light MERCEDES-BENZ SLC 2018 Service Manual

Problems with the windshield wipers Problem
Possible causes/consequences and P Solutions
The windshield wipers
are jammed. Leaves or snow, for example, may be obstructing the windshield wiper
movement .T he wiper motor has been deactivated. X
For safety reasons, you should remove the SmartKey from the igni-
tion lock.
or X
Switch off the engine using the Start/Stop button and open the
driver's door. X
Remove the cause of the obstruction. X
Switch the windshield wipers back on.
The windshield wipers
fail completely. The windshield wiper drive is malfunctioning. X
Select another wiper speed on the combination switch. X
Have the windshield wipers checked at aq ualified specialist work-
shop.
The windshield washer
fluid from the spray noz-
zles no longer hits the
center of the windshield. The spray nozzles are misaligned. X
Have the spray nozzles adjusted at aq ualified specialist workshop.Windshield wipers 103
Lights and windshiel dw ipers Z

ECO start/stop function During automatic engine switch-off ,t he climate
control system only operate satar educed capa-
city. If you require full climate control capacity,
th eE CO start/sto pf unction can be deactivated
by pressin gt he ECO button ( Y
page 120).
Operating th ec limat ec ontrol sys-
tems
Activating/deactivatin gc limat ec on-
trol
General notes When th ec limate control is switched off ,t he air
supply and air circulation are also switched off.
The windows coul df og up. Therefore, switch off
climate control only briefly
i Activate climate control primarily usin gt he
X butto n( Y
page 109).
Air-conditioning system X
Turn th eS ma rtKey to position H in th ei gni-
tio nl oc k( Y
page 116).X
To switch on: tur na irflow control k clock-
wise to th ed esired position (excep tp osition
0 )( Y
page 104).X
To switch off: tur na irflow control k coun-
ter-clockwise to position 0 ( Y
page 104).
3-zone automatic climat ec ontrolX
Turn th eS ma rtKey to position H in th ei gni-
tio nl oc k( Y
page 116).X
To switch on: pres st he X button.
The indicator lamp in the X button lights
up. Airflow and air distribution are set to auto-
matic mode.
or X
Press the x button.
The indicator lamp in the x button goes
out .T he previously selecte ds ettings are
restored. X
To switch off: pres st he x button.
The indicator lamp in the x button lights
up. Switching cooling with air dehumidi-
fication on/off
General notes If you deactivate th e" Coolin gw ith air-dehumid-
ification" function ,t he air inside th ev ehicle will
no tbec ooled. The air inside th ev ehicle will also
no tbed ehumidified. The windows can fog up
mor eq uickly. Therefore, deactivate th ec ooling
with air-dehumidification function only briefly.
The "Coolin gw ith air dehumidification "f unction
is only availabl ew hen th ee ngine is running. The
air inside th ev ehicle is cooled and dehumidified
according to th et em peratur es elected.
Condensation may drip from th eu ndersid eo f
th ev ehicle when it is in cooling mode. This is
normal and no tas ign that there is am alfunc-
tion.
Activating/deactivating X
To activate: pres st he Z or V button.
The indicator lamp in the Z or V button
light su p. X
To deactivate: pres st he Z or V but-
ton.
The indicator lamp in the Z or V button
goes out .T he "Coolin gw ith air dehumidifica-
tion" function has ad elayed switch-off fea-
ture.108
Operating th ec limate control systems
Climate control

Problems with the "Cooling with air dehumidification" function Problem
Possible causes/consequences and P Solutions
The indicator lamp in the
Z or V button
flashes three times or
remains off. The "Cool-
ing with air dehumidifi-
cation" function cannot
be switched on. Cooling with air dehumidification has been deactivated due to am al-
function. X
Visit aq ualified specialist workshop.
Setting climate control to automatic
General notes Automatic mode is only available with 3-zone
automatic climate control.
In automatic mode, the set temperature is main-
tained automatically at ac onstant level. The
system automatically regulates the temperature
of the dispensed air, the airflow and the air dis-
tribution.
The automatic mode functions optimally when
the "Cooling with air dehumidification" function
is activated. If necessary, cooling with air dehu-
midification can be deactivated.
If you deactivate the "Cooling with air-dehumid-
ification" function, the air inside the vehicle will
not be cooled. The air inside the vehicle will also
not be dehumidified .T he windows can fog up
more quickly. Therefore, deactivate the cooling
with air-dehumidification function only briefly.
Automatic control X
Turn the SmartKey to position H in the igni-
tion lock ( Y
page 116).X
Set the desired temperature. X
To activate: press the X button.
The indicator lamp in the X button lights
up. Automatic air distribution and airflow are
activated. X
To switch to manua lm ode: press the

