engine MERCEDES-BENZ M-Class 2015 W166 Workshop Manual

Problems with the rear window defroster
Problem
Possible causes/consequences and
0050
0050Solutions The rear window
defroster has deactiva-
ted prematurely or can-
not 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-recircula-
tion mode
General notes You can deactivate the flow of fresh air if
unpleasant odors are entering the vehicle
from outside. The air already inside the vehi-
cle will then be recirculated.
If you switch on air-recirculation mode, the
windows can fog up more quickly, in particu-
lar at low temperatures. Only use air-recircu-
lation 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 igni-
tion lock (Y page 157).
X To activate: press the0089button.
The indicator lamp in the 0089button lights
up.
i In the event of high pollution levels (3-
zone automatic climate control only) or at high outside temperatures, air-recircula-
tion mode is automatically activated. When
air-recirculation mode is activated auto-
matically, the indicator lamp in the 0089
button is not lit.
Outside air is added after about
30 minutes.
X To deactivate: press the0089button.
The indicator lamp in the 0089button goes
out.
i Air-recirculation mode deactivates auto-
matically:
R after approximately five minutes at out-
side temperatures below approximately
41 ‡ (5 †)
R after approximately five minutes if cool-
ing with air dehumidification is deactiva-
ted
R after approximately 30 minutes at out-
side temperatures above approximately
41 ‡ (5 †) if the "Cooling with air dehu-
midification" function is activated Activating/deactivating the residual
heat function
General notes The residual heat function is only available on
vehicles for Canada.
It is possible to make use of the residual heat
of the engine to continue heating the station- ary vehicle for up to 30 minutes after the
engine has been switched off. The heating
time depends on the set interior temperature. Operating the climate control systems
151Climate control

Switching on/off
X
To activate: press the004B/0056 button.
The indicator lamp in the 004B/0056but-
ton lights up.
i The blower will run at a low speed regard-
less 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.
X To deactivate: press the004B/0056 but-
ton.
The indicator lamp in the 004B/0056but-
ton goes out.
Residual heat is deactivated automatically: R after approximately 30 minutes
R when the ignition is switched on
R if the battery voltage drops Setting the air vents
Important safety notes
G
WARNING
Very hot or very cold air can flow from the air vents. This could result in burns or frostbite in the immediate vicinity of the air vents. There
is a risk of injury.
Make sure that all vehicle occupants always
maintain a sufficient distance to the air out-
lets. If necessary, redirect the airflow to
another area of the vehicle interior. 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 inlet grille on the hood and in
the engine compartment on the front-
passenger side free of blockages, such as
ice, snow or leaves.
R never cover the air vents or air intake grilles
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
0043
Center air vent, left
0044 Center air vent, right
0087 Center vent thumbwheel, right
0085 Center vent thumbwheel, left
X To open/close: turn thumbwheels 0087
and 0085to the right or left. 152
Setting the air ventsClimate control

Useful information
i This Operator's Manual describes all
models and all standard and optional equip- ment 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 special-
ist workshops (Y page 29). Notes on breaking-in a new vehicle
Important safety notes
The sensor system of some driving and driv-
ing safety systems adjusts automatically
while a certain distance is being driven after
the vehicle has been delivered or after
repairs. Full system effectiveness is not
reached until the end of this teach-in proce-
dure.
New and replaced brake pads and discs only
reach their optimum braking effect after sev-
eral hundred kilometers of driving. Compen-
sate for this by applying greater force to the
brake pedal. 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 You should therefore drive at varying vehi-
cle and engine speeds for the first
1000 miles (1500 km).
R Avoid heavy loads, e.g. driving at full throt-
tle, during this period.
R Change gear in good time, before the tach-
ometer needle is 00C3of the way to the red
area of the tachometer. R
Do not manually shift to a lower gear to
brake the vehicle.
R Try to avoid depressing the accelerator
pedal beyond the point of resistance (kick-
down).
After 1000 miles (1500 km), you can increase
the engine speed gradually and accelerate
the vehicle to full speed.
Additional breaking-in notes for AMG vehi-
cles:
R Do not drive faster than 85 mph
(140 km/h) for the first 1,000 miles
(1,500 km).
R Only allow the engine to reach a maximum
engine speed of 4,500 rpm briefly.
R Change gear in good time.
R Ideally, for the first 1,000 miles (1,500 km),
drive in program C.
i You should also observe these notes on
breaking in if the engine or parts of the drive
train on your vehicle have been replaced.
i Always observe the respective speed lim-
its. Driving
Important safety notes
G
WARNING
Objects in the driver's footwell can restrict the pedal travel or obstruct a depressed pedal.
The operating and road safety of the vehicle is
jeopardized. There is a risk of an accident.
Make sure that all objects in the vehicle are
stowed correctly, and that they cannot enter
the driver's footwell. Install the floormats
securely and as specified in order to ensure
sufficient clearance for the pedals. Do not use loose floormats and do not place floormats on
top of one another. 156
DrivingDriving and parking

