ECU MERCEDES-BENZ A-CLASS HATCHBACK 2018 Service Manual

*
NO
TEDama gefrom auto matic braking If one of
thefo llowing functions is switched
on, theve hicle brakes automatically in cer‐
ta in situations:
R Active Brake Assi st
R Active Dis tance Assi stDISTRONIC
R HOLD function
R Active Parking Assist
To avo id damage totheve hicle, deactivate
th ese sy stems in thefo llowing or similar sit‐
uations: #
During towing #
In a car wash Re
quirements:
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 engine is running or has been au tomati‐
cally switched off bythe ECO start/ stop
function. R
The electric parking brake is released.
R Active Dis tance Assi stDISTRONIC is deacti‐
va ted.
R The transmission is in position h,kori.
Ac tivating the HOLD function #
Dep ress the brake pedal and af ter a short
time quickly depress fur ther until theë
display appears in the multifunction displa y. #
Release the brake pedal.
Deactivating the HOLD function #
Depress the accelerator pedal topull away.
or #
Depress the brake pedal until theë dis‐
play disappears from the multifunction dis‐
pla y.
The HOLD function is deactivated in thefo llow‐
ing situations:
R Active Dis tance Assi stDISTRONIC is acti va‐
te d.
R The transmission is switched toposition j.R
The vehicle is secured with the electric park‐
ing brake.
In thefo llowing situations, theve hicle is held by
th e transmission position jorby the electric
parking brake:
R The seat belt is unfas tened and the driver's
door is opened.
R The drive sy stem is switched off.
R There is a malfunction in the sy stem or the
po we r supp lyis insuf ficient. St
art-off assi st Fu
nction of thest art-off assi st
The start-off assist enables optimal vehicle
acceleration from a standstill. Forth is, a suitably
high-grip road sur face is requ ired, the tyres and
ve hicle must also be in good condition.
Do not activate thest art-off assist on public
ro ads.
Be sure toobser vethe saf ety no tes and informa‐
tion on ESP ®
. Driving and parking
213

of
fatigue or increasing lapses in concentration
on the part of the driver, it suggests taking a
brea k.
AT TENTION ASSIST is only an aid. It cannot
alw ays de tect fatigue or increased lapses in con‐
centration in time. The sy stem is not a substitute
fo r a well-res ted and attentive driver. On long
journe ys,ta ke regular breaks in good time that
allow for adequ aterecuperation.
Yo u can choose between two settings.
R Standard: normal sy stem sensitivity.
R Sensitive: higher system sensitivity. The
driver is warned earlier and the attention
le ve l de tected byATTENTION ASSIST is adap‐
te d according ly.
If dr owsiness or increasing lapses in concentra‐
tion are de tected, theATTENTION ASSIST: Take
a break! warning appears in the Instrument Dis‐
pla y.Yo u can ackn owledge the message and
tak e a break if necessar y.Ifyo u do not take a
break and ATTENTION ASSIST continues to
de tect increasing lapses in concentration, you
will be warned again af ter a minimum of
15 minutes. Yo
u can ha vethefo llowing status information for
AT TENTION ASSIST displa yed in the assis tance
menu of the on-board computer:
R The length of the journey since the last
break.
R The attention le vel de term ined byATTENTION
ASSIS T:
- the fuller the circle, the higher the atten‐
tional le vel de term ined
- asyour attention wanes, the circle in the
centre of the display becomes smaller If
AT TENTION ASSIST is unable tocalculate the
attention le vel and cannot issue a warning, the
System suspended messageappears.
If a warning is given in the Instrument Displa y,
th e multimedia sy stem of fers to sear chfor a rest
area. You can select a rest area and start naviga‐
tion tothis rest area. This function can be activa‐
te d and deactivated in the multimedia sy stem.
If AT TENTION ASSIST is deactivated, theé
symbol appears in the assis tance graphic in the
Instrument Display when the engine is running.
AT TENTION ASSIST is activated automatically
when the engine is re-sta rted. The last selected
sensitivity le velre mains stored.
Sy stem limitations
AT TENTION ASSIST is active in the 60 km/h to
200 km/h speed range.
The functionality of ATTENTION ASSIST is
re stricted, and warnings may be dela yed or not
occur at all in thefo llowing situations:
R Ifyo u ha vebeen driving for less than appr ox‐
imately 30 minutes. 232
Driving and parking

