2017 MERCEDES-BENZ GLS-Class SUV engine

Problems with fuel and the fuel tank
ProblemPossible causes/consequences andMSolutions
Fuel is leaking from the
vehicle.GWARNING
The fuel line or the fuel tank is faulty.
Risk of explosion or fire.
XApply the electric parking brake.
XSwitch off the engine.
XRemove the SmartKey from the ignition lock.
or, on vehicles with KEYLESS‑GO:
XOpen the driver's door.
The on-board electronics now have status 0. This is the same as the
SmartKey having been removed.
XDo not restart the engine under any circumstances.
XConsult a qualified specialist workshop.
The engine does not
start.The fuel tank of a vehicle with a diesel engine has been run completely
dry.
XRefuel the vehicle with at least 5.3 US qt (5 liters) of diesel.
XTurn the ignition on for approximately ten seconds (Ypage 138).
XStart the engine continuously for up to ten seconds until it runs
smoothly.
If the engine does not start:
XTurn the ignition on again for approximately ten seconds
(Ypage 138).
XStart the engine again continuously for up to ten seconds until it
runs smoothly.
If the engine does not start after three attempts:
XConsult a qualified specialist workshop.
The fuel filler flap cannot
be opened.The fuel filler flap is not unlocked.
XUnlock the vehicle (Ypage 74).
The SmartKey battery is discharged or nearly discharged.
XUnlock the vehicle using the mechanical key (Ypage 76).
The fuel filler flap is unlocked, but the opening mechanism is jammed.
XConsult a qualified specialist workshop.
DEF (BlueTEC vehicles only)
General notes
To function properly, BlueTEC exhaust gas after-
treatment must be operated with the reducing
agent DEF. Adding DEF is one of the tasks per-
formed during maintenance. Under normal operating conditions, a tank of DEF lasts until
the next service due date.
When the supply of DEF is almost used up, the
Check Additive See Operator's Manualmessage is shown in the multifunction display.
If you drive the vehicle faster than 10 mph
(16 km/h), the
Check Additive See Opera‐
156Refueling
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tor's Manualmessage goes out after approx-
imately one minute.
When the DEF supply drops to a minimum, the
Remaining Starts: 16
message is shown in
the multifunction display.
If the Remaining Starts: 16
message
appears in the multifunction display, you can
start the engine another 16 times. If DEF is not
refilled, you will subsequently be unable to
start the engine.
XAdd at least 1 gal (3.8 l)of DEF.
XSwitch on the ignition for at least 60 seconds.
XStart the engine.
iHave the DEF tank refilled at a qualified spe-
cialist workshop.
Use the special DEF refill bottle when adding
DEF between maintenance intervals. You can
obtain further information from an authorized
Mercedes-Benz Center or, if necessary, contact
Roadside Assistance (
Ypage 27).
If the outside temperature is below 12 ‡(Ò11 †)
it may be difficult to top up. If DEF is frozen and
there is an active warning indicator, it may not
be possible to add DEF. Park the vehicle in a
warmer place, e.g. in a garage, until DEF has
become fluid again. It will then be possible to
add DEF again. Alternatively, have the DEF tank
refilled at a qualified specialist workshop.
Further information about BlueTEC exhaust gas aftertreatment and DEF is available at any
authorized Mercedes-Benz Center.
Important safety notes
DEF is a water-soluble fluid for the exhaust gas
aftertreatment of diesel engines. It is:
Rnot poisonous
Rcolorless and odorless
Rnot flammable
When you open the DEF container, small
amounts of ammonia vapor may be released.
Ammonia vapors have a pungent odor and are
particularly irritating to the skin, to mucous
membranes and to the eyes. You may experi-
ence a burning sensation in your eyes, nose and
throat. Coughing and watering of the eyes are
possible.
Do not inhale ammonia vapors. Fill the DEF tank
only in well-ventilated areas. DEF must not come into contact with your skin,
eyes or clothing and must not be swallowed.
Keep DEF away from children.
If you or other persons come into contact with
DEF, observe the following:
RRinse DEF from your skin immediately with
soap and water.
RIf DEF comes into contact with your eyes,
immediately rinse them thoroughly with clean
water. Seek medical assistance without
delay.
RIf DEF has been swallowed, rinse your mouth
out immediately. Drink plenty of water. Seek
medical assistance without delay.
RChange out of clothing contaminated with
DEF immediately.
