engine MERCEDES-BENZ GL-Class 2016 X166 Workshop Manual

Problems with the rear window defroster
ProblemPossible causes/consequences andMSolutions
The rear window
defroster has deactiva-
ted prematurely or can-
not be activated.The battery has not been sufficiently charged.
XSwitch 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.
Switching air-recirculation mode
on/off
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 or deactivating
XTurn the SmartKey to position 2in the igni-
tion lock (
Ypage 165).
XTo activate: press thedbutton.
The indicator lamp in the dbutton lights
up.
iIn 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
d
button is not lit.
Outside air is added after about
30 minutes.
XTo deactivate: press thedbutton.
The indicator lamp in the dbutton goes
out.
iAir-recirculation mode deactivates auto-
matically:
Rafter approximately five minutes at out-
side temperatures below approximately
41 ‡ (5 †)
Rafter approximately five minutes if cool-
ing with air dehumidification is deactiva-
ted
Rafter approximately 30 minutes at out-
side temperatures above approximately
41 ‡ (5 †) if the "Cooling with air dehu-
midification" function is activated
Switching the residual heat on or off
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 systems159
Climate 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.
iRead the information on qualified special-
ist workshops (
Ypage 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.
RYou should therefore drive at varying vehi-
cle and engine speeds for the first
1000 miles (1500 km).
RAvoid heavy loads, e.g. driving at full throt-
tle, during this period.
RChange gear in good time, before the tach-
ometer needle is Ôof the way to the red
area of the tachometer.
RDo not manually shift to a lower gear to
brake the vehicle.
RTry 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 Mercedes-
AMG vehicles:
RDo not drive faster than 85 mph
(140 km/h) for the first 1,000 miles
(1,500 km).
ROnly allow the engine to reach a maximum
engine speed of 4,500 rpm briefly.
RChange gear in good time.
RIdeally, for the first 1,000 miles (1,500 km),
drive in program C.
You should also observe these notes on
breaking in if the engine or parts of the drive
train on your vehicle have been replaced.
Always observe the maximum permissible
speed.
Driving
Important safety notes
GWARNING
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.
164Driving
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GWARNING
Unsuitable footwear can hinder correct usage of the pedals, e.g.:
Rshoes with thick soles
Rshoes with high heels
Rslippers
There is a risk of an accident.
Wear suitable footwear to ensure correct
usage of the pedals.
GWARNING
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.
GWARNING
If the parking brake has not been fully
released when driving, the parking brake can:
Roverheat and cause a fire
Rlose its hold function.
There is a risk of fire and an accident. Release
the parking brake fully before driving off.
!Do not warm up the engine with the vehi-
cle stationary. Drive off immediately. Avoid
high engine speeds and driving at full throt-
tle until the engine has reached its operat-
ing 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.
!Mercedes-AMG vehicles: at low engine
oil temperatures below 68 ‡ (+20 †), the
maximum engine speed is restricted in
order to protect the engine. To protect the engine and maintain smooth engine oper-
ation, avoid driving at full throttle when the
engine is cold.
SmartKey positions
SmartKey
gTo remove the SmartKey
1Power supply for some consumers, such
as the windshield wipers
2Ignition (power supply for all consumers)
and drive position
3To start the engine
iThe 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.
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.
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.
Driving165
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Z

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.
To start the vehicle without actively using the
SmartKey:
Rthe Start/Stop button must be inserted in
the ignition lock.
Rthe SmartKey must be in the vehicle.
Rthe vehicle must not be locked with the
SmartKey or KEYLESS-GO (
Ypage 83).
Do not keep the SmartKey:
Rwith electronic devices, e.g. a mobile
phone or another SmartKey.
Rwith metallic objects, e.g. coins or metal
foil.
Rinside 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 (
Ypage 349).
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:
Ryou will not be able to switch on the ignition
with the Start/Stop button.
Ryou 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 (
Ypage 91), you can
continue to start the engine with the Start/
Stop button.
The engine can be switched off while the vehi-
cle is in motion by pressing and holding the
Start/Stop button for three seconds. This
function operates independently of the ECO start/stop automatic engine switch-off func-
tion.
Key positions with KEYLESS-GO
:Start/Stop button
;Ignition lock
As soon as the ignition is switched on, all the
indicator lamps in the instrument cluster light
up. Further information on situations where
an indicator lamp either fails to go out after
starting the engine or lights up while driving
(
Ypage 326).
If Start/Stop button :has not yet been
pressed, this corresponds to the key being
removed from the ignition.
XTo switch on the power supply: press
Start/Stop button :once.
The power supply is switched on. You can
now activate the windshield wipers, for
example.
The power supply is switched off again if:
Rthe driver's door is opened and
Ryou press Start/Stop button :twice when
in this position
XTo switch on the ignition: press Start/
Stop button :twice.
The ignition is switched on.
If you press Start/Stop button :once
when in this position, the ignition is deac-
tivated again.
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.
166Driving
Driving and parking

