2013 MERCEDES-BENZ CLA check engine

Indicator and warning display
Blind Spot Assist is not active at speeds below
approximately 30 km/h. Vehicles in the mon-
itoring range are then not indicated.:Yellow indicator lamp/red warning lamp
If Blind Spot Assist is activated, indicator
lamp : in the exterior mirrors lights up yel-
low up to a speed of 30 km/h. At speeds
above 30 km/h, the indicator lamp goes out
and Blind Spot Assist is operational.
If a vehicle is detected within the monitoring
range of Blind Spot Assist at speeds above
30 km/h, warning lamp : on the corre-
sponding side lights up in red. This warning
always occurs when a vehicle enters the blind
spot monitoring range from behind or from
the side. When you overtake a vehicle, the
warning only occurs if the difference in speed
is less than 12 km/h.
The yellow indicator lamp goes out if reverse
gear is engaged. Blind Spot Assist is then
deactivated.
The brightness of the indicator/warning
lamps is adjusted automatically according to
the ambient light.
Collision warning
If a vehicle is detected in the monitoring range
of Blind Spot Assist and you switch on the
corresponding turn signal, a double warning
tone sounds. Red warning lamp : flashes. If
the turn signal remains on, detected vehicles
are indicated by the flashing of red warning
lamp :. There are no further warning tones.
Activating Blind Spot AssistXMake sure that Blind Spot Assist is activa-
ted in the on-board computer
( Y page 219).XTurn the key to position 2 in the ignition
lock.
Warning lamps : in the exterior mirrors
light up red for approximately
1.5 seconds and then turn yellow.
Towing a trailer
If you attach a trailer, make sure that you have
correctly established the electrical connec-
tion. This can be accomplished by checking
the trailer lighting. Blind Spot Assist is then
deactivated. The indicator lamp lights up yel-
low in the exterior mirrors and the Blind
Spot Assist currently unavailable
See Owner's Manual message appears in
the multifunction display.
i You can deactivate the indicator lamps in
the exterior mirrors.
To do so, deactivate Blind Spot Assist if:
R the key is in position 2 in the ignition lock
R the engine is not running
R the electrical connection to the trailer
has been established
Lane Keeping Assist
General notes
Lane Keeping Assist monitors the area in
front of your vehicle by means of a camera at
the top of the windscreen. Lane Keeping
Assist detects lane markings on the road and
warns you before you leave your lane unin-
tentionally.
Driving systems199Driving and parkingZ

(Y page 197) availability is limited or not avail-
able at all.
i The height of the ball coupling changes
with the load of the vehicle. If necessary,
use a trailer with a height-adjustable draw-
bar.
Driving tips
i Observe the notes on ESP ®
trailer stabi-
lisation ( Y page 70).
The maximum permissible speed for vehicle/
trailer combinations depends on the type of
trailer. Before beginning the journey, check
the trailer's documents to see what the max-
imum permitted speed is. Observe the legally
prescribed maximum speed in the relevant
country.
For certain Mercedes-Benz vehicles, the max-
imum permissible rear axle load is increased
when towing a trailer. Refer to the "Technical
data" section to find out whether this applies
to your vehicle. If you utilise any of the added
maximum rear axle load when towing a trailer,
the vehicle/trailer combination may not
exceed a maximum speed of 100 km/h for
reasons concerning the operating permit.
This also applies in countries in which the
permissible maximum speed for vehicle/
trailer combinations is above 100 km/h.
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
to when driving without a trailer and it will
consume more fuel.
Change into a lower gear in good time on long
and steep downhill gradients. For vehicles
with automatic transmission, you need to
have selected manual drive program
M (Y page 156).
i This also applies if you have activated
cruise control, SPEEDTRONIC or DIS-
TRONIC PLUS.
This will use the braking effect of the engine,
so less braking will be required to maintain
vehicle speed. This relieves the load on the
brake system and prevents the brakes from
overheating and wearing too quickly. If you
need additional braking, depress the brake
pedal repeatedly rather than continuously.
i Briefly depressing the accelerator pedal
on downhill gradients while the manual
drive program M is temporarily activated
(vehicles with automatic transmission): the
automatic transmission may switch back to
the last active automatic drive program E
or S. The automatic transmission may shift
to a higher gear. This can reduce the
engine's braking effect.
Driving tips
If the trailer swings from side to side:
XDo not accelerate.XDo not countersteer.XBrake if necessary.
R Maintain a greater distance from the vehi-
cle in front than when driving without a
trailer.
R Avoid braking abruptly. If possible, brake
gently at first to allow the trailer to run on.
Then, increase the braking force rapidly.
R The values given for gradient-climbing
capabilities from a standstill refer to sea
level. When driving in mountainous areas,
note that the power output of the engine,
and consequently the vehicle's gradient-
climbing capability, decrease with increas-
ing altitude.
Folding out the ball coupling
GWARNING
If you release the ball coupling or it does not
engage correctly when folding in, it will swing
out. Within pivoting range of the ball coupling,
there is an increased risk of an accident and
injury.
Only release the ball coupling if the pivoting
range is unobstructed. Always make sure that
the ball coupling engages when folding in.
Towing a trailer203Driving and parkingZ

