Lights MERCEDES-BENZ R-Class 2012 W251 Owner's Guide

:Backup lampXTurn the bulb holder counter-clockwise and
remove it.XRemove the bulb from the bulb holder.XInsert the new bulb into the bulb holder.XInsert the bulb holder and turn it clockwise.XClose the side trim panel ( Y page 123).
License plate lamps
XSwitch off the lights.XOpen the tailgate.XRemove screws :.XRemove the license plate lamp.XReplace the bulb.XInsert the license plate lamp.XReplace and tighten screws :.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 windows 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 113Å
Intermittent wipe, high 124°
Continuous wipe, slow11
Rain sensor set to low sensitivity.
12 Rain sensor set to high sensitivity.124Windshield wipersLights and windshield wipers

5¯ 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.
Switching the rear window wiper on/
off
Combination switch
:è Switch2ô To wipe with washer fluid3I To switch on intermittent wiping40 To switch off intermittent wiping5ô To wipe with washer fluidXTurn the SmartKey to position 1 or 2 in the
ignition lock.XTurn switch : on the combination switch
to the corresponding position.
When the rear window wiper is switched on,
the icon appears in the instrument cluster.
Replacing the wiper blades
Important safety notes
GWARNING
For safety reasons, switch off the windshield
wipers and remove the key 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.
! 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
windshield.
Never fold a windshield wiper arm without
a wiper blade back onto the windshield/
rear window.
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.
Windshield wipers125Lights and windshield wipersZ

Replacing the windshield wiper blades
Removing the wiper blades
XRemove the SmartKey from the ignition
lock.XFold the wiper arm away from the
windshield.XPress both release clips ;.XFold wiper blade : in the direction of
arrow = away from wiper arm ?.XRemove wiper blade : in the direction of
arrow A.
Installing the wiper blades
XPosition the new wiper blade : with
recess B on lug A.XFold wiper blade : in the direction of
arrow = onto the wiper arm, until retaining
clips ; engage in bracket ?.XMake sure that wiper blade : is seated
correctly.XFold the wiper arm back onto the
windshield.Replacing the rear window wiper blade
Removing the wiper blade
XRemove the SmartKey from the ignition
lock.XFold wiper arm : away from the rear
window until it engages.XPosition wiper blade ; at a right angle to
wiper arm :.XHold wiper arm : and press wiper
blade ; in the direction of the arrow until
it releases.XRemove wiper blade ;.
Installing the wiper blade
XPlace new wiper blade ; onto wiper
arm :.XHold wiper arm : and press wiper
blade ; in the opposite direction to the
arrow until it engages.XMake sure that wiper blade ; is seated
correctly.XPosition wiper blade ; parallel to wiper
arm :.XFold wiper arm : back onto the rear
window.
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.
126Windshield wipersLights and windshield wipers

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.
The windshield wipers are inoperative
The windshield wiper drive is malfunctioning.
XSelect another wiper speed on the
combination switch.XHave the windshield wipers checked at a
qualified specialist workshop.
The spray nozzles are misaligned
The windshield washer fluid from the spray
nozzles no longer hits the center of the
windshield. The spray nozzles are misaligned.
XHave the spray nozzles adjusted at a
qualified specialist workshop.Windshield wipers127Lights and windshield wipersZ

HTo reduce the airflow (Y page 138)ITo switch the rear window defroster on/off ( Y page 139)JTo activate/deactivate air-recirculation mode ( Y page 140)KInterior temperature sensorLTo switch climate control on/off ( Y page 134) Rear control panelMTo increase the airflow ( Y page 138)NTo set the temperature ( Y page 137)OTo set the rear-compartment climate control to automatic ( Y page 136)PTo direct the airflow through the rear air vents ( Y page 138)QTo direct the airflow through the footwell vents ( Y page 138)RTo switch rear-compartment climate control on/off ( Y page 134)STo reduce the airflow ( Y page 138)Notes on using 3-zone automatic
climate control
The following contains instructions and
recommendations to enable you to get the
most out of your automatic climate control.
R Activate climate control using the à and
Á buttons. The indicator lamps in the
à and Á buttons light 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 MONO function if you want to
adopt the temperature and air distribution
settings from the driver's side for all
climate zones. The indicator lamp in the
º button lights up.
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 system
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 button ( Y page 136).
134Operating the climate control systemClimate control