!Only use DEF in accordance with
ISO 22241. Do not mix any additives with
DEF, and do not dilute DEF with water. This
may destroy the BlueTEC exhaust gas after-
treatment system.
!The vehicle must be parked on level ground
to fill the DEF tank. The DEF tank can only be
filled as intended with the vehicle parked on a
level surface. This avoids false level readings.
Filling the tank is not permitted if the vehicle
is not parked on a level surface. There is a
danger of overfil
ling, which could result in
damage to components of the BlueTEC
exhaust gas aftertreatment.
!Rinse surfaces that have come into contact
with DEF immediately with water or remove
DEF using a damp cloth and cold water. If the
DEF has already crystallized, use a sponge
and cold water to clean it. DEF residues crys-
tallize after time and contaminate the affec-
ted surfaces.
!DEF is not a fuel additive and must not be
added to the fuel tank. If DEF is added to the
fuel tank, this can lead to engine damage.
For further information on DEF, see
(
Ypage 381).
Refueling157
Driving and parking
Z

overfilling. DEF may leak if overfilled. Mercedes-
Benz offers a special disposable hose with over-
fill protection. You can obtain this from any
authorized Mercedes-Benz Center. DEF is avail-
able in a variety of containers and receptacles.
Only use the disposable hose with the
Mercedes-Benz DEF refill canisters.
DEF refill bottle
!Only screw on the DEF refill bottle hand-
tight. Otherwise, the thread of the DEF refill
bottle could be damaged and DEF could leak
out.
XUnscrew the protective cap from DEF refill
bottle :.
XPlace DEF refill bottle :on the filler neck as
shown and screw it on clockwise until hand-
tight.
XPress DEF refill bottle :towards the filler
neck.
The DEF tank is filled. This may take up to one
minute.
iWhen DEF refill bottle :is no longer
pressed, filling stops and the bottle may be
taken off again after being only partially emp-
tied.
XRelease DEF refill bottle :.
XTurn DEF refill bottle:counter-clockwise
and remove it.
XScrew the protective cap onto DEF refill bot-
tle : again.
DEF refill canisters are available at many gas
stations or at a qualified specialist workshop.
Refill bottles without a threaded cap do not pro-
vide overfill protection. DEF may leak if overfil-
led. Mercedes Benz offers special refill bottles
with a threaded seal. These are available at any
authorized Mercedes-Benz Center.
Parking
Important safety notes
GWARNING
Flammable material such as leaves, grass or
twigs may ignite if they come into contact with
hot parts of the exhaust system or exhaust
gas flow. There is a risk of fire.
Park the vehicle so that no flammable mate-
rials come into contact with parts of the vehi-
cle which are hot. Take particular care not to
park on dry grassland or harvested grain
fields.
GWARNING
If you leave children unsupervised in the vehi-
cle, they could set it in motion by, for example:
Rrelease the parking brake.
Rshift the automatic transmission out of the
parking position P.
Rstart the engine.
In addition, they may operate vehicle equip-
ment and become trapped. 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 unsupervised in the vehicle.
!Always secure the vehicle correctly against
rolling away. Otherwise, the vehicle or its driv-
etrain could be damaged.
To ensure that the vehicle is secured against
rolling away unintentionally:
Rthe electric parking brake must be applied.
Rthe transmission must be in position Pand the
SmartKey must be removed from the ignition
lock.
Rthe front wheels must be turned towards the
curb on steep uphill or downhill gradients.
Rthe empty vehicle must be secured at the
front axle with a wheel chock or similar, for
example, on uphill or downhill gradients.
Ra laden vehicle must also be secured at the
rear axle with a wheel chock or similar, for
example, on uphill or downhill gradients.
Parking159
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Switching off the engine
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.
XApply the electric parking brake.
XShift the transmission to position P.
XWith the SmartKey:turn the SmartKey to
position 0in the ignition lock and remove it.
The immobilizer is activated.
XWith KEYLESS-GO:
Press the Start/Stop button (
Ypage 138)
The engine stops and all the indicator lamps in
the instrument cluster go out.
If you switch the engine off with the transmis-
sion in position Ror D, the automatic transmis-
sion shifts to Nautomatically.
If you then open the driver's or front-passenger door, the automatic transmission shifts to P
automatically.
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:
XVehicles with a SmartKey: switch on the
ignition.
XVehicles with KEYLESS-GO: remove the
Start/Stop button from the ignition lock.
XInsert the SmartKey into the ignition lock.
