engine MERCEDES-BENZ S-Class 2012 W221 Service Manual

The automatic headlamp feature is only an
aid. The driver is responsible for the vehicle's
lighting at all times.GWARNING
When it is dark or foggy, turn the light switch
quickly from c to L . Otherwise, the
headlamps could switch off temporarily and
you could cause an accident.
Front fog lamps
GWARNING
If you suspect that driving conditions will be
foggy, turn the light switch to L before you
start your journey. Otherwise, your vehicle
may not be visible and you could endanger
yourself and others.
GWARNING
In low ambient lighting or foggy conditions,
only switch from position c to L with
the vehicle at a standstill in a safe location.
Switching from c to L will briefly
switch off the headlamps. Doing so while
driving in low ambient lighting conditions may
result in an accident.
XTo switch on the front fog lamps: turn
the SmartKey in the ignition lock to position
2 or start the engine.XTurn the light switch to L or T . If the
light switch is set to c, you cannot
switch on the fog lamps.XPull the light switch out to the first detent.
The green N indicator lamp on the light
switch lights up.XTo switch off the front fog lamps: press
the light switch in as far as it will go.
The green N indicator lamp on the light
switch goes out.Rear fog lampXTo switch on the rear fog lamp: turn the
SmartKey in the ignition lock to position 2
or start the engine.XTurn the light switch to L or T
(vehicles with front fog lamps), or turn the
light switch to L (vehicles without front
fog lamps). If the light switch is set to
c , you cannot switch on the rear fog
lamp.XTurn the light switch to L. If the light
switch is set to T, you cannot switch on
the rear fog lamp.XPull the light switch out to the second stop
(vehicles with front fog lamps) or pull it out
to the stop (vehicles without front fog
lamps).
The yellow R indicator lamp on the light
switch lights up.XTo switch off the rear fog lamp: press the
light switch in as far as it will go.
The yellow R indicator lamp on the light
switch goes out.
Headlamp cleaning system
The headlamps are cleaned automatically if
the "Wipe with washer fluid" function is
operated ten times while the lights are on and
the engine is running (Y page 285). When you
switch off the ignition, the automatic
headlamp cleaning system is reset and
counting is resumed from 0.
278Exterior lightingLights and windshield wipers

Combination switch
Turn signals:High-beam headlamps;Right turn signal=High-beam flasher?Left turn signalXTo 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 ?.
High-beam headlamps
XTo switch on the high-beam headlamps:
turn the SmartKey in the ignition lock to
position 2 or start the engine.XTurn the light switch to L.XPress the combination switch beyond the
pressure point in the direction of
arrow :.
The K indicator lamp in the instrument
cluster lights up.XTo switch off the high-beam
headlamps: move the combination switch
back to its normal position.
The K indicator lamp in the instrument
cluster goes out.High-beam flasherXTo switch on: turn the SmartKey in the
ignition lock to position 1 or 2 or start the
engine.XPull the combination switch in the direction
of arrow =.
Hazard warning lamps
The hazard warning lamps automatically
switch on if:
R an air bag is deployed.
R the vehicle is slowed down severely from a
speed of over 45 mph (70 km/h) and comes
to a halt.
XTo switch on the hazard warning lamps:
press button :.
All turn signals flash. If you now switch on
a turn signal using the combination switch,
only the turn signal lamp on the
corresponding side of the vehicle will flash.XTo switch off the hazard warning
lamps: press button :.
The hazard warning lamps are deactivated
automatically if the vehicle returns to a speed
of over 6 mph(10 km/h) after a full
application of the brakes.
i The hazard warning lamps still operate if
the ignition is switched off.
Exterior lighting279Lights and windshield wipersZ

Rear-compartment overhead control panel
:Reading lamp;Press p consecutively:to switch the reading lamp and interior
lighting onto switch only the reading lamp onto switch the reading lamp off=Interior lighting
Interior lighting control
Important notes
In order to prevent the vehicle's battery from
discharging, the interior lighting functions are
automatically deactivated after some time
except for when the SmartKey is in position
2 in the ignition lock.
Automatic interior lighting control
XTo switch on/off: press the | button.
The OFF indicator lamp shows whether the
automatic interior lighting control is
deactivated (indicator lamp on) or
activated (indicator lamp off).
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
ignition lock. You can activate this delayed
switch-off using COMAND ( Y page 263).
Manual interior lighting controlXTo switch the front interior lighting on/
off: press the c button.XTo switch the rear interior lighting on/
off: press the u button.XTo switch the reading lamps on/off:
press the p button.
Replacing bulbs
Important safety notes
Xenon bulbs
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.
GDANGER
Xenon bulbs carry a high voltage. You could
get an electric shock and be seriously or even
fatally injured if you touch the electric
contacts on Xenon bulbs. Therefore, never
remove the cover from Xenon bulbs.
Do not change Xenon bulbs yourself, but have
them replaced at a qualified specialist
workshop which has the necessary specialist
knowledge and tools to carry out the work
required.
Mercedes-Benz recommends that you use an
authorized Mercedes-Benz Center for this
purpose. In particular, work relevant to safety
or on safety-related systems must be carried
out at a qualified specialist workshop.
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.
282Replacing bulbsLights and windshield wipers