Useful information
i This Owner's Manual describes all mod-
els, series and optional equipment for your
vehicle that were available at the time of
going to press. National variations are pos-
sible. Note that your vehicle may not be
equipped with all of the functions descri-
bed. This is also the case for systems and
functions relevant to safety.
i Read the information on qualified special-
ist workshops: ( Y page 24).
Important safety notes
GWARNING
Operating the integrated information systems
and communications equipment in the vehicle
while driving will distract you from traffic con-
ditions. You could then lose control of the
vehicle. There is a risk of an accident.
Only operate these devices if road traffic con-
ditions permit. If you are unsure about the
surrounding conditions, pull over to a safe
location and make entries only while the vehi-
cle is stationary.
GWARNING
If the instrument cluster has failed or mal-
functioned, you may not recognise function
restrictions relevant to safety. The operating
safety of your vehicle may be impaired. There
is a risk of an accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop immedi-
ately.
You must observe the legal requirements for
the country in which you are currently driving
when operating the on-board computer.
The on-board computer only shows messages
or warnings from certain systems in the mul-
tifunction display. You should therefore make
sure your vehicle is operating safely at all
times. Otherwise, a vehicle that is not oper-
ating safely may cause an accident.
For an overview, see the instrument panel
illustration ( Y page 30).
Displays and operation
Instrument cluster lighting
The lighting in the instrument cluster, in the
displays and the controls in the vehicle inte-
rior can be adjusted using the brightness con-
trol knob.
The brightness control knob is on the bottom
left of the instrument cluster ( Y page 30).
XTurn the brightness control knob clockwise
or anti-clockwise.
If the light switch is set to Ã, T or
L , the brightness is dependant upon
the brightness of the ambient light.
i The light sensor in the instrument cluster
automatically controls the brightness of
the multifunction display.
In daylight, the displays in the instrument
cluster are not illuminated.
Coolant temperature gauge
GWARNING
If you open the bonnet while the engine is
overheating or while there is a fire in the
engine compartment, you could come into
contact with hot gases or other leaking
service products. There is a danger of injury.
Allow an overheating engine to cool down
before opening the bonnet. If there is a fire in
the engine compartment, leave the bonnet
closed and notify the fire brigade.
The coolant temperature gauge is in the
instrument cluster on the right-hand side.
Under normal operating conditions and with
the specified coolant level, the coolant tem-
perature may rise to 120 †.
208Displays and operationOn-board computer and displays

Display messagesPossible causes/consequences and M SolutionsJ
Check brake fluid
levelThere is insufficient brake fluid in the brake fluid reservoir.
In addition, the red J warning lamp lights up in the instrument
cluster and a warning tone sounds.GWARNING
The braking efficiency may be impaired.
There is a risk of an accident.
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.XSecure the vehicle against rolling away ( Y page 162).XConsult a qualified specialist workshop.XDo not top up the brake fluid. This does not correct the fault.#
Check brake pad
wearThe brake pads/linings have reached their wear limit.XVisit a qualified specialist workshop.PRE-SAFE
inoperative See
Owner's ManualImportant functions of PRE-SAFE ®
have failed. All other occupant
safety systems, e.g. airbags, remain available.XVisit a qualified specialist workshop immediately.Collision Preven‐
tion Assist Plus
currently unavail‐
able See Owner's
ManualCOLLISION PREVENTION ASSIST PLUS is temporarily inoperative.
Possible causes:
R the radar sensor cover in the radiator trim is dirty.
R the function is impaired due to heavy rain or snow.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
Once the causes listed above no longer apply, the display message
goes out.
COLLISION PREVENTION ASSIST PLUS is operational again.
If the display message does not disappear:XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XSecure the vehicle against rolling away ( Y page 162).XClean the radar sensor cover in the radiator grille
( Y page 291).XRestart the engine.Display messages233On-board computer and displaysZ

