mobile phones
R electronic devices (no tebooks, tablets) R
shielding due tome tal objects or induction
loops for electrical gate systems or automatic
bar riers #
Make sure that there is su1cient distance
between theke y and the po tential sou rce of
inter fere nce.
Y
Y ou hav
ou hav e los
e lost a key
t a key #
Have theke y deactivated at a quali/ed spe-
cialist workshop. #
If necessar y,ha ve the mechanical lock
re placed as well. Doors
Doors
N
No
ot
tes on t
es on t he additional door lock
he additional door lock The additional door lock is only
available forve hi-
cles forth e United Kingdom. 84
84
Opening and closing

%
Further information on con venience closing
(/ page 97).
If yo u open theta ilgate from outside, it is auto-
matically unloc ked. Pr
Pr
oblems wit
oblems wit h KEYLESS-GO, tr
h KEYLESS-GO, tr oubleshoo
oubleshooting
ting Y
Y
ou can no long
ou can no long er loc
er lock or unloc
k or unloc k t
k the v
he v ehicle using
ehicle using
KEYLESS-GO
KEYLESS-GO
Po ssible causes:
R The function of theke y has been deactivated.
R The key battery is weak or dischar ged. #
Activate the function of theke y (/ page 82). #
Check the battery using the indicator lamp
(/ page 81). #
Replace theke y batter y,if necessary
(/ page 83). #
Use there placement key. #
Use the emer gency keyto lock or unlock
(/ page 88). #
Have theve hicle and keych ecked at a quali-
/ed specialist workshop. Ther Ther
e is int
e is int erf
erfer
erence fr
ence fr om a pow
om a pow er
erful r
ful r adio signal
adio signal
sour
sour ce
ce
Po ssible causes if the function of KEYLESS-GO is
impaired:
R high voltage po wer lines
R mobile phones
R electronic devices (no tebooks, tablets)
R shielding due tome tal objects or induction
loops for electrical gate systems or automatic
bar riers #
Make sure that there is su1cient distance
between theke y and the po tential sou rce of
inter fere nce. A
A
ctiv
ctiv ating/deactiv
ating/deactiv ating t
ating the aut
he automatic loc
omatic loc king f
king fea-
ea-
ture
ture The
vehicle is loc ked automatically when theve hi-
cle is switched on and the wheels are turning
fa ster than walking pace. #
T To activ o activ at
ate:
e: press and hold button 2for
appr oximately /ve seconds until an acoustic
signal sounds. #
T To deactiv
o deactiv at
ate:
e: press and hold button 1for
appr oximately /ve seconds until an acoustic
signal sounds.
The red indicator lamp on button 2lights up
once theve hicle is loc ked. Opening and closing
87 87

A side windo
A side windo
w canno
w canno t be closed and y
t be closed and y ou cannot
ou cannot
see t
see t he cause.
he cause. #
Che cktosee whe ther any objects are in the
wind owguide. #
Adjust the side windo ws.
A
A djus
djus ting t
ting t he side window
he side window s
s
If a side window is obstructed during closing and
re opens again immediatel y:#
Immediately aTer this, pull and hold the cor re-
sponding button again until the side window
has closed and hold the button for at least one
more second (re-adjustment).
The side window will be closed without the
automatic reve rsing function.
If th e side window is obstructed again and
re opens again immediatel y:#
Immediately aTer this, pull and hold the cor re-
sponding button again until the side window
has closed and hold the button for at least one
more second (follo w-up adjustment).
The side window will be closed without the
automatic reve rsing function. The side window The side window
s canno
s cannot be opened or closed
t be opened or closed
using t
using t he conv
he conv enience opening f
enience opening f eatur
eatur e.
e.
Po ssible causes:
R The key battery is weak or dischar ged. #
Check the battery using the indicator lamp
(/ page 81). #
Replace theke y batter y,if necessary
(/ page 83). Sliding sunr
Sliding sunr
oof
oof Opening and closing t
Opening and closing t
he sliding sunr
he sliding sunroof
oof %
The term "sliding sunroof" also refers to the
panorama sliding sunroof. &
W
WARNING
ARNING Risk of becoming trapped when
th e sliding sunroof is being opened and
closed
Body parts may become trapped in thera nge
of mo vement. #
During opening and closing, make sure
th at no body parts are in thera nge of
mo vement. #
Release the button immediately if some-
body becomes trapped.
or #
Brie0y press the button in any direction
during automatic operation.
The opening or closing process will be
stopped. &
W WARNING
ARNING Risk of entrapment if the slid-
ing sunroof is operated bychildren
Children operating the sliding sunroof could
get caught in the moving parts, particular lyif
unattended. #
Never lea vechildren unattended in the
ve hicle. #
When leaving theve hicle, alw aysta ke the
ke y with you and lock theve hicle. 98
98
Opening and closing

