2018 MERCEDES-BENZ A-CLASS SALOON engine

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

Display messages
Possible causes/consequences and M
MSolutions
Place the key in the
marked space See Owner's
Manual
À
Replace key See Owner's
Manual *
Ve hicles with a digital vehicle key:only a few or no authorisations remain forst arting the engine. #
Make sure that the internet connection is not limited bycer tain mobile phone settings. #
Open the Mercedes me connect http://www.mercedes.me and call up the digital vehicle key service. #
Deactivate the service firs t and then activate it again. #
Ifth e display message still appears, con tact the Mercedes-Benz Cus tomer Assis tance Center (C AC).
Ve hicles with a digital vehicle keyst icke r:on lyafe w or no authorisations remain forst arting the engine. #
Order a new digital vehicle keyst icke r from a Mercedes-Benz Service Centre or at http://www.mercedes-
benz.com/connect. Ve
hicle Display messages
Possible causes/consequences and M MSolutions
ï Operation only possible in
transmission position N *
Ve hicles with manual transmission: you attem ptedto swivel the ball neck and the transmission is not in neutral
i. #
Shift the transmission toneutral i. Display messa
ges and warning/indicator lamps 551

Display messages
Possible causes/consequences and M
MSolutions
ï Check trailer hitch lock
(white display message) *T
he trailer tow hit chis not operational when you are driving with a trailer. #
Stop theve hicle immediately, paying attention toroad and traf fic conditions, and switch off the engine. #
Uncouple the trailer and secure it against rolling away. #
Initiate a new swivelling procedure (/ page248). #
Ifth e ball neck is extended, press and hold the button on theta ilgate until the ball neck engages beneath the
bumper. #
When the display message disappears, couple up the trailer and drive on. &
WARNING Risk of an accident if the ball neck is not loc ked
If th e ball neck is not in the loc ked position, the trailer may come loose. #
Pull over and stop theve hicle safely as soon as possible, paying attention toroad and traf fic conditions.
Do not continue driving under any circums tances. #
Uncouple the trailer and secure it against rolling away. #
Initiate a new swivelling procedure and do not re-couple the trailer until the display message disappears. If
th e display message does not disappear, the trailer tow hit chis defective and the ball neck is not loc ked. #
Do not couple up the trailer. Drive on without the trailer. No tethere duced ground clearance due tothe
unlo cked ball nec k. #
Consult a qualified specialist workshop.
The trailer tow hit chis not operational when theve hicle is at a standstill. 552
Display messages and warning/indicator lamps

Display messages
Possible causes/consequences and M
MSolutions
Active bonnet malfunction
See Owner's Manual *T
he active bonnet (pedestrian pr otection) is malfunctioning or inoperative af ter having already been triggered. #
Consult a qualified specialist workshop.
M *T
he bonnet is open. &
WARNING Risk of accident due todriving with the engine bonn etunlo cked
An unloc ked engine bonn etmay open up when theve hicle is in motion and block your vie w. #
Never unlock the engine bonn etwhen driving. #
Before every trip, ensure that the engine bonn etis loc ked. #
Stop theve hicle immediately, paying attention toroad and traf fic conditions. #
Close the bonn et.
C *A
t least one door is open. #
Close all doors.
N *T
he boot lid is open. &
DANG ER Risk of exhaust gas poisoning
Combustion engines emit poisonous exhaust gases such as carbon monoxide. Exhaust gases can enter the
ve hicle interior if the boot lid is open when the engine is running, especially if theve hicle is in motion. #
Alw ays switch off the engine before opening the boot lid. Display messages and
warning/indicator lamps 555

