warning light MERCEDES-BENZ S-CLASS SEDAN 2012 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. Your vehicle may
otherwise 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
If the "Wipe with washer fluid" function is
operated five times ( Y page 289) while the
lights are on and the engine is running, the
headlamps are cleaned automatically. When
you switch off the ignition, the automatic
headlamp cleaning system is reset and
counting is resumed from 0.
282Exterior 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 rapidly 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 :.
If the vehicle returns to a speed of over
6 mph (10 km/h) after a full application of the
brakes, the hazard warning lamps are
deactivated automatically.
i The hazard warning lamps still operate if
the ignition is switched off.
Exterior lighting283Lights and windshield wipersZ

the high-beam headlamps are switched on
automatically. The K indicator lamp in
the instrument cluster also lights up.
If you drive at speeds below approximately
30 mph (45 km/h) or if other road users
are identified or if the roads are sufficiently
illuminated:
the high-beam headlamps are switched off
automatically. The K indicator lamp in
the instrument cluster goes out. The _
indicator lamp in the instrument cluster
stays on.XTo deactivate: move the combination
switch back to its normal position.
The _ indicator lamp in the instrument
cluster goes out.GWARNING
The Adaptive Highbeam Assist is only an aid
intended to support you while driving. The
driver is and remains responsible for proper
vehicle lighting in accordance with the
prevailing light, sight and traffic conditions.
The system may be impaired or unavailable
when
R visibility is poor, e.g. due to snow, rain, fog,
or heavy spray
R the optical sensor area of the windshield is
dirty, fogged up, or covered by a sticker for
example
The system cannot recognize the following
road users:
R Road users without a lighting system of
their own, e.g. pedestrians
R Road users with dim lighting of their own,
e.g. cyclists
R Road users whose lighting is obstructed,
e.g. road users behind a guardrail
R In some seldom cases, even road users with
a lighting system of their own may be
recognized too late or not at all.
The automatic high-beam headlamps will then
not be deactivated or it will be activated in
spite of preceding or oncoming road users.
This could endanger you and/or others and
cause an accident. Always pay close attention
to the traffic situation and switch off the high
beam manually if necessary.
Headlamps fogged up on the inside
The headlamps may fog up on the inside if
there is high atmospheric humidity.
XDrive with the headlamps switched on.
The level of moisture diminishes,
depending on the length of the journey and
the weather conditions (humidity and
temperature).
If the level of moisture does not diminish:
XHave the headlamps checked at a qualified
specialist workshop.
Interior lighting
Overview of interior lighting
Front overhead control panel
:p Switches the left-hand reading lamp
on/off;u Switches the rear interior lighting
on/off=c Switches the front interior lighting
on/off?| Switches the automatic interior
lighting control on/offAp Switches the right-hand reading
lamp on/offInterior lighting285Lights and windshield wipersZ

can burn into the glass surface and reduce
the service life of the bulbs. Always use a lint-
free cloth or only touch the base of the bulb
when installing.
Only use bulbs of the correct type.
If the new bulb still does not light up, consult
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.GWARNING
Bulbs and lamps can become very hot. For
this reason, allow them to cool down before
changing them. Otherwise, you could burn
yourself when you touch them.
Keep bulbs out of the reach of children.
Otherwise, they could, for example, damage
the bulbs and injure themselves.
Never use a bulb which has been dropped.
Such a bulb may explode and injure you.
Halogen bulbs are pressurized and could
explode when you change them, especially if
they are very hot. You should therefore wear
eye protection and gloves when you are
changing them.
Overview: changing bulbs/bulb types
You can change the following bulbs. The bulb
type can be found in the legend.
Bi-Xenon headlamps (vehicles with halogen
daytime running lamps)
:High-beam spot lamp: H7 55 W
Bi-Xenon headlamps (vehicles with LED daytime
running lamps)
:High-beam spot lamp 13
: H11 55 W;Infrared light (Night View Assist Plus):
H11 55 W13 Due to their location, have the bulbs in the left-hand headlamp changed at a qualified specialist workshop,
e.g. an authorized Mercedes-Benz Center.Replacing bulbs287Lights and windshield wipersZ