G
WARNING
Unsuitable footwear can hinder correct usage of the pedals, e.g.:
R shoes with thick soles
R shoes with high heels
R slippers
There is a risk of an accident.
Wear suitable footwear to ensure correct
usage of the pedals. G
WARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with limitations, or not at all. This could affect, for example, the power steering and the brake
boosting effect. You will require considerably
more effort to steer and brake. There is a risk of an accident.
Do not switch off the ignition while driving. G
WARNING
If the parking brake has not been fully
released when driving, the parking brake can:
R overheat and cause a fire
R lose its hold function.
There is a risk of fire and an accident. Release
the parking brake fully before driving off.
! 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.
! AMG vehicles:
at low engine oil temper-
atures below 68 ‡ (+20 †), the maximum
engine speed is restricted in order to pro-
tect the engine. To protect the engine and
maintain smooth engine operation, avoid driving at full throttle when the engine is
cold. Key positions
SmartKey 005A
To remove the SmartKey
0047 Power supply for some consumers, such
as the windshield wipers
0048 Ignition (power supply for all consumers)
and drive position
0049 To start the engine
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
starting the engine or lights up while driving,
see (Y page 320).
If the SmartKey is in position 0in the ignition
lock for an extended period of time, it can no
longer be turned in the ignition lock. The
steering is then locked. To unlock, remove the SmartKey and reinsert it into the ignition lock.
The steering is locked when you remove the
SmartKey from the ignition lock.
X Remove the SmartKey when the engine is
switched off.
The starter battery could otherwise be dis-
charged.
If you cannot turn the SmartKey in the ignition
lock, the starter battery may not be charged
sufficiently. Driving
157Driving and parking Z

X
Check the starter battery and recharge if
necessary (Y page 389).
or
X Jump-start the vehicle (Y page 391).
i The SmartKey can be turned in the igni-
tion lock even if it is not the correct Smart- Key for the vehicle. The ignition is not
switched on. The engine cannot be started.
KEYLESS-GO General notes
Vehicles with KEYLESS-GO are equipped with
a SmartKey featuring an integrated KEYLESS- GO function and a detachable Start/Stop but-
ton.
The Start/Stop button must be inserted in the ignition lock and the SmartKey must be in the
vehicle.
When you insert the Start/Stop button into
the ignition lock, the system needs approx-
imately two seconds recognition time. You
can then use the Start/Stop button.
Pressing the Start/Stop button several times
in succession corresponds to the different
key 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 immedi-
ately.
A check which periodically establishes a radio
connection between the vehicle and the
SmartKey determines whether a valid Smart- Key is in the vehicle. This occurs, for example,
when starting the engine.
To start the vehicle without actively using the SmartKey:
R the Start/Stop button must be inserted in
the ignition lock.
R the SmartKey must be in the vehicle.
R the vehicle must not be locked with the
SmartKey or KEYLESS-GO (Y page 81).Do not keep the SmartKey:
R with electronic devices, e.g. a mobile
phone or another SmartKey
R with metallic objects, e.g. coins or metal
foil
R inside metallic objects, e.g. a metal case
This can impair the functionality of the KEY-
LESS-GO key.
Do not keep the KEYLESS-GO key in the tem-
perature-controlled cup holder (Y page 346).
Otherwise, the KEYLESS-GO key will not be
recognized.
If you lock the vehicle with the SmartKey's
remote control or with KEYLESS-GO, after a
short time:
R you will not be able to switch on the ignition
with the Start/Stop button.
R you will not be able to start the engine with
the Start/Stop button until the vehicle is
unlocked again.
If you lock the vehicle centrally using the but-
ton on the front door (Y page 87), you can
continue to start the engine with the Start/
Stop button.
i The engine can be turned off while the
vehicle is in motion by pressing and holding the Start/Stop button for approximately
three seconds. This function operates inde-
pendently of the ECO start/stop automatic
engine switch-off function.
Key positions with KEYLESS-GO 0043
Start/Stop button
0044 Ignition lock 158
DrivingDriving and pa
rking

