2018 MERCEDES-BENZ CLA COUPE engine overheat

Display messagesPossible causes/consequences andMSolutions
StopVehicl eShifttoPLeave EngineRunnin g
The automatic transmission has overheated.
XDrive on carefully.
The automatic transmission is available again when th edisplay
message goe sout.
If th emultifunction display still shows th edisplay message :
XPull overand stop th evehicl esafely as soo naspossible, payin g
attention to roa dand traffic conditions.
XSecur ethe vehicl eagainst rollin gaway (Ypage 141).
XWait until th eautomatic transmission has cooled down and th edis-
play message has disappeared.
Auxiliary Batter yMalfunctionThe auxiliary battery for th eautomatic transmission is no longer bein g
charged.
XVisit aqualified specialist workshop .
XUntilthen, set th etransmission to position Pbefore you switch off
th ee ngine.
XBefor eleaving th evehicle, apply th eelectric parking brake.
Trans. Oil Overhea‐ted Drive on wit hCare
Mercedes-AMG vehicles: th etransmission oil has overheated.
Manual drive progra mM and th etem porarily active manual drive pro -
gra ma re no longer available. The engin epowe routput is reduced.
XAllow th evehicl etoc ooldown .
4matic CurrentlyUnavailable4MATIC has overheated. The vehicl eisonlyd riven by th efront wheels.
XDrive on .
The airflow cools 4MATIC mor equickly.
Whe nthe display message goe sout,4 MATIC is available again and
th ev ehicl eisd riven by all fou rwheels.
4matic Inoperative4MATIC is malfunctioning .The vehicl eisonlyd riven by th efront
wheels.
XVisit aqualified specialist workshop .
NThe trunk lid is open.
XClosethe trunk lid.
MThe hoo disopen.
Aw arning tone also sounds.
GWARNIN G
The open hoo dmay bloc kyour vie wwhen th evehicl eisinm otion.
There is ariskofana ccident.
XPull overand stop th evehicl esafely as soo naspossible, payin g
attention to roa dand traffic conditions.
XSecur ethe vehicl eagainst rollin gaway (Ypage 141).
XClosethe hood.
Display messages215
On-boardc omputer andd isplays
Z

Warning/
indicator
lampNSignal type
Possiblec auses/consequences and M
Solutions
?NThe red coolant warning lamp comes on while the engine is running.
The coolant levelist oo low.
If the coolant levelisc orrect, the airflow to the engine radiator may be blocked or
the electric engine radiator fan may be defective.
The coolant is too hot and the engine is no longer being cooleds ufficiently.
XObserve the additionaldisplay messages in the multifunction display.
XPullover and stop the vehicles afelyand switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehiclea gainst rolling away(Ypage141).
XLeave the vehiclea nd keepasafe distance from the vehicleu ntil the engine has
cooledd own.
XCheck the coolant levela nd add coolant, observing the warning notes
(Ypage2 60).
XIf you have to add coolant frequently, have the engine cooling system checked.
XMake sure that the air supply to the engine radiator is not blocked,e .g. by snow,
slush or ice.
XDo not start the engine again until the coolant temperature is below 248 ‡
(120 †). Otherwise, the engine coul dbedamaged.
XDrive to the neares tqualified specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-and-go traffic.
?NThe red coolant warning lamp comes on while the engine is running. Awarning
tone als osounds.
The coolant temperature has exceeded2 48‡(120 †). The airflow to the engine
radiator may be blocked or the coolant levelm ay be too low.
GWARNING
The engine is not being cooleds ufficiently and may be damaged.
Do not drive whe nyoure ngine is overheated. This can cause some fluids which
may have leaked into the engine compartment to catch fire.
Steam from the overheated engine can also cause serious burns which can occur
just by opening the hood.
There is arisk of injury.
XObserve the additiona ldisplaym essages in the multifunction display.
XPullover and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehicle against rolling away (Ypag e141).
XLeav ethe vehicle and keep asafe distance from the vehicle until the engine has
cooledd own.
XCheck the coolant levela nd add coolant, observing the warning notes
(Ypag e260).
XIf you have to add coolant frequently, have the engine cooling system checked.
XMake sure that the ai rsupply to the engine radiator is not blocked, e.g. by snow,
slush or ice.
226Warning and indicator lamps in the instrument cluster
On-board computer and displays

