engine MERCEDES-BENZ GLS-Class SUV 2017 X166 Repair Manual

Automa tic engine start
The engin estart sautomatically if:
Ryou switch off th eECO start/sto pfunction by
pressing th eECO butto n
Rin transmission position Dor Nthebrak e
pedal is release dand th eHOLD function is no t
active
Ryou depress th eaccelerato rpedal
Ryou engage revers egear R
Ryou mov eth etransmission out of position P
Ryou switch to theSport Plu sor Sport drive
program (Mercedes-AM Gvehicles)
Ryou activat emanual gearshifting (Mercedes-
AM Gvehicles)
Ryou switch to th eOffroa ddrive program
(vehicles without Off-Road Engineering pack- age)
Ryou switch to th eOffroa dor Offroa dPlu s
drive program (vehicles wit hOff-Road Engi-
neering package)
Ryou unfasten your seat belt or open th edriv-
er' sdoor
Rth evehicl estart sto rol l
Rthebrak esystem require sthis
Rth etemperature in th evehicl einterior devi-
ate sfrom th eset range
Rth esystem detects moisture on th ewind-
shield when th eair-conditioning system is
switched on
Rth ebattery's condition of charge is to olow
Shifting th etransmission to position Pdoes no t
start th eengine.
Deactivating oractivating the ECO
start/stop function
All vehicles (excep tMercedes-AM G vehi-
cles)
XTo deactivate: press ECO butto n:.
Indicato rlamp ;goe sout .
XTo activate: press ECO butto n:.
Indicato rlamp ;lights up.
If indicator lamp ;is off ,th eECO start/sto p
function has been deactivated manually or as
th eresult of amalfunction .
Mercedes-AM G vehicles
XTo deactivate: in theComfor tdrive pro -
gram ,press ECO butto n:.
or
XActivat emanual gearshifting (Ypage 150).
or
XSwitc hto th eSport Plu sor Sport drive pro -
gram (Ypage 145).
Indicato rlamp ;goes out .
XTo activate: press ECO butto n:.
Indicato rlamp ;lights up. When th e
Sport Plu sor Sport drive program is activa-
ted, th eautomatic transmission switches to
th eComfor tdrive program .
Driving143
Driving and parking
Z

If indicator lamp;is off, the ECO start/stop
function has been deactivated manually or as
the result of a malfunction.
Problems with the engine
ProblemPossible causes/consequences and MSolutions
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 SmartKey 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 139). 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 338).
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.
144Driving
Driving and parking

ProblemPossible causes/consequences andMSolutions
Vehicles with a gasoline
engine:
The engine is not running
smoothly and is misfir-
ing.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 converter
and damage it.
XHave the cause rectified immediately at a qualified specialist work-
shop.
The coolant temperature
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 322). Observe the warning notes
as you do so and add coolant if necessary.
DYNAMIC SELECT controller
Use the DYNAMIC SELECT controller to change
the drive program. Depending on the drive pro-
gram selected the following vehicle character-
istics will change:
Rthe drive (engine and transmission manage-
ment)
Rthe transmission
Rthe suspension
Rthe steering
Rthe availability of the ECO start/stop function
Each time you start the engine with the Smart-
Key or the Start/Stop button, the Comfortdrive
program is activated. For further information
about starting the engine, see (
Ypage 139).
XAll vehicles (except Mercedes-AMG vehi-
cles): turn DYNAMIC SELECT controller :as many times as necessary until the desired
drive program is selected.
The selected drive program appears in the
multifunction display. After five seconds the
display goes out.
In addition, the current drive program settings
are displayed in the multimedia system dis-
play.
Drive programs available (all vehicles
except Mercedes-AMG vehicles):
IndividualIndividual settings
SportSporty driving characteris-
tics
ComfortComfortable and economi-
cal driving characteristics
SlipperyOptimal driving characteris-
tics on slippery or snow-
covered roads
Off-roadOptimal driving characteris-
tics for easily negotiable off-
road terrain
Offroad Plus
(vehicles with
Off-Road Engi-
neering pack-
age)Optimal driving characteris-
tics for rough terrain
DYNAMIC SELECT controller145
Driving and parking
Z