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 replaced by a qualified
specialist workshop, e.g. at an authorized
Mercedes-Benz Center.
! Always position the windshield wiper
arms vertically before folding them away
from the windshield. By doing so, you will
avoid damage to the hood.
Replacing the wiper blades
Moving the wiper blades to a vertical
position
Vehicles without KEYLESS-GO
XTurn the SmartKey to position 1 or 2 in the
ignition lock.XSet the windshield wipers to
position °.XWhen the wiper arms have reached a
vertical position, turn the SmartKey to
position 0 and remove it from the ignition
lock.
Vehicles with KEYLESS-GO
XSwitch off the engine.XRemove your foot from the brake pedal.XSet the windshield wipers to
position °.XPress the Start/Stop button repeatedly
until the windshield wipers start.XWhen the wiper arms have reached a
vertical position, press the Start/Stop
button.Removing the wiper bladesXFold the wiper arm away from the
windshield until it engages.XSet the wiper blade at right angles to the
wiper arm.XRemove the wiper blade from the retaining
pin on the wiper arm in the direction of the
arrow.
Installing the wiper blades
XPush the new wiper blade onto the
retaining pin on the wiper arm in the
opposite direction to the arrow.
Make sure that the wiper blade slides fully
onto the retaining pin on the wiper arm.XTurn the wiper blade parallel to the wiper
arm.XFold the wiper arm back onto the
windshield.
Problems with the windshield wipers
The windshield wipers are obstructed
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 ignition 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.286Windshield wipersLights and windshield wipers

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment 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 Please read the information on qualified
specialist workshops ( Y page 31).
Overview of climate control systems
Important safety notes
GWARNING
Severe conditions (e.g. strong air pollution)
may require replacement of the filter before
its scheduled replacement interval. A clogged
filter will reduce the air volume to the interior
and the windows could fog up, impairing
visibility and endangering you and others.
Have a blocked filter replaced at a Mercedes-
Benz Center as soon as possible.
GWARNING
Follow the recommended settings for heating
and cooling given on the following pages.
Otherwise, the windows could fog up,
impairing visibility and endangering you and
others.
The automatic climate control controls the
temperature and the humidity in the vehicle
interior and filters undesirable substances
from the air.
The automatic climate control is only
operational when the engine is running 16
.
Optimum operation is only achieved if you
drive with the side windows and sliding
sunroof/panorama roof with power tilt/
sliding panel closed.
You can also set some automatic climate
control functions via COMAND (Y page 265).
i Ventilate the vehicle for a brief period
during warm weather, e.g. using the
convenience opening feature ( Y page 93).
This will speed up the cooling process and
the desired vehicle interior temperature
will be reached more quickly.
i The integrated filter can filter out most
particles of dust and completely filters out
pollen. A clogged filter reduces the amount
of air supplied to the vehicle interior. For
this reason, you should always observe the
interval for replacing the filter, which is
specified in the Service Booklet. As it
depends on environmental conditions, e.g.
heavy air pollution, the interval may be
shorter than stated in the Service Booklet.
i It is possible that the blower may be
activated automatically 40 minutes after
the SmartKey is removed. The vehicle is
then ventilated for 30 minutes to dry the
air-conditioning system.16 The residual heat function can only be activated/deactivated if the ignition is switched off.290Overview of climate control systemsClimate control