Problems with the rear window defroster Problem
Possible causes/consequences and P Solutions
The indicator lamp on
the l button flashes.
The rear window
defroster has deactiva-
ted prematurely or can-
not be activated. The on-board voltage is too low because too many electrical consum-
ers are switched on. X
Switch off any consumers that are not required, e.g. reading lamps,
interior lighting or the seat heating.
When the battery is sufficiently charged, the rear window defroster
can be activated again.
The roof is open. X
Close the roof.
When the roof is closed, the rear window defroster can be activated
again.
Switching air-recirculation mode
on/off
General notes If you switch on air-recirculation mode, the win-
dows can fog up more quickly, in particular at
low temperatures. Only use air-recirculation
mode briefly to prevent the windows from fog-
ging up.
Activating/deactivating X
Turn the SmartKey to position H in the igni-
tion lock ( Y
page 116).X
To activate: press the r button.
The indicator lamp in the r button lights
up.
i Air-recirculation mode is automatically acti-
vated at high levels of pollution (dual-zone
automatic climate control only) or at high out-
side temperatures. When air-recirculation
mode is activated automatically, the indicator
lamp in the r button is not lit. Outside air
is added after about 30 minutes. X
To deactivate: press the r button.
The indicator lamp in the r button goes
out. i Air-recirculation mode deactivates auto-
matically: R
after approximately five minutes at outside
temperatures below approximately 41 ‡
(5 †) R
after approximately five minutes if cooling
with air dehumidification is deactivated R
after approximately 30 minutes at outside
temperatures above approximately 41 ‡
(5 †) if the "Cooling with air dehumidifica-
tion" function is activated
Switching the residual heat on or off
General notes The residual heat function is only available on
vehicles for Canada.
It is possible to make use of the residual heat of
the engine to continue heating the stationary
vehicle for up to 30 minutes after the engine has
been switched off. The heating time depends on
the set interior temperature.
Activating/deactivating X
Turn the SmartKey to position

As soo na st he ignition is switched on, al lt he
indicator lamps in the instrument cluster light
up .F urther informatio nons it uations where an
indicator lamp either fails to go ou ta fte rs tarting
the engine or lights up whil ed riving
( Y
page 204).
If Start/Stop button C ha sn ot ye tb ee n
pressed, thi sc orrespond stot he key being
remove df rom the ignition.X
To switc hont he power supply: press
Start/Stop button C once.
The powe rs uppl yiss wi tched on. Yo uc an now
activate the windshield wipers, for example.
The powe rs uppl yiss wi tched off agai ni f:R
the driver's door is opene da ndR
yo up ress Start/Stop button C twice when
in thi sp ositionX
To switc hont he ignition: press Start/Stop
button C twice.
The ignition is switched on.
If yo up ress Start/Stop button C once when
in thi sp osit ion, the ignition is switched off
again.
Removing the Start/Sto pb uttonYo uc an remove the Start/Stop button from the
ignition lock and start the vehicl easn ormal
using the SmartKey. X
Remove Start/Stop button C from ignition
lock D .
Yo udon ot have to remove the Start/Stop but-
ton from the ignition lock when yo ul eave the
vehicle. Yo us hould, however, always take the
SmartKe yw it hy ou when leaving the vehicle. As
long as the Sma rtKe y isint h
e vehicle:R
the vehicl ec an be started using the Start/
Stop button R
the electrically powered equipment can be
operated
Starting the engine
Important safety notes
G WARNING
If children ar el ef tu nsupervised in the vehicle,
they could: R
operate the vehicle's equipment. Additionally, children could set the vehicl ei n
motion if, for example, they: R
release the parking brake R
shift the automatic transmission ou tofp ar k
position P R
start the engine
There is ar is kofana ccident and injury.
Never leav ec hildren or animals unattended in
the vehicle.
Whe nl eavi ng the vehicle, always take the
SmartKe yw it hy ou and lock the vehicle. This
also applie stom obil ep hones if the "Digital
Ca rK ey in smartphone "f un ctio ni sa ctivated
via the Mercedes me connect we ba pp .
G WARNING
Combustion engine se mi tp oiso nou se xhaust
gases such as carbo nm onoxide. Inhaling
thes ee xhaus tg as es lead stop oiso ning. There
is ar is koff ata li njury .T herefore neve rl eave
the engine running in enclose ds paces with-
ou ts uf ficient ventilation.
G WARNING
Flammabl em at erial si ntroduced through
environmenta li nfluence or by animals can
ignite if in contact with the exhaus ts ys tem or
parts of the engine tha th ea tu p. There is ar isk
of fire.
Carry ou tr egular checks to make sure that
ther ea re no flammabl ef oreig nm at erial si n
the engine compartment or in the exhaust
system.
During ac ol ds tart, the engine runs at higher
speed stoe nabl et he catalytic converter to
reach its operating temperature .T he sound of
the engine ma yc hange during thi st ime.
Automati ct ransmission X
Depres st he brake peda la nd kee pi t
depressed. X
Shift the transmission to position ] .
Transmission positio nd is play ] is shown in
the multifunctio nd is play.Driving 117
Driving an dp arking Z

