check engine light MERCEDES-BENZ CLA COUPE 2016 Owner's Manual

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

Cleaning the exhaust tail pipes
G
WARNING
The exhaust tail pipe and tail pipe trim can
become very hot. If you come into contact
with these parts of the vehicle, you could burn
yourself. There is a risk of injury.
Always be particularly careful around the
exhaust tail pipe and the tail pipe trim. Allow
these components to cool down before touch-
ing them.
! Do not clean the exhaust pipe with acid-
based cleaning agents, such as sanitary
cleanser or wheel cleaner.
! Mercedes-AMG vehicles with black exhaust
pipes: the black-chrome tailpipe finishers
should not be polished with a chrome polish.
They will otherwise lose their black sheen. For optimal care, the finishers should be rubbed
with a lightly oiled cloth after every car wash.
Commercially available engine and care oils
are suitable for this.
For heavier soiling, you can apply a fine paint- work polish with a microfibre cloth. Remove
the excess polish residue after polishing.
Impurities combined with the effects of road grit and corrosive environmental factors may cause
flash rust to form on the surface. You can
restore the original shine of the exhaust pipe by
cleaning it regularly, especially in winter and
after washing the vehicle.
X Clean the exhaust pipe with a care product
tested and approved by Mercedes-Benz.
Cleaning the trailer tow hitch H
Environmental note
Dispose of oily and greasy cloths in an envi-
ronmentally-responsible manner.
! Do not clean the ball coupling with a high-
pressure cleaner. Do not use solvents.
! Please note the care instructions in the
trailer coupling manufacturer's operating
instructions. X
Remove rust, e.g. with a wire brush.
X Remove dirt with a clean, lint-free cloth or a
brush.
X After cleaning, lightly oil or grease ball cou-
pling :.
X Check that the vehicle's trailer tow hitch is
working properly.
i You can also have the maintenance work on
the ball coupling and the trailer tow hitch car-
ried out by a qualified specialist workshop. Interior care
Cleaning the display !
For cleaning, do not use any of the following:
R alcohol-based thinner or petrol
R abrasive cleaning agents
R commercially-available household cleaning
agents
These may damage the display surface. Do
not put pressure on the display surface when
cleaning. This could lead to irreparable dam-
age to the display.
X Before cleaning the display, make sure that it
is switched off and has cooled down.
X Clean the display surface using a commer-
cially available microfibre cloth and TFT/LCD
display cleaner.
X Dry the display surface using a dry microfibre
cloth.
Cleaning the plastic trim G
WARNING
Care products and cleaning agents containing solvents can cause surfaces in the cockpit to 290
CareMaintenance and care

vehicle will then use very little energy, thus con-
serving battery power.
If the power supply has been interrupted, e.g. if
the battery was discharged, you will have to:
R set the clock using the multimedia system;
see the separate operating instructions.
R reset the function for folding the exterior mir-
rors in/out automatically, by folding the mir-
rors out once (Y page 104) Charging the battery
G
WARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, naked flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery. G
WARNING
Battery acid is caustic. There is a risk of injury. Avoid contact with the skin, eyes or clothing.
Do not breathe in any battery gases. Do not
lean over the battery. Keep the batteries out
of the reach of children. Immediately rinse off
battery acid thoroughly with plenty of clean
water and seek medical attention at once. G
WARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing the vehicle or charging the battery, gases can escape from the battery. There is a risk of
an explosion.
Allow the frozen battery to thaw out before
charging it or jump-starting.
! Only use battery chargers with a maximum
charging voltage of 14.8 V.
! Only
charge the battery using the jump-start
connection point.
The jump-starting connection point is in the
engine compartment (Y page 301).
X Open the bonnet.
X Connect the battery charger to the positive
terminal and earth point in the same order as
when connecting the donor battery in the
jump-starting procedure (Y page 301).
If the indicator/warning lamps do not light up in
the instrument cluster at low temperatures, it is very likely that the discharged battery has fro-
zen. In this case, you may neither jump-start the
vehicle nor charge the battery. The service life of a battery that has been thawed may be reduced. The starting characteristics may be impaired,
especially at low temperatures. Have the
thawed battery checked at a qualified specialist workshop.
Only charge the installed battery with a battery
charger which has been tested and approved byMercedes-Benz. A battery charger unit specially
adapted for Mercedes-Benz vehicles and tested
and approved by Mercedes-Benz is available as an accessory. This device permits charging of
the battery while it is installed. Contact a
Mercedes-Benz Service Centre for information
and availability. Read the battery charger's
operating instructions before charging the bat-
tery. Jump-starting
For the jump-starting procedure, use only the jump-starting connection point, consisting of a pos- itive terminal and an earth point, in the engine compartment. G
WARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with the skin, eyes or clothing. Do not breathe in any battery gases. Do not lean over the battery. Keep the batteries out of the reach of children. Immediately rinse off battery acid
thoroughly with plenty of clean water and seek medical attention at once. Jump-starting
301Breakdown assistance Z