#
Alw ays be sure the ball neck is engaged
when folding in wards. Re
quirements:
R The transmission has been shif tedto posi‐
tion jori.
R The range of mo vement is clear.
R When folding in onl y:trailer cables or
adap ter plugs ha vebeen remo ved. Fo
lding the ball neck out #
Pull release switch 2until the ball neck
unloc ks.
The ball neck folds out from under there ar
bumper.
Indicator lamp 1flashes. #
Pull the ball neck in the direction of the
ar row until it en gage s audibly in a vertical
position.
Indicator lamp 1onthe ball neck release
switch goes out.
If th e ball neck is not securely loc ked in
place, theTrailer coupling Check lock display
message appears on the multifunction dis‐
pla y. Driving and pa
rking 243

#
Remo vethe co ver from the ball head and
st ore it in a safe place.
Make sure that the ball of the ball neck is clean.
Check that it is either greased or dr y (grease
free), depending on the instructions forthe
traile r.
Fo lding the ball neck in #
Pull release switch 2until the ball neck
unloc ks.
The ball neck folds up under there ar
bumper.
Indicator lamp 1flashes. #
Push the ball neck in the direction of the
ar row until it en gage s audibly behind the
bumper.
Indicator lamp 1goes out and the message
on the multifunction display disappears.
Obser vethe information on the displa yson the
instrument clus ter:
R Warning and indicator lamps (→ page548)
R Displ aymessa ges (→ page 498) Coupling up/uncoupling a trailer
Re
quirements:
R the ball neck must be extended and engaged
in the securely loc ked position
Tr ailers with a 7-pin plug can be connec tedto
th eve hicle with thefo llowing adap ters:
R adap ter plug
R adapte r cable
The trailer will be cor rectly de tected bytheve hi‐
cle only if thefo llowing conditions are me t:
R the trailer is connected cor rectly
R the trailer lighting sy stem is in working order
The functions of thefo llowing sy stems are af fec‐
te dby a cor rectly connected traile r:
R Active Lane Keeping Assist
R ESP ®
trailer stabilisation
R Parking Assist PARKTRONIC
R Active Parking Assist
R Blind Spot Assist or Active Blind Spot Assi stCoupling up a trailer
* NO
TEDama getotheve hicle battery due
to full dischar ge Charging
the trailer battery using the po wer
supply of the trailer can damage theve hicle
batter y. #
Do not use theve hicle's po wer supply
to charge the trailer batter y. #
Remo vethe co ver from the ball head and
st ore it in a safe place (→ page101). #
Position the trailer on a le vel sur face behind
th eve hicle and couple it up totheve hicle. 244
Driving and pa rking

#
Open the soc ket cap. #
Inse rtthe plug with lug 1in groo ve3 on
th e soc ket. #
Turn bayonet coupling 2clockwise as far as
it will go. #
Let the cap engage. #
Secure the cable tothe trailer with cable ties
(only if you are using an adap ter cable). #
Make sure that the cable is alw ays slack for
ease of mo vement during cornering.
A display messa gemay appear on the multifunc‐
tion display even if the trailer has been connec‐
te d cor rectly:
R LEDs ha vebeen ins talled in the trailer light‐
ing sy stem
R The cur rent has fallen below the trailer light‐
ing sy stem's minimum cur rent (50 mA).
% Accessories can be connected tothe perma‐
nent po wer supp lyup to180W, and tothe
po we r supp lythat is swit ched on via the igni‐
tion loc k. Un
coupling a trailer &
WARNING Risk of being crushed and
becoming trapped when uncoupling a
trailer
When uncoupling a trailer wi than engaged
ine rtia-activated brake, your hand may
become trapped between theve hicle and the
trailer dr awbar. #
Do not uncouple trailers with an
engaged overrun brake. #
Secu rethe trailer against rolling away. #
Disconnect the electrical connection
between theve hicle and the trailer. #
Uncouple the trailer. #
Place the co ver on the ball head. Bicycle
rackfunction &
WARNING Risk of an accident when
using the bicycle rack incor rectly
The bicycle rack may become de tach ed from
th eve hicle in thefo llowing cases:
R the permissible load capacity of the
trailer hitch is exceeded.
R the bicycle rack is used incor rectl y.
R the bicycle rack is secured tothe ball
neck beneath the ball head.
Obser vethefo llowing foryo ur ow n sa fety
and that of other road users: #
always adhere tothe permissible load
capacity of the trailer hitch. #
only use the bicycle rack totranspo rt
bicycles. #
always proper lysecure the bicycle rack
by attaching it tothe ball head. #
only use bicycle rack s appr ovedby
Mercedes-Benz. Driving and parking
245

