2018 MERCEDES-BENZ CLA light

Display messages
Possible causes/consequences and P Solutions
The yellow $ warning lamp lights up and th er ed I (US Ao nl y)
or $ (Canada only) indicator lamp flashes .
It is no tp ossibl etoa pply th ee lectric parking brak em anually.X
Shift th et ra nsmission to position E .X
Visit aq ualified specialist workshop .
' (US Ao nl y)
M (Canada only)
Check Brake Fluid
Level There is no te no ugh brak ef lui dint he brak ef luid reservoir .
Aw arning tone sounds. The ' (US Ao nl y) or M (Canada only)
warning lamp sint he instrumen tc luste rm ay also ligh tu p.
G WARNIN G
The braking effec tm ay be impaired.
There is ar is kofana ccident.X
Pull ove ra nd stop th ev ehicl es afely as soo nasp ossible, payin g
attention to roa da nd traffic conditions. Do no tc ontinue drivin g
under any circumstances. X
Secur et he vehicl ea gainst rollin ga way ( Y
page 141).X
Consult aq ualified specialist workshop .X
Do no ta dd brak ef luid .T his does no tc orrect th em alfunction .
& Check Brake Pad Wea r The brak ep ads/linings hav er eached their wear limit.X
Visit aq ualified specialist workshop .
S Inoperative On eorm or em ain features of th em brace system are malfunctioning .X
Visit aq ualified specialist workshop .
Active Brake Assist
Functions Currently
Limite dS ee Opera‐
tor's Manual Active Brake Assis tist em porarily inoperative.
Possibl ec auses are: R
The radar sensor system is temporarily inoperative, e.g. due to
electromagneti cr adiation emitted by nearby TV or radi os ta tion so r
other source sofe lectromagneti cr adiation .R
The system is outside th eo perating temperature range.R
The on-boar dv oltag eist oo low.
Whe nt he causes state da bov enol onger apply, th ed isplay message
disappears.
Active Brake Assis tiso perational again .
If th ed isplay message does no td isappear :X
Pull ove ra nd stop th ev ehicl es afely as soo nasp ossible, payin g
attention to roa da nd traffic conditions.X
Secur et he vehicl ea gainst rollin ga way ( Y
page 141).X
Restart th ee ng ine.
Active Brake
Assist : System Inop‐
erativ e Active Brake Assis tisu navailable due to am alfunction .S ituation -
dependen tb raking assistanc em ay also hav ef ailed.X
Visit aq ualified specialist workshop immediately. Display messages 19 7
On-boar dc omputer an dd isplays Z

Display messages
Possible causes/consequences and P Solutions
Radar Sensor s Dirty
See Operator' sM an ‐
ual The radar sensor system is malfunctioning .
Possibl ec auses are: R
Dirt on sensor sR
Heavy rain or snow R
Whe nd rivin goni nter-urban roads without traffic or infrastructure,
e.g. in desert-like area s
At least on ed rivin gs ystem or drivin gs afet ys ystem is malfunctioning
or is temporarily unavailable :R
Active Brake Assis tR
Distanc eP ilo tD ISTR ONI C
Aw arning tone also sounds.
Once th ec aus eoft he problem is no longer present, th ed rivin ga nd
drive safet ys ystems will be available again .T he display message dis-
appears.
If th ed isplay message does no td isappear :X
Pull ove ra nd stop th ev ehicl es afely as soo nasp ossible, payin g
attention to roa da nd traffic conditions.X
Secur et he vehicl ea gainst rollin ga way ( Y
page 141).X
Switc ho ff th ee ng ine.X
Clean all sensor s( Y
page 265).X
Restart th ee ng ine.
The display message disappears.
u SRS Malfunction Ser ‐
vic eR equired The restrain ts ystem is malfunctioning .T he u warning lamp also
lights up in th ei nstrumen tc luster.
G WARNIN G
The air bags or Emergency Tensioning Devices may either be triggered
unintentionally or, in th ee vent of an accident, may no tbet ri ggered .
There is an increased ris kofi njury.X
Visit aq ualified specialist workshop immediately.
Fo rf urther information about th er estrain ts ystem, see ( Y
page 40) .
u Front Lef tM alfunc‐
tio nS ervic e
Required or Front
Right Malfunction
Servic eR equired The restrain ts ystem is malfunctioning at th ef ront on th el ef torr ight .
The u warning lamp also lights up in th ei nstrumen tc luster.
G WARNIN G
The air bags or Emergency Tensioning Devices may either be triggered
unintentionally or, in th ee vent of an accident, may no tbet ri ggered .
There is an increased ris kofi njury.X
Visit aq ualified specialist workshop immediately.198
Display messages
On-boar dc omputer an dd isplays