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 afterstarting the engine or lights up while driving,
see (Y page 320).
If Start/Stop button 0043has not yet been
pressed, this corresponds to the SmartKey
being removed from the ignition.
X To switch on the power supply: press
Start/Stop button 0043once.
The power supply is switched on. You can
now activate the windshield wipers, for
example.
i The power supply is switched off again if:
R the driver's door is opened and
R you press Start/Stop button 0043twice
when in this position.
X To switch on the ignition: press Start/
Stop button 0043twice.
The ignition is switched on.
i The ignition is switched off when:
R the driver's door is opened and
R you press Start/Stop button 0043once
when in this position. 0087
Start/Stop button USA
0085 Start/Stop button Canada
Removing the Start/Stop button
You can remove the Start/Stop button from
the ignition lock and start the vehicle as nor-
mal using the SmartKey.
It is only possible to switch between KEY-
LESS-GO mode and SmartKey operation
when the transmission is in position P.X
Remove Start/Stop button 0043from ignition
lock 0044.
i You do not have to remove the Start/Stop
button from the ignition lock when you
leave the vehicle. You should, however,
always take the SmartKey with you when
leaving the vehicle. As long as the Smart-
Key is in the vehicle:
R the vehicle can be started using the
Start/Stop button
R electrically powered equipment can be
operated. Starting the engine
Important safety notes G
WARNING
If children are left unsupervised in the vehicle, they could:
R open the doors, thus endangering other
people or road users.
R get out and disrupt traffic.
R operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
R release the parking brake.
R shifting the automatic transmission out of
park position P
R Start the engine.
There is a risk of an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children. G
WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Inhaling
these exhaust gases leads to poisoning. There is a risk of fatal injury. Therefore never leave
the engine running in enclosed spaces with-
out sufficient ventilation. Driving
159Driving an d parking Z

G
WARNING
Flammable materials introduced through
environmental influence or by animals can
ignite if in contact with the exhaust system or parts of the engine that heat up. There is a risk
of fire.
Carry out regular checks to make sure that
there are no flammable foreign materials in
the engine compartment or in the exhaust
system.
! Do not depress the accelerator when
starting the engine.
General notes i
Vehicles with a gasoline engine:
the
catalytic converter is preheated for up to
30 seconds after a cold start. The sound of the engine may change during this time.
Automatic transmission X
Shift the transmission to position P
(Y page 168).
The transmission position display in the
multifunction display shows
P (Y page 168).
i You can start the engine in transmission
position Pand N.
Starting procedure with the SmartKey X
To start a gasoline engine: turn the
SmartKey to position 3in the ignition lock
(Y page 157) and release it as soon as the
engine is running.
X To start a diesel engine: turn the Smart-
Key to position 2in the ignition lock
(Y page 157).
The 0028 preglow indicator lamp in the
instrument cluster lights up.
X When the 0028preglow indicator lamp
goes out, turn the SmartKey to position 3
(Y page 157) and release it as soon as the
engine is running. i
You can start the engine without preglow
if the engine is warm.
Using KEYLESS-GO to start the engine X
Depress the brake pedal and keep it
depressed.
X To start a gasoline engine: press the
Start/Stop button (Y page 158) once.
The engine starts.
X To start a diesel engine: press the Start/
Stop button once (Y page 158).
Preglow is activated and the engine starts.
i The Start/Stop button can be used to
start the vehicle without inserting the
SmartKey into the ignition lock. The Start/
Stop button must be inserted in the ignition
lock and the SmartKey must be in the vehi-
cle. This mode for starting the engine oper-
ates independently of the ECO start/stop
automatic engine start function. Pulling away
Automatic transmission G
WARNING
If the engine speed is above the idling speed
and you engage transmission position Dor R,
the vehicle could pull away suddenly. There is a risk of an accident.
When engaging transmission position Dor R,
always firmly depress the brake pedal and do not simultaneously accelerate.
X Depress the brake pedal and keep it
depressed.
X Shift the transmission to position Dor R
(Y page 168).
X Release the brake pedal.
X Carefully depress the accelerator pedal.
The electric parking brake (Y page 184) is
automatically released. 160
DrivingDriving and parking

