engine MERCEDES-BENZ SL ROADSTER 2018 Service Manual

light switch to theTposition, the daytime
running lamps and parking lamps switch on.
If the engine is running and you turn the light
switch to L, the manual settings take prec-
edence over the daytime running lamps.
USA only:
The daytime running lamps improve the visibility
of your vehicle during the day. To do this, the
daytime running lamps function must be
switched on using the on-board computer
(
Ypage 195).
If the engine is running and you turn the light
switch to TorL, the manual settings
take precedence over the daytime running
lamps.
Low-beam headlamps
GWARNING
When the light switch is set to Ã, the low-
beam headlamps may not be switched on
automatically if there is fog, snow or other
causes of poor visibility due to the weather
conditions such as spray. There is a risk of an
accident.
In such situations, turn the light switch to
L.
Even if the light sensor does not detect that it is
dark, the parking lamps and low-beam head-
lamps switch on when the ignition is switched on and the light switch is set to the Lposition.
This is a particularly useful function in the event
of rain and fog.
XTo switch on the low-beam headlamps:
turn the SmartKey to position 2in the igni-
tion lock or start the engine.
XTurn the light switch to L.
The green Lindicator lamp in the instru-
ment cluster lights up.
Parking lamps
!If the battery charge is very low, the parking
lamps or standing lamps are automatically
switched off to enable the next engine start.
Always park your vehicle safely and in a well lit
area, in accordance with the relevant legal
stipulations. Avoid using the Tparking
lamps over a period of several hours. If pos-
sible, switch on the right-hand Xor left-
hand W standing lamps.
XTo switch on: turn the light switch to T.
The green Tindicator lamp in the instru-
ment cluster lights up.
Standing lamps
Switching on the standing lamps ensures the
corresponding side of the vehicle is illuminated.
XTo switch on the standing lamps: the
SmartKey is not in the ignition lock or it is in
position uin the ignition lock.
XTurn the light switch to W(left-hand side of
the vehicle) or X(right-hand side of the
vehicle).
Combination switch
:High-beam headlamps
;Turn signal, right
=High-beam flasher
?Turn signal, left
XTo indicate briefly: press the combination
switch briefly to the pressure point in the
direction of arrow ;or?.
The corresponding turn signal flashes three
times.
XTo indicate: press the combination switch
beyond the pressure point in the direction of
arrow ;or?.
XTo switch on the high-beam headlamps:
turn the light switch to LorÃ.
XPress the combination switch beyond the
pressure point in the direction of arrow :.
In the Ãposition, the high-beam head-
lamps are only switched on when it is dark and
the engine is running.
Exterior lighting107
Lights and windshield wipers
Z

Replacing the wiper blades
Important safety notes
GWARNING
If the windshield wipers begin to move while
you are changing the wiper blades, you could be trapped by the wiper arm. There is a risk of
injury.
Always switch off the windshield wipers and
ignition before changing the wiper blades.
!To avoid damaging the wiper blades, make
sure that you touch only the wiper arm of the
wiper.
!Never open the hood if a windshield wiper
arm has been folded away from the wind-
shield.
Never fold a windshield wiper arm without a
wiper blade back onto the windshield.
Hold the windshield wiper arm firmly when
you change the wiper blade. If you release the
windshield wiper arm without a wiper blade
and it falls onto the windshield, the windshield
may be damaged by the force of the impact.
Mercedes-Benz recommends that you have
the wiper blades changed at a qualified spe-
cialist workshop.
!Always position the windshield wiper arms
vertically before folding them away from the
windshield. By doing so, you will avoid dam-
age to the hood.
Changing the windshield wiper blades
Moving the wiper arm to a vertical posi-
tion
On vehicles without KEYLESS-GO:
XTurn the SmartKey to position 1or2 in the
ignition lock.
XSet the windshield wiper to position °.
XWhen the wiper arms are vertical to the hood,
turn the SmartKey to positionuin the igni-
tion lock and remove it.
XFold the wiper arm away from the windshield
until you feel it engage. On vehicles with KEYLESS-GO:
XSwitch off the engine.
XRemove your foot from the brake pedal.
XSet the windshield wiper to the
°position.
XPress the Start/Stop button repeatedly until
the windshield wiper starts.
XWhen the wiper arms are in a vertical position
to the hood, press the Start/Stop button.
XFold the wiper arm away from the windshield
until you feel it engage.
Removing a wiper blade
XTo bring the wiper blade into position to
be removed: hold the wiper arm firmly with
one hand. With the other hand, turn the wiper
blade in the direction of arrow =beyond the
point of resistance.
The wiper blade engages in the removal posi-
tion with an audible click.
XTo remove a wiper blade: firmly press
release knob ;and pull the wiper blade
upwards :.
Installing the wiper blades
Windshield wipers111
Lights and windshield wipers
Z

