window MERCEDES-BENZ M-Class 2014 W166 Service Manual

Switching the ZONE function on/off
X
To activate: press the0004button.
The indicator lamp above the 0004button
lights up.
Dual-zone automatic climate control: the
temperature setting for the driver's side is
not adopted for the front-passenger side.
3-zone automatic climate control: the
temperature setting for the driver's side is
not adopted for the front-passenger side
and the rear compartment.
X To deactivate: press the0004button.
The indicator lamp above the 0004button
goes out.
Dual-zone automatic climate control: the
temperature setting for the driver's side is
adopted for the front-passenger side.
3-zone automatic climate control: the
temperature setting for the driver's side is
adopted for the front-passenger side and
the rear compartment. Defrosting the windshield
You can use this function to defrost the
windshield or to defrost the inside of the
windshield and the side windows.
Switch off the "Windshield defrosting"
function as soon as the windshield is clear
again. X
Turn the SmartKey to position 2in the
ignition lock (Y page 157).
X To activate: press the0009button.
The indicator lamp in the 0009button lights
up.
The climate control system switches to the
following functions:
R high airflow
R high temperature
R air distribution to the windshield and
front side windows
R air-recirculation mode off
X To deactivate: press the0009button.
The indicator lamp in the 0009button goes
out. The previously selected settings are
restored. Air-recirculation mode remains
deactivated.
or
X Press the 0006button.
The indicator lamp in the 0009button goes
out. Airflow and air distribution are set to
automatic mode.
or
X Turn controls 0002or0021 clockwise or
counter-clockwise:
Dual-zone automatic climate control
(Y page 139)
3-zone automatic climate control
(Y page 142)
or
X Press the 0019or0018 button. MAX COOL maximum cooling
The MAX COOL function is only available in
vehicles for the USA. Operating the climate control systems
149Climate control

MAX COOL is only operational when the
engine is running.
X
To activate: press the0001button.
The indicator lamp in the button lights up.
X To activate: press off-road button 0001
again.
The indicator lamp goes out. The previously
selected settings are restored.
When you activate MAX COOL, climate
control switches to the following functions:
R maximum cooling
R maximum airflow
R air-recirculation mode on Defrosting the windows
Windows fogged up on the inside X
Activate the 0007/0005cooling with air
dehumidification function.
X Activate automatic mode 0006.
X If the windows continue to fog up, activate
the "windshield defrosting" function
(Y page 149).
i You should only select this setting until
the windshield is clear again.
Windows fogged up on the outside X
Press the 0017button repeatedly until the
001C or001B symbol appears in the
display.
i You should only select this setting until
the windshield is clear again. Rear window defroster
Activating/deactivating 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.
X
Turn the SmartKey to position 2in the
ignition lock (Y page 157).
X Press the 000Dbutton.
The indicator lamp in the 000Dbutton lights
up or goes out. 150
Operating the climate control systemsClimate control

Problems with the rear window defroster
Problem Possible causes/consequences and
0001 Solutions
The rear window
defroster has
deactivated
prematurely or cannot
be activated. The battery has not been sufficiently charged.
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. Activating/deactivating air-
recirculation mode
General notes You can deactivate the flow of fresh air if
unpleasant odors are enteringt he vehicle
from outside. The air already inside the
vehicle will then be recirculated.
If you switch on air-recirculation mode, the
windows can fog up more quickly, in
particular at low temperatures. Only use air-
recirculation mode briefly to prevent the
windows from fogging up.
Activating/deactivating The operation of air-recirculation mode is the
same for all control panels.
X Turn the SmartKey to position 2in the
ignition lock (Y page 157).
X To activate: press the0016button.
The indicator lamp in the 0016button lights
up.
i In the event of high pollution levels (3-
zone automatic climate control only) or at high outside temperatures, air-
recirculation mode is automatically
activated. When air-recirculation mode is
activated automatically, the indicator lamp
in the
0016button is not lit.
Outside air is added after about
30 minutes.
X To deactivate: press the0016button.
The indicator lamp in the 0016button goes
out.
i Air-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†) if the "Cooling
with air dehumidification" function is
activated Activating/deactivating the residual
heat function
The "residual heat" function is only available
in Canada. Operating the climate control systems
151Climate control