It is only possible to switch between KEY-
LESS-GO mode and SmartKey operation
when the transmission is in positionP.
XRemove Start/Stop button:from ignition
lock ;.
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 vehi-
cle. As long as the SmartKey is in the vehicle:
Rthe vehicle can be started using the Start/
Stop button
Rthe electrically powered equipment can be
operated
Starting the engine
Important safety notes
GWARNING
If children are left unsupervised in the vehicle,
they could:
Ropen the doors, thus endangering other
people or road users.
Rget out and disrupt traffic.
Roperate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
Rrelease the parking brake.
Rshifting the automatic transmission out of
park position P
RStart 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.
GWARNING
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.
GWARNING
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
Vehicles with a gasoline engine: the cata-
lytic converter is preheated for up 30 seconds
after a cold start. The sound of the engine may
change during this time.
Automatic transmission
XShift the transmission to position P
(
Ypage 174).
The transmission position display in the
multifunction display shows
P (
Ypage 174).
iYou can start the engine in transmission
position Pand N.
Starting procedure with the SmartKey
XTo start a diesel engine : turn the Smart-
Key to position 2in the ignition lock
(
Ypage 165).
The % preglow indicator lamp in the
instrument cluster lights up.
XTurn the SmartKey to position 3in the igni-
tion lock and release it as soon as the
engine is running (
Ypage 165).
iVehicles with a diesel engine: you can
start the engine without preglow if the
engine is warm.
Driving167
Driving and parking
Z

Using KEYLESS-GO to start the engine
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 vehicle. This mode
for starting the engine operates independ-
ently of the ECO start/stop automatic engine
start function.
XDepress the brake pedal and keep it
depressed.
XPress the Start/Stop button once
(
Ypage 165).
Vehicles with a gasoline engine: the
engine starts.
Vehicles with a diesel engine: preglow is
activated and the engine starts.
Pulling away
General notes
GWARNING
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.
Depress the accelerator carefully when pull-
ing away.
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 locking
feature (
Ypage 285).
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 you do not depress
the brake pedal, the DIRECT SELECT lever can still be moved but the parking lock remains
engaged.
iUpshifts take place at higher engine
speeds after a cold start. This helps the
catalytic converter to reach its operating
temperature more quickly.
Information on the automatic release of the
electric parking brake (
Ypage 190).
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.
XPress and hold handle :.
The electric parking brake continues to
brake and prevent the vehicle from rolling
backwards.
The red F(USA only) or !(Canada
only) indicator lamp in the instrument clus-
ter remains on.
XDepress the accelerator pedal.
XAs soon as the vehicle/trailer combination
is held by the driving force of the engine,
release lever :.
The electric parking brake is released.
The red F(USA only) or !(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
168Driving
Driving and parking

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.
GWARNING
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.
Hill start assist is not active if:
Ryou are pulling away on a level road or on a downhill gradient.
Rthe transmission is in position N.
Rthe electric parking brake is applied.
RESP®is malfunctioning.
ECO start/stop function
Introduction
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
GWARNING
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
:ECO start/stop display
The ECO start/stop function is activated
whenever you start the engine using the
SmartKey or the Start/Stop button.
If the engine has been switched off automat-
ically by the ECO start/stop function, the
¤ symbol is shown in the multifunction
display.
Mercedes-AMG vehicles: the ECO start/
stop function is only available in drive pro-
gram C.
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
when:
Rthe indicator lamp in the ECO button is lit
green.
Rthe outside temperature is within the range that is suitable for the system.
Rthe engine is at normal operating temper-
ature.
Rthe set temperature for the vehicle interior
has been reached.
Rthe battery is sufficiently charged.
Rthe system detects that the windshield is
not fogged up when the air-conditioning
system is switched on.
Rthe hood is closed.
Rthe driver's door is closed and the driver's
seat belt is fastened.
All of the vehicle's systems remain active
when the engine is stopped automatically.
Driving169
Driving and parking
Z

