engine MERCEDES-BENZ M-Class 2014 W166 Service Manual

00050011
Left-hand standing lamps
00060013 Right-hand standing lamps
00070016 Parking lamps, license plate and
instrument cluster lighting
000C0006 Automatic headlamp mode,
controlled by the lights ensor
000D000D Low-beam/high-beam headlamps
00210010 Rear fog lamp
Even if the light sensor does not detec tthat
it is dark, the parking lamps and low-beam
headlamps switch on when the ignition is
switched on and the light switch is set to the
000D position. This is a particularly useful
function in the event of rain and fog.
X To switch on the low-beam headlamps:
turn the SmartKey in the ignition lock to
position 2or start the engine.
X Turn the light switch to 000D.
The green 000Dindicator lamp in the
instrumentc luster lights up.
Rear fog lamp 00050011
Left-hand standing lamps
00060013 Right-hand standing lamps 00070016
Parking lamps, license plate and
instrumen tcluste rlighting
000C0006 Automatic headlamp mode,
controlled by the light sensor
000D000D Low-beam/high-beam headlamps
00210010 Rear fog lamp
The rear fog lamp improves visibility of your
vehicle for the traffic behind in the event of
thick fog. Please take note of the country-
specific regulations for the use of rear fog
lamps.
X To switch on the rea rfog lamps: turn the
SmartKey in the ignition lock to position 2
or start the engine.
X Turn the light switch to 000Dor0006.
X Press the 0010button.
The yellow 0010indicator lamp in the
instrumen tcluster lights up.
X To switch off th erear fog lamp: press the
0010 button.
The yellow 0010indicator lamp in the
instrumen tcluster goes out.
Parking lamps
! If the battery has been excessively
discharged, the parking lamps or standing
lamps are automatically switched off to
enable the nex tengine start. Always park
your vehicle safely and sufficiently lit
according to legal standards .Avoid the
continuous use of the 0016parking lamps
for several hours .Ifpossible, switch on the
0013 right or the 0011left standing lamp. 122
Exterior lightingLights and windshiel
dwipers

High-beam headlamps
0002
High-beam headlamps
0003 Turn signal, right
0023 High-beam flasher
0022 Turn signal, left
X To switch on the high-beam headlamps:
turn the SmartKey in the ignition lock to
position 2or start the engine.
X Turn the light switch to 000Dor0006.
X Press the combination switch beyond the
pressure point in the direction of
arrow 0002.
In the 0006position, the high-beam
headlamps are only switched on when it is
dark and the engine is running.
The blue 000Cindicator lamp in the
instrument cluster lights up when the high-
beamh eadlamps are switched on.
X To switch off the high-beam
headlamps: move the combination switch
back to its normal position.
The blue 000Cindicator lamp in the
instrument cluster goes out.
i Vehicles with Adaptive Highbeam Assist:
when Adaptive Highbeam Assist is active,
it controls activation of the high-beam
headlamps (Y page 125). High-beam flasher 0002
High-beam headlamps
0003 Turn signal, right
0023 High-beam flasher
0022 Turn signal, left
X To switch on: turn the SmartKey in the
ignition lock to position 1or 2or start the
engine.
X Pull the combination switch in the direction
of arrow 0023. Hazard warning lamps
X
To switch on the hazard warning lamps:
press button 0002.
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.
X To switch off the hazard warning
lamps: press button 0002.124
Exterior lightingLights and windshield wipers