Setting the side air vents
0002
Side window defroster vent
0003 Side air vent
0023 Control for side air vent
X To open/close: turn thumbwheel 0023up or
down. Setting the glove box air vent
! Close the air vent when heating the
vehicle.
At high outside temperatures, open the air
vent and activate the "cooling with air
dehumidification" function. Otherwise,
temperature-sensitive items stored in the
glove box could be damaged. 0002
Air vent thumbwheel
0003 Air vent
When automatic climate control is activated,
the glove box can be ventilated, for instance
to cool its contents. The level of airflow
depends on the airflow and air distribution
settings. X
To open/close: turn thumbwheel 0002
clockwise or counter-clockwise. Setting the rear-compartment air
vents
Setting the center vents in the rear
compartment Example: center vents with rear control panel
0002
Rear-compartment air vent thumbwheel
0003 Rear-compartment air vent, right
0023 Rear control panel
0022 Rear-compartment air vent, left
X To open/close: turn thumbwheel 0002up or
down.
Setting the B-pillar air vent Second row of seats
0002
B-pillar air vent
0003 Thumbwheel for B-pillar air vent Setting the air vents
153Climate control Z

Winter driving
General notes G
WARNING
If you shift dow nonaslippery road surface in
an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
There is an increased danger of skidding and
accidents.
Do not shift down for additional engine
braking on a slippery road surface. G
DANGER
If the exhaust pipe is blocked or adequate
ventilation is not possible, poisonous gases
such as carbon monoxide (CO) may enter the
vehicle. This is the case, e.g. if the vehicle
becomes trapped in snow. There is a risk of
fatal injury.
If you leave the engine or the auxiliary heating
running, make sure the exhaust pipe and area
around the vehicle are clear of snow. To
ensure an adequate supply of fresh air, open
a window on the side of the vehicle that is not
facing into the wind.
Have your vehicle winterproofed at a qualified
specialist workshop at the onset of winter.
i Vehicles with adiesel engine: do not
cover the radiator, e.g. with a protective
cover. The measuring function of the
onboard diagnosis syste mmay otherwise
provide inaccurate values .Some of these
values are required by law and must
therefore always be accurate.
Observe the notes in the "Winter operation"
section (Y page 400).
Driving with summer tires Observe the notes in the "Winter operation"
section (Y
page 400). Slippery road surfaces G
WARNING
If you shift down on a slippery road surface in
an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
There is an increased danger of skidding and
accidents.
Do not shift down for additional engine
braking on a slippery road surface.
If the vehicle threatens to skid or cannot be
stopped when moving at low speed:
X Shift the transmission to position N.
i For more information on driving with
snow chains, see (Y page 401).
Drive particularly carefully on slippery road
surfaces. Avoid sudden acceleration, steering
and braking maneuvers. Do not use the cruise
control or DISTRONIC PLUS.
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Changes in the outside temperature are
displayed after a short delay.
Indicated temperatures just above the
freezing point do not guarantee that the road
surface is free of ice. The road may still be icy,
especially in wooded areas or on bridges. You
should pay special attention to road
conditions when temperatures are around
freezing point. Off-road driving
Important safety notes G
WARNING
If you drive on a steep incline at an angle or
turn when driving on an incline, the vehicle
could slip sideways, tip and rollover. There is
a risk of an accident.
Always drive on a steep incline in the line of
fall (straight up or down) and do not turn the
vehicle. Driving tips
187Driving and parking Z

