check engine MERCEDES-BENZ CLA 2016 Owner's Manual

Problems with the transmission Problem
Possible causes/consequences and P Solutions
The transmission has
problems shifting gear. The transmission is losing oil. X
Have the transmission checked at a qualified specialist work-
shop immediately.
The acceleration ability
is deteriorating.
The transmission no
longer shifts into all of
the gears.
Reverse gear can no
longer be engaged. The transmission is in emergency mode. X
Stop the vehicle. X
Shift the transmission to position P .X
Switch off the engine. X
Wait at least ten seconds before restarting the engine. X
Shift the transmission to position D .X
Have the transmission checked at a qualified specialist work-
shop immediately.
Refueling
Important safety notes
G WARNING
Fuel is highly flammable. If you handle fuel
incorrectly, there is a risk of fire and explo-
sion.
You must avoid fire, open flames, creating
sparks and smoking. Switch off the engine
and, if applicable, the auxiliary heating before
refueling.
G WARNING
Fuel is poisonous and hazardous to health.
There is a risk of injury.
You must make sure that fuel does not come
into contact with your skin, eyes or clothing
and that it is not swallowed. Do not inhale fuel
vapors. Keep fuel away from children.
If you or others come into contact with fuel,
observe the following: R
Wash away fuel from skin immediately
using soap and water. R
If fuel comes into contact with your eyes,
immediately rinse them thoroughly with clean water. Seek medical assistance with-
out delay. R
If fuel is swallowed, seek medical assis-
tance without delay. Do not induce vomit-
ing. R
Immediately change out of clothing which
has come into contact with fuel.
G WARNING
Electrostatic buildup can create sparks and
ignite fuel vapors. There is a risk of fire and
explosion.
Always touch the vehicle body before opening
the fuel filler flap or touching the fuel pump
nozzle. Any existing electrostatic buildup is
thereby discharged.
! Do not use diesel to refuel vehicles with a
gasoline engine. Do not switch on the igni-
tion if you accidentally refuel with the
wrong fuel. Otherwise, the fuel will enter
the fuel system. Even small amounts of the
wrong fuel could result in damage to the
fuel system and the engine. Notify a quali-
fied specialist workshop and have the fuel
tank and fuel lines drained completely. Refueling 167
Driving and parking Z

Servicing the brakes
! The brake fluid level may be too low, if: R
if the red brake warning lamp lights up in
the instrument cluster and R
you hear a warning tone while the engine
is running
Observe additional warning messages in
the multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked immedi-
ately. Consult a qualified specialist work-
shop to arrange this.
! A function or performance test should
only be carried out on a 2-axle dynamom-
eter. If you wish to operate the vehicle on
such a dynamometer, please consult a
qualified specialist workshop in advance.
You could otherwise damage the drive train
or the brake system.
! As the ESP ®
system operates automati-
cally, the engine and the ignition must be
switched off (the SmartKey must be in posi-
tion 0 or 1 in the ignition lock) if:R
the electric parking brake is tested on a
brake dynamometer (for a maximum of
ten seconds) R
the vehicle is towed with the front axle
raised.
Braking triggered automatically by ESP ®
may seriously damage the brake system.
All checks and maintenance work on the
brake system must be carried out at a quali-
fied specialist workshop.
Have brake pads installed and brake fluid
replaced at a qualified specialist workshop.
If the brake system has only been subject to
moderate loads, you should test the function-
ality of your brakes at regular intervals.
You can find a description of Brake Assist
(BAS) on ( Y
page 66).
Mercedes-Benz recommends that you only
have brake pads/linings installed on your vehicle which have been approved for
Mercedes-Benz vehicles or which correspond
to an equivalent quality standard. Brake
pads/linings which have not been approved
for Mercedes-Benz vehicles or which are not
of an equivalent quality could affect your vehi-
cle's operating safety.
Mercedes-Benz recommends that you only
use brake fluid that has been specially
approved for your vehicle by Mercedes-Benz,
or which corresponds to an equivalent quality
standard. Brake fluid which has not been
approved for Mercedes-Benz vehicles or
which is not of an equivalent quality could
affect your vehicle's operating safety.
Checking brake lining thickness You can measure the break pad/lining thick-
ness using a test gage. Color-coding (green or
red) on the test gage allows you to determine
whether the brake pad/lining thickness is still
sufficient. The test gage is in the vehicle docu-
ment wallet in the glove box.
Front wheel176
Driving tips
Driving and parking

