2015 MERCEDES-BENZ CLA-Class check engine light

Problems with the seat heating
Problem
Possible causes/consequences and
M
MSolutions The seat heating has
switched off prema-
turely or cannot be
switched on. The on-board voltage is too low because too many electrical con-
sumers are switched on.
X Switch off electrical consumers that you do not need, such as
the rear window defroster or interior lighting.
Once the battery is sufficiently charged, the seat heating will
switch back on automatically. Steering wheel
Important safety notes
G
WARNING
You could lose control of your vehicle if you do the following while driving:
R adjust the driver's seat, head restraint,
steering wheel or mirrors
R fasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint, steer-
ing wheel and mirror and fasten your seat belt before starting the engine. G
WARNING
Children could injure themselves if they
adjust the steering wheel. There is a risk of
injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never leave children unsupervised in the vehicle. Adjusting the steering wheel
G
WARNING
If the steering wheel is unlocked while the
vehicle is in motion, it could change position
unexpectedly. This could cause you to lose
control of the vehicle. There is a risk of an
accident. Before starting off, make sure the steering
wheel is locked. Never unlock the steering
wheel while the vehicle is in motion. :
Release lever
; To adjust the steering wheel height
= To adjust the steering wheel position
(fore-and-aft adjustment)
X Push release lever :down completely.
The steering column is unlocked.
X Adjust the steering wheel to the desired
position.
X Push release lever :up completely.
The steering column is locked.
X Check if the steering column is locked.
When doing so, try to push the steering
wheel up or down or try to move it in the
fore-and-aft direction. 102
Steering wheelSeats, steering wheel and mirrors

Interior lighting control
General notes In order to prevent the vehicle's battery from
discharging, the interior lighting functions are
automatically deactivated after some time
unless the SmartKey is in position 2in the
ignition lock.
The color and brightness for the ambient
lighting may be set using COMAND or Audio
20 (see the separate operating instructions).
Automatic interior lighting control X
To switch on: set the switch to center
position B.
X To switch off: set the switch to the |
position.
The interior lighting automatically switches
on if you: R unlock the vehicle
R open a door
R remove the SmartKey from the ignition
lock.
The interior light is activated for a short while when the SmartKey is removed from the igni-
tion lock. This delayed switch-off can be
adjusted using COMAND or Audio 20 (see the separate Operator's Manual).
Manual interior lighting control X
To switch the front interior lighting on:
set the switch to the cposition.
X To switch the front interior lighting off:
set the switch to the |position or (if the
door is closed) to the center position.
X To switch the rear interior lighting on/
off: press the ubutton.
X To switch the reading lamps on/off:
press the pbutton. Crash-responsive emergency lighting
The interior lighting is activated automatically
if the vehicle is involved in an accident.
X To switch off the crash-responsive
emergency lighting: press the hazard
warning lamp button.
or X Lock and then unlock the vehicle using the
SmartKey. Replacing bulbs
Important safety notes
Xenon bulbs G
DANGER
Xenon bulbs carry a high voltage. You can get an electric shock if you remove the cover of
the Xenon bulb and touch the electrical con-
tacts. There is a risk of fatal injury.
Never touch the parts or the electrical con-
tacts of the Xenon bulb. Always have work on
the Xenon bulbs carried out at a qualified spe-
cialist workshop.
If your vehicle is equipped with Xenon bulbs,
you can recognize this by the following: the
cone of light from the Xenon bulbs moves
from the top to the bottom and back again
when you start the engine. For this to be
observed, the lights must be switched on
before starting the engine.
Bulbs and lamps are an important aspect of
vehicle safety. You must therefore make sure that these function correctly at all times.
Have the headlamp setting checked regularly.
Other bulbs G
WARNING
Bulbs, lamps and connectors can get very hot when operating. If you change a bulb, you
could burn yourself on these components.
There is a risk of injury.
Allow these components to cool down before changing a bulb. 116
Replacing bulbsLights and windshield wipers

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