Switching the rear-compartment
climate control on/off using the rear
control panelXTurn the SmartKey to position 2 in the
ignition lock.XTo switch on: press rocker switch
K (Y page 291) up or down and select
AUTO .
or
XPress rocker switch K(Y page 291) up or
down and select MAN.XTo switch off: press rocker switch
K (Y page 291) up or down and select
OFF .
Activating/deactivating cooling with
the air dehumidification function
Important information
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.
GWARNING
If you switch off the cooling function, the
vehicle will not be cooled when weather
conditions are warm. The windows can fog up
more quickly. Window fogging may impair
visibility and endanger you and others.
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
malfunction.
You can activate or deactivate the cooling
with air dehumidification function via
COMAND ( Y page 267).
i The cooling with air dehumidification
function uses refrigerant R134a. This
coolant does not contain
chlorofluorocarbons, and therefore does
not damage the ozone layer.
Problems with the cooling with air
dehumidification function
If you can no longer switch on the cooling with
air dehumidification function via COMAND,
the cooling with air dehumidification function
is switched off due to a malfunction.
XConsult a qualified specialist workshop.
Setting climate control to automatic
GWARNING
If you switch off the cooling function, the
vehicle will not be cooled when weather
conditions are warm. The windows can fog up
more quickly. Window fogging may impair
visibility and endanger you and others.
In automatic mode, the set temperature is
maintained automatically at a constant level.
The system automatically regulates the
temperature of the dispensed air, the airflow
and the air distribution.
Automatic mode will achieve optimal
operation if cooling with air dehumidification
is also activated. If desired, cooling with air
dehumidification can be deactivated.
Controlling the front climate control
using the front control panel
XTurn the SmartKey to position 2 in the
ignition lock.XSet the desired temperature.X To switch on: press the à rocker
switch up or down.
The indicator lamp in the à rocker
switch lights up.Operating the climate control system293Climate controlZ

Setting the rear-compartment airflow
using the front control panelXTurn the SmartKey to position 2 in the
ignition lock.XActivate the Y rear compartment
function via COMAND ( Y page 268).
The rear-compartment climate control can
be controlled via the front control panel
using the Y rear compartment function.XTo increase/reduce: press the K
rocker switch up or down.
Setting the rear-compartment airflow
using the rear control panel
XTurn the SmartKey to position 2 in the
ignition lock.XTo increase/reduce: press rocker switch
J up or down ( Y page 291).
Defrosting the windshield
You can use this function to defrost the
windshield or to defrost the inside of the
windshield and the side windows.
i You should only select the defrosting
function until the windshield is clear again.
XTurn the SmartKey to position 2 in the
ignition lock.XTo switch on: press the ¬ rocker
switch up or down.
The indicator lamp in the ¬ rocker
switch lights up.
The climate control system switches to the
following functions:
R cooling with air dehumidification on
R high airflow 17
R high temperature 17
R air distribution to the windshield and
front side windows
R air-recirculation mode offXTo deactivate: press the ¬ rocker
switch up or down.
The indicator lamp in the ¬ rocker
switch goes out. The previously selected
settings come into effect again. The cooling
with air dehumidification function remains
on. Air-recirculation mode remains
deactivated.
or
XPress the w rocker switch up or down.
or
XPress the K rocker switch up or down.
MAX COOL maximum cooling
The MAX COOL function is only available in
vehicles for the USA.
MAX COOL is only operational when the
engine is running.
The MAX COOL function is activated
automatically:
R if climate control is set to automatic
( Ã ) on both sides
R if additional cooling is used
The display shows MAX COOL.
This is the quickest way to cool the vehicle
interior when the sliding sunroof and the side
windows are closed.
Defrosting the windows
Windows fogged up on the inside
XActivate the cooling with air
dehumidification function via COMAND
( Y page 267).XActivate automatic mode Ã.XIf the windows continue to fog up, activate
the defrosting function ( Y page 296).
i
You should only select this setting until
the windshield is clear again.
17 Depending on the outside temperature.296Operating the climate control systemClimate control

Activating/deactivating the residual
heat function
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 temperature that has
been set.
i The blower will run at a low speed
regardless of the airflow setting.
i If you activate the residual heat function
at high temperatures, only the ventilation
will be activated. The blower runs at
medium speed.XTurn the SmartKey to position 0 in the
ignition lock or remove it.XTo activate: press the Ì rocker switch
up or down.
The indicator lamp in the Ì rocker
switch lights up.XTo deactivate: press the Ì rocker
switch up or down.
The indicator lamp in the Ì rocker
switch goes out.
i Residual heat is deactivated
automatically:
R after about 30 minutes
R when the ignition is switched on
R if the battery voltage drops
R if the coolant temperature is too low
Setting the air vents
Important safety notes
GWARNING
When operating the climate control, the air
that enters the passenger compartment
through the air vents can be very hot or very
cold (depending on the set temperature). This
could cause burns or frostbite to unprotected
skin in the immediate area of the air vents.
Always keep sufficient distance between
unprotected parts of the body and the air
vents. If necessary, use the air distribution
adjustment to direct the air to air vents in the
vehicle interior that are not in the immediate
area of unprotected skin.
In order to ensure the direct flow of fresh air
through the air vents into the vehicle interior,
please observe the following notes:
R keep the air intake grille on the hood free
of blockages, such as ice, snow or leaves
R never cover the air vents or air intake grille
in the vehicle interior.
i For virtually draft-free ventilation, adjust
the sliders of the air vents to the center
position.
Setting the center air vents
:Fixed center air vent;Center air vent, right=Center vent thumbwheel, right?Center vent thumbwheel, leftACenter air vent, leftXTo open/close: turn thumbwheels =
and ? up or down.298Setting the air ventsClimate control

