2016 MERCEDES-BENZ CLA COUPE check engine

Display messages
Possible causes/consequences and
M
MSolutions j
Check Check
trailer
trailer hitch
hitch
lock
lock The trailer tow hitch is not correctly engaged.
A warning tone also sounds.
G WARNING
If the ball coupling is not engaged, the trailer may come loose. There
is a risk of an accident.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 155).
X Engage the ball coupling of the trailer tow hitch in the end position
(Y page 197). &
inoperative inoperative
Battery
Battery
Low
Low The on-board voltage is too low. The auxiliary heating has switched
itself off or cannot be switched on (Y page 126).
X Drive for a considerable distance.
The battery charges. The auxiliary heating is operational again as
soon as the on-board electrical system voltage is sufficient. &
inoperative Refuel inoperative Refuel
vehicle vehicle There is too little fuel in the fuel tank. The auxiliary heating cannot be
switched on (Y page 126).
X Refuel at the nearest filling station. &
inoperative inoperative
See
SeeOwn‐
Own‐
er's Man.
er's Man. The auxiliary heating is temporarily malfunctioning or faulty.
If the vehicle is on a level surface and the engine has cooled down:
X Make up to four attempts to switch on the auxiliary heating, waiting
several minutes between each attempt (Y page 126).
If the auxiliary heating does not switch on:
X Consult a qualified specialist workshop. Ð
Power steering mal‐ Power steering mal‐
function See Own‐ function See Own‐
er's Manual er's Manual The power steering assistance is faulty.
A warning tone also sounds.
G WARNING
You will need to use more force to steer.
There is a risk of an accident.
X Check whether you are able to apply the extra steering force
required.
If you are able to steer safely:
X Drive on carefully.
X Consult a qualified specialist workshop immediately.
If you are unable to steer safely:
X Do not drive on.
X Consult a qualified specialist workshop. Display
messages
245On-board computer and displays Z

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions å
N
The yellow ESP ®
OFF warning lamp is lit while the engine is running.
ESP ®
is deactivated. ESP ®
will not stabilise the vehicle if it starts to skid or if a
wheel starts to spin.
G WARNING
If ESP ®
is deactivated, ESP ®
is unable to stabilise the vehicle.
Further driving systems or driving safety systems are thus restricted.
Increased risk of skidding and/or accident!
X Reactivate ESP ®
.
In exceptional cases (Y page 71) it may be better to deactivate ESP ®
.
Observe the important safety notes on ESP ®
(Y page 70).
X Adapt your driving style to suit the road and weather conditions.
If ESP ®
cannot be activated:
X Drive on carefully.
X Contact a qualified specialist workshop immediately and have the ESP ®
system
checked. M
N
Mercedes-AMG vehicles only:
The yellow SPORT handling mode warning lamp lights up while the engine is run-
ning.
SPORT handling mode is activated.
G WARNING
When SPORT handling mode is activated, ESP ®
is unable to stabilise the vehicle.
Increased risk of skidding and/or accident!
X Only switch to SPORT handling mode in accordance with the conditions descri-
bed in the "Activating/deactivating ESP ®
" section (Y page 71). ֌
N
The yellow ESP ®
and ESP ®
OFF warning lamps are lit while the engine is running.
ESP ®
, ESP ®
trailer stabilisation, BAS, Active Brake Assist, the HOLD function, hill
start assist, the adaptive brake lights and PRE‑SAFE ®
are not available due to a
malfunction.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed above.
The braking distance may thus increase in an emergency braking situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
Increased risk of skidding and/or accident!
X Observe the additional display messages in the multifunction display.
X Drive on carefully.
X Consult a qualified specialist workshop immediately. Warning and indicator lamps in the instrument cluster
253On-board computer and displays Z