G
WARNING
If the vehicle level is high, the vehicle center
of gravity is raised. This could cause the
vehicle to tip over more easily on uphill or
downhill gradients. There is arisk of an
accident.
Selec tthe lowest possible vehicle level.
When driving off-road, sand, mud and water,
possibly mixed with oil, for example, could get
into the brakes. This could result in a reduced
braking effect or in total brake failure and also
in increased wear and tear. The braking
characteristics change depending on the
material ingressing the brakes. Cleant he
brakes after driving off-road. If you detect a
reduced braking effect or grinding noises,
have the brake system checked in a qualified
specialist workshop as soon as possible.
Adapt your driving style to the different
braking characteristics.
Driving off-road increases the likelihood of
damage to the vehicle, which, in turn, can lead
to failure of the mechanical assembly or
systems. Adapt your driving style to suit the
terrain conditions. Drive carefully. Have
damage to the vehicle rectified immediately
at a qualified specialist workshop.
Do not switch to transmission position N
when driving off-road. You could lose control
of the vehicle if you attempt to brake using
the service brake. If the gradient is too steep,
drive backwards in reverse gear.
General notes Read this section carefully before driving your
vehicle off-road. Practice by driving over more
gentle off-road terrain first.
Familiarize yourself with the characteristics
of your vehicle and the gear shift operation
before driving through difficult terrain. The following driving systems are specially
adapted to off-road driving:
R
Off-road ABS (Y page 67)
R AIRMATIC package (vehicle level)
(Y page 207)
R DSR (Downhill Speed Regulation)
(Y page 246)
Observe the following notes:
R Stop the vehicle before starting to drive
along an off-road route.
R For vehicles with the AIRMATIC
package: select a vehicle level that is
suitable for the off-road terrain. To avoid
damaging the vehicle, make sure there is
always sufficient ground clearance.
R Check that items of luggage and loads are
stowed safely and are well secured
(Y page 337).
R Always keep the engine running and in gear
when driving on a downhill gradient.
Activate DSR (Y page 246).
R Always keep the doors, tailgate, windows
and sliding sunroof closed while driving.
R Adapt your speed to the terrain. The
rougher, steeper or more ruts on the
terrain, the slower your speed should be.
R Drive slowly and at an even speed through
the water. Ensure that a bow wave does not
form as you drive.
R Drive with extreme care on unfamiliar off-
road routes where visibility is poor. For
safety reasons, get out of the vehicle first
and survey the off-road route.
R Look out for obstacles, such as rocks,
holes, tree stumps and furrows.
R Check the depth of water before fording
rivers and streams.
R When fording, do not stop and do not
switch off the engine.
R On sand, drive quickly to overcome the
rolling resistance. Otherwise the vehicle's
wheels could become stuck in loose
ground. 188
Driving tipsDriving and parking

R
Secure any objects on the traile rto prevent
the cargo from slipping when the vehicle is
in motion.
R If you couple up a trailer, regularly check
that the cargo is securely fastened and
make sure that the trailer lamps and (if
applicable) the trailer brakes are
functioning correctly.
R Bear in mind that the handling will be less
stable when towing a trailer than when
driving without one. Avoid sudden steering
movements.
R The vehicle/trailer combination is heavier,
accelerates more slowly, has a decreased
gradient climbing capability and a longer
braking distance.
It is more susceptible to side winds and
requires more careful steering.
R If possible, avoid abrupt braking. Depress
the brake pedal moderately at first, so that
the trailer can activate its own brakes. Then
increase the pressure on the brake pedal.
R If the automatic transmission repeatedly
shifts between gears on uphill or downhill
gradients, shift to a lower gear using the
left-hand steering wheel paddle shifter.
Al ower gear and lower speed reduce the
risk of engine failure.
R When driving downhill, shift to a lower gear
to utilize the engine's braking effect.
Avoid continuous brake application as this
may overheat the vehicle brakes and, if
installed, the trailer brakes.
R If the coolant temperature increases
dramatically while the air-conditioning
system is switched on, switch off the air-
conditioning system.
Coolant heat can additionally be dissipated
by opening the windows and by setting the
blower fan and the interior temperature to
maximum.
R When overtaking, pay particular attention
to the extended length of your vehicle/
trailer combination. Due to the length of your vehicle/trailer
combination, you will have to travel an
additional distance beyond the vehicle you
are overtaking before returning to the
previous lane. Decoupling
atrailer G
WARNING
If you uncouple a trailer with the overrun
brake engaged, you could trap your hand
between the vehicle and the trailer drawbar.
There is a risk of injury.
Do not uncouple a trailer if the overru nbrake
is engaged. G
WARNING
Vehicles with level control:
The vehicle is lowered as soon as you
disconnect the trailer cable. This could result
in yourl imbs or those of other people that are
betwee nthe vehicle body and tires or
underneath the vehicle being trapped. There
is a risk of injury.
Make sure that nobody is in the immediate
vicinity of the wheel housings or under the
vehicle when you disconnectt he trailer cable.
! Do not disconnect a trailer with an
engaged overrun brake. Otherwise, your
vehicle could be damaged by the
rebounding of the overrun brake.
X Make sure that the automatic transmission
is set to position P.
X Apply the vehicle's electric parking brake.
X Start the engine.
X Close all doors and the tailgate.
X Apply the trailer's parking brake.
X Detach the trailer cable and decouple the
trailer.
X Switch off the engine. 258
Towing
atrailerDriving an d parking