XSwitch on the ignition.
XAll vehicles: depress 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.
iThe engine can be switched off in an emer-
gency while the vehicle is in motion by press-
ing and holding the Start/Stop button for
three seconds.
Electric parking brake
General notes
GWARNING
If you leave children unsupervised in the vehi-
cle, they could set it in motion by, for example:
Rrelease the parking brake.
Rshift the automatic transmission out of the
parking position P.
Rstart the engine.
In addition, they may operate vehicle equip-
ment and become trapped. 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 unsupervised in the vehicle.
The function of the electric parking brake is
dependent on the on-board voltage. If the on-
board voltage is low or there is a malfunction in
the system, it may not be possible to apply the
released parking brake.
XIf this is the case, only park the vehicle on
level ground and secure it to prevent it rolling
away.
XShift the automatic transmission to position
P.
It may not be possible to release an applied
parking brake if the on-board voltage is low or
there is a malfunction in the system. Contact a
qualified specialist workshop.
iThe electric parking brake performs a func-
tion test at regular intervals while the engine
is switched off. The sounds that can be heard
while this is occurring are normal.
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Driving and parking

Emergency braking
The vehicle can also be braked during an emer-gency by using the electric parking brake.
XWhile driving, push handle :of the electric
parking brake.
The vehicle is braked for as long as the handle
of the electric parking brake is pressed. The
longer the electric parking brake handle is
depressed, the greater the braking force.
During braking:
Ra warning tone sounds
Rthe ReleasePark.Brakemessage appears
Rthe red F(USA only) or !(Canada
only) indicator lamp in the instrument cluster flashes
When the vehicle has been braked to a stand-
still, the electric parking brake is engaged.
Parking the vehicle for a long period
If you leave the vehicle parked for longer than
four weeks, the battery may be damaged by
exhaustive discharging.
If you leave the vehicle parked for longer than six
weeks, the vehicle may suffer damage as a
result of lack of use.
XVisit a qualified specialist workshop and seek
advice.
iYou can obtain information about trickle
chargers from a qualified specialist work-
shop.
Driving tips
General notes
Important safety notes
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 you operate mobile communication equip-
ment while driving, you will be distracted from traffic conditions. You could also lose control
of the vehicle. There is a risk of an accident.
Only operate this equipment when the vehicle
is stationary.
Observe the legal requirements for the country
in which you are driving. Some jurisdictions pro-
hibit the driver from using a mobile phone while
driving a vehicle.
If you make a call while driving, always use
hands-free mode. Only operate the telephone
when the traffic situation permits. If you are
unsure, pull over to a safe location and stop
before operating the telephone.
Bear in mind that at a speed of only 30 mph
(approximately 50 km/h), the vehicle covers a
distance of 44 ft (approximately 14 m)per sec-
ond.
Drive sensibly – save fuel
Observe the following tips to save fuel:
XThe tires should always be inflated to the rec-
ommended tire pressure.
XRemove unnecessary loads.
XRemove roof carriers when they are not nee-
ded.
XWarm up the engine at low engine speeds.
XAvoid frequent acceleration or braking.
XHave all maintenance work carried out as
indicated by the service intervals in the Main-
162Driving tips
Driving and parking

tenance Booklet or by the service interval dis-
play.
Fuel consumption also increases when driving in cold weather, in stop-start traffic and in hilly ter-
rain.
Drinking and driving
GWARNING
Drinking and driving and/or taking drugs and driving are very dangerous combinations.
Even a small amount of alcohol or drugs can
affect your reflexes, perceptions and judg-
ment.
The possibility of a serious or even fatal acci-
dent is greatly increased when you drink or
take drugs and drive.
Do not drink or take drugs and drive or allow
anyone to drive who has been drinking or tak-
ing drugs.
Emission control
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.
Certain engine systems are designed to keep
the level of poisonous components in exhaust
fumes within legal limits.
These systems only work at peak efficiency if
they are serviced exactly in accordance with the
manufacturer's specifications. Always have
work on the engine carried out at a qualified
specialist workshop. Mercedes-Benz recom-
mends that you use an authorized Mercedes-
Benz Center for this purpose. In particular, work
relevant to safety or on safety-related systems
must be carried out at a qualified specialist
workshop.
The engine settings must not be changed under any circumstances. Furthermore, all specific
service work must be carried out at regular
intervals and in accordance with the Mercedes-
Benz service requirements. Details can be found in the Maintenance Booklet.