The red
0049(USA only) or 0024(Canada
only) indicator lamp in the instrument clus-
ter goes out.
i It is only possible to shift the transmission
from position Pto the desired position if
you depress the brake pedal. Only then is
the parking lock released. If the brake
pedal is not depressed, the DIRECT SELECT
lever can still be moved but the parking lock remains engaged.
i The vehicle locks centrally once you have
pulled away. The locking knobs in the doors
drop down.
You can open the doors from the inside at
any time.
You can also deactivate the automatic lock-
ing feature (Y page 279).
i Upshifts take place at higher engine
speeds after a cold start. This helps the
catalytic converter to reach its operating
temperature more quickly.
Pulling away with a trailer To ensure that you do not roll backwards
when pulling away on an uphill slope, engage
the electric parking brake.
X Press and hold handle 0043.
The electric parking brake continues to
brake and prevent the vehicle from rolling
backwards. The red
0049(USA only) or 0024(Canada
only) indicator lamp in the instrument clus- ter remains on.
X Depress the accelerator pedal.
X As soon as the vehicle/trailer combination
is held by the driving force of the engine,
release lever 0043.
The electric parking brake is released.
The red 0049(USA only) or 0024(Canada
only) indicator lamp in the instrument clus-
ter goes out.
Hill start assist Hill start assist helps you when pulling away
forwards or in reverse on an uphill gradient. It
holds the vehicle for a short time after you
have removed your foot from the brake pedal. This gives you enough time to move your foot
from the brake pedal to the accelerator pedal and to depress it before the vehicle begins to
roll. G
WARNING
After a short time, hill start assist will no lon-
ger brake your vehicle and it could roll away.
There is a risk of an accident and injury.
Therefore, quickly move your foot from the
brake pedal to the accelerator pedal. Never
leave the vehicle when it is held by hill start
assist.
X Remove your foot from the brake pedal.
The vehicle is then held for about a second.
X Pull away.
Hill start assist is not active if: R you are pulling away on a level road or on a
downhill gradient.
R the transmission is in position N.
R the electric parking brake is applied.
R ESP ®
is malfunctioning. Driving
161Driving and parking Z