The hazard warning lamps automatically
switch on if:
R
an air bag is deployed.
R the vehicle decelerates rapidly from a
speed of more than 45mph (70 km/h) and
comes to a standstill.
The hazard warning lamps switch off
automatically if the vehicle reaches a speed
of over 6mph (10km/h) again after a full
brake application.
i The hazard warning lamps still operate if
the ignition is switched off. Headlamp cleaning system
The headlamps are cleaned automatically if
the "Wipe with washer fluid" function is
operated five times (Y page 132) while the
lights are on and the engine is running. When
you switch off the ignition, the automatic
headlamp cleaning system is reset and
counting is resumed from 0. Active light function
The active light function is a system that
moves the headlamps according to the
steering movements of the front wheels. In
this way, relevant areas remain illuminated
while driving. This allows you to recognize
pedestrians, cyclists and animals.
Active: whenthe lights are switched on. Cornering light function
The cornering light function improves the
illumination of the road over a wide angle in
the direction you are turning, enabling better
visibility in tight bends, for example. It can
only be activated when the low-beam
headlamps are switched on.
Active:
R
if you are driving at speeds below
25mph (40 km/h) and switch on the turn
signal or turn the steering wheel
R if you are driving at speeds between
25mph (40 km/h) and45mph (70 km/h)
and turn the steering wheel
Not active: if your speed exceeds
25mph (40 km/h) or if you switch off the turn
signal or turn the steering wheel to the
straight-ahead position.
The cornering light function may remain lit for
a short time, but is automatically switched off
after no more than three minutes. Adaptive Highbeam Assist
Important safety notes G
WARNING
Adaptive Highbeam Assist does not recognize
road users:
R who have no lights, e.g. pedestrians
R who have poor lighting, e.g. cyclists
R whose lighting is blocked, e.g. by a barrier Exterior lighting
125Lights and windshield wipers
Z

Crash-responsive emergency lighting
The interio rlighting is activated automatically
if the vehicle is involved in an accident.
X To switch off the crash-responsive
emergency lighting: press the hazard
warning lamp button.
or
X Loc kand then unlock the vehicle using the
SmartKey. Replacing bulbs
Important safety notes
G
DANGER
Xeno nbulbs carry a high voltage. You can get
an electric shock if you remove the cover of
the Xenon bulb and touch the electrical
contacts. There is a risk of fatal injury.
Never touch the parts or the electrical
contacts of the Xenon bulb. Always have work
on the Xenon bulbs carried out at a qualified
specialist workshop.
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. G
WARNING
Bulbs, lamps and connectors can get very hot
when operating. If you change a bulb, you
could burn yourself on these components.
There is a ris kofinjury.
Allow these components to cool down before
changing a bulb.
Do not use a bulb tha thas been dropped or if
its glass tube has been scratched.
The bulb may explode if:
R you touch it
R it is hot R
you drop it
R you scratch it
Only operate bulbs in enclosed lamps
designed for that purpose. Only install spare
bulbs of the same type and the specified
voltage.
Marks on the glass tube reduce the service
life of the bulbs. Do no ttouch the glass tube
with your bare hands. If necessary, clean the
glass tube when cold with alcohol or spirit and
rub it off with a lint-free cloth.
Protec tbulbs from moisture during
operation .Do not allow bulbs to come into
contact with liquids.
There are bulbs other than the Xenon bulbs
that you cannot replace. Replace only the
bulbs listed (Y page 129). Have the bulbs that
you cannot replace yourself changed at a
qualified specialist workshop.
If you require assistance changing bulbs,
consult a qualified specialist workshop.
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. Overview: changing bulbs/bulb types
You can change the following bulbs. The bulb
type can be found in the legend. Replacing bulbs
129Lights and windshiel dwipers Z

Problems with the windshield wipers
Problem Possible causes/consequences and
0001 Solutions
The windshield wipers
are jammed. Leaves or snow, for example, may be obstructing the windshield
wiper movement.T
he wiper motor has been deactivated.
X For safety reasons, you should remove the SmartKey from the
ignition lock.
or
X Switch off the engine using the Start/Stop button and open the
driver's door.
X Remove the cause of the obstruction.
X Switch the windshield wipers back on. The windshield wipers
fail completely. The windshield wiper drive is malfunctioning.
X
Select another wiper speed on the combination switch.
X Have the windshield wipers checked at a qualified specialist
workshop. 136
Windshield 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 Read the information on qualified
specialist workshops: (Y page 28).Overview of climate control systems
Important safety notes
Observe the settings recommended on the
following pages. The windows could
otherwise fog up.
To preven tthe windows from fogging up:
R switch off climate control only briefly
R switch on air-recirculation mode only
briefly
R switch on the cooling with air
dehumidification function
R switch 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.
The residual heat function can only be
activated or deactivated with the ignition
switched off (Y page 151).
i Ventilate the vehicle for a brief period
during warm weather, e.g. using the
convenience opening feature (Y page 95).
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. Aclogged 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 Maintenance Booklet .As it
depends on environmental conditions, e.g.
heavy air pollution, the interval may be
shorter than stated in the Maintenance
Booklet.
i It is possible that the dehumidification
function 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. 138
Overview of climate control systemsClimate control