Engine compartment
Hood
Important safety notes
GWARNING
If th ehood is unlatched, it may open up when
th ev ehicle is in motion and blocky our view.
Thereisar isk of an accident.
Never unlatch th ehood while driving .Before
ever ytrip, ensure that th ehood is locked.
GWARNING
When opening and closingt hehood,itm ay
suddenly fall int othe closed position.T hereis
ar isk of injury to personsw ithin range of
movementoft hehood.
Open and close th ehood only when no onei s
within its range of movement.
GWARNING
Opening th ehood when th eengine is over-
heated or when there is afireint heengine
compartmen tcoul de xpose you to hot gases
or other servic eproducts. Thereisar isk of
injury.
Let an overheate dengine coo ldown before
opening th ehood.Ift here is afireint he
engine compartment, keep th ehood closed
and contac tthe fired epartment.
GWARNING
The engine compartmen tcontain smoving
components. Certain components, sucha s
th er adiator fan ,may continue to run or start
again suddenly when th eignition is off .There
is ar isk of injury.
If you nee dtodoany work inside th eengine
compartment:
Rswitch off th eignition
Rnever reac hintot he area wheret here is a
risk of danger from moving components,
suchast hefan rotatio narea
Rremove jewelry and watches
Rkeep items of clothing and hair, for exam-
ple, away from moving parts
GWARNING
The ignition system and th efuel injection sys-
te mw ork unde rhigh voltage. If you touch
component swhicha re unde rvoltage, you
coul dget an electric shock. Thereisar isk of
injury.
Never touch component softheignition sys-
te morf uel injection system when th eignition
is switched on.
Opening th ehood
GWARNING
Certain component sintheengine compart-
ment, suchast heengine ,radiator and parts
of th eexhaust system, can become ver yhot.
Workin gintheengine compartmen tposesa
risk of injury.
Wherep ossible, let th eengine coo ldown and
touch only th ecomponent sdescribe dinthe
following.
GWARNING
When th ehood is open and th ewindshield
wipersa re set in motion,y ou can be injured by
th ew iper linkage. Thereisar isk of injury.
Always switch off th ewindshield wipersa nd
th ei gnition before opening th ehood.
!Makes ure that th ewindshield wipersa re
no tfolded away from th ewindshield. You
coul dotherwise damag ethe windshield wip-
ers or th ehood.
Engine compartment257
Maintenance and care
Z

ModelMB-Freigabe orMB-Approval
All models229.5
Use only SAE 0W-40 or SAE 5W-40 engine oils
for Mercedes-AMG vehicles.
iMB approval is indicated on the oil contain-
ers.
Fillingc apacities
The following values refer to an engine oil
change, including the oil filter.
ModelCapacity
Mercedes‑AM Gvehicles5.8 US qt (5.5 l)
All other models5.9 US qt (5.6 l)
Additives
!Do not use any additives in the engine oil.
This could damage the engine.
Brake fluid
GWARNING
The brake flui dconstantly absorbs moisture
from the air. This lowers the boiling point of
the brake fluid. If the boiling point of the brake
flui dist oo low,v aporpockets may form in the
brake system when the brakes are applied
hard. This would impair braking efficiency.
There is arisk of an accident.
You should have the brake flui dreneweda t
the specified intervals.
When handling brake fluid, observe the impor-
tant safety notes on service products
(
Ypag e315).
The brake flui dchange interval scan be found in
the Maintenance Booklet.
Only use brake flui dapproved by Mercedes-
Benz in accordance with MB-Freigabe or MB-
Approval3 31.0.
Information about approved brake flui dcan be
obtained at any qualified specialist workshop or
on the Internet at
http://bevo.mercedes-benz.com.
iHave the brake flui dregularl yreplaced at a
qualified specialist workshop and the replace-
ment confirmed in the Maintenance Booklet.
Coolant
Important safety notes
GWARNING
If antifreeze comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is arisk of fire and injury.
Let the engine cool down before you add anti-
freeze. Make sure that antifreeze is not spilled
next to the filler neck. Thoroughly cleant he
antifreeze from components before starting
the engine.
!Only add coolant that has been premixed
with the desired antifreeze protection. You
coul dotherwise damage the engine.
Further information on coolants can be found
in the Mercedes-Benz Specifications for Ser-
vice Products, MB BeVo 310.1, e.g. on the
Internet at http://bevo.mercedes-benz.com.
Or contact aqualified specialist workshop.
!Always use asuitable coolant mixture, even
in countries where high temperatures prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosiona nd
overheating.
iHave the coolant regularl yreplaced at a
qualified specialist workshop and the replace-
ment confirmed in the Maintenance Booklet.
Comply with the important safety precautions
for service products when handling coolant
(
Ypag e315).
The coolant is amixture of water and corrosion
inhibitor/antifreeze concentrate. It performs
the following tasks:
RAnti-corrosion protection
RAntifreeze protection
RRaising the boiling point
If the coolant has antifreeze protection down to -35 ‡(-37 †), the boiling point of the coolant
during operation is approximatel y266 ‡
(130 †).
318Servicep roducts and filling capacities
Technical data