Display messages Possible causes/consequences and
0001 Solutions
001F
Front Left
Malfunction
Service
Required orFront
Right Malfunction
Service Required SRS has malfunctioned at the front on the left or right. The
001F
warning lamp also lights up in the instrumen tcluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop. 001F
Rear Left
Malfunction
Service Required
or
Rear Right Malfunction
Service Required SRS has malfunctione
dat the rear on the left or right. The 001F
warning lamp also lights up in the instrument cluster.
G WARNING
The ai rbags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased ris kofinjury.
X Visi taqualified specialist workshop. 001F
Rear Center
Malfunction
Service Required SRS has malfunctioned at the rear center. The
001Fwarning lamp
also lights up in the instrument cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop. 001F
Left Side Curtain
Airbag Malfunction
Service
Required orRight
Side Curtain
Airbag Malfunction
Service Required There is a malfunction in the left-hand or right-hand window
curtain air bag. The
001Fwarning lamp also lights up in the
instrument cluster.
G WARNING
The left or right window curtain air bag may either be triggered
unintentionally or, in the event of an accident, may not be
triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop. 292
Display messagesOn-board computer and displays

There is a bag hook in the cargo compartment
on the left-hand side.
X
Press bag hook marking 0002.
X Turn bag hook 0002until it engages.
Securing hooks There is one securing hook
0002on each side
of the cargo compartment.
Only secure lightweight luggage items on the
securing hooks (maximum 9lbs (4 kg)). Cargo compartment cover
Important safety notes G
WARNING
On its own, the cargo compartment cover
cannot secure or restrain heavy objects,
items of luggage and heavy loads. You could
be hit by an unsecured load during sudden
changes in direction, braking or in the event
of an accident. There is an increased risk of
injury or even fatal injury. Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping over, e.g. by
using tie downs, even if you are using the
cargo compartment cover.
! When loading the vehicle, make sure that
you do not stac kthe load in the cargo
compartmenth igher than the lower edge of
the side windows .Do not place heavy
objects on top of the cargo compartment
cover.
A cargo compartment cover or a combined
cargo cover and net (cargo compartment
cover with cargo net) is installed, depending
on equipment, behind the rear bench seat
backrest.
Extending/retracting the cargo
compartment cover X
To extend: pull the cargo compartment
cover back by grab handle 0002and clip it
into retainers 0003on the left and right.
X To retract: unhook the cargo compartment
cover from left-hand and right-hand
retainers 0003.
X Guide cargo compartment cover forwards
by grab handle 0002until it is completely
rolled up. 338
Stowage areasStowage and features

Sun visors
Overview G
WARNING
If the mirror cover of the vanity mirror is folded
up when the vehicle is in motion, you could be
blinded by incident light. There is a risk of an
accident.
Always keep the mirror cover folded down
while driving. 0002
Mirror light
0003 Bracket
0023 Retaining clip, e.g. for a car park ticket
0022 Vanity mirror
0020 Mirror cover
Vanity mirror in the sun visor Mirror light
0002only functions if the sun visor
is clipped into bracket 0003and mirror cover
0020 has been folded up.
Glare from the side X
Fold down sun visor 0002.
X Pull sun visor 0002out of retainer 0023.
X Swing sun visor 0002to the side.
X Slide sun visor 0002horizontally as required.
X Fold down additional sun visor 0003to the
windshield. Roller sunblinds on the rear side
windows
! Always guide the roller sunblind by hand.
Do not let it snap back suddenly as this
would damage the automatic roller
mechanism.
! Do not drive the vehicle with the roller
sunblind hooked in and the side windows
opened simultaneously .The roller sunblind
can jump out of the retainers and spring
back suddenly when driving at high speeds,
e.g. when driving on the freeway. This could
damage the inertia reel. Therefore, either
close the side window or retract the roller
sunblind before driving at high speeds. X
To extend: pull the roller sunblind out by
tab 0002and hook it onto retainers 0003at the
back of the window. Features
345Stowage and features Z