XPush the new wiper blade in the direction of
arrow:onto the wiper arm until lug ;
engages.
XPush the wiper blade out of the removal posi- tion in the direction of arrow =beyond the
point of resistance.
The wiper blade disengages with an audible
click and is freely movable again.
XMake sure that the wiper blade is seated cor-
rectly.
XFold the wiper arm back onto the windshield.
Problems with the windshield wipers
ProblemPossible causes/consequences and MSolutions
The windshield wipers
are jammed.Leaves or snow, for example, may be obstructing the windshield wiper
movement. The wiper motor has been deactivated.
XFor safety reasons, you should remove the SmartKey from the igni-
tion lock.
or
XSwitch off the engine using the Start/Stop button and open the
driver's door.
XRemove the cause of the obstruction.
XSwitch the windshield wipers back on.
The windshield wipers
fail completely.The windshield wiper drive is malfunctioning.
XSelect another wiper speed on the combination switch.
XHave the windshield wipers checked at a qualified specialist work-
shop.
112Windshield wipers
Lights and windshield wipers

Overview of climate control systems
General notes
Observe the settings recommended on the fol-
lowing pages. The windows could otherwise fog
up.
To prevent the windows from fogging up:
Rswitch off climate control only briefly
Rswitch on air-recirculation mode only briefly
Rswitch on the cooling with air dehumidifica-
tion function
Rswitch on the defrost windshield function
briefly, if required
Climate control regulates the temperature and
the humidity in the vehicle interior and filters
undesirable substances out of the air. Climate control can only be operated when the
engine is running. Optimum operation is only
achieved with the side windows and roof closed.
iWhen the weather is warm, ventilate the
vehicle for a brief period. This will speed up
the cooling process and the desired vehicle
interior temperature will be reached more
quickly.
iIt is possible that the dehumidification func-
tion of the climate control system may be
activated automatically an hour after the
SmartKey has been removed. The vehicle is
then ventilated for 30 minutes to dry the air-
conditioning system.
Control panel for dual-zone automatic climate control
Canada only
:Sets the temperature, left (Ypage 116)
;Sets climate control to automatic (Ypage 116)
=Defrosts the windshield (Ypage 117)
?Switches the residual heat on or off (Ypage 119)
ASwitches cooling with air dehumidification on/off (Ypage 115)
BSwitches the rear window defroster on/off (Ypage 118)
CSwitches the ZONE function on/off (Ypage 117)
DSets the temperature, right (Ypage 116)
EActivates/deactivates climate control (Ypage 115)
FSets the air distribution (Ypage 117)
GSets the airflow (Ypage 117)
Overview of climate control systems113
Climate control

