change key battery MERCEDES-BENZ A-CLASS SALOON 2018 Owners Manual

Problem
Possible causes/consequences and M
MSolutions
R The key is faulty. #
Check the battery using the battery check lamp and replace if necessary (/ page75). #
Use the emer gency keyto lock or unlock (/ page75). #
Have theke ych ecked at a qualified specialist workshop.
Yo u ha velost a key. #
Have theke y deacti vated at a qualified specialist workshop. #
If necessar y,ha ve the mechanical lock changed as well. Doors
Note
s onthe additional door lock The additional door lock is only
available for
ve hicles forth eUni ted Kingdom. &
WARNING Risk of inju ryto persons
inside theve hicle when the additional
door lock is activated
If th e additional door lock is activated, the
doors can no longer be opened from the
inside. If
th ere are persons in theve hicle, they can
no longer le aveth eve hicle, e.g. in hazardous
situations. #
Never lea vepersons unattended in the
ve hicle, particularly children, elderly
persons or persons in need of help. #
Ifth ere are persons in theve hicle, do
not activate the additional door loc k. The additional door lock is automatically activa‐
te d in thefo llowing situations:
R The vehicle is loc ked using thekey. R
The vehicle is loc ked using KEYLESS-GO.
If th eve hicle has been loc ked via Mercedes me
connect, the additional door lock is not activa‐
te d.
If th e additional door lock is activated, the doors
cann otbe opened from the inside.
% After locking you can issue a signal with the
horn.
Yo u can pr eventthe additional door lock from
being activated bydeactivating interior pr otec‐
tion before locking theve hicle (/ page 96). Opening and closing
77

Display messages
Possible causes/consequences and M
MSolutions
If th eke y de tection function has a malfunction due toast ro ng radio signal source: #
Pull over and stop theve hicle safely as soon as possible, paying attention toroad and traf fic conditions. #
Place theke y in the slot forst arting the engine with theke y (/ page157).
Á
Replace key *T
hekey needs tobe replaced. #
Consult a qualified specialist workshop.
Á Key not detected (white
display message) *T
hekey is cur rently und etected. #
Change the location of theke y in theve hicle. #
Ifth eke y is still not recognised, start the engine with theke y in the slot (/ page157).
Á Cha nge key batteries *T
hekey bat tery is dischar ged. #
Replace the battery (/ page75).
Á *T
hekey de tection function is malfunctioning. #
Change the location of theke y in theve hicle. #
Start theve hicle with theke y in the slot (/ page157). 550
Displaymessa ges and warning/indicator lamps

Ac
tive Steering Assist cur rently
una vailable See Owner's Manual .........525
Ac tive Steering Assist inoperative .......524
Ad aptive Highbeam Assist cur rently
una vailable See Owner's Manual .........559
Ad aptive Highbeam Assist inopera‐
tive ...................................................... 559
Ad aptive Highbeam Assist Plus cur‐
re ntly una vailable See Owner's Man‐
ual ...................................................... .560
Ad aptive Highbeam Assist Plus inop‐
erative ................................................ .560
¯ AdBlue sy stem fault Engine
st art not possible ................................ 539
¯Ad Blue system fault Perf.
re duced in XXX miles See Owner's
Manual ................................................ 538
¯ AdBlue sy stem fault Perf.
re duced: XXX km/h Nostart in XXX
km ...................................................... .538 ¯
AdBlue sy stem fault See Own‐
er's Manual ........................................ .538
4Ad d 1 litre engine oil when next
re fuelling ............................................. 536
Anti-theft ala rmsystem Malfunction ... 556
Apply brake todeselect Park (P)
position ...............................................5 40
Apply brake toselect R ........................ 543
À ATTENTION ASSIST inoperative ... 526
ÀAT TENTION ASSIS T:Take a
break! .................................................. 525
bAu tomatic driving lights inoper‐
ative .................................................... 559
Au xilia rybattery malfunction ...............541
_ Before starting the engine, turn
th esteering wheel. .............................. 544
Blind Spot Assi stcur rently una vaila‐
ble See Owner's Manual ...................... 523
Blind Spot Assist inope rative ............... 524 Blind Spot Assi
stnot available when
to wing a trailer See Owner's Manual ...5 26
Brake immediate ly............................... 51 0
Á Changekey bat teries .................. 550
JCheck brake fluid le vel................ .515
Check brake pads See Owner's Man‐
ual ...................................................... .523
ïChe cktrailer hitch lo ck(white
display message) .................................5 52
Che cktyre pressu resth en restart
Ru n Flat Indicator ................................ 549
h Check tyre(s) .............................. .546
!Clean the fuel filter ...................... 531
Clutch overheated Avoid pulling away
fo r XX:XX mins .................................... .541
? Coolant Stop vehicle Switch
engine off ............................................ 534
Cruise contro l and Limiter inope ra‐
tive ...................................................... 529
Cruise control inope rative ................... 529 584
Index