Deactivating or activating th eE CO
start/stop function X
To deactivate : press EC Ob utto n C .
Indicator lamp D goe so ut .X
To activate : press EC Ob utto n C .
Indicator lamp D lights up.
If indicator lamp D is off, th eE CO start/sto p
function has bee nd eactivated manually or as
th er esult of am alfunction .T he engin ew ill then
no tbes witched of fa utomatically when th ev ehi-
cl es to ps .
Problem sw it ht he engin eProblem
Possible causes/consequences an d P Solutions
The engin ed oe sn ot
start . The HOLD function or Distanc eP ilo tD ISTR ONIC is activated.X
Deactivat et he HOLD function ( Y
page 148) or Distanc eP ilo t
DISTRONIC ( Y
page 146).X
Tr yt os ta rt th ee ng in ea gain .
The engin ed oe sn ot
start .T he starter moto r
can be heard. R
There is am alfunction in th ee ng in ee lectronics.R
There is am alfunction in th ef ue ls upply.
Before attemptin gtos ta rt th ee ng in ea gain :X
Tur nt he SmartKey bac ktop osition

Problem
Possible causes/consequences and P Solutions
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 235). Observe the warning notes
as you do so and add coolant if necessary.
If the coolant level is correct ,t he engine radiator fan may be faulty. The
coolant is too hot and the engine is no longer being cooled sufficiently. 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 moun-
tainou st errai na nd stop-and-go traffic.
DYNAMIC SELEC Tb uttonUse the DYNAMIC SELECT button to change the
drive program. Depending on the drive program
selected the following vehicle characteristics
wil lc hange: R
the drive (engine and transmission manage-
ment) R
the suspensio nort he adaptive adjustable
damping (only on vehicles with AMG RIDE
CONTROL sports suspension) R
the sound of the exhaust system (vehicles
with sports exhaust system) R
the steering R
the availability of the ECO start/stop function
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
pag e1 17). X
Press DYNAMIC SELECT button C as many
times as necessary until the desired drive
progra miss elected.
The selected drive progra ma ppears in the
multifunction display. After as hort period of
time, the displa yg oes out and the symbol for
the selected drive progra ma ppears.
In addition, the current drive progra ms ettings
are displayed briefly in the multimedi as ystem
display.
i In af ew countries, the ECO start/stop func-
tion is deactivated at the factory due to the
available fuel grade. In this case, the ECO
start/stop function is not available in anyDYNAMI CS ELEC Tb utton 121
Driving and parking Z

In addition to driving style, the actual consump-
tion is affected by other factors, such as: R
load R
tire pressure R
cold start R
choice of route R
active electrical consumers
These factors are not include dint he ECO dis-
play.
An economical driving style specially requires
driving at moderate engine speeds.
Achieving ah igher valu eint he categories
"Acceleration" and "Constant": R
observe the gearshift recommendations. R
drive the vehicle in drive program C or E .
In urba nt raffic and stop-start traffic, drive pro-
gram C is recommended.
On long journeys at ac onstant speed ,e .g. on the
highway, only the outer area for "constant" will
change.
The ECO display summarizes the driving style
from the start of the journey to its completion.
Therefore, there are more marked changes in
the outer area satt he start of aj ourney. On lon-
ger journeys, there are fewer changes. For more
marked changes, perform am anua lr est
( Y
page 167).
Further information on the ECO display
( Y
page 166).
Braking
Important safety notes
G WARNING
If you shift down on as lippery road surface in
an attempt to increase the engine's braking
effect, the drive wheel sc ould lose their grip.
There is an increased danger of skidding and
accidents.
Do not shift down for additional engine brak-
ing on as lippery road surface.
Downhill gradients
! On long, steep gradients, you must reduce
the load on the brakes. To use engine braking,
shift to al owe rg ear in good time. This helps you to avoid overheating the brakes and wear-
ing them out excessively.
When making use of the engine braking
effect, it is possible that ad rive wheel may not
turn for some time, e.g. in the case of sud-
denly changing or slippery road surface con-
ditions. This could cause damage to the drive
train. This type of damage is not covered by
the Mercedes-Benz warranty.
Change into al owe rg ear in good time on long
and steep downhill gradients. This is especially
important if the vehicle is laden.
This also applies if you have activated cruise
control or Distance Pilo tD ISTRONIC.
Heavy and light loads
G WARNING
If you rest you rf oot on the brake peda lw hile
driving, the braking system can overheat. This
increases the stopping distance and can even
cause the braking system to fail .T here is a
risk of an accident.
Never use the brake peda lasaf ootrest. Never
depres st he brake peda la nd the accelerator
peda latt he same time.
! Depressing the brake peda lc onstantly
results in excessive and premature wea rt o
the brake pads.
If the brakes have been subjected to ah eavy
load ,don ot stop the vehicle immediately ,b ut
drive on for as hort while. This allows the airflow
to cool the brakes more quickly.
Wet roads If you have driven for al ong time in heavy rain
withou tb raking, there may be ad elayed reac-
tion from the brakes when braking for the first
time. This may also occur after the vehicle has
been washed or driven through deep water.
You then have to depres st he brake peda lm ore
firmly .M aintai nag reater distance from the
vehicle in front.
After driving on aw et road or having the vehicle
washed, brake firmly whil ep aying attention to
the traffic conditions. This wil lw arm up the
brake discs, thereby drying them more quickly
and protecting them against corrosion.136
Driving tips
Driving and parking