RUse the residual heat function if you want to
heat or ventilate the vehicle interior when the
ignition is switched off. The residual heat
function can only be activated or deactivated
with the ignition switched off.
RVehicles with COMAND:if you change the
settings of the climate control system, the
climate status display appears for three sec-
onds at the bottom of the screen in the
COMAND display. You will see the current
settings of the various climate control func-
tions.
ECO start/stop function
During automatic engine switch-off, the climate
control system only operates at a reduced capa-
city. If you require full climate control capacity,
the ECO start/stop function can be deactivated
by pressing the ECO button (
Ypage 126).
Operating the climate control sys-
tems
Activating/deactivating climate con-
trol
General notes
When the climate control is switched off, the air
supply and air circulation are also switched off.
The windows could fog up. Therefore, switch off
climate control only briefly
iActivate climate control primarily using the
à button (Ypage 116).
Activating/deactivating
XTurn the SmartKey to position 2in the igni-
tion lock (Ypage 122).
XTo activate: press theÃbutton.
The indicator lamp in the Ãbutton lights
up. Airflow and air distribution are set to auto-
matic mode.
or
XPress the ^button.
The indicator lamp in the ^button goes
out. The previously selected settings are
restored.
XTo deactivate: press the^button.
The indicator lamp in the ^button lights
up.
Switching cooling with air dehumidi-
fication on/off
General notes
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. The windows can fog up
more quickly. Therefore, deactivate the cooling
with air-dehumidification function only briefly.
The "Cooling with air dehumidification" function is only available when the engine is running. The
air inside the vehicle is cooled and dehumidified
according to the temperature selected.
Condensation may drip from the underside of
the vehicle when it is in cooling mode. This is
normal and not a sign that there is a malfunc-
tion.
Activating/deactivating
XTo activate: press the¿button.
The indicator lamp in the ¿button lights
up.
XTo deactivate: press the¿button.
The indicator lamp in the ¿orÁ button
goes out. The "Cooling with air dehumidifica-
tion" function has a delayed switch-off fea-
ture.
The indicator lamp in the ¿button goes
out. The "Cooling with air dehumidification"
function has a delayed switch-off feature.
Operating the climate control systems115
Climate control

MAX COOL maximum cooling
The MAX COOL function is only available in vehi-
cles for the USA.
MAX COOL is only operational when the engine
is running.
XTo activate:press theÙbutton.
The indicator lamp in the button lights up.
XTo deactivate: press theÙbutton.
The indicator lamp in the button goes out. The
previously selected settings are restored.
When you activate MAX COOL, climate control
switches to the following functions:
Rmaximum cooling
Rmaximum airflow
Rair-recirculation mode on
Defrosting the windows
Windows fogged up on the inside
XActivate the ¿cooling with air dehumidi-
fication function.
XActivate the Ãmode button.
XIf the windows continue to fog up, activate the
¬ "Windshield defrosting" function.
iYou should only select this setting until the
windshield is clear again.
Windows fogged up on the outside
XActivate the windshield wipers.
XPress the _button repeatedly until the
P orO symbol appears in the display.
iYou should only select this setting until the
windshield is clear again.
Rear window defroster
General notes
The rear window defroster has a high current
draw. You should therefore switch it off as soon
as the rear window is clear. Otherwise, the rear window defroster switches off automatically
after several minutes.
If the battery voltage is too low, the rear window
defroster may switch off.
Activating/deactivating
XTurn the SmartKey to position 2in the igni-
tion lock (Ypage 122).
XPress the ¤button.
The indicator lamp in the ¤button lights
up or goes out.
Problems with the rear window defroster
ProblemPossible causes/consequences and MSolutions
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.
XSwitch 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.
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
XTurn the SmartKey to position 2in the igni-
tion lock (Ypage 122).
XTo activate: press thegbutton.
The indicator lamp in the gbutton lights
up.
iAir-recirculation mode is automatically acti-
vated at high levels of pollution or at high out-
118Operating the climate control systems
Climate control

side temperatures. When air-recirculation
mode is activated automatically, the indicator
lamp in thegbutton is not lit. Outside air
is added after about 30 minutes.
XTo deactivate: press thegbutton.
The indicator lamp in the gbutton goes
out.
iAir-recirculation mode deactivates auto-
matically:
Rafter approximately five minutes at outside
temperatures below approximately 41 ‡
(5 †)
Rafter approximately five minutes if cooling
with air dehumidification is deactivated
Rafter 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
XTurn the SmartKey to position uin the igni-
tion lock or remove it (Ypage 122).
XTo activate: press theÌbutton.
The indicator lamp in the Ìbutton lights
up.
iThe blower will run at a low speed regardless
of the airflow setting.
iIf you activate the residual heat function at
high temperatures, only the ventilation will be
activated. The blower runs at medium speed.
XTo deactivate: press theÌbutton.
The indicator lamp in the Ìbutton goes
out.
Residual heat is deactivated automatically:
Rafter approximately 30 minutes
Rwhen the ignition is switched on
Rif the battery voltage drops
Setting the air vents
Important safety notes
GWARNING
Very hot or very cold air can flow from the air
vents. This could result in burns or frostbite in
the immediate vicinity of the air vents. There
is a risk of injury.
Make sure that all vehicle occupants always
maintain a sufficient distance to the air out-
lets. If necessary, redirect the airflow to
another area of the vehicle interior.
GWARNING
When AIRSCARF is switched on, very hot air
can flow from the vents in the head restraints. This could result in burns in the immediate
vicinity of the air vents. There is a risk of injury.
Reduce the heater output before it becomes
too hot.
In order to ensure the direct flow of fresh air
through the air vents into the vehicle interior,
please observe the following notes:
Rkeep the air inlet grille on the hood and in the engine compartment on the front-passenger
side free of blockages, such as ice, snow or
leaves.
Rnever cover the air vents or air intake grilles in
the vehicle interior.
iYou can move the adjusters for the air vents
vertically or horizontally to set the direction of
the airflow.
iFor optimal climate control in the vehicle,
open the air vents completely and set the
adjusters to the central position.
Setting the air vents119
Climate control
Z

