check engine light MERCEDES-BENZ CLA-Class 2015 C117 User Guide

Problem
Possible causes/consequences and
M
MSolutions The engine is not run-
ning smoothly and is
misfiring. There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
X Only depress the accelerator pedal slightly.
Otherwise, non-combusted fuel may get into the catalytic con-
verter and damage it.
X Have the cause rectified immediately at a qualified specialist
workshop. The coolant tempera-
ture gauge shows a
value above 248 ‡
(120 †). The coolant
warning lamp may also
be on and a warning
tone may sound. The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.
X Stop as soon as possible and allow the engine and the coolant to
cool down.
X Check the coolant level (Y page 289). Observe the warning
notes as you do so and add coolant if necessary. Automatic transmission
Important safety notes
G
WARNING
If the engine speed is above the idling speed
and you engage transmission position Dor R,
the vehicle could pull away suddenly. There is a risk of an accident.
When engaging transmission position Dor R,
always firmly depress the brake pedal and do not simultaneously accelerate. G
WARNING
The automatic transmission switches to neu-
tral position Nwhen you switch off the engine.
The vehicle may roll away. There is a risk of an
accident.
After switching off the engine, always switch
to parking position P. Prevent the parked vehi-
cle from rolling away by applying the parking
brake.
Bear in mind that the power transmission
between the engine and the transmission is
interrupted when the engine is switched off. To prevent the vehicle from rolling away:
R when the engine is switched off and the
vehicle is stationary shift the automatic
transmission to park position Pand
R apply the electric parking brake DIRECT SELECT lever
Overview of transmission positions j
Park position with parking lock
k Reverse gear
i Neutral
h Drive 148
Automatic transmissionDriving and parking

!
Overfilling the fuel tank could damage the
fuel system.
! Take care not to spill any fuel on painted
surfaces. You could otherwise damage the
paintwork.
! Use a filter when refueling from a fuel can.
Otherwise, the fuel lines and/or injection
system could be blocked by particles from
the fuel can.
Do not get into the vehicle again during the
refueling process. Otherwise, electrostatic
charge could build up again.
If you overfill the fuel tank, fuel could spray
out when the fuel pump nozzle is removed.
For further information on fuel and fuel quality (Y page 353). Refueling
General information The fuel filler flap is unlocked or locked auto-
matically when you unlock or lock the vehicle
with the key.
The position of the fuel filler cap is displayed
æ in the instrument cluster. The arrow on
the filling pump indicates the side of the vehi-
cle.
Opening the fuel filler flap :
To open the fuel filler flap
; Tire pressure table =
To insert the fuel filler cap
? Instruction label for fuel type to be refu-
eled
X Remove the SmartKey from the ignition
lock.
X Press the fuel filler flap in the direction of
arrow :.
The fuel filler flap swings up.
X Turn the fuel filler cap counterclockwise
and remove it.
X Insert the fuel filler cap into the holder on
the inside of fuel filler flap =.
X Completely insert the filler neck of the fuel
pump nozzle into the tank, hook in place
and refuel.
X Only fill the tank until the pump nozzle
switches off.
Do not add any more fuel after the pump
stops filling for the first time. Otherwise, fuel may leak out.
Closing the fuel filler flap X
Replace the cap on the filler neck and turn
clockwise until it engages audibly.
X Close the fuel filler flap.
Close the fuel filler flap before locking the
vehicle.
If you are driving with the fuel filler cap open,
the 8 reserve fuel warning lamp flashes. A
message appears in the multifunction display
(Y page 234).
In addition, the ;Check Engine warning
lamp may light up (Y page 256).
For further information on warning and indi-
cator lamps in the instrument cluster, see
(Y page 256). Refueling
159Driving and parking Z