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions ֌
N
The yellow ESP ®
and ESP ®
OFF warning lamps are lit while the engine is running.
ESP ®
, ESP ®
trailer stabilisation, BAS, the HOLD function, hill start assist and PRE-
SAFE ®
are temporarily unavailable.
The adaptive brake lights and Active Brake Assist may also have failed.
ATTENTION ASSIST is deactivated.
Self-diagnosis is not yet complete.
G WARNING
The brake system continues to function normally, but without the functions listed above.
The braking distance may thus increase in an emergency braking situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
Increased risk of skidding and/or accident!
X Carefully drive on a suitable stretch of road, making slight steering movements
at a speed above 20 km/h.
The functions mentioned above are available again when the warning lamp goesout.
If the warning lamp is still on:
X Observe the additional display messages in the multifunction display.
X Drive on carefully.
X Consult a qualified specialist workshop immediately. !
N
The red indicator lamp for the electric parking brake flashes or lights up and/or
the yellow warning lamp for the electric parking brake lights up.
X Observe the additional display messages in the multifunction display. 6
N
The red restraint system warning lamp is lit while the engine is running.
The restraint system is malfunctioning.
G WARNING
The airbags or belt tensioners may either be triggered unintentionally or, in the
event of an accident, may not be triggered.
This poses an increased risk of injury.
X Observe the additional display messages in the multifunction display.
X Drive on carefully.
X Contact a qualified specialist workshop immediately and have the restraint sys-
tem checked.
Further information about the restraint system (Y page 39).254
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Engine
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ;
N
The yellow engine diagnostics warning lamp lights up while the engine is run-
ning.
There may be a fault with the following, for example:
R Engine management
R Fuel injection system
R Exhaust system
R Ignition system (for vehicles with petrol engines)
R Fuel system
The emission limit values may be exceeded and the engine may be running in
emergency mode.
X Consult a qualified specialist workshop immediately.
Vehicles with a diesel engine: the fuel tank has been run dry (Y page 155).
X Start the engine three to four times after refuelling.
If the yellow engine diagnostics warning lamp goes out, emergency mode is
cancelled. The vehicle does not have to be checked. æ
N
The yellow reserve fuel warning lamp lights up while the engine is running.
The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated if the fuel level drops into the
reserve range.
X Refuel at the nearest filling station. ?
N
The red coolant warning lamp lights up while the engine is running and the
coolant temperature gauge is at the start of the scale.
The temperature sensor for the coolant temperature gauge is malfunctioning.
The coolant temperature is no longer being monitored. The engine could be dam-
aged if the coolant temperature is too high.
X Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine. Do not continue driving.
X Secure the vehicle against rolling away (Y page 155).
X Consult a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
255On-board computer and displays Z

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions ?
N
The red coolant warning lamp lights up while the engine is running.
The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator may be blocked or the electric engine radiator fan may be malfunctioning.
The coolant is too hot and the engine is not being cooled sufficiently.
X Observe the additional display messages in the multifunction display.
X Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine.
X Secure the vehicle against rolling away (Y page 155).
X Leave the vehicle and keep a safe distance from the vehicle until the engine has
cooled down.
X Check the coolant level and top up the coolant, making sure to observe the
warning notes (Y page 283).
X If you have to top up the coolant frequently, have the engine cooling system
checked.
X Make sure that the air supply to the engine radiator is not blocked, e.g. by frozen
slush.
X Do not start the engine again until the coolant temperature is below 120 †. The
engine may otherwise be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-start traffic. ?
N
The red coolant warning lamp lights up while the engine is running. A warning
tone also sounds.
The coolant temperature has exceeded 120 †. The airflow to the engine radiator may be blocked or the coolant level may be too low.
G WARNING
The engine is not being cooled sufficiently and may be damaged.
Never drive with an overheated engine. Driving when your engine has overheated
can cause any fluids that may have leaked into the engine compartment to catch fire.
In addition, steam from an overheated engine can cause serious burns, which can
occur just by opening the bonnet.
There is a risk of injury.
X Observe the additional display messages in the multifunction display.
X Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine.
X Secure the vehicle against rolling away (Y page 155).
X Leave the vehicle and keep a safe distance from the vehicle until the engine has
cooled down.
X Check the coolant level and top up the coolant, making sure to observe the
warning notes (Y page 283).
X If you have to top up the coolant frequently, have the engine cooling system
checked. 256
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Closing the bonnet
X
Raise the bonnet slightly and, at the same
time, remove support strut ?from yellow
retaining clip =.
X Swing support strut ?down and press it into
bracket Auntil it engages.
X Lower the bonnet and let it fall from a height
of approximately 20 cm.
X Check that the bonnet has engaged properly.
If the bonnet can be raised slightly, it is not
properly engaged. Do not press the bonnet
closed. Open the bonnet again and close it
with a little more force. Engine oil
General notes Depending on your driving style, the vehicle
consumes up to 0.8 litres of oil per 1,000 km.
The oil consumption may be higher than this
when the vehicle is new or if you frequently drive
at high engine speeds.
Depending on the engine, the oil dipstick may be installed at a different location.
When checking the oil level:
R park the vehicle on a level surface
R the engine should be switched off for approx-
imately five minutes if the engine is at normal
operating temperature.
R if the engine is not at normal operating tem-
perature, e.g. if the engine was only started
briefly, wait approximately 30 minute sbefore
carrying out the measurement
Checking the oil level using the oil dip-
stick G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. Example: vehicles with a petrol engine
Example: vehicles with a diesel engine
(except the CLA 180 d model)
Example: CLA 180 d model
X All models except CLA 180 d: pull out oil
dipstick :.
X The CLA 180 d model: release the oil filler
cap and pull it out together with integrated oil dipstick :.
X Slowly slide oil dipstick :into the guide tube
to the stop, and take it out again.
If the level is between MIN mark =and MAX
mark ;, the oil level is correct.
X If the oil level has dropped to MIN mark =or
below, top up with 1.0 lof engine oil. 282
Engine compartmentMaintenance and care