Display messages
Possible causes/consequences and P Solutions
' (USA
only)
M (Canada
only)
Check Brake Fluid
Level There is no t enough brak e flui d in th e brak e flui d reservoir .
A warnin g tone sounds. The ' (US A only) or M (Canada
only) warnin g lamp s in th e instrumen t cluster may also ligh t up.
G WARNIN G
The brakin g effec t may be impaired.
There is a ris k of an accident. X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions. Do no t continue drivin g
under any circumstances. X
Secur e th e vehicl e against rollin g away ( Y
page 169).X
Consult a qualified specialist workshop .X
Do no t add brak e fluid. This does no t correc t th e malfunction .
& Check Brake Pad
Wea r The brak e pads/lining s hav e reached their wear limit.X
Visit a qualified specialist workshop .
S Inoperative On e or mor e main features of th e mbrace system are malfunc -
tioning. X
Visit a qualified specialist workshop .
Collision Preven ‐
tio n Assist Plu s
Currently Unavail‐
abl e See Opera‐
tor's Manual COLLISION PREVENTION ASSIST PLU S is temporarily no t opera-
tional.
Possibl e causes are: R
th e rada r sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radi o sta-
tion s or other source s of electromagnetic radiation .R
th e system is outside th e operating temperature range.R
th e on-boar d voltag e is to o low.
Whe n th e causes state d abov e no longer apply, th e display mes -
sage disappears.
COLLISION PREVENTION ASSIST PLU S is operational again .
If th e display message does no t disappear :X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 169).X
Restart th e engine.234
Display messages
On-board computer and displays

Problem
Possible causes/consequences and P Solutions
I (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.
u
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
Contact a qualified specialist workshop and have the restraint
system checked.
For further information about the restraint system, see
( Y
page 42).266
Warning and indicator lamps in the instrument cluster
On-board computer and displays

Problem
Possible causes/consequences and P SolutionsX
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 299). X
If you have to add 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 snow, slush or ice. X
At coolant temperatures below 248 ‡ (120 †), 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.
Driving systems
Problem
Possible causes/consequences and P Solutions

Checking the oil level using the oil dip-
stick
G WARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and
touch only the components described in the
following.
Example X
Pull oil dipstick C out of the dipstick guide
tube. X
Wipe off oil dipstick C .X
Slowly slide oil dipstick C into the guide
tube to the stop, and take it out again.
If the level is between MIN mark

Example: engine oil cap X
Turn cap C counter-clockwise and remove
it. X
Add engine oil.
If the oil level is at or below the MIN mark on
the oil dipstick, add 1.1 US qt (1.0 l) of
engine oil. X
Replace cap C on the filler neck and turn
clockwise.
Ensure that the cap locks into place
securely. X
Check the oil level again with the oil dip-
stick ( Y
page 298).
Further information on engine oil
( Y
page 368).
Checking and adding other service
products
Checking coolant level
G WARNING
The cooling system is pressurized, particularly
when the motor 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. Slowly
open the cap to relieve pressure.
! The coolant may only be checked and cor-
rected when the engine is cool (coolant
temperature below 104 ‡ (40 †). Check-
ing the coolant when the coolant tempera-
ture is above 104 ‡ (40 †) may result in
damage to the engine or to the engine cool-
ing system. Example X
Park the vehicle on a level surface.
Only check the coolant level when the vehi-
cle is on a level surface and the engine has
cooled down. X
Turn the SmartKey to position 2 in the igni-
tion lock ( Y
page 147). X
Check the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
104 ‡ (40 †). X
Turn the SmartKey to position 0 in the igni-
tion lock ( Y
page 147). X
Slowly turn cap C counter-clockwise and
to relieve excess pressure. X
Turn cap C further counter-clockwise and
remove it.
If the coolant is at the level of marker bar