Further information on:
RtheIndividual ,Sport ,Comfort andSlippery
drive programs (Ypage 149)
Rthe Offroad drive program (vehicles without
Off-Road Engineering package)
(
Ypage 217)
Rthe Offroad andOffroad Plus drive pro-
grams (vehicles with Off-Road Engineering
package) (
Ypage 218)
XMercedes-AMG vehicles: turn DYNAMIC
SELECT controller :as many times as nec-
essary until the desired drive program is
selected.
The selected drive program appears in the
multifunction display. After five seconds the
display goes out.
In addition, the current drive program settings are displayed in the multimedia system dis-
play.
Drive programs available (Mercedes-AMG
vehicles):
IndividualIndividual settings
ComfortComfortable and economi-
cal driving characteristics
SportSporty driving characteris-
tics
Sport PlusParticularly sporty driving
characteristics
SlipperyOptimal driving characteris-
tics on slippery or snow-
covered roads
Additional information for drive programs
(Ypage 149).
Automatic transmission
Important safety notes
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 posi-
tion P,R, Nor Dappears in the transmission
position display in the multifunction display
(
Ypage 148).
Engaging park position P
!If the engine speed is too high or the vehicle
is moving, do not shift the automatic trans-
mission directly from Dto R, from Rto Dor
directly to P. The automatic transmission
could otherwise be damaged.
146Automatic transmission
Driving and parking

XPush the DIRECT SELECT lever in the direction
of arrowP.
Engaging park position P automatically
Park position Pis automatically engaged if:
Ryou switch off the engine using the SmartKey
and remove the SmartKey
Ryou switch off the engine using the SmartKey
or using the Start/Stop button and open the
driver's door or front-passenger door
Rthe driver's door is opened when the vehicle is
stationary or driving at very low speed and the
transmission is in position Dor R
Under certain conditions, the automatic trans-
mission shifts automatically to transmission
position Pif the HOLD function or Distance Pilot
DISTRONIC is activated. Observe the informa-
tion on the HOLD function (
Ypage 185) and on
Distance Pilot DISTRONIC (Ypage 177).
Engaging reverse gear R
!Only shift the automatic transmission to R
when the vehicle is stationary.
XIf the transmission is in position Dor N: push
the DIRECT SELECT lever up past the first
point of resistance.
XIf the transmission is in position P: depress
the brake pedal and push the DIRECT SELECT lever up past the first point of resistance.
Shifting to neutral N
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.
XIf the transmission is in position Dor R: push
the DIRECT SELECT lever up or down to the
first point of resistance.
XIf the transmission is in position P: depress
the brake pedal and push the DIRECT SELECT
lever up or down to the first point of resist-
ance.
If you switch the engine off with the transmis-
sion in position Ror D, the automatic transmis-
sion shifts to Nautomatically.
With the SmartKey: if you then open the driv-
er's door or the front-passenger door or remove
the SmartKey from the ignition, the automatic
transmission shifts to Pautomatically.
With the Start/Stop button: if you then open
the driver's door or the front-passenger door,
the automatic transmission shifts to Pautomat-
ically.
If you want the automatic transmission to
remain in neutral N, e.g. when having the vehicle
cleaned in an automatic car wash with a towing
system:
Using the SmartKey:
XSwitch on the ignition.
XDepress the brake pedal and keep it
depressed.
XShift to neutral N.
XRelease the brake pedal.
XRelease the electric parking brake.
XSwitch off the ignition and leave the SmartKey
in the ignition lock.
With the Start/Stop button:
XRemove the Start/Stop button from the igni-
tion lock.
XInsert the SmartKey into the ignition lock.
XSwitch on the ignition.
XDepress the brake pedal and keep it
depressed.
XShift to neutral N.
XRelease the brake pedal.
Automatic transmission147
Driving and parking
Z

ANeutral
Do not shift the transmission toN
while driving. Otherwise, the auto-
matic transmission could be dam-
aged.
No power is transmitted from the
engine to the drive wheels.
Releasing the brakes will allow you to
move the vehicle freely, e.g. to push
it or tow it.
If ESP
®is deactivated or faulty: shift
the transmission to position Nif the
vehicle is in danger of skidding, e.g.
on icy roads.
If you switch the engine off with the
transmission in position Ror D, the
automatic transmission shifts to N
automatically.
!Rolling in neutral Ncan damage
the drive train.
7Drive
The automatic transmission changes
gear automatically. All forward gears
are available.
Driving tips
Changing gear
The automatic transmission shifts to the indi-
vidual gears automatically when it is in trans-
mission position D. This automatic gear shifting
behavior is determined by:
Rthe selected drive program
Rthe position of the accelerator pedal
Rthe road speed
Accelerator pedal position
Your style of driving influences how the auto-
matic transmission shifts gear:
Rlittle throttle: early upshifts
Rmore throttle: late upshifts
Kickdown
Use kickdown for maximum acceleration.
XDepress the accelerator pedal beyond the
pressure point.
The automatic transmission shifts to a lower
gear depending on the engine speed.
XEase off the accelerator pedal once the
desired speed is reached.
The automatic transmission shifts back up.
Rocking the vehicle free
Shifting the transmission repeatedly between
gears Dand Rmay help to free the vehicle if it
has become stuck in slush or snow. The vehi-
cle's engine management system limits the
speed to a maximum of 5 mph (9 km/h) when
shifting back and forth. To shift back and forth
between transmission positions Dand R, move
the DIRECT SELECT lever up and down past the
point of resistance.
Towing a trailer
XDrive in the middle of the engine speed range
on uphill gradients.
XDepending on the uphill or downhill gradient,
use the left-hand steering wheel paddle
shifter (
Ypage 150) to select a lower gear,
even if cruise control or Distance Pilot
DISTRONIC are activated.
Drive programs
Slippery drive program
The Slippery drive program has the following
characteristics:
Rreduced engine and transmission settings for
optimum propulsion on slippery or snow-cov-
ered roads.
Roptimized ESP®stability control on slippery or
snow-covered roads.
Rthe vehicle has improved driving stability on
slippery or snow-covered roads, for example.
Automatic transmission149
Driving an d parking
Z