Notes on breaking-in a new vehicle
Important safety notes
The sensor system of some driving and driving
safety systems adjusts automatically while a
certain distance is being driven after the vehiclehas been delivered or after repairs. Full system
effectiveness is not reached until the end of this
teach-in procedure.
New and replaced brake pads and discs only
reach their optimum braking effect after several hundred kilometers of driving. Compensate for
this by applying greater force to the brake pedal.
The first 1000 miles (1500 km)
The more you look after the engine when it is
new, the more satisfied you will be with its per-
formance in the future.
RYou should therefore drive at varying vehicle
and engine speeds for the first 1,000 miles
(1,500 km).
RAvoid heavy loads, e.g. driving at full throttle,
during this period.
RChange gear in good time, before the tach-
ometer needle is Ôof the way to the red area
of the tachometer.
RDo not manually shift to a lower gear to brake
the vehicle.
RTry to avoid depressing the accelerator pedal
beyond the point of resistance (kickdown).
Additional breaking-in notes for Mercedes-AMG
vehicles:
RDo not drive faster than 85 mph (140 km/h)
for the first 1,000 miles (1,500 km).
ROnly allow the engine to reach a maximum
engine speed of 4,500 rpm briefly.
RIdeally, for the first 1000 miles (1500 km),
driv ein progra mC.
RChange gear ingood time.
After 1000 miles (1500 km), you can increase
the engine speed gradually and accelerate the
veh icle to full speed.
You should also observe these notes on break-
ing in if the engine or parts of the drive train on
your veh
i
cle have been replace d.
Alwa ys observe the maximum permis sible
speed.
Self-locking rear axle differential
(Mercedes-AMG vehicles)
Your vehicle isequipped with a self-locking dif-
ferential on the rear axle.
Change the oil to improve protection of the rear axle differential:
Rafter a breaking-in period of 2000 miles (USA)
Rafter a breaking-in period of 3000 km (Can-
ada)
Revery 30,000 miles or 3 years (USA)
Revery 60,000 km or 4 years (Canada)
These oil changes prolong the service life of the
differential. Have the oil change carried out at a
qualified specialist workshop.
Driving
Important safety notes
GWARNING
Objects inthe driver's footwell may restrict
the clearance around the pedals or block a
depressed pedal. This jeopardizes the oper-
ating and road safety of the vehicle. There isa
risk of an accident.
St ow all objects securely inthe vehicle so that
they do not get into the driver's footwell.
When using floormats or carpets, make sure
that they are properly secured so that they do
not slip or obstruct the pedals. Do not place
several floormats or carpets on top of one
another.
GWARNING
Unsuitable footwear can hinder correct usage
of the pedals, e.g.:
Rshoes with thick soles
Rshoes with high heels
Rslippers
There isa risk of an accident.
Wear suitable footwear to ensure correct
usage of the pedals.
Driving121
Driving and parking
Z

GWARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with limitations, or not at all. This could affect, for example, the power steering and the brake
boosting effect. You will require considerably
more effort to steer and brake. There is a risk
of an accident.
Do not switch off the ignition while driving.
GWARNING
If the parking brake has not been fully
released when driving, the parking brake can:
Roverheat and cause a fire
Rlose its hold function.
There is a risk of fire and an accident. Release
the parking brake fully before driving off.
!Do not warm up the engine while stationary.
Pull away immediately. Avoid high engine
speeds and full throttle until the engine has
reached its operating temperature.
In vehicles with automatic transmission,
engage positions P and R only when the vehi-
cle is stationary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery roads.
You could otherwise damage the drive train.
!Mercedes-AMG vehicles: at low engine oil
temperatures below 68 ‡ (+20 †), the max-
imum engine speed is restricted in order to
protect the engine. To protect the engine and
maintain smooth engine operation, avoid driv-
ing at full throttle when the engine is cold.
Key positions
SmartKey
gTo remove the SmartKey
1Power supply for some consumers, such as
the windshield wipers
2Ignition (power supply for all consumers)
and drive position
3To start the engine
iThe SmartKey can be turned in the ignition
lock even if it is not the correct SmartKey for
the vehicle. The ignition is not switched on.
The engine cannot be started.
KEYLESS-GO
General notes
Vehicles with KEYLESS-GO are equipped with a
SmartKey featuring an integrated KEYLESS-GO
start function and a detachable Start/Stop but-
ton.
The Start/Stop button must be inserted in the
ignition lock and the SmartKey must be in the
vehicle.
When you insert the Start/Stop button into the
ignition lock, the system needs approximately
two seconds recognition time. You can then use
the Start/Stop button.
Pressing the Start/Stop button several times in
succession corresponds to the different key
positions in the ignition lock. This is only the
case if you are not depressing the brake pedal.
If you depress the brake pedal and press the
Start/Stop button, the engine starts immedi-
ately.
A check which periodically establishes a radio
connection between the vehicle and the Smart-
Key determines whether a valid SmartKey is in
122Driving
Driving and parking

the vehicle. This occurs, for example, when
starting the engine.
To start the vehicle without actively using the
SmartKey:
Rthe Start/Stop button must be inserted in the
ignition lock.
Rthe SmartKey must be in the vehicle.
Rthe vehicle must not be locked with the
SmartKey or KEYLESS-GO (Ypage 73).
Do not keep the SmartKey:
Rwith electronic devices, e.g. a mobile phone
or another SmartKey.
Rwith metallic objects, e.g. coins or metal foil.
Rinside metallic objects, e.g. a metal case.
This can impair the functionality of the KEY-
LESS-GO key.
If you lock the vehicle with the SmartKey's
remote control or with KEYLESS-GO, after a
short time:
Ryou will not be able to switch on the ignition
with the Start/Stop button.
Ryou will not be able to start the engine with the
Start/Stop button until the vehicle is
unlocked again.
The engine can be switched off while the vehicle
is in motion by pressing and holding the Start/
Stop button for three seconds. This function
operates independently of the ECO start/stop
automatic engine switch-off function.
Key positions with KEYLESS-GO
:Start/Stop button
;Ignition lock
As soon as the ignition is switched on, all the
indicator lamps in the instrument cluster light
up. Further information on situations where an
indicator lamp either fails to go out after starting
the engine or lights up while driving
(
Ypage 228). If Start/Stop button
:has not yet been
pressed, this corresponds to the key being
removed from the ignition.
XTo switch on the power supply: press
Start/Stop button :once.
The power supply is switched on. You can now activate the windshield wipers, for example.
The power supply is switched off again if:
Rthe driver's door is opened and
Ryou press Start/Stop button :twice when
in this position
XTo switch on the ignition: press Start/Stop
button :twice.
The ignition is switched on.
If you press Start/Stop button :once when
in this position, the ignition is switched off
again.
Removing the Start/Stop button
You can remove the Start/Stop button from the
ignition lock and start the vehicle as normal
using the SmartKey.
XRemove Start/Stop button :from ignition
lock ;.
You do not have to remove the Start/Stop but-
ton from the ignition lock when you leave the
vehicle. You should, howe
ver, always take the
SmartKey with you when leaving the vehicle. As
long as the SmartKey is in the vehicle:
Rthe vehicle can be started using the Start/
Stop button
Rthe electrically powered equipment can be
operated
Starting the engine
Important safety notes
GWARNING
If children are left unsupervised in the vehicle,
they could:
Roperate the vehicle's equipment.
Driving123
Dr iving an d parking
Z