Useful information
i This Operator's Manual describes all
models and all standard and optional equip- ment of your vehicle available at the time of
publication of the Operator's Manual.
Country-specific differences are possible.
Please note that your vehicle may not be
equipped with all features described. This
also applies to safety-related systems and
functions.
i Read the information on qualified special-
ist workshops (Y page 24). Important safety notes
G
WARNING
If you operate information systems and com-
munication equipment integrated in the vehi- cle while driving, you will be distracted from
traffic conditions. You could also lose control of the vehicle. There is a risk of an accident.
Only operate the equipment when the traffic
situation permits. If you are not sure that this
is possible, park the vehicle paying attention
to traffic conditions and operate the equip-
ment when the vehicle is stationary.
You must observe the legal requirements for
the country in which you are currently driving when operating the on-board computer. G
WARNING
If the instrument cluster has failed or mal-
functioned, you may not recognize function
restrictions in systems 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.
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.
If the operating safety of your vehicle is
impaired, pull over as soon as it is safe to do
so. Contact a qualified specialist workshop.
For an overview, see the instrument panel
illustration (Y page 31). Displays and operation
Instrument cluster lighting
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.
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 located on the
bottom left of the instrument cluster
(Y page 31).
X Turn the brightness control knob clockwise
or counter-clockwise.
If the light switch is set to Ã,Tor
L, the brightness is dependent upon
the brightness of the ambient light. Coolant temperature display
G
WARNING
Opening the hood when the engine is over-
heated or when there is a fire in the engine
compartment could expose you to hot gases
or other service products. There is a risk of
injury.
Let an overheated engine cool down before
opening the hood. If there is a fire in the
engine compartment, keep the hood closed
and contact the fire department.
! A display message is shown if the coolant
temperature is too high. 200
Displays and operationOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions $(USA
only)J
(Canada
only)
Check Brake Fluid Check Brake Fluid
Level Level There is not enough brake fluid in the brake fluid reservoir.
A warning tone sounds. The
$(USA only)/ J(Canada only)
warning lamps in the instrument cluster may also light up.
G WARNING
The braking effect may be impaired.
There is a risk of an accident. X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 160).
X Consult a qualified specialist workshop.
X Do not add brake fluid. This does not correct the malfunction. #
Check Brake Pad Check Brake Pad
Wear Wear The brake pads/linings have reached their wear limit.
X Visit a qualified specialist workshop. G
Inoperative
Inoperative One or more main features of the mbrace system are malfunc-
tioning.
X Have the mbrace system checked immediately at a qualified
specialist workshop. Collision Preven‐ Collision Preven‐
tion Assist Plus tion Assist Plus
Currently Unavail‐ Currently Unavail‐
able See Opera‐ able See Opera‐
tor's Manual tor's Manual COLLISION PREVENTION ASSIST PLUS is temporarily not opera-
tional.
Possible causes are:
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.
R AMG vehicles: ESP ®
is deactivated.
When the causes stated above no longer apply, the display mes-
sage disappears.
COLLISION PREVENTION ASSIST PLUS is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 160).
X Restart the engine.
X AMG vehicles: reactivate ESP ®
(Y page 68). 224
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions Ð
Power Power
Steering
Steering Mal‐
Mal‐
function See Oper‐
function See Oper‐
ator's Manual ator's Manual The power steering is malfunctioning.
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 force required.
X If you are able to steer safely: carefully drive on to a qualified
specialist workshop.
X If you are unable to steer safely: do not drive on. Contact the
nearest qualified specialist workshop. Ð
Steering Malfunc‐ Steering Malfunc‐
tion See Opera‐ tion See Opera‐
tor's Manual tor's Manual The electric steering lock is malfunctioning.
G WARNING
The steering may be locked by the electric steering lock.
There is a risk of an accident. X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 160).
X Do not drive on and consult the nearest qualified specialist
workshop. _
Before Starting Before Starting
the Engine, Turn the Engine, Turn
Steering Wheel Steering Wheel The electric steering lock was unable to unlock the steering.
X Remove the SmartKey from the ignition lock.
X To unlock the steering, move the steering wheel slightly.
X Insert the SmartKey into the ignition lock again. Phone No Service
Phone No Service Your vehicle is outside the network provider's transmitter/
receiver range.
X Wait until the mobile phone operational readiness symbol
appears in the multifunction display. ¥
Check Washer Fluid Check Washer Fluid The washer fluid level in the washer fluid reservoir has dropped
below the minimum.
X Add washer fluid (Y page 290). Wiper Malfunction‐ Wiper Malfunction‐
ing ing The windshield wipers are malfunctioning.
X Visit a qualified specialist workshop. Hazard Warning
Hazard Warning
Flashers Malfunc‐ Flashers Malfunc‐
tioning tioning The hazard warning lamps are faulty.
X Visit a qualified specialist workshop. Display
messages
245On-board computer and displays Z

Problem
Possible causes/consequences and
M
MSolutions F
(USA only)
! (Canada only)
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
The red restraint sys-
tem warning lamp is lit
while the engine is run-
ning.
The restraint system is faulty.
G WARNING
The air bags or Emergency Tensioning Devices may either be trig- gered unintentionally or, in the event of an accident, may not be
triggered.
There is an increased risk of injury.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Have the restraint system checked at a qualified specialist
workshop immediately.
For further information about the restraint system, see
(Y page 40). Warning and indicator lamps in the instrument cluster
255On-board computer and displays Z