Comfort drive program
TheComfort drive program has the following
characteristics:
Rcomfort-oriented engine and transmission
settings.
Roptimal fuel consumption resulting from the
automatic transmission shifting up sooner.
Rthe vehicle pulling away more gently in
forward and reverse gears, unless the accel-
erator pedal is depressed fully.
Rthe automatic transmission shifting up
sooner. This results in the vehicle being driven
at lower engine speeds and the wheels being
less likely to spin.
Sport drive program
The Sport drive program has the following char-
acteristics:
Rsporty engine and transmission settings.
Rthe automatic transmission shifting up later.
the fuel consumption possibly being higher as
a result of the later automatic transmission
shift points.
Rthe suspension exhibits sporty damping (vehi-
cles with AIRMATIC).
Drive program Sport Plus (Mercedes-
AMG vehicles)
The Sport Plus drive program has the following
characteristics:
Rthe vehicle exhibits particularly sporty driving
characteristics.
Rthe vehicle pulling away in first gear.
Rthe automatic transmission shifting up later.
the fuel consumption possibly being higher as
a result of the later automatic transmission
shift points.
Rthe suspension exhibits particularly firm
springing and damping settings (vehicles with AIRMATIC).
Rthe ECO start/stop function is deactivated, it
can, however, be activated again using the
ECO button (
Ypage 143).
Individual drive program
In the Individual drive program, the following
properties of the drive program can be selected:
Rthe drive (engine and transmission manage-
ment)
Rthe transmission
Rthe suspension
Rall vehicles (except Mercedes-AMG vehicles):
the steering
Rall vehicles (except Mercedes-AMG vehicles):
availability of the ECO start/stop function
To select the gears in the Individualdrive pro-
gram permanently using the steering wheel pad-
dle shifters, select the permanent manual gear-
shift program.
Information about configuring the Individual
drive program with the multimedia system can
be found in the Digital Operator's Manual.
Manual gear shifting
General notes
You can change gear yourself using the steering
wheel paddle shifters. The transmission must be
in position D.
Depending on which steering wheel paddle
shifter is pulled, the automatic transmission
immediately shifts into the next gear down or
up, if permitted.
To use manual shifting, you have two options:
Rtemporary setting
Rpermanent setting
If you activate manual gearshifting, the multi-
function display will show the current gear
instead of transmission position D.
If manual gearshifting is deactivated, the gears
will be selected automatically.
150Automatic transmission
Driving and parking

Temporary setting
XTo activate:shift the DIRECT SELECT lever to
position D.
XPull steering wheel paddle shifter :or;.
Temporary setting will be active for a certain
amount of time. Under certain conditions the
minimum amount of time is extended, e.g. in the case of lateral acceleration, during an overrun
phase or when driving on steep terrain.
XTo deactivate: pull steering wheel paddle
shifter ;and hold it in place.
or
XUse the DIRECT SELECT lever to switch the
transmission position.
or
XUse the DYNAMIC SELECT controller to
change the drive program.
Permanent setting (all vehicles except
Mercedes-AMG vehicles)
XTo activate: shift the DIRECT SELECT lever to
position D.
XPress button :.
XTo deactivate: press button:.
or
XUse the DYNAMIC SELECT controller to
change the drive program.
Permanent setting (Mercedes-AMG
vehicles)
XTo activate: shift the DIRECT SELECT lever to
position D.
XPress button :.
Indicator lamp ;lights up.
XTo deactivate: press button:.
or
XUse the DYNAMIC SELECT controller to
switch to the Individualdrive program.
Indicator lamp ;goes out.
Shifting gears
!Mercedes-AMG vehicles: the automatic
transmission does not shift up automatically
even when the engine limiting speed for the
current gear is reached. When the engine lim-
iting speed is reached, the fuel supply is cut to
prevent the engine from overrevving. Always
make sure that the engine speed does not
reach the red area of the tachometer. There is
otherwise a risk of engine damage.
Automatic transmission151
Driving an d parking
Z