Limited braking performance on salt-
treated roads If you driv eons alted roads ,al ayer of salt resi-
due may for mont he brak ed isc sa nd brake
pads. This can result in as ignificantly longer
braking distance. R
In orde rtop revent any salt build-up, apply the
brakes occasionally while paying attention to
th et ra ffic conditions.R
Carefully depress th eb rak ep edal and the
beginnin ga nd end of aj ou rney.R
Maintain ag reater distanc etot he vehicle
ahead.
Servicing th eb rakes
! The brak ef luid level may be to ol ow, if:R
if th er ed brak ew arning lamp light supi n
th ei nstrumen tc luster andR
you hear aw arning tone while th ee ngine is
running
Observe additional warning messages in the
multifunction display.
The brak ef luid level may be to ol ow due to
brak ep ad wear or leaking brak el ines.
Hav et he brak es ystem checked immediately.
Consult aq ualifie ds pecialist workshop to
arrange this.
! As th eE SP ®
system operates automatically,
th ee ngine and th ei gnitio nm ust be switched
off (th eS ma rtKey must be in position

are no persons, animals or object sint he pat ho f
your vehicle when you are maneuvering or park-
ing.
! When parking ,p ay particular attention to
object sa bov eorb elow th es ensors, suc ha s
flowe rp ot sort ra iler drawbars. PARKTRONIC
does no td etect suc ho bject sw hen they are in
th ei mmediat ev icinit yoft he vehicle .Y ou
coul dd amage th ev ehicle or th eo bjects.
The sensor sm ay no td etect snow and other
object st ha ta bsor bu ltrasonic waves.
Ultrasonic sources suc hasana utomatic car
wash, th ec ompressed-air brakes on at ru ck
or ap neumatic drill coul dc aus eP AR KTRONIC
to malfunction.
PARKTRONIC may no tf unction correctly on
uneven terrain.
Parking Assist PARKTRONIC is activated auto-
matically when you: R
switch on th ei gnitionR
shif tt he transmission to position [ , ^ or
\\ R
release th ee lectric parking brake
Parking Assist PARKTRONIC is deactivate da t
speeds abov e1 1m ph (18 km/h). It is reactiva-
te datl ower speeds.
Range of th es ensors
General notes Parking Assist PARKTRONIC does no tt ak ei nto
accoun to bstacle sl ocated:R
below th ed etection range, e.g .p eople, ani-
mals or objects. R
abov et he detection range, e.g .o verhanging
loads, truck overhangs or loadin gr amps.
C
Sensor sint he fron tb umper, left-hand side
(example) The sensor sm ust be free from dirt ,i ce or slush.
They can otherwise no tf unction correctly. Clean
th es ensor sr egularly, taking car en ot to scratch
or damage them ( Y
page 242).
Range
Fron ts ensors
Center Approx .4 0in( approx.
10 0c m)
Corners Approx .2 4in( approx.
60 cm)
Rear sensors
Center Approx .4 8in( approx.
12 0c m)
Corners Approx .3 2in( approx.
80 cm)
Minimum distance
Center Approx .8 in (approx .2 0c m)
Corners Approx .6 in (approx .1 5c m)
If there is an obstacle within this range, th er el-
evan tw arning displays light up and aw arning150
Driving systems
Driving and parking