R
always distribute the load on the bicycle rack
as eve nly as possible across theve hicle's
longitudinal axis
Mercedes-Benz recommends removing all
de tach able parts from bicycles, e.g. bask ets,
ch ild seats or rech arge able bat teries, before
loading them onto the bicycle rack . This
impr ovesth e wind resis tance and centre of gr av‐
ity of the bicycle rack.
Alw ays secure the bicycles topreve ntthem from
moving around and check they are secured at
re gular inter vals.
Do not use tarp aulins or other co vers. The driv‐
ing characteristics and rear view may be
impaired. In addition, the wind resis tance and
load on the trailer hitch increase. Distribution of
the load on the bicycle rack
1 Vertical dis tance between centre of gr avity
and ball head
2 Horizon tal dis tance between centre of gr av‐
ity and ball head
3 The centre of gr avity is on theve hicle's
centre axis Obser
vethefo llowing information when
loading the bicycle rack: Nu
mber
of bicy‐
cles To
tal
we ight
of bicy‐
cle rack
and load Max. dis‐
tance
1 1Max. dis‐
tance
2 2
3U pto
75 kg 420 mm 300 mm Ve
hicle towing instructions
The vehicle is not suitable forth e use of tow- bar
sy stems, which are used forflat towing or ding hy
to wing, forex ample. Attach ing and using tow- bar
sy stems can lead todamage on theve hicle.
When towing a vehicle with tow- bar sy stems,
safe, dynamic driving behaviour of theto wing
ve hicle and theve hicle being towe d is not guar‐
anteed. The vehicle-trailer combination can
swer vefrom side toside. Comply with the per‐
mitted towing me thods (→ page449) and the
instructions forto wing with bo thaxles on the
ground (→ page 450). Driving and parking
247

Using
this function, a tablet PC or no tebook
can be connec ted, forex ample. The connec‐
te d device can use the data tariff of theve hi‐
cle. A maximum of thre e devices can be con‐
nected with the hotspot at the same time.
% The use of theve hicle data tariff by extern al
devices is not available in all countries.
To estab lish a connection, you can use thefo l‐
lowing me thods:
R WPS PIN
The connection toa secure Wi-Fi network is
made via a PIN.
R WPS PBC
The connection toa secure Wi-Fi network is
made bypressing a button (push button).
R Security key
The connection toa secure Wi-Fi network is
made via a secu rity key.
Setting up Wi-Fi
Requ irements:
R The device tobe connec ted supports one of
th eth re e means of connection described. Multimedia sy
stem:
, © .
Settings .
System .
Wi-Fi &
Bluetooth
Switching on Wi-Fi #
Select Wi-Fi.
The Wi-Fi is switched on and you can con‐
nect the multimedia sy stem with extern al
hotspots.
Swit ching off Wi-Fi #
Select Settings . #
Deactivate Wi-Fi.
If Wi-Fi is deactivated, communication via Wi-
Fi to all devices is inter rupte d. This also
means that a connection tothe communica‐
tion module cann otbe es tablished. Then
some functions such as dynamic route guid‐
ance with Live Traf fic Information are not
av ailable.
Connecting the multimedia sy stem with a
new device via Wi-Fi
This function is available if a communication
module is not ins talled. The type of connection es
tablished must be
selected on the multimedia sy stem and on the
device tobe connec ted.
% The connection procedure may dif fer
depending on the device. Follow the instruc‐
tions that are shown in the displa y.Fu rther
information (see the manufacturer's operat‐
ing instructions). #
Select Connect via Wi-Fi. #
Select Add hotspot.
Connecting using a security key #
Select the options rofthe desired Wi-Fi
networ k. #
Select Connect using security key . #
Have the security key displa yed on the device
to be connec ted (see the manufacturer's
operating instructions). #
Ente rth is security key on the multimedia sys‐
te m. #
Confirm the entry with¡.
% All devices support a security key as a
means of connection. 314
MBUX multimedia sy stem