Display messagesPossible causes/consequences and M SolutionsAdaptive Main-beam
Assist inoperativeAdaptive Highbeam Assist is faulty.XVisit a qualified specialist workshop.Adaptive Main-beam
Assist currently
unavailable See
Owner's ManualAdaptive Highbeam Assist is deactivated and temporarily inoper-
ative. Possible causes:
R the windscreen is dirty in the camera's field of vision.
R visibility is impaired due to heavy rain, snow or fog.XClean the windscreen.
If the system detects that the camera is fully operational again,
the Adaptive Main-beam Assist available again message
is displayed.
Adaptive Highbeam Assist is operational again.
Engine
Display messagesPossible causes/consequences and M Solutions+
Top up coolant See
Owner's ManualThe coolant level is too low.
! Avoid making long journeys with too little coolant in the engine
cooling system. The engine will otherwise be damaged.XTop up the coolant, observing the warning notes before doing
so ( Y page 285).XIf the coolant needs topping up more often than usual, have the
engine coolant system checked at a qualified specialist work-
shop.?The fan motor is faulty.XIf the coolant temperature is below 120 †, you can continue
driving to the nearest qualified specialist workshop.XAvoid heavy loads on the engine as you do so, e.g. driving in
mountainous terrain and stop-start traffic.240Display messagesOn-board computer and displays

Display messagesPossible causes/consequences and M Solutions?
Coolant Stop car,
turn engine offThe coolant is too hot.
A warning tone also sounds.GWARNING
Never drive with an overheated engine. Driving when your engine
is overheated can cause some fluids which may have leaked into
the engine compartment to catch fire.
Steam from an overheated engine can cause serious burns, which
can occur just by opening the bonnet.
There is a risk of injury.
XStop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.XSecure the vehicle against rolling away ( Y page 162).XWait until the engine has cooled down.XMake sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.XDo not start the engine again until the display message goes out
and the coolant temperature is below 120 †. The engine may
otherwise be damaged.XPay attention to the coolant temperature display.XIf the temperature increases again, visit a qualified specialist
workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 120 †.
#The battery is not being charged.
A warning tone also sounds.
Possible causes:
R faulty alternator
R torn poly-V-belt
R a malfunction in the electronicsXStop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.XOpen the bonnet.XCheck whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
XConsult a qualified specialist workshop.
If the poly-V-belt is OK:
XVisit a qualified specialist workshop immediately.Display messages241On-board computer and displaysZ

Display messagesPossible causes/consequences and M Solutions4
Check eng. oil
lev. when next
refuellingThe engine oil level has dropped to the minimum level.
A warning tone also sounds.XCheck the oil level when next refuelling, at the latest
( Y page 284).XIf necessary, top up the engine oil ( Y page 285).XHave the engine checked at a qualified specialist workshop if
the engine oil needs topping up more often than usual.æ
Reserve fuel levelThe fuel level has dropped into the reserve range.
The auxiliary heating cannot be operated.XRefuel at the nearest filling station.çThere is very little fuel in the fuel tank.
The auxiliary heating cannot be operated.XRefuel at the nearest filling station without fail.¸
Replace air
cleaner elementVehicles with a diesel engine: the engine air filter is dirty and must
be replaced.XVisit a qualified specialist workshop.!
Clean fuel filterVehicles with a diesel engine: there is water in the fuel filter. The
water must be drained off.XVisit a qualified specialist workshop.
Driving systems
Display messagesPossible causes/consequences and M SolutionsÀ
Attention Assist
Drowsiness detec‐
tedBased on certain criteria, ATTENTION ASSIST has detected fatigue
or a lack of concentration on the part of the driver. A warning tone
also sounds.XIf necessary, take a break.
During long journeys, take regular breaks in good time so that you
get enough rest.
À
Attention Assist
inoperativeATTENTION ASSIST is inoperative.XVisit a qualified specialist workshop.242Display messagesOn-board computer and displays

Display messagesPossible causes/consequences and M Solutionsj
Check trailer
hitch lockThe trailer tow hitch is not correctly engaged.
A warning tone also sounds.XStop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.XApply the electric parking brake.XEngage the trailer coupling's ball coupling in the end position
( Y page 203).
Otherwise, the trailer may detach itself.
Ð
Power steering mal‐
function See Own‐
er's ManualThe power steering assistance is faulty.
A warning tone also sounds.GWARNING
You will need to use more force to steer.
There is a risk of an accident.
XCheck whether you are able to apply the extra force required.XIf you are able to steer safely: carefully drive on to a qualified
specialist workshop.XIf you are unable to steer safely: do not drive on. Contact the
nearest qualified specialist workshop.&
inoperative Bat‐
tery lowYou have attempted to switch on the auxiliary heating or to acti-
vate a departure time using the on-board computer after operating
the auxiliary heating twice.XLet the engine run for 10 seconds.
The auxiliary heating is operational again.The on-board voltage is too low. The auxiliary heating has switched
itself off or cannot be switched on ( Y page 136).XDrive for a longer distance.
The battery is being charged. The auxiliary heating is operational
again as soon as the on-board electrical system voltage is suf-
ficient.&
inoperative Refuel
vehicleThere is too little fuel in the fuel tank. The auxiliary heating cannot
be switched on ( Y page 136).XRefuel at the nearest filling station.Display messages253On-board computer and displaysZ