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment 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 Please read the information on qualified
specialist workshops ( Y page 31).
Breaking-in notes
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
performance in the future.
R Drive at varying vehicle speeds and engine
speeds for the first 1000 miles (1500 km)
for this reason.
R Avoid overstraining the vehicle during this
period, e.g. driving at full throttle.
R Change gear in good time, at the latest
when the tachometer needle is 2
/ 3 of the
way to the red area in the tachometer
display.
R Do not manually shift to a lower gear to
brake the vehicle.
R If possible, do not depress the accelerator
pedal past the point of resistance
(kickdown).
R Only select shift ranges 3, 2 or 1 when
driving slowly, e.g. in mountainous terrain.
R If possible, drive in drive program E (in AMG
vehicles in drive program C) for the first
1000 miles (1500 km).
After 1000 miles (1500 km), you can increase
the engine speed gradually and bring the
vehicle up to full speed.
Additional breaking-in notes for AMG
vehicles:
R do not drive faster than 85 mph
(140 km/h) in the first 1000 miles
(1500 km).
R only allow the engine to reach a maximum
engine speed of 4500 rpm briefly.
R change gear in good time.
i You should also observe these notes on
running in if the engine or parts of the drive
train on your vehicle have been replaced.
i Always observe the respective speed
restrictions.
Driving
Important safety notes
GWARNING
Make sure absolutely no objects are
obstructing the pedals' range of movement.
Keep the driver's footwell clear of all
obstacles. If there are any floormats or
carpets in the footwell, make sure the pedals
still have sufficient clearance.
During sudden driving or braking maneuvers
the objects could get caught between the
pedals. You could then no longer brake or
accelerate. This could lead to accidents and
injury.
GWARNING
On slippery road surfaces, never downshift in
order to obtain braking action. This could
result in drive wheel slip and reduced vehicle
control. Your vehicle's ABS will not prevent
this type of loss of control.
GWARNING
It is dangerous to shift the automatic
transmission out of parking position P or
neutral position N if the engine speed is
higher than idle speed. If your foot is not firmly
on the brake pedal, the vehicle could
accelerate quickly forward or in reverse. You
302DrivingDriving and parking

could lose control of the vehicle and hit
someone or something. Only shift into gear
when the engine is idling normally and when
your right foot is firmly on the brake pedal.GWARNING
HYBRID vehicles: It is imperative that you read
the HYBRID Supplemental Operating
Instructions included in your vehicle literature
portfolio. You may otherwise not receive all
necessary safety information and warning for
the operation of your vehicle.
! Warm up the engine quickly. Do not use
the engine's full performance until it has
reached operating temperature.
Only shift the automatic transmission to
the desired drive position when the vehicle
is stationary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery
roads. You could otherwise damage the
drive train.
! S 63 AMG: at low engine oil temperatures
below 68 ‡ (+20 † ), the maximum engine
speed is restricted in order to protect the
engine. To protect the engine and maintain
smooth engine operation, avoid driving at
full throttle when the engine is cold.
SmartKey positions
SmartKeygTo remove the SmartKey1Power supply for some consumers, such
as the windshield wipers2Ignition (power supply for all consumers)
and drive position3To start the engine
i The 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 information
Vehicles with KEYLESS-GO are equipped with
a SmartKey featuring an integrated KEYLESS-
GO function and a detachable Start/Stop
button.
The Start/Stop button must be inserted into
the ignition lock and the SmartKey must be in
the vehicle.
Pressing the Start/Stop button several times
in succession corresponds to the different
SmartKey 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
immediately.
The Start/Stop button can be removed from
the ignition lock. Then, you can insert the
SmartKey into the ignition lock.
Driving303Driving and parkingZ