Vehicles equipped with MOExtended tires are
not equipped with a TIREFIT kit at the factory.
It is therefore recommended that you addi-
tionally equip your vehicle with a TIREFIT kit if
you mount tires that do not feature run-flat
properties, e.g. winter tires. A TIREFIT kit may
be obtained from a qualified specialist work-
shop.
Information on changing and mounting
wheels ( Y
page 351).X
Stop the vehicle on solid, non-slippery and
level ground, as far away as possible from
traffic. X
Switch on the hazard warning lamps. X
Secure the vehicle against rolling away
( Y
page 169). X
If possible, bring the front wheels into the
straight-ahead position. X
Switch off the engine. X
Vehicles without KEYLESS-GO: remove
the SmartKey from the ignition lock. X
Vehicles with KEYLESS-GO start-func-
tion or KEYLESS-GO: open the driver's
door.
The on-board electronics now have status
0 . This is the same as the SmartKey having
been removed. X
Vehicles with KEYLESS-GO start-func-
tion or KEYLESS-GO: remove the Start/
Stop button from the ignition lock
( Y
page 147). X
Make sure that the engine cannot be star-
ted via your smartphone ( Y
page 169).X
Make sure that the passengers are not
endangered as they do so. Make sure that
no one is near the danger area while a
wheel is being changed. Anyone who is not
directly assisting in the wheel change
should, for example, stand behind the bar-
rier. X
Get out of the vehicle. Pay attention to traf-
fic conditions when doing so. X
Close the driver's door. MOExtended tires (tires with run-flat
properties)
General notes With MOExtended tires (tires with run flat
characteristics), you can continue to drive
your vehicle even if there is a total loss of
pressure in one or more tires. The affected
tire must not show any clearly visible damage.
You can recognize MOExtended tires by the
MOExtended marking which appears on the
sidewall of the tire. You will find this marking
next to the tire size designation, the load-
bearing capacity and the speed index
( Y
page 345).
MOExtended tires may only be used in con-
junction with an active tire pressure loss
warning system or with an active tire pressure
monitor.
If a pressure loss warning message
appears in the multifunction display: R
observe the instructions in the display mes-
sages ( Y
page 250). R
check the tire for damage. R
if driving on, observe the following notes.
The driving distance possible in run-flat mode
is approximately 50 miles (80 km) when the
vehicle is partially laden. When the vehicle is
fully laden it is approximately 19 miles
(30 km).
In addition to the vehicle load, the driving dis-
tance possible depends upon: R
vehicle speed R
road condition R
outside temperature
The driving distance possible in run-flat mode
may be reduced by extreme driving condi-
tions or maneuvers, or it can be increased
through a moderate style of driving.
The driving distance possible in run-flat mode
is counted from the moment the tire pressure
loss warning appears in the multifunction dis-
play. Flat tire 311
Breakdown assistance

should have all work involving the battery car-
ried out at a qualified specialist workshop.
For further information about ABS and ESP ®
,
see ( Y
page 65) and ( Y
page 69).
G WARNING
Electrostatic build-up can lead to the creation
of sparks, which could ignite the highly explo-
sive gases of a battery. There is a risk of an
explosion.
Before handling the battery, touch the vehicle
body to remove any existing electrostatic
build-up.
The highly flammable gas mixture forms when
charging the battery as well as when jump-
starting.
Always make sure that neither you nor the
battery is electrostatically charged. A build-
up of electrostatic charge can be caused, for
example: R
by wearing clothing made from synthetic
fibers R
due to friction between clothing and seats R
if you push or pull the battery across the
carpet or other synthetic materials R
if you wipe the battery with a cloth
G WARNING
During the charging process, a battery produ-
ces 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 con-
tact with vehicle parts. R
Never place metal objects or tools on a bat-
tery. R
It is important that you observe the descri-
bed 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 dis-
connecting the jumper cables. R
Never connect or disconnect the battery
terminals while the engine is running.
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.
H Environmental note
Batteries contain dangerous
substances. It is against the
law to dispose of them with
the household rubbish. They
must be collected separately
and recycled to protect the
environment.
Dispose of batteries in an
environmentally friendly
manner. Take discharged
batteries to a qualified spe-
cialist workshop or a special
collection point for used bat-
teries.
! Have the battery checked regularly at a
qualified specialist workshop.
Observe the service intervals in the Main-
tenance Booklet or contact a qualified spe-
cialist workshop for more information.
! You should have all work involving the
battery carried out at a qualified specialist
workshop. In the exceptional case that it is
necessary for you to disconnect the battery
yourself, make sure that: R
you switch off the engine and remove the
key. On vehicles with KEYLESS-GO,
ensure that the ignition is switched off.
Check that all the indicator lamps in the
instrument cluster are off. Otherwise,316
Battery (vehicle)
Breakdown assistance

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 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 319).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 319).
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
Mercede s-Benz C enter for further informa-
ti on and availability. Read the battery charg-
er's operating instructions before charging
the battery.318
Battery (vehicle)
Breakdown assistance