Switching the front climate control on/
off using the front control panelXTurn the SmartKey to position 2 in the
ignition lock.XTo switch on: press the à button.
The indicator lamp in the à button lights
up. Airflow and air distribution are set to
automatic mode.
or
XPress the ^ button.
The indicator lamp in the ^ button goes
out. The previously selected settings come
into effect again.XTo switch off: press the ^ button.
The indicator lamp in the ^ button lights
up.
Switching the rear-compartment
climate control on/off using the front
control panel
2-zone automatic climate control
XTurn the SmartKey to position 2 in the
ignition lock.XTo switch on/off: press the ± button.
The indicator lamp in the ± button lights
up or goes out.
3-zone automatic climate control
USA only:
XTurn the SmartKey to position 2 in the
ignition lock.XTo switch on/off: press the ± button.
The indicator lamp in the ± button lights
up or goes out.
Canada only:
XTurn the SmartKey to position 2 in the
ignition lock.XTo switch on: press the Y button.
ON and MODE are shown in the automatic
climate control display behind the Y
symbol. The MODE display goes out after
three seconds. The display switches back
to the standard display.XTo switch off: press the Y button.
MODE is shown in the display behind the
Y symbol.XPress button ^.
OFF is shown in the display behind the
Y symbol.
Switching the rear-compartment
climate control on/off using the rear
control panel
3-zone automatic climate control
XTurn the SmartKey to position 2 in the
ignition lock.XSwitch on automatic climate control using
the front control panel.XTo switch on: press the à button.
The indicator lamp in the à button lights
up.XTo switch off: press the ^ button.
The indicator lamp in the ^ button lights
up.
Activating/deactivating the cooling
with 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.
Operating the climate control system135Climate controlZ

iThe cooling with air dehumidification
function uses refrigerant R134a. This
coolant does not contain
chlorofluorocarbons, and therefore does
not damage the ozone layer.
Activating/deactivating
! If the cooling with air dehumidification
does not switch on, it is possible that the
climate control system has lost coolant.
Have the cooling with air dehumidification
checked at a qualified specialist workshop.
XTo activate: press the Á button.
The indicator lamp in the Á button lights
up.XTo switch off: press the Á button.
The indicator lamp in the Á button goes
out. The cooling with air dehumidification
function has a delayed switch-off feature.
Problems with the cooling with air
dehumidification function
If the indicator lamp in the Á button does
not go out when the function is activated, the
cooling with air dehumidification function is
deactivated due to a malfunction. You can no
longer switch on the cooling with air
dehumidification function.
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 panelXTurn the SmartKey to position 2 in the
ignition lock.XSet the desired temperature.XTo activate: press the à button.
The indicator lamp in the à button lights
up. Automatic air distribution and airflow
are activated.XTo deactivate: press the K or I
button.
The indicator lamp in the à button goes
out. Automatic airflow is deactivated and
the airflow is controlled according to the
level set. Automatic air distribution
remains activated.
or
XPress the Z, M , ¯ , \ , P ,
c or O button.
The indicator lamp in the à button goes
out. Automatic air distribution is
deactivated. Air distribution is controlled
according to the position set. Automatic
airflow remains activated.
Controlling the rear-compartment
climate control automatically using the
rear control panel
XTurn the SmartKey to position 2 in the
ignition lock.XSwitch on automatic climate control using
the front control panel.XSet the desired temperature.XTo activate: press the à button.
The indicator lamp in the à button lights
up. Automatic air distribution and airflow
are activated.136Operating the climate control systemClimate control