The HOLD function can also be activated if the
engine has been switched off automatically. It
is then not necessary to continue applying the
brakes during the automatic stop phase.
When you depress the accelerator pedal, the
engine starts automatically and the braking
effect of the HOLD function is deactivated.
All vehicles (except Mercedes-AMG vehi-
cles): automatic engine switch-off can take
place a maximum of four times in a row (initial
stop, then three subsequent stops).
Mercedes-AMG vehicles: the number of
consecutive automatic engine switch-offs is
unlimited.
Automatic engine start
The engine starts automatically if:
Ryou switch off the ECO start/stop function
by pressing the ECO button
Rin transmission position Dor Nthe brake
pedal is released and the HOLD function is
not active
Ryou depress the accelerator pedal
Ryou engage reverse gear R
Ryou move the transmission out of position
P
Ryou switch to drive program Sor M
(Mercedes-AMG vehicles)
Ryou switch to an off-road program (except
Mercedes-AMG vehicles)
Ryou unfasten your seat belt or open the
driver's door
Rthe vehicle starts to roll
Rthe brake system requires this
Rthe temperature in the vehicle interior devi-
ates from the set range
Rthe system detects moisture on the wind-
shield when the air-conditioning system is
switched on
Rthe battery's condition of charge is too low
Shifting the transmission to position Pdoes
not start the engine.
Deactivating or activating the ECO
start/stop function
All vehicles (except Mercedes-AMG vehi-
cles)
XTo deactivate: press ECO button :.
Indicator lamp ;goes out.
XTo activate: press ECO button :.
Indicator lamp ;lights up.
If the indicator lamp on the ECO button is off,
the ECO start/stop function has been deac-
tivated manually or as the result of a mal-
function.
Mercedes-AMG vehicles
XTo deactivate: in drive program C, press
ECO button :.
or
XSwitch to drive program Sor M
(
Ypage 177).
Indicator lamp ;goes out.
170Driving
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Problems with the engine
ProblemPossible causes/consequences andMSolutions
The engine does not
start. The starter motor
can be heard.RThere is a malfunction in the engine electronics.
RThere is a malfunction in the fuel supply.
Before attempting to start the engine again:
XTurn the key back to position 0in the ignition lock.
or
XPress the Start/Stop button repeatedly until all indicator lamps in the instrument cluster go out.
XTry to start the engine again (Ypage 167). Avoid excessively
long and frequent attempts to start the engine as these will drain
the battery.
If the engine does not start after several attempts:
XConsult a qualified specialist workshop.
The engine does not
start. You cannot hear
the starter motor.The on-board voltage is too low because the battery is too weak or
discharged.
XJump-start the vehicle (Ypage 395).
If the engine does not start despite attempts to jump-start it:
XConsult a qualified specialist workshop.
The starter motor was exposed to a thermal load that was too high.
XAllow the starter motor to cool down for approximately two
minutes.
XTry to start the engine again.
If the engine still does not start:
XConsult a qualified specialist workshop.
172Driving
Driving and parking

ProblemPossible causes/consequences andMSolutions
Vehicles with a gaso-
line engine:
The engine is not run-
ning smoothly and is
misfiring.There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
XOnly depress the accelerator pedal slightly.
Otherwise, non-combusted fuel may get into the catalytic con-
verter and damage it.
XHave the cause rectified immediately at a qualified specialist
workshop.
The coolant tempera-
ture gage shows a value
above 248 ‡ (120 †).The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.
XStop as soon as possible and allow the engine and the coolant to
cool down.
XCheck the coolant level (Ypage 373). Observe the warning
notes as you do so and add coolant if necessary.
Automatic transmission
Important safety notes
GWARNING
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.
GWARNING
The automatic transmission switches to neu-
tral position Nwhen you switch off the engine.
The vehicle may roll away. There is a risk of an
accident.
After switching off the engine, always switch
to parking position P. Prevent the parked vehi-
cle from rolling away by applying the parking
brake.
DIRECT SELECT lever
Overview of transmission positions
jPark position with parking lock
kReverse gear
iNeutral
hDrive
The DIRECT SELECT lever is on the right of the
steering column.
The DIRECT SELECT lever always returns to
its original position. The current transmission
position P,R, Nor Dappears in the transmis-
sion position display in the multifunction dis-
play (
Ypage 174).
Automatic transmission173
Driving and parking
Z