check engine MERCEDES-BENZ CLA 2018 User Guide

Problem
Possible causes/consequences and P Solutions
The engine does not
start. You cannot hear
the starter motor. The on-board voltage is too low because the battery is too weak or
discharged. X
Jump-start the vehicle ( Y
page 278).
If the engine does not start despite attempt stoj ump-start it:X
Consult aq ualified specialist workshop.
The starter motor was exposed to at hermal load that was too high.X
Allow the starter motor to cool down for approximately two minutes. X
Try to start the engine again.
If the engine still does not start: X
Consult aq ualified specialist workshop.
The engine is not running
smoothly and is misfir-
ing. There is am alfunction in the engine electronics or in am echanical
componen toft he engine management system.X
Only depress the accelerator pedal slightly.
Otherwise, non-combusted fuel may get into the catalytic converter
and damage it. X
Have the cause rectified immediately at aq ualified specialist work-
shop.
The coolant temperature
gauge shows av alue
above 248 ‡( 120 †).
The coolant warning
lamp may also be on and
aw arning 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 260). Observe the warning notes
as you do so and add coolant if necessary.
DYNAMIC SELEC Tb utton (all vehicles
except Mercedes-AMG vehicles) Use the DYNAMIC SELECT button to change the
drive program. Depending on the drive program
selected the following vehicle characteristics
will change: R
the drive (engine and transmission manage-
ment) R
the suspension (vehicles with damping sys-
tem or AMG adaptive sport suspension sys-
tem) R
the steering R
the availability of the ECO start/stop function R
the climate control:
Each time you start the engine with the Smart-
Key or the Start/Stop button, drive program C is
activated. For further information about starting
the engine, see ( Y
page 125). X
Press DYNAMIC SELECT button C as many
times as necessary until the desired drive
program is selected.
The selected drive program appears in the
multifunction display .A fter five seconds the
display goes out and the status icon of the
selected drive program appears.128
DYNAMIC SELECT button (all vehicles except Mercedes-AMG vehicles)
Driving and parking

Transmission positions E Park position
Thi sp revents the vehicl ef ro mr olling
away when stopped.
Onl ys hift the transmission to posi-
tion ] when the vehicl eiss tation-
ary. The parkin gl oc ks houl dn ot be
used as ab rake when parking.
Alway sa pply the electronic parking
brake in additio ntot he parkin gl oc k
in order to secur et he vehicle.
In the event of am al functio noft he
vehicle's electronics ,t he transmis-
sion ma yl oc kinp osit ion ] .H ave
the vehicl ee le ctronics checked
immediatel yataq uali fied specialist
workshop.
Park position ] is automatically
engaged if: R
yo us wi tch off the engine using the
SmartKe ya nd remove the Smart-
Key R
yo us wi tch off the engine using the
SmartKe yoru si ng the Start/Stop
button and open the driver's door
or front-passenge rd oo rR
yo uo pe nt he driver's door when
the vehicl eiss tationar yorw he n
drivin gatav er yl ow spee da nd the
transmission is in position [ or
^
F Revers eg ea r
Onl ys hift the transmission into posi-
tion ^ when the vehicl eiss tation-
ary. D Neutral
Do not shift the transmission to \\
whil ed riving. The automatic trans-
mission could otherwis ebed am -
aged.
No powe rist ransmitted fro mt he
engine to the drive wheels.
Releasing the brakes will allo wy ou to
mov et he vehicl ef reely, e.g .top us h
it or tow it.
If ESP ®
is deactivated or faulty: shift
the transmission to position \\ if the
vehicl eisind an ge rofs kidding ,e .g.
on icy roads.
If yo us wi tch the engine off with the
transmission in position ^ or [ ,
the automatic transmission shifts to
\\ automatically.
! Coasting in neutral \\ may
cause damage to the drive train.
: Drive
The automatic transmission changes
gear automatically. All forward gears
ar ea vailable.
Driving tips
Changin gg ea rThe automatic transmission shifts throug ht he
individual gear sa ut omaticall yw he nitisint rans-
mission position [ .T hi sa ut omatic gear shift-
ing behavio risd et ermine db y:R
the selecte dd rive program R
the positio noft he accelerator pedal R
the roa ds peed
Accelerator peda lp ositionYour style of drivin gi nfluences how the auto-
matic transmission shifts gear: R
little throttle :e ar ly upshifts R
mor et hrottle :l at eu ps hiftsAutomati ct ransmission 133
Driving an dp arking Z