G
WARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, naked flames, creating sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting. Do not lean over a battery. G
WARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or sparks
are created, the hydrogen gas can ignite. There is a risk of an explosion.
R Make sure that the positive terminal of a connected battery does not come into contact with
vehicle parts.
R Never place metal objects or tools on a battery.
R It is important that you observe the described order of the battery terminals when connecting
and disconnecting a battery.
R When jump-starting, make sure that the battery poles with identical polarity are connected.
R It is particularly important to observe the described order when connecting and disconnecting
the jump leads.
R Never connect or disconnect the battery terminals while the engine is running. G
WARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting the
vehicle or charging the battery, gases can escape from the battery. There is a risk of an explosion.
Allow the frozen battery to thaw out before charging it or jump-starting.
! Vehicles with a petrol engine:
avoid repeated and lengthy starting attempts. Otherwise, the
non-combusted fuel may damage the catalytic converter.
If the indicator/warning lamps do not light up in the instrument cluster at low temperatures, it is very likely that the discharged battery has frozen. In this case you may neither jump-start the vehicle norcharge the battery. Let the battery thaw first. The service life of a battery that has been thawed may
be reduced. The starting characteristics may be impaired, especially at low temperatures. Have the
thawed battery checked at a qualified specialist workshop.
Do not use a rapid charging device to start the vehicle. If your vehicle's battery is discharged, the
engine can be jump-started from another vehicle or from a second battery using jump leads.
Observe the following points:
R The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible, jump-
start the vehicle using a second battery or a jump-starting device.
R Vehicles with a petrol engine: jump-start the vehicle only when the engine and exhaust system
are cold.
R Do not start the engine if the battery is frozen. Let the battery thaw first.
R Jump-starting may be performed only using batteries with a nominal voltage of 12 V.
R Only use jump leads that are not damaged and have a sufficient cross-section and insulated
terminal clamps.
R Make sure that the two vehicles do not touch. 302
Jump-startingBreakdown assistance

Make sure that:
R The jump leads are not damaged.
R Non-insulated parts of the terminal clamps do not come into contact with other metal parts while
the jump leads are connected to the battery
R The jump leads cannot come into contact with parts that can move when the engine is running,
such as the V-belt pulley or the fan
X Secure the vehicle by applying the electric parking brake.
X Manual transmission: depress the clutch pedal fully and engage neutral.
X Automatic transmission: shift the transmission to position P.
X Turn the key to position 0in the ignition lock and remove it.
X Switch off all electrical consumers, e.g. rear window heating, lighting etc.
X Open the bonnet. Position number
Bidentifies the charged battery of the other vehicle or an equivalent jump-starting
device.
X Press together cover :of positive clamp ;and slide it back.
X Connect positive terminal ;on your vehicle to positive terminal =of donor battery Busing the
jump lead, beginning with your own battery.
X Start the engine of the donor vehicle and run it at idling speed.
X Connect negative terminal ?of donor battery Bto earth point Aof your vehicle using the jump
lead, connecting the jump lead to donor battery Bfirst.
X If the battery is fully discharged, leave the battery that is being used to jump-start connected for
a few minutes before attempting to start. This charges the empty battery a little.
X Start the engine.
X Before disconnecting the jump leads, let the engines run for several minutes.
X First, remove the jump leads from earth point Aand negative terminal ?, then from positive
clamp ;and positive terminal =. Each time, begin at the contacts on your own vehicle first.
X Close cover :of positive clamp ;after removing the jump leads.
X Close the bonnet.
X Have the battery checked at a qualified specialist workshop.
i Jump-starting is not considered to be a normal operating condition. Jump-starting
303Breakdown assistance Z