Display messages
Possible causes/consequences and P Solutions
u Rea rL ef tM alfunc‐
tio nS ervic e
Required or Rea r
Right Malfunction
Servic eR equired The rear left-han dorr ight-hand restrain ts ystem is malfunctioning .
The u warning lamp also lights up in th ei nstrumen tc luster.
G WARNIN G
The air bags or Emergency Tensioning Devices may either be triggered
unintentionally or, in th ee vent of an accident, may no tbet ri ggered .
There is an increased ris kofi njury.X
Visit aq ualified specialist workshop immediately.
u Lef tS id eC urtai n
Airbag Malfunction
Servic eR equired or
Right Sid eC urtai n
Airbag Malfunction
Servic eR equired The left-han dorr ight-hand window curtai na ir bag is malfunctioning .
The u warning lamp also lights up in th ei nstrumen tc luster.
G WARNIN G
The lef torr ight window curtai na ir bag may either be triggered unin-
tentionally or, in th ee vent of an accident, may no tbet ri ggered .
There is an increased ris kofi njury.X
Visit aq ualified specialist workshop immediately. Display messages 19 9
On-boar dc omputer an dd isplays Z

Display messages
Possible causes/consequences and P Solutions
If th ec onditi on sa re no tf ulfilled ,t he system is no to perating correctly.X
Visit aq ualified specialist workshop immediately.
Fo rf urther information about th eO cc upant Classification System, see
( Y
page 48).
Lights
i Vehicles wit hL ED bulbs in th el igh tc lusters :
The display message for th ec orre spondin gl amp only appear sw hen all of th eL ED sint he lamp
hav ef ailed.
Display messages
Possible causes/consequences and P Solutions
I Check Lef tC orner ‐
ing Light or Check
Right Cornering
Light The lef torr ight-hand cornering ligh tisd efective.X
Chec kw hether you are permitte dtor eplace th eb ulb yourself
( Y
page 104).
or X
Visit aq ualified specialist workshop .
I Check Lef t Low Bea m
or Check Right Low
Bea m The lef torr ight-hand low-beam headlamp is defective. X
Chec kw hether you are permitte dtor eplace th eb ulb yourself
( Y
page 104).
or X
Visit aq ualified specialist workshop .
I Check Rea rL ef t
Tur nS ignal or
Check Rea rR ight
Tur nS ignal The rear left-han dorr ear right-hand tur ns ignal is defective.X
Chec kw hether you are permitte dtor eplace th eb ulb yourself
( Y
page 104).
or X
Visit aq ualified specialist workshop .
I Check Front Lef t
Tur nS ignal or
Check Front Right
Tur nS ignal The fron tl eft-han dorf ront right-hand tur ns ignal is defective.X
Chec kw hether you are permitte dtor eplace th eb ulb yourself
( Y
page 104).
or X
Visit aq ualified specialist workshop .
I Check Lef tM irror
Tur nS ignal or
Check Right Mirror
Tur nS ignal The tur ns ignal in th el eft-han dorr ight-hand exterio rm irror is defec -
tive. X
Visit aq ualified specialist workshop .
I Check Center Brake
Lam p The high-mounte db rak el amp is faulty.X
Visit aq ualified specialist workshop .202
Display messages
On-boar dc omputer an dd isplays

Display messages
Possible causes/consequences and P Solutions
I Check Lef tB rake
Lam p or Check Right
Brake Lam p The lef torr ight-hand brak el amp is defective.X
Chec kw hether you are permitte dtor eplace th eb ulb yourself
( Y
page 104).
or X
Visit aq ualified specialist workshop .
I Check Lef t Tai l and
Brake Lamps or
Check Right Tai l
and Brake Lamps The lef torr ight-hand tai ll amp/brake lamp is defective.X
Chec kw hether you are permitte dtor eplace th eb ulb yourself
( Y
page 104).
or X
Visit aq ualified specialist workshop .
I Check Lef t Hig h Bea m
or Check Right
Hig hB ea m The lef torr ight-hand high beam is defective. X
Chec kw hether you are permitte dtor eplace th eb ulb yourself
( Y
page 104).
or X
Visit aq ualified specialist workshop .
I Licens eP late Lam p The lef torr ight-hand license plat el amp is faulty.X
Visit aq ualified specialist workshop .
I Rea rF og Lam p The rear fog lamp is faulty. X
Chec kw hether you are permitte dtor eplace th eb ulb yourself
( Y
page 104).
or X
Visit aq ualified specialist workshop .
I Check Front Lef t
Parkin gL am p or
Check Front Right
Parkin gL am p The fron tl ef torf ront right parking or standing lamp is defective.X
Chec kw hether you are permitte dtor eplace th eb ulb yourself
( Y
page 104).
or X
Visit aq ualified specialist workshop .
I Backup Light The backup lamp is defective. X
Chec kw hether you are permitte dtor eplace th eb ulb yourself
( Y
page 104).
or X
Visit aq ualified specialist workshop .
I Check Lef tT ai l
Lam p or Check Right
Tai lL am p The lef torr ight-hand tai ll amp is defective.X
Visit aq ualified specialist workshop .Display messages 20 3
On-boar dc omputer an dd isplays Z