Befor et he engine speed reaches the red area,
an upshift indicator will be show nint he multi-
function display. X
Shift to recommende dg ear C whe nm es-
sage D is show nint he multifunction display.
Kickdown X
For maximum acceleration, depress the
accelerator pedal beyond the pressure point.
The automatic transmission shifts to al ower
gea rd epending on the engine speed.X
Shift back up once the desire ds peed is
reached. During kickdown, yo uc annot shift gears using
the steering wheel paddl es hifters.
If yo ua pply ful lt hrottle ,t he automatic trans-
missio ns hifts up to the next gea rw he nt he
maximum engine speed is reached .T hi sp re-
vents the engine from overrevving.
Mercedes-AMG vehicles: it is only possible to
use kickdown in temporary manual drive pro-
gram M .W he nm anual drive program M is per-
manently activated, kickdown is not possible.
Problems with the transmission Problem
Possible causes/consequence sa nd P Solutions
The transmission has
problem ss hifting gear. The transmission is losing oil. X
Have the transmission checke dataq uali fied specialist workshop
immediately.
The acceleration ability
is deteriorating.
The transmission no lon-
ger shifts into al loft he
gears.
Revers eg ea rc an no lon-
ger be engaged. The transmission is in emergency mode. X
Stop the vehicle. X
Shift the transmission to position ] .X
Switch off the engine. X
Wait at least ten seconds before restarting the engine. X
Shift the transmission to position [ .X
Have the transmission checke dataq uali fied specialist workshop
immediately.
Refueling
Important safety notes
G WARNING
Fue lish ighly flammable. If yo uh andle fuel
incorrectly ,t here is ar is koff ire and explo-
sion. You mus ta void fire ,o pe nf lames, creating
sparks and smoking. Switch off the engine
and ,ifa ppli cable, the auxiliary heating before
refueling.
G WARNING
Fue lisp oisonou sa nd hazardou stoh ealth.
There is ar isk of injury.138
Refueling
Drivin ga nd parking

Warning/
indicator
lamp Q Signal type
Possibl ec auses/consequences and P Solutions
$I
Q 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 additiona ld isplay messages in the multifunction display.
u
Q The red restraint system warning lamp is lit while the engine is running.
The restraint system is malfunctioning.
G WARNING
The air bag sorE mergency Tensioning Devices may either be triggere du ninten-
tionally or, in the event of an accident, may not be triggered.
There is an increased risk of injury. X
Observe the additiona ld isplay messages in the multifunction display.X
Drive on carefully. X
Contact aq ualified specialist worksho pa nd have the restraint system checked.
For further information about the restraint system, see ( Y
pag e4 0).
Engine Warning/
indicator
lamp Q Signal type
Possibl ec auses/consequences and P Solutions

the househol dr ubbish .T hey
must be collected separately
and recycle dtop rotect the
environment.
Dispose of batteries in an
environmentall yf riendly
manner. Take discharged
batteries to aq uali fied spe-
cialist workshop or as pe cial
collectio np oi nt for used bat-
teries.
! Hav et he battery checked regularly at a
qualified specialis tw or kshop.
Observe the service intervals in the Mainte-
nanc eB ookle torc ontact aq uali fied specialist
workshop for mor ei nformation.
! Yo us houl dh av ea ll work involvin gt he bat-
tery carrie do ut at aq uali fied specialis tw or k-
shop. In the exceptiona lc as et ha titi sn eces-
sary for yo utod is connect the battery your-
self, make sure that: R
yo us wi tch off the engine and remove the
key .Onv ehicles with KEYLESS-GO, ensure
tha tt he ignition is switched off .C he ck that
al lt he indicator lamps in the instrument
cluste ra re off .O therwise, electronic com-
ponents ,s uc hast he alternator, ma yb e
damaged. R
yo uf irst remove the negative terminal
clamp and the nt he positive terminal
clamp. Never swap the termina lc lamps.
Otherwise, the vehicle' se le ctronic system
ma ybed amaged .R
in vehicles with automatic transmission,
the transmission is locked in position P
after disconnecting the battery .T he vehicle
is secur ed a gainst rolling away .Y ou ca
n
the nnol on ge rm ov et he vehicle.
The battery and the cove roft he positive ter-
minal clamp must be installe ds ec urel yd ur ing
operation.
Compl yw it hs af ety precautions and take pro-
tective measures when handling batteries. Risk of explosion.
Fire, open flames and smoking are
prohibited when handling the bat-
tery .A voi dc reating sparks.
Battery aci disc austic. Avoi dc ontact
with skin, eyes or clothing.
Wear suitabl ep rotective clothing,
especiall yg lo ves, apron and face-
guard.
Rinse any aci ds pills immediately
with clear water. Contact ap hysician
if necessary.
Wear ey ep rotection.
Kee pc hildren away.
Observe thi sO pe rator' sM an ual.
For safety reasons, Mercedes-Benz recom-
mend st ha ty ou onl yu se batteries which have
been tested and approved for your vehicl eb y
Mercedes-Benz. Thes eb at teries provide
increase di mpact protection to prevent vehicle
occupants fro ms uf ferin ga ci db ur ns shoul dt he
battery be damage dint he event of an accident.
In order for the battery to achieve the maximum
possibl es er vice life, it must always be suffi-
ciently charged.
Like othe rb at teries ,t he vehicl eb at tery may
discharge ove rt im eify ou do not us et he vehicle.
In thi sc ase, have the battery disconnecte data
qualified specialis tw or kshop .Y ou can also
charge the battery with ac harge rr ecommended
by Mercedes-Benz. Contact aq uali fied special-
is tw or kshop for furthe ri nformation.
Hav et he battery condition of charge checked
mor ef requentl yify ou us et he vehicl em ai nl yf or
short trip sorify ou leav eits tanding idle for a
length yp er iod. Consult aq uali fied specialist
workshop if yo uw is htol eave your vehicle
parked for al on gp er io doft ime.
Onl yr eplace ab at tery with ab at tery tha th as
been recommended by Mercedes-Benz.Battery (vehicle) 277
Breakdow na ssistance Z