ECO start/stop function (all vehicles
except the ML 250 BlueTEC 4MATIC)
Introduction This section describes the ECO start/stop
function for all vehicles except the ML 250
BlueTEC 4MATIC. Information about the ECO
start/stop function on the ML 250 BlueTEC
4MATIC (Y page 164).
The ECO start/stop function switches the
engine off automatically if the vehicle is stop- ped under certain conditions.
The engine starts automatically when the
driver wants to pull away again. The ECO
start/stop function thereby helps you to
reduce the fuel consumption and emissions
of your vehicle.
Important safety notes G
WARNING
If the engine is switched off automatically and you exit the vehicle, the engine is restarted
automatically. The vehicle may begin moving. There is a risk of accident and injury.
If you wish to exit the vehicle, always turn off
the ignition and secure the vehicle against
rolling away.
General notes 0043
ECO start/stop display
If the 00A7 symbol is shown in green in the
multifunction display, the ECO start/stop
function switches the engine off automati-
cally if the vehicle stops moving.
Every time you switch on the engine using the SmartKey or the Start/Stop button, the ECO
start/stop function is activated. If the ECO start/stop function has been man-
ually deactivated (Y page 163) or a malfunc-
tion has caused the system to be deactivated, the 00A7 symbol is not displayed.
AMG vehicles: the ECO start/stop function
is only available in drive program C.
For further information on automatic engine
switch-off (Y page 162) and automatic
engine start (Y page 163).
Automatic engine switch-off If the vehicle is braked to a standstill in
Dor N,
the ECO start/stop function switches off the engine automatically.
The ECO start/stop function is operational
and the 00A7symbol is displayed in green in
the multifunction display, if:
R the indicator lamp in the ECO button is lit
green.
R no off-road program has been selected.
R the outside temperature is within the range
that is suitable for the system.
R the engine is at normal operating temper-
ature.
R the set temperature for the vehicle interior
has been reached.
R the battery is sufficiently charged.
R the system detects that the windshield is
not fogged up when the air-conditioning
system is switched on.
R the hood is closed.
R the driver's door is closed and the driver's
seat belt is fastened.
If conditions for automatic engine switch-off
have not been fulfilled, the 00A7symbol will
be shown in yellow.
i All of the vehicle's systems remain active
when the engine has been stopped auto-
matically.
i The HOLD function can be activated if the
engine has been switched off automati-
cally. It is then not necessary to continue
applying the brakes during the automatic 162
DrivingDriving and parking

stop phase. When you depress the accel-
erator pedal, the engine starts automati-
cally and the braking effect of the HOLD
function is deactivated.
i All vehicles (apart from AMG vehicles):
automatic engine switch-off can take place a maximum of four times consecutively (ini-
tial stop then repeated three times). The
00A7 symbol is shown in yellow in the mul-
tifunction display after the engine has been started automatically for the fourth time.
When the 00A7symbol is shown in green in
the multifunction display, automatic engine switch-off is again possible.
i AMG vehicles:
times which the engine
can be automatically switched off.
Automatic engine start The engine starts automatically if:
R you switch off the ECO start/stop function
by pressing the ECO button.
R in transmission position Dor Nthe brake
pedal is released and the HOLD function is not active.
R you depress the accelerator pedal.
R you engage reverse gear R.
R you move the transmission out of position
P.
R you switch to drive program Sor M(AMG
vehicles).
R you switch to an off-road program (except
for AMG vehicles).
R you unfasten your seat belt or open the
driver's door.
R the vehicle starts to roll.
R the brake system requires this.
R the temperature in the vehicle interior devi-
ates from the set range.
R the system detects moisture on the wind-
shield when the air-conditioning system is
switched on.
R the battery's condition of charge is too low. i
Shifting the transmission to position
P
does not start the engine.
i If you shift the transmission from
Rto D,
the ECO start/stop function is available
again once the 00A7symbol reappears in
green in the multifunction display.
Deactivating/activating the ECO start/
stop function All vehicles (except AMG vehicles)
X
To deactivate: press ECO button 0043.
Indicator lamp 0044and the 00A7ECO sym-
bol in the multifunction display go out.
X To activate: press ECO button 0043.
Indicator lamp 0044lights up. If all conditions
for automatic engine switch-off
(Y page 162) are fulfilled, the 00A7symbol
is shown in green in the multifunction dis-
play.
If not all conditions for automatic engine
switch-off (Y page 162) are fulfilled, the
00A7 symbol is shown in yellow in the mul-
tifunction display. If this is the case, the
ECO start/stop function is not available.
i If indicator lamp
0044is off, the ECO start/
stop function has been deactivated man-
ually or as the result of a malfunction. The
engine will then not be switched off auto-
matically when the vehicle stops. Driving
163Driving and parking Z