XTo shift up:pull steering wheel paddle
shifter ;.
The automatic transmission shifts up to the
next gear.
All vehicles (except Mercedes-AMG vehi-
cles): if the maximum engine speed on the
currently engaged gear is reached and you
continue to accelerate, the automatic trans-
mission automatically shifts up in order to
prevent engine damage.
XTo shift down: pull steering wheel paddle
shifter :.
The automatic transmission shifts down to
the next gear.
Automatic down shifting occurs when coast-
ing.
If the engine exceeds the maximum engine
speed when shifting down, the automatic
transmission protects against engine damage
by not shifting down.
Shift recommendation
The gearshift recommendations assist you in
adopting an economical driving style. The rec-
ommended gear is shown in the multifunction
display.
XShift to recommended gear ;according to
gearshift recommendation :when shown in the multifunction display of the instrument
cluster.
Upshifting (Mercedes-AMG vehicles)
!The automatic transmission does not shift
up automatically even when the engine limit-
ing speed for the current gear is reached.
When the engine limiting speed is reached,
the fuel supply is cut to prevent the engine
from overrevving. Always make sure that the
engine speed does not reach the red area of
the tachometer. There is otherwise a risk of
engine damage.
:Gear indicator
;Upshift indicator
Before the engine speed reaches the red area,
an upshift indicator will be shown in the multi-
function display.
XWhen the UPmessage appears in the multi-
function display, pull on the right-hand steer-
ing wheel paddle shifter.
Kickdown
Mercedes-AMG vehicles: kickdown is only
possible in the temporary setting.
XFor maximum acceleration, depress the
accelerator pedal beyond the pressure point.
The automatic transmission shifts to a lower
gear depending on the engine speed.
XShift back up once the desired speed is
reached.
During kickdown, you cannot shift gears using
the steering wheel paddle shifters.
If you apply full throttle, the automatic trans-
mission shifts up to the next gear when the
maximum engine speed is reached. This pre-
vents the engine from overrevving.
152Automatic transmission
Driving an d parking

Problems with the transmission
ProblemPossible causes/consequences andMSolutions
The transmission has
problems shifting gear.The transmission is losing oil.
XHave the transmission checked at a qualified specialist workshop
immediately.
7G-TRONIC:
The acceleration ability
is deteriorating.
The transmission no lon-
ger changes gear.The transmission is in emergency mode.
It is only possible to shift intosecondgear and reverse gear.
XStop the vehicle.
XShift the transmission to position P.
XSwitch off the engine.
XWait at least ten seconds before restarting the engine.
XShift the transmission to positionDor R.
If D is selected, the transmission shifts into secondgear; ifRis
selected, the transmission shifts into reverse gear.
XHave the transmission checked at a qualified specialist workshop
immediately.
9G-TRONIC:
The acceleration ability
is deteriorating.
The transmission no lon-
ger changes gear.The transmission is in emergency mode.
It is only partly possible to engage the gears or the transmission is in
position N.
XStop the vehicle.
XShift the transmission to position P.
XSwitch off the engine.
XWait at least ten seconds before restarting the engine.
XShift the transmission to positionDor R.
XHave the transmission checked at a qualified specialist workshop
immediately.
Transfer case
This section is only valid for vehicles with 4-
wheel drive (4MATIC). Power is always trans-
mitted to both axles.
!Performance tests may only be carried out
on a 2-axle dynamometer. The brake system
or transfer case could otherwise be damaged. Contact a qualified specialist workshop for a
performance test.
!Because ESP®is an automatic system, the
engine and ignition must be switched off
(SmartKey in position 0or 1or Start/Stop
button in position 0or 1) when the electric
parking brake is being tested on a brake dyna-
mometer (maximum 10 seconds).
Braking triggered automatically by ESP
®may
seriously damage the brake system.
!Vehicles with 4MATIC must not be towed
with either the front or the rear axle raised, as
doing so will damage the transmission.
Refueling
Important safety notes
GWARNING
Fuel is highly flammable. If you handle fuel
incorrectly, there is a risk of fire and explo-
sion.
You must avoid fire, open flames, creating
sparks and smoking. Switch off the engine
and, if applicable, the auxiliary heating before refueling.
Refueling153
Driving and parking
Z