G WARNING
During charging and jump-starting, explosive gase sc an escap ef rom the battery .T here is ar isk
of an explosion.
Particularl ya voi df ire, open flames, creating sparks and smoking. Ensure there is sufficient ven-
tilation while charging and jump-starting. Do not lea no ver ab attery.
G WARNING
During the charging process ,ab attery produces hydrogen gas. If as hort circui to ccurs or sparks
are created ,t he hydrogen gas can ignite. There is ar isk of an explosion.R
Make sure that the positive terminal of ac onnected battery does not come into contact with
vehicl ep arts.R
Never place metal objects or tools on ab attery.R
It is important that you observe the described order of the battery terminal sw hen connecting
and disconnecting ab attery.R
When jump-starting, make sure that the battery pole sw ith identical polarity are connected.R
It is particularl yi mportant to observe the described order when connecting and disconnecting
the jumper cables. R
Never connect or disconnect the battery terminal sw hile the engine is running.
G WARNING
Ad ischarged battery can freeze at temperatures below freezing point. When jump-starting the
vehicl eorc harging the battery ,g ase sc an escap ef rom the battery .T here is ar isk of an explosion.
Allow the frozen battery to thaw out before charging it or jump-starting.
! Avoid repeated and lengthy starting attempts. Otherwise, the catalytic converter coul db e
damaged by the non-combusted fuel.
If the indicator/warning lamp sdon ot light up in the instrument cluster at low temperatures, it is very
likel yt hat the discharged battery has frozen. In this case you may neither jump-start the vehicl en or
charge the battery .L et the battery thaw first. The service life of at hawed-out battery may be shorter.
The starting characteristics can be impaired ,p articularl yatl ow temperatures. Have the thawed-out
battery checked at aq ualified specialist workshop.
Do not start the vehicl eu sing ar api dc harging device. If you rv ehicle's battery is discharged, the
engine can be jump-started from another vehicl eorf rom as econd battery using jumper cables.
Observe the following points: R
The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible ,j ump-
start the vehicl eu sing as econd battery or aj ump-starting device.R
You may only jump-start the vehicl ew hen the engine and exhaust system are cold.R
Do not start the engine if the battery is frozen. Let the battery thaw first. R
Only jump-start from batterie sw ith a12Vv oltag er ating.R
Only use jumper cables that are not damaged and have as ufficient cross-section and insulated
terminal clamps. R
Make sure that the two vehicles do not touch. Jump-starting 279
Breakdown assistance Z