0023
To direct the airflow through the rear air vents
0022 To direct the airflow through the footwell vents Information about using dual-zone
automatic climate control
The following contains notes and
recommendations on optimum use of dual-
zone automatic climate control.
R Activate climate control using the 0006and
0007/0005 buttons. The indicator lamps in
the 0006 and0007/0005 buttons light up.
R Set the temperature to 72 ‡ (22 †).
R Only use the "Windshield 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, since no fresh air is drawn
into the vehicle in air-recirculation mode.
R Use the ZONE function to adopt the
temperature settings on the driver's side
for the front-passenger side as well. The
indicator lamp above the 0004button goes
out.
R Vehicles with COMAND: if you change the
settings of the climate control system, the
climate status display appears for
approximately three seconds at the bottom
of the screen in the COMAND display .See
also the separate COMAND operating
instructions. You will see the current
settings of the various climate control
functions.
During automatic engine switch-off, the
climate control only operates at a reduced
capacity. If you require the full climate control
output, you can switch off the ECO start/stop
function by pressing the ECO button
(Y page 163). Overview of climate control systems
141Climate control

0027
To switch rear-compartment climate control on/off (Y page 144)
0028 To reduce the airflow (Y page 148)Information about 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 0006and
0007 buttons. The indicator lamps above
the 0006 and0007 buttons light up.
R In automatic mode, you can also use the
000C button to set a climate mode
(FOCUS/MEDIUM/DIFFUSE). The
MEDIUM level is recommended.
R Set the temperature to 72 ‡ (22 †).
R Only use the "Windshield 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, since no fresh air is drawn
into the vehicle in air-recirculation mode.
R Use the ZONE function to adopt the
temperature settings on the driver's side
for the front-passenger side and the rear
compartment as well. The indicator lamp
above the 0004button goes out.
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.
R Vehicles with COMAND: if you change the
settings of the climate control system, the
climate status display appears for
approximately three seconds at the bottom
of the screen in the COMAND display .See
also the separate COMAND operating
instructions. You will see the current
settings of the various climate control
functions. During automatic engine switch-off, the
climate control function only operates at a
reduced capacity. If you require the full
climate control output, you can switch off the
ECO start/stop function by pressing the ECO
button (Y
page 163). Operating the climate control
systems
Switching climate control on/off
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.
i
Switch on climate control primarily using
the 0006 button (Y page 146).
In the rear compartment, you can also switch
climate control on and off using the 0006and
000C buttons.
Activating/deactivating X
Turn the SmartKey to position 2in the
ignition lock (Y page 157).
X To activate: press the0006button.
The indicator lamp in the 0006button lights
up. Airflow and air distribution are set to
automatic mode.
or
X Press the 000Cbutton.
The indicator lamp in the 000Cbutton goes
out. The previously selected settings are
restored.
X To deactivate: press the000Cbutton.
The indicator lamp in the 000Cbutton lights
up. 144
Operating the climate control systemsClimate control

Activating/deactivating cooling with
air dehumidification
General notes If you deactivate the "Cooling with air-
dehumidification" function, the air inside the
vehicle will no tbe cooled. The air inside the
vehicle will also not be dehumidified. The
windows can fog up more quickly. Therefore,
only deactivate the "Cooling with air-
dehumidification" function 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
malfunction.
Activating/deactivating Example:
0007button
X To activate: press the0007/0005 button.
The indicator lamp in the 0007/0005
button lights up.
X To deactivate: press the0007/0005
button.
The indicator lamp in the 0007/0005
button goes out. The "Cooling with air
dehumidification" function has a delayed
switch-off feature. Operating the climate control systems
145Climate 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