Display messages
Possible causes/consequences and M
MSolutions #
Never drive with the boot lid open. #
Close the boot lid.
Anti-theft alarm system
Malfunction *T
he anti-theft alarm sy stem is malfunctioning. #
Consult a qualified specialist workshop.
¥ Top up washer fluid *T
hewasher fluid le vel in thewa sher fluid reser voir has dropped below the minimum. #
Top up thewa sher fluid (/ page 435). Climate cont
rol Display messages
Possible causes/consequences and M MSolutions
& inoperative See Owner's
Man. *T
hestationary heater is temp orarily malfunctioning. #
When theve hicle is on a le vel sur face and the engine has cooled down, make up tofour attem ptsto switch on
th est ationary heater, waiting se veral minutes between each attem pt. #
Ifth est ationary heater does not swit chon, consult a qualified specialist workshop. 556
Display messages and warning/indicator lamps

Display messages
Possible causes/consequences and M
MSolutions #
Drive on.
Once the cause of the problem is no longer present, the sy stem will be available again. The Adaptive Highbeam
Assist available again display message appears.
Adaptive Highbeam Assist
Plus inoperative *A
daptive Highbeam Assist Plus is faulty. #
Consult a qualified specialist workshop.
Adaptive Highbeam Assist
Plus currently unavailable
See Owner's Manual *A
daptive Highbeam Assist Plus is temp orarily una vailable.
The sy stem limits ha vebeen reached (/ page133). #
Drive on.
Once the cause of the problem is no longer present, the sy stem will be available again. The Adaptive Highbeam
Assist Plus available again display message appears.Wa
rning and indicator lamps Overview of
warning and indicator lamps Some sy
stems will per form a self-test when the
ignition is switched on. Some warning and indi‐
cator lamps may brief lylight up or flash. This
behaviour is non-critical. These warning and indi‐
cator lamps indicate a malfunction only if they
light up or flash af terth e engine has been star‐
te d or during a journe y.560
Display messages and warning/indicator lamps

Instrument display (standard)
Instrument display in
the widescreen cockpit Depending on
the display setting, the positions
of the indicator lamps on the instrument display
may dif fer from theex ample shown.
Wa rning and indicator lamps:
L Low beam (/
page127)
T St
anding lights (/ page127)
K High beam (/
page129)
#! Tu
rn signal indicators
(/ page129)
R Re
ar fog light (/ page127)
6 Re
stra int sy stem (/ page 562)
ü Seat belt not
fastened
(/ page 567)
J Brakes (yellow) (/
page 562)
J Brakes (red) (/
page 562)
! Elect
ric pa rking brake (yellow)
(/ page 562)
! Electric parking brake (red)
(/
page 562) !
ABS malfunction (/
page 562)
÷ ESP®
(/ page 562)
å ESP®
OFF (/ page 562)
L Distance warning (/ page 568)
Ð Po
we r-assis tedsteering malfunction
(/ page572)
; Engine diagnostics (/
page 568)
% Preglow
# Electrical
fault( / page 568)
æ Fu
elreser vewith fuel filler cap loca‐
tion indicator (/ page 568)
? Ve
hicles with widescreen cock pit:
Coolant too hot/cold
(/ page 568)
h Ty
re pressure monitor
(/ page571)
ï Tr
ailer hit chis not operational or is
swivelling (/ page572) Displ
aymessa ges and warning/indicator lamps 561

Saf
ety sy stems Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions
J Brake sy stem warning lamp
(red) The
red brake sy stem warning lamp is lit while the engine is running.
Po ssible causes:
R The brake forc e boosting is malfunctioning and the braking characteristics may be af fected.
R The reis insuf ficient brake fluid in the brake fluid reser voir. &
WARNING Risk of accident and inju ryif brake forc e boosting is malfunctioning
If brake forc e boosting is malfunctioning, increased brake pedal forc e may be necessary for braking. The braking
ch aracteristics may be impaired. The braking dis tance can increase in eme rgency braking situations. #
Stop in a safe location immediately. Do not continue driving! #
Consult a qualified specialist workshop. &
WARNING Risk of an accident due tolow brake fluid le vel
If th e brake fluid le vel is too lo w,the braking ef fect and the braking characteristics may be impaired. #
Stop theve hicle as soon as possible, paying attention toroad and traf fic conditions. Do not continue driving. #
Consult a qualified specialist workshop. #
Do not top up the brake fluid. 562
Display messages and warning/indicator lamps