Display messages
Possible causes/consequences and P Solutions
I Check Front Lef t
Sidemarke rL am p or
Check Front Right
Sidemarke rL am p The fron tl eft-han dorf ront right-hand side marke rl amp is faulty.X
Visit aq ualified specialist workshop .
I Check Rea rL ef t
Sidemarke rL am p or
Check Rea rR ight
Sidemarke rL am p The rear left-han dorr ear right-hand side marke rl amp is faulty.X
Visit aq ualified specialist workshop .
I Check Lef tD aytim e
Runnin gL ight or
Check Right Daytim e
Runnin gL ight The lef torr ight-hand daytime runnin gl amp is faulty.X
Chec kw hether you are permitte dtor eplace th eb ulb yourself
( Y
page 104).
or X
Visit aq ualified specialist workshop .
I Malfunction See
Operator' sM anual The exterio rl ighting is malfunctioning .X
Visit aq ualified specialist workshop .
I Aut oL am pF unction
Inoperative The ligh ts ensor is defective. X
Visit aq ualified specialist workshop .
I Switch Off Lights The lights are still switched on when you leav et he vehicle. Aw arning
tone also sounds. X
Turn th el igh ts witch to th e X position .
I Switch On Headlamps You are drivin gw it hl ow-beam headlamp ss witched off .X
Turn th el igh ts witch to th e X or X position .
Adaptive Highbeam
Assist Currently
Unavailable See
Operator' sM anual Adaptive Highbea mA ss is tisd eactivated and temporarily inoperative.
Possibl ec auses are: R
The windshield in th ec amera' sf ield of vision is dirty.R
Visibilit yisi mpaire dd ue to heav yr ain ,s no worf og .X
Clean th ew indshield.
If th es ystem detects that th ec amera is full yo perational again ,t he
Adaptive Highbeam Assist Now Available message is displayed.
Adaptive Highbea mA ss is tiso perational again .
Adaptive Highbeam
Assist Inoperative Adaptive Highbea mA ss is tisf aulty.X
Visit aq ualified specialist workshop .204
Display messages
On-boar dc omputer an dd isplays

Warning and indicator lamps in the instrument cluster
General notes Some systems carry out as elf-diagnosis when the ignition is switched on. Therefore, some indicator
and warning lamps may light up or flas ht emporarily .T his behavior is non-critical.
These indicator and warning lamps only indicate am alfunction if they light up or flas ha fter starting
the engine or whilst driving.
Safety
Seat belts Warning/
indicator
lamp Q Signal type
Possibl ec auses/consequence sa nd P Solutions

Warning/
indicator
lamp Q Signal type
Possibl ec auses/consequences and P Solutions
%
Q The yellow ABS warning lamp is lit while the engine is running.
ABS (Anti-lock Braking System) is deactivated due to am alfunction. Therefore,
BAS (Brake Assist), Active Brake Assist, ESP ®
(Electronic Stability Program), the
HOLD function and hil ls tart assist, for example, are als od eactivated.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed
above. The wheels coul dt herefore lock if you brake hard ,f or example.
The steerability and braking characteristics may be severely affected. The braking
distance in an emergency braking situation can increase.
If ESP ®
is not operational ,E SP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident. X
Observe the additiona ld isplay messages in the multifunction display.X
Drive on carefully. X
Visi taq ualified specialist worksho pi mmediately.
If the ABS control unit is faulty, there is als oap ossibility that other systems ,s uch
as the navigation system or the automatic transmission, wil ln ot be available.
%
Q The yellow ABS warning lamp is lit while the engine is running.
ABS is temporarily unavailable .T herefore, BAS, Active Brake Assist, ESP ®
,E BD
(electronic brake force distribution), the HOLD function and hil ls tart assist, for
example, are als od eactivated.
Possible causes are: R
Self-diagnosi sisn ot yet complete.R
The on-board voltag em ay be insufficient.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed
above. The front and rear wheels coul dt herefore lock if you brake hard ,f or exam-
ple.
The steerability and braking characteristics may be severely affected. The braking
distance in an emergency braking situation can increase.
If ESP ®
is not operational ,E SP ®
is unable to stabilize the vehicle.
There is ar isk of an accident.X
Carefully drive as uitable distance, making slight steering movements at as peed
above 12 mph (20 km/h).
The functions mentioned above are available again when the warning lamp goes
out.
If the warning lamp is still on: X
Observe the additiona ld isplay messages in the multifunction display.X
Drive on carefully. X
Visi taq ualified specialist worksho pi mmediately.220
Warning and indicator lamps in the instrument cluster
On-board computer and displays