Tire-mounting tools should not be used near
the valve. This could damage the electronic
components.
Only have tires changed at aq ualified spe-
cialist workshop.
Observe the instructions and safety notes in the
"Changing aw heel" section ( Y
page 307).
The wear pattern sont he front and rear tires
differ, depending on the operating conditions.
Rotate the wheels before ac lear wear pattern
has formed on the tires. Fron tt ires typically
wear more on the shoulders and the rear tires in
the center.
On vehicles that have the same size front and
rear wheels, you can rotat et he wheels accord-
ing to the intervals in the tire manufacturer's
warranty book in your vehicle documents. If no
warranty book is available, the tires should be
rotated every 3,000 to 6,000 miles (5,000 to
10,00 0k m) .D ependin gont ire wear, this may
be required earlier. Do not change the direction
of wheel rotation.
Clean the contact surfaces of the wheel and the
brake disc thoroughly every time aw heel is rota-
ted. Check the tire pressure and, if necessary,
restart the tire pressure loss warning system
(Canada only) or the tire pressure monitor (USA
only).
Direction of rotation Tires with as pecified direction of rotation have
additional benefits ,e .g. if there is ar isk of hydro-
planing. These advantages can only be gained if
the tires are installed corresponding to the
direction of rotation.
An arrow on the sidewall of the tire indicates its
correc td irection of rotation.
Storing wheels Stor ew heels that are not being used in ac ool,
dry and preferably dark place. Protec tt he tires
from oil, grease, gasoline and diesel. Mounting aw heel
Preparing the vehicle X
Stop the vehicle on solid, non-slippery and
level ground. X
Apply the electric parking brake manually. X
Bring the front wheels into the straight-ahead
position. X
Shift the transmission to position ] .X
Switch off the engine. X
Vehicles without KEYLESS-GO: remove the
SmartKey from the ignition lock. X
Vehicles with KEYLESS-GO start-function
or KEYLESS-GO: open the driver's door.
The vehicle electronics are now in position

The antifreeze concentrate/corrosion inhibitor
concentration in the engine cooling system
should: R
be at least 50%. This will protec tt he engine
cooling system against freezin gd own to
approximately -35 ‡( -37 †)R
not exceed 55% (antifreez ep rotection down
to -49 ‡[ -45 †]) .O th erwise ,h ea tw ill no tb e
dissipated as effectively
Mercedes-Ben zr ecommends ac oo lan torc or -
rosio ni nh ibitor/antifreez ec oncentrat ei n
accordance wit h
MB Specification sf or Servic eP ro ducts 310. 1.
i When the vehicle is first delivered, it is filled
with ac oolant mixture that ensures adequate
antifreeze and anti-corrosion protection.
i The coolant is checked with every mainte-
nanc ei nterval at aq ualified specialist work-
shop.
Filling capacities Model Capacity
Mercedes ‑ AMG
vehicles Approx .1 2. 6USq t
(11. 9l )
Al lo th er models
Approx. 8.2 US qt
(7.8 l)
Windshield washe rs ystem
Important safety notes
G WARNING
Windshiel dw as her concentrate coul di gnite if
it comes into contact with hot engine compo-
nents or the exhaust system .T here is ar isk of
fire and injury.
Make sure that no windshield washer con-
centrate is spilled next to the filler neck.
! Only MB SummerFi ta nd MB WinterFit
washer flui ds hould be mixed together. The
spra yn ozzles may otherwise become
blocked.
Do not use distille dord e-ionized water. Other-
wise, the leve ls ensor may give af als er eading. When handling washer fluid, observe the impor-
tant safety notes on service products
( Y
pag e3 15).
At temperatures above freezing: X
Fill the washer flui dr eservoir with am ixture of
water and windshield washer fluid, e.g. MB
SummerFit.
Add 1p art MB SummerFi tto1 00 parts water.
At temperatures below freezing: X
Fill the washer flui dr eservoir with am ixture of
water and washer fluid, e.g. MB WinterFit.
For the correct mixing ratio refer to the infor-
mation on the antifreeze reservoir.
i Add windshield washer fluid, e.g. MB Sum-
merFit or MB WinterFit, to the washer flui da ll
yea rr ound.
Climate control system refrigerant
Important safety notes The climate control system of you rv ehicl eisf il-
led with refrigerant R ‑ 134a.
The instruction label regarding the refrigerant
type use dc an be found on the left, on the under-
side of the hood.
! Only the refrigerant R ‑ 134a and the PAG oil
approved by Mercedes-Benz may be used.
The approved PAG oil may not be mixed with
any other PAG oil that is not approved for
R-134a refrigerant. Otherwise, the climate
control system may be damaged.
Service work, such as refilling with refrigerant or
replacing component parts, may only be carried
out by aq ualified specialist workshop. All appli-
cabl er egulations, as wel lasS AE standard J639,
must be adhered to.
Always have work on the climate control system
carrie do ut at aq ualified specialist workshop.Service products and filling capacities 319
Technical data Z