Engine
Problem
Possible causes/consequences and
M
MSolutions ;
The yellow Check
Engine warning lamp
lights up while the
engine is running.
There may be a malfunction, for example:
R in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system
R in the fuel system
The emission limit values may be exceeded and the engine may be
in emergency mode.
X Have the vehicle checked as soon as possible at a qualified
specialist workshop.
i In some states, you must immediately visit a qualified special-
ist workshop as soon as the yellow Check Engine warning lamp
lights up. This is due to the legal requirements in effect in these
states. If in doubt, check whether such legal regulations apply in the state in which you are currently driving. æ
The yellow reserve fuel
warning lamp lights up
while the engine is run-
ning.
The fuel level has dropped into the reserve range.
X Refuel at the nearest gas station. æ
The yellow reserve fuel
warning lamp flashes
while the vehicle is in
motion.
In addition, the
;
Check Engine warning
lamp may light up. The fuel system pressure is too low. The fuel filler cap is not closed
correctly or the fuel system is leaking.
X Check that the fuel filler cap is correctly closed.
X If the fuel filler cap is not correctly closed: close the fuel filler
cap.
X If the fuel filler cap is closed: visit a qualified specialist work-
shop. ?
The red coolant warn-
ing lamp lights up while
the engine is running
and the coolant tem-
perature gauge is at the start of the scale. The temperature sensor for the coolant temperature gauge is
defective.
The coolant temperature is no longer being monitored. There is a risk of engine damage if the coolant temperature is too high.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions. Do not continue
driving under any circumstances.
X Secure the vehicle against rolling away (Y page 160).
X Consult a qualified specialist workshop. 256
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
M
MSolutions X
Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and add coolant, observing the warning
notes (Y page 289).
X If you need to add coolant more often than usual, have the
engine coolant system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X At coolant temperatures below 248 ‡ (120 †), drive to the
nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in moun-
tainous terrain, and stop-and-go traffic. Driving systems
Problem
Possible causes/consequences and
M MSolutions ·
The red distance warn-
ing lamp lights up while
the vehicle is in motion. A warning tone also
sounds. You are approaching a vehicle or a stationary obstacle in your line
of travel at too high a speed.
X Be prepared to brake immediately.
X Pay careful attention to the traffic situation. You may have to
brake or take evasive action.
For further information about the distance warning function of
COLLISION PREVENTION ASSIST PLUS, see (Y page 64).258
Warning and indicator lamps in the instrument clusterOn-board computer and displays

!
Make sure that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield
wipers or the hood. X
Make sure that the windshield wipers are
switched off.
X Pull release lever :on the hood.
The hood is released. X
Reach into the gap between the hood and
the radiator trim and press hood catch
lever ;to the left.
X Raise the hood. X
Pull support strut ?out of bracket A.
X Lift up support strut ?and insert it into
yellow retaining clip =.
Closing the hood X
Raise the hood 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 hood and let it fall from a height
of approximately 8 in (20 cm).
X Check that the hood has engaged properly.
If the hood can be raised slightly, it is not
properly engaged. Do not press the hood
closed. Open the hood again and close it
with a little more force. Engine oil
General notes Depending on your driving style, the vehicle
consumes up to 0.9 US qt (0.8 liters) of oil per 600 miles (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 in a different location.
When checking the oil level:
R park the vehicle on a level surface.
R the engine should be switched off for
approximately five minutes if the engine is
at normal operating temperature.
R if the engine is not at normal operating
temperature, e.g. if the engine was only
started briefly, wait about 30 minutes
before carrying out the measurement. Engine compartment
287Maintenance and care Z

G
WARNING
Battery acid is caustic. There is a risk of injury. Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten- tion. 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 maxi-
mum charging voltage of 14.8 V.
! Only
charge the battery using the jump-
starting connection point.
The jump-starting connection point is in the
engine compartment (Y page 309).
X Open the hood.
X Connect the battery charger to the positive
terminal and ground point in the same
order as when connecting the donor bat-
tery in the jump-starting procedure
(Y page 309).
If the indicator/warning lamps do not light up at low temperatures, it is very likely that the
discharged battery has frozen. In this case
you may neither jump-start the vehicle nor
charge the battery. The service life of a
thawed-out battery may be shorter. The start-
ing characteristics can be impaired, particu-
larly at low temperatures. Have the thawed-
out battery checked at a qualified specialist
workshop.
Only charge the installed battery with a bat-
tery charger which has been tested and
approved by Mercedes-Benz. A battery
charger unit specially adapted for Mercedes-
Benz vehicles and tested and approved by Mercedes-Benz is available as an accessory.
It permits the charging of the battery in its
installed position. Contact an authorized
Mercedes-Benz Center for further informa-
tion and availability. Read the battery charg-
er's operating instructions before charging
the battery.308
Battery (vehicle)Roadside Assistance