Only change the temperature setting in
small increments. Start at 72 ‡ (22 †).
Setting the air distribution
Air distribution settings
Automatic climate control: the air distribution
can be set individually for the driver's and
front-passenger sides. 17
Front control unit:
ZDirects the airflow through the
defroster ventsMDirects the airflow through the
defroster vents¯Directs the airflow through the
defroster ventscDirects the airflow through the
footwell and side air ventsODirects the airflow through the
footwell and side air vents\Directs the airflow through the center
and side air ventsPDirects the airflow through the center
and side air vents
Rear control panel:
MDirects the airflow through the rear-
compartment air ventsODirects the airflow through the
footwell air vents
Adjusting
XTurn the SmartKey to position 2 in the
ignition lock.XPress the Z, M , ¯ , c , O ,
\ or P button.Setting the airflowXTurn the SmartKey to position 2 in the
ignition lock.XTo increase/reduce: press the K or
I button.
Vehicles with Voice Control System: when the
Voice Control System is switched on, the
airflow is restricted to 50%. When command
input is complete, the airflow is adjusted back
to the previous setting.
Activating/deactivating the MONO
function
The MONO function is only available with
automatic climate control. 18
You can use the MONO function to adopt the
settings configured for temperature, air
distribution and airflow on the driver's side for
the front-passenger side and the rear
compartment.
XPress the º button.
The indicator lamp in the º button lights
up or goes out.
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 activate: press the ¦ button.
The indicator lamp in the ¦ button lights
up.17 Canada only.
18 Canada only.138Operating the climate control systemClimate control

The climate control system switches to the
following functions:
R cooling with air dehumidification on
R high airflow 19
R high temperature 19
R air distribution to the windshield and
front side windows
R air-recirculation mode offXTo switch off: press the ¦ button.
The indicator lamp in the ¦ button 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 ^ button.
or
XPress the à button.
or
XTurn the temperature control clockwise or
counter-clockwise.
or
XPress the K or I button.
Defrosting the windows
Windows fogged up on the inside
XActivate the cooling with air
dehumidification function Á.XActivate automatic mode Ã.XIf the windows continue to fog up, activate
the defrosting function ( Y page 138).
i
You should only select this setting until
the windshield is clear again.
Windows fogged up on the outsideXSwitch on the windshield wipers.XPress the P/\ 20
or O /c 20
air distribution button.
i You 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 as it only 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 ª button.
The indicator lamp in the ª button lights
up or goes out.
Problems with the rear window
defroster
If the indicator lamp in the ª rear window
defroster button flashes, the on-board
voltage is too low or the roof is open. The rear
window defroster has deactivated itself
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.19 Depending on the outside temperature.
20 Canada only.Operating the climate control system139Climate controlZ

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.
The operation of air-recirculation mode is the
same for all control panels.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 d button.
The indicator lamp in the d button lights
up.
i Air-recirculation mode is activated
automatically at high outside
temperatures. When air-recirculation mode
is activated automatically, the indicator
lamp in the d button is not lit.
Outside air is added after about 30
minutes.
XTo switch off: press the d button.
The indicator lamp in the d button goes
out.i Air-recirculation mode deactivates
automatically:
R after approximately five minutes if
outside temperatures are less than about
41 ‡ (5 †)
R after approximately five minutes if
cooling with air dehumidification is
deactivated
R after approximately 30 minutes if outside
temperatures are over about
41 ‡ (5 †)
i The air-recirculation mode is not
deactivated automatically at outside
temperatures above 79 ‡ (26 †). After
approximately 30 minutes, outside air is
added. 21
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 Á button.
The indicator lamp in the Á button lights
up.XTo switch off: press the Á button.
The indicator lamp in the Á button goes
out.21 Vehicles with automatic climate control140Operating the climate control systemClimate control