Connecting using a WPS PIN
#
Select the options rofthe desired Wi-Fi
networ k. #
Select Connect using WPS PIN input .
The multimedia sy stem generates an eight-
digit PIN. #
Enter this PIN on the device tobe connec ted. #
Confirm the entry.
Connecting using a but ton#
Select the options rofthe desired Wi-Fi
networ k. #
Select Connect via WPS PBC .#
Select "Connect via WPS PBC" in the options
on the device tobe connec ted (see the man‐
ufacturer's operating instructions). #
Press the WPS button on the device tobe
connec ted. #
Select Continue inthe multimedia sy stem.
Ac tivating automatic connection #
Select Connect via Wi-Fi . #
Select the options rofthe desired Wi-Fi
networ k. #
Activate Permanent Internet connection .
Connecting with a known Wi-Fi #
Select Connect via Wi-Fi . #
Select a Wi-Fi networ k.
The connection is es tablished again.
Setting up a Wi-Fi hotspot
Multimedia sy stem:
, © .
Settings .
System .
Wi-Fi &
Bluetooth
Configuring the multimedia sy stem as a Wi-
Fi hotspot
The type of connection es tablished depends on
th e device tobe connec ted. The function must
be suppor tedby the multimedia sy stem and by
th e device tobe connec ted. The type of connec‐
tion es tablished must be selected on the multi‐
media sy stem and on the device tobe connec‐
te d. #
Select Vehicle hotspot. #
Select Connect device to vehicle hotspot .Connecting using WPS PIN
generation #
Select Connect using WPS PIN generation. #
Ente rth e PIN shown in the media display on
th e device tobe connec ted and con firm.
Connecting using WPS PIN entry #
Select Connect using WPS PIN input. #
Enterth e PIN that is shown on theex tern al
device's display on the multimedia sy stem.
Connecting using a button #
Select Connect via WPS PBC. #
Press the push button on the device tobe
connec ted (see the manufacturer's operating
instructions). #
Select Continue.
Connecting using a security key #
Select Connect device to vehicle hotspot .
A secu rity key is displa yed. #
Select theve hicle from the device tobe con‐
nec ted. The vehicle is displa yed with theMB
Hotspot XXXXX network name. MBUX multimedia sy
stem 315

#
Enter the security key which is shown in the
media display on the device tobe connec ted. #
Confirm the entry.
Connecting using NFC #
Select Connect via NFC. #
Activate NFC on the mobile device (see the
manufacturer's operating instructions). #
Bring the mobile device into the NFC area of
th eve hicle (→ page372). #
Select Finished.
The mobile device is now connected tothe
multimedia sy stem hotspot via NFC.
Generating a new security key#
Select Vehicle hotspot. #
Select Generate security key .
A connection will be es tablished with the
newly crea ted security key. #
Tosave a security key:select Save.
When a new security key is sa ved, all existing
Wi -Fi connections are then disconnected. If
th eWi -Fi connections are being re-es tab‐
lished, the new security key must be en tere d. Sy
stem language Note
s onthe sy stem language
This function allo wsyouto determ ine the lan‐
guage forth e menu displa ysand the navigation
announcements. The selected language af fects
th ech aracters available for entr y.The navigation
announcements are not available in all lan‐
guages. If a language is not available, the naviga‐
tion announcements will be in Engl ish.
Setting the sy stem language
Multimedia sy stem:
, © .
Settings .
System .
Lan-
guage #
Set the language.
% Ifyo u are using Arabic map data, thete xt
information can also be shown in Arabic on
th e navigation map. Todo so, select 

Fu
rther information about software updates can
be found at http://me.mercedes-benz.com
Pe rforming a software upda te
Re quirements:
R For online updates: an Internet connection
is es tablished (→ page 396).
R For automatic online updates: your vehicle
has a permanently installed communication
module.
Multimedia sy stem:
, © .
Settings .
System .
Soft-
ware update
Au tomatically #
Activate Automatic online updates.
The upda tes will be downloaded and ins talled
automaticall y.
The cur rent status of the updates is dis‐
pla yed.
Manually #
Deactivate Automatic online updates. #
Select an update from the list and start the
update.
Ac tivating the so ftwa reupdate #
Restart the sy stem.
The modifications from the software update
will be active.
Fu nction of important sy stem upda tes
Impor tant sy stem updates may be necessary for
th e security of your multimedia sy stem's data.
Ins tallth ese updates, or else the security of your
multimedia sy stem cann otbe ensured.
% If automatic software updates are activated,
th e sy stem updates will be downloaded auto‐
matically (→ page319).
As soon as an upda teisavailable for download,
a cor responding message appears onthe media
displa y.
Yo u ha vethefo llowing selection options:
R Accept and install
The update will be downloaded in the back‐
ground.
R Information Information about
the pending sy stem
update is displa yed.
R Later
The update can be downloaded manually at a
later time (→ page319).
Dee p sy stem upda tes
Deep sy stem updates access vehicle or sy stem
settings and can therefore only be car ried out
when theve hicle is stationary and the ignition is
switched off.
If th e download of a deep sy stem update is com‐
ple ted and the update is ready for ins tallation,
yo u will be informed of this af terth e next igni‐
tion cycle, forex ample.
% Park theve hicle safely in a suitable location
before starting the ins tallation.
Re quirements forth e ins tallation:
R The ignition is switched off.
R Notes and warnings ha vebeen read and
accep ted.
R The elect ric pa rking brake is applied. MBUX multimedia sy
stem 319