Windshield wipers
Switching the windshield wipers on/
off
GWARNING
Wiper blades are components that are subject
to wear and tear. Replace the wiper blades
twice a year, preferably in the spring and fall.
Otherwise the windshield will not be wiped
properly. As a result, you may not be able to
observe surrounding traffic conditions and
could cause an accident.
! Do not operate the windshield wipers
when the windshield is dry, as this could
damage the wiper blades. Moreover, dust
that has collected on the windshield can
scratch the glass if wiping takes place when
the windshield is dry.
! If the windshield wipers leave smears on
the windshield after the vehicle has been
washed in an automatic car wash, wax or
other residues may be the reason for this.
Clean the windshield using washer fluid
after washing the vehicle in an automatic
car wash.
Combination switch
1$ Windshield wipers off2Ä Intermittent wipe, low 143Å
Intermittent wipe, high 154°
Continuous wipe, slow5¯ Continuous wipe, fastBí Single wipe/ î To wipe the
windshield using washer fluidXSwitch on the ignition.XTurn the combination switch to the
corresponding position.
! Intermittent wiping with rain sensor: due
to optical influences and the windshield
becoming dirty in dry weather conditions,
the windshield wipers may be activated
inadvertently. This could then damage the
windshield wiper blades or scratch the
windshield.
For this reason, you should always switch
off the windshield wipers in dry weather.
In the Ä or Å position, the appropriate
wiping frequency is set automatically
according to the intensity of the rain. In
the Å position, the rain sensor is more
sensitive than in the Ä position, causing
the windshield wipers to wipe more
frequently.
Replacing the wiper blades
Important safety notes
GWARNING
For safety reasons, switch off the windshield
wipers and remove the SmartKey from the
ignition lock before changing the wiper blades
(vehicles with KEYLESS-GO: make sure that
the on-board electronics are in state 0).
Otherwise, the wiper motor could be switched
on suddenly and cause injury.
! Never open the hood if a windshield wiper
arm has been folded away from the
windshield.
Never fold a windshield wiper arm without
a wiper blade back onto the windshield.
14 Rain sensor set to low sensitivity.
15 Rain sensor set to high sensitivity.Windshield wipers289Lights and windshield wipersZ

Notes on using climate control
Below, you can find a number of notes and
recommendations to help you use climate
control optimally.
R Activate climate control using the Ã
rocker switch. The indicator lamp in the
à rocker switch lights up.
R Set the temperature to 72 ‡ (22 † ).
R Only use the "defrosting" function briefly
until the windshield is clear again.
R Only use "air-recirculation" mode briefly,
e.g. if there are unpleasant outside odors
or when in a tunnel. The windows could
otherwise fog up as in air-recirculation
mode no fresh air is drawn into the vehicle.
R Use 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.
Operating the climate control
systems
Activating/deactivating climate
control
Important information
GWARNING
When the climate control system is
deactivated, the outside air supply and
circulation are also deactivated. Only choose
this setting for a short time. Otherwise the
windows could fog up, impairing visibility and
endangering you and others.
i Switch on climate control primarily using
the à rocker switch ( Y page 297).
Switching the front climate control on/
off using the front control panelXTurn the SmartKey to position 2 in the
ignition lock.XTo activate: press the ^ rocker switch
up or down.
The indicator lamp in the rocker switch
goes out. The previously selected settings
come into effect again.XTo deactivate: press the ^ rocker
switch up or down.
The indicator lamp in the rocker switch
lights up.
Switching the rear-compartment
climate control on/off using the front
control panel
XTurn the SmartKey to position 2 in the
ignition lock.XActivate the Y rear compartment
function via COMAND ( Y page 273).
The rear-compartment climate control can
be controlled via the front control panel
using the Y rear compartment function.XTo activate: press the ^ rocker switch
up or down.
The indicator lamp in the rocker switch
goes out. The previously selected settings
come into effect again.XTo deactivate: press the ^ rocker
switch up or down.
The indicator lamp in the rocker switch
lights up.296Operating the 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 295) up or down and select
AUTO .
or
XPress rocker switch K(Y page 295) up or
down and select MAN.XTo switch off: press rocker switch
K (Y page 295) up or down and select
OFF .
Activating/deactivating cooling with
air dehumidification
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 271).
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 systems297Climate controlZ