Topping up engine oil
G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. G
WARNING
If engine oil comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Make sure that engine oil does not spill out
over the filler neck. Allow the engine to cool
down and thoroughly clean the components
that have come into contact with engine oil
before you start the engine. H
Environmental note
When topping up the oil, take care not to spill
any. If oil enters the soil or waterways, it is
harmful to the environment.
! Use only engine oils and oil filters that are
approved for vehicles with a service system. A
list of the engine oils and oil filters that have
been tested and approved in accordance with Mercedes-Benz Specifications for Service
Products is available at any Mercedes-Benz
Service Centre.
The following cause engine failure or damage
to the exhaust system:
R Use of engine oils and oil filters that have
not been expressly approved for the service system
R Replacement of engine oil and oil filter after
the replacement interval specified by the
service system has expired
R Use of engine oil additives
! Do not add too much oil. Topping up with too
much engine oil can result in damage to the
engine or to the catalytic converter. Have
excess engine oil siphoned off. Example: engine oil filler cap
X Turn cap :anti-clockwise and remove it.
X Top up the engine oil.
If the oil level is at or below the MIN mark on
the oil dipstick, top up with 1.0 lof engine oil.
X Replace cap :on the filler neck and turn
clockwise.
Make sure that the cap locks securely into
place.
X Check the oil level again with the oil dipstick
(Y page 282).
Further information on engine oil (Y page 330). Checking and adding other service
products
Checking the coolant level G
WARNING
The cooling system is pressurised, particu-
larly when the engine is warm. If you open the cap, you could be scalded if hot coolant
sprays out. There is a risk of injury.
Let the engine cool down before you open the
cap. Wear gloves and eye protection. Open
the cap slowly to release the pressure.
! The coolant level must only be checked and
corrected when the engine has cooled down
(coolant temperature under 40 †). Checking
the coolant level when the coolant tempera-
ture is over 40 † can lead to damage to the
engine or engine cooling system. Engine compartment
283Maintenance and care Z

X
Park the vehicle on a level surface.
Check the coolant level only if the vehicle is
on a level surface and the engine has cooled
down.
X Turn the key to position 2in the ignition lock
(Y page 133).
X Check the coolant temperature display in the
instrument cluster.
The coolant temperature must be below
40 †.
X Turn the key to position 0in the ignition lock
(Y page 133).
X Slowly turn cap :anti-clockwise and to
relieve excess pressure.
X Turn cap :further anti-clockwise and
remove it.
If the coolant is at the level of marker bar =
in the filler neck when cold, there is enough
coolant in coolant expansion tank ;.
X If necessary, top up with coolant that has
been tested and approved by Mercedes-Benz.
X Replace cap :and turn it clockwise as far as
it will go.
Further information on coolant (Y page 332).
Windscreen washer system G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. G
WARNING
If windscreen washer concentrate comes into contact with hot components of the engine or
the exhaust system, it can ignite. There is a
risk of fire and injury.
Make sure the windscreen washer concen-
trate does not come into contact with the filler neck. X
To open: pull cap:upwards by the tab.
X Top up with the premixed washer fluid.
X To close: press cap :onto the filler neck
until it engages.
If the washer fluid level drops below the recom- mended minimum of 1 litre, a message appears in the multifunction display prompting you to
top up the washer fluid (Y page 246).
Further information on windscreen washer
fluid/antifreeze (Y page 332). ASSYST PLUS
Service message
The ASSYST PLUS service interval display
informs you of the next service due date.
You can find information on the type of service
and service intervals in the Service Booklet.
You can obtain further information from a
Mercedes-Benz Service Centre.
i The ASSYST PLUS service interval display
does not show any information on the engine oil level. Observe the notes on the engine oil
level (Y page 282). 284
ASSYST PLUSMaintenance and care