It is possible
tomake use of there sidual heat
from the engine tocontinue heating or ventilating
th e front compartment of theve hicle for appr ox-
imately 30 minutes, depending on thete mp era-
ture set. #
T To activ o activ at
ate:
e: press the 0056 button.
Re sidual heat will be switched o. automaticall y.Pr
Pr
e-entr
e-entr y climat
y climat e contr
e control using t
ol using t hekey
he key F
F
unction of pr
unction of pr e-entr
e-entry climat
y climat e contr
e control using t
ol using t he
he
key
key
Before entering theve hicle, the driver's seat area
or the whole vehicle interior can be brie0y pre-
wa rmed or pre-cooled.
When pre-cooling, thefo llowing functions are acti-
va ted as needed:
R Automatic climate control
R Blower
R Seat ventilation
When pre-heating, thefo llowing functions are acti-
va ted as needed:
R Automatic climate control R
Blower
R Seat heater
R Steering wheel heater
R Mirror heater
R Rear wind owheater
Se
Se tting pr tting pr e-entr
e-entry climat
y climat e contr
e control via t
ol via thekey
he key
Multimedia system:
4 Climate menu 5
Pre-entry climate ctrl
Switc
Switc hing
hingon/o.
on/o. #
Select Z. #
Select Pre-entry climate control via key.
Switc Switc hing pr hing pr e-entr
e-entry climat
y climat e contr
e control via t
ol via thekey
he key
on/o.
on/o.
R R eq
eq uir
uir ements:
ements:
R The high-voltage battery is charge d su1-
cient ly.
R The function has been activated via the multi-
media system. #
T
To switc
o switc h on:
h on: unlock theve hicle.
The climate cont rol functions are activated for
up to/ve minutes for pre-heating and pre-
cooling.
Pre-entry climate control via theke y cann otbe
activated more than twice when theve hicle is
switched o.. #
T
To switc
o switc h
h o.:
o.: push the003B button up or
down.
The following functions will remain active once the
ve hicle has been star ted:
R Seat heating
R Seat ventilation 160
160
Climate cont
rol

Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/consequences and uences and0050
0050Solutions
Solutions
PRE-SAFE inoperative See
Owner's Manual *
The PRE‑SAFE ®
functions are malfunctioning. #
Consult a quali/ed specialist workshop. K K
e
ey
y Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/conseq uences and
uences and0050
0050Solutions
Solutions
Á
Replace key *H
aveth eke yre placed. #
Consult a quali/ed specialist workshop.
Á
Change key batteries *T
hekey battery is dischar ged. #
Replace the battery (/ page 83). Display messages and
warning/indicator lamps
417
417

Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/consequences and uences and0050
0050Solutions
Solutions
003B
Pre-entry climate control
(via key) available again
after engine start *Y
ou ha veattem pted toswitch on pre-ent ryclimate cont rol more than twice with theve hicle switched o.. #
Start theve hicle forte n seconds.
Pre-entry clima tecont rol is operational again.
003B Pre-entry climate control
(via key) inoperative HV-
battery low *T
hecharge ofthe high-voltage battery is too lo w.Pre-entry clima tecont rol cannot be switched on. #
Char gethe high-voltage batter y.
When the high-voltage battery is su1ciently charge d, pre-ent ryclimate cont rol will be operational again. Display message
s andwarning/indicator lamps
425 425