Windows fogged up on the outsideXSwitch on the windshield wipers.XActivate automatic climate control.
iYou should only select this setting until
the windshield is clear again.
Rear window defroster
Activating/deactivating
GWARNING
Any accumulation of snow and ice should be
removed from the rear window before driving.
Visibility could otherwise be impaired,
endangering you and others.
The rear window defroster has a high current
draw. You should therefore switch it off as
soon as the 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.
XTurn the SmartKey to position 2 in the
ignition lock.XPress the ¤ rocker switch up or down.
The indicator lamp in the ¤ rocker
switch lights up or goes out.
Problems with the rear window
defroster
The rear window defroster has deactivated
prematurely or cannot be activated.
XSwitch off any consumers that are not
required, e.g. reading lamps or interior
lighting.
When the battery is sufficiently charged,
the rear window defroster is activated
again automatically.Activating/deactivating air-
recirculation mode
You can deactivate the flow of fresh air if
unpleasant odors are entering the vehicle
from outside. The air already inside the
vehicle will then be recirculated.GWARNING
Fogged windows impair visibility,
endangering you and others. If the windows
begin to fog on the inside, switching off the
air recirculation mode immediately should
clear interior window fogging. If interior
window fogging persists, make sure the air
conditioning is activated, or press the ¬
button.
XTurn the SmartKey to position 2 in the
ignition lock.XTo activate: press the g rocker switch
up or down.
The indicator lamp in the g rocker
switch lights up.
i Air-recirculation mode is activated
automatically at high outside
temperatures. The indicator lamp in the
g rocker switch is not lit when
automatic air-recirculation mode is
activated.
Outside air is added after about
30 minutes.
X To deactivate: press the g rocker
switch up or down.
The indicator lamp in the g rocker
switch goes out.Operating the climate control systems301Climate controlZ

iAir-recirculation mode deactivates
automatically:
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 †)
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, right302Setting the air ventsClimate control

iYou do not have to remove the Start/Stop
button from the ignition lock when you
leave the vehicle. However, you should
always take the SmartKey with you when
leaving the vehicle. The vehicle can be
started with the Start/Stop button and the
electrical equipment can be operated while
the SmartKey is in the vehicle.:Start/Stop button;Ignition lockXInsert Start/Stop button : into ignition
lock ;.
i
When you insert Start/Stop button :
into ignition lock ;, the system requires a
detection time of approximately
two seconds before you can use Start/
Stop button :.
Start/Stop button
=USA only?Canada onlyXPosition 0: if Start/Stop button : has not
yet been pressed, this corresponds to the
SmartKey being removed from the ignition.XPosition 1: press Start/Stop button :.
You can now activate the windshield
wipers, for example.
i If you then open the driver's door when in
this position, the power supply is
deactivated.
XPosition 2 (ignition): press Start/Stop
button : twice.
i
If you press Start/Stop button : once
when in this position and the driver's door
is open, the power supply is deactivated
again.
As soon as the ignition is switched on, all the
indicator lamps in the instrument cluster light
up. If an indicator lamp does not go out after
the engine is started or if it lights up while the
vehicle is in motion, see ( Y page 424).
Starting the engine
Important safety notes
GWARNING
Inhalation of exhaust gas is hazardous to your
health. All exhaust gas contains carbon
monoxide (CO), and inhaling it can cause
unconsciousness and possible death.
Do not run the engine in confined areas (such
as a garage) which are not properly ventilated.
If you think that exhaust gas fumes are
entering the vehicle while driving, have the
cause determined and corrected
immediately. If you must drive under these
conditions, drive only with at least one
window fully open at all times.
! Do not depress the accelerator pedal
when starting the engine.
308DrivingDriving and parking