ECO display
The ECO display shows you how economical
your driving style is. The ECO display assists you
in achieving the most economical driving style
for the selected settings and prevailing condi-
tions. Your driving style can significantly influ-
ence the vehicle's consumption.
:Acceleration
;Coasting
=Constant
?Additional range achieved
Range ?is shown under Bonus
fr.Startand
represents the additional range achieved since
the beginning of the journey as a result of an
adapted driving style.
If the fuel level has dropped into the reserve
range, the Reserve Fuel
message is shown in
the multifunction display instead of range ?.
The 8 warning lamp in the instrument cluster
also lights up (
Ypage 283).
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The ECO display consists of three sections, with
an inner and outer area. The sections corre-
spond to the following three categories:
:Acceleration(evaluation of all accel-
eration processes):
Rthe outer area fills up and the inner area lights up green: moderate
acceleration, especially at higher
speeds
Rthe outer area empties and the
inner area is gray: sporty acceler-
ation
;Coasting (evaluation of all decelera-
tion processes):
Rthe outer area fills up and the inner area lights up green: anticipatory
driving, keeping your distance and
early release of the accelerator.
The vehicle can coast without use
of the brakes.
Rthe outer area empties and the
inner area is gray: frequent heavy
braking
=Constant (continuous evaluation
over the entire journey):
Rthe outer area fills up and the inner area lights up green: constant
speed and avoidance of unneces-
sary acceleration and deceleration
Rthe outer area empties and the
inner area is gray: fluctuations in
speed
The three inner areas display the current driving
style and light up green as a result of a particu-
larly economical driving style. Depending on thedriving situation, up to two areas may light up
simultaneously.
At the beginning of the journey, the three outer
areas are empty and fill up as a result of eco-
nomical driving. A higher level indicates a more
economical driving style. If the three outer areas
are completely filled at the same time, the driver
has adopted the most economical driving style
for the selected settings and prevailing condi-
tions. The ECO display border lights up.
The ECO display does not indicate the actual fuel consumption. The additionally achieved range
displayed under Bonus fr. Start
does not
indicate a fixed consumption reduction. In addition to driving style, the actual consump-
tion is affected by other factors, such as:
Rload
Rtire pressure
Rcold start
Rchoice of route
Relectrical consumers switched on
These factors are not included in the ECO dis-
play.
An economical driving style specially requires
driving at moderate engine speeds.
Achieving a higher value in the categories
"Acceleration" and "Constant":
Robserve the gearshift recommendations.
Rdrive the vehicle in the Comfortdrive pro-
gram.
On long journeys at a constant speed, e.g. on the
highway, only the outer area for "constant" will
change.
The ECO display summarizes the driving style
from the start of the journey to its completion.
Therefore, there are more marked changes in
the outer areas at the start of a journey. On lon- ger journeys, there are fewer changes. For more
marked changes, perform a manual rest
(
Ypage 233).
For further information on the ECO display, see
(
Ypage 232).
Braking
Important safety notes
GWARNING
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 brak-
ing on a slippery road surface.
Downhill gradients
!On long and steep gradients, you must
reduce the load on the brakes by shifting to a
lower gear in good time. This allows you to
take advantage of the engine's braking effect.
164Driving tips
Driving and parking

This helps you to avoid overheating the
brakes and wearing them out excessively.
When you take advantage of engine braking, a
drive wheel may not turn for some time, e.g.
on a slippery road surface. This could cause
damage to the drive train. This type of damage is not covered by the Mercedes-Benz war-
ranty.
Do not depress the brake pedal continuously
while the vehicle is in motion, e.g. causing the
brakes to rub by constantly applying light pres-
sure to the pedal. This results in excessive and
premature wear to the brake pads.
Use the left-hand steering wheel paddle shifter
to shift into a lower gear in good time on long
and steep downhill gradients. This is especially
important if the vehicle is laden.
This also applies if you have activated cruise
control, the speed limiter or Distance Pilot
DISTRONIC.
This will use the braking effect of the engine, so
that less braking will be required to maintain the
speed. This relieves the load on the brake sys-
tem and prevents the brakes from overheating
and wearing too quickly.
Heavy and light loads
GWARNING
If you rest your foot on the brake pedal while
driving, the braking system can overheat. This increases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time.
!Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately. Drive
on for a short while. This allows the airflow to
cool the brakes more quickly.
Wet roads
If you have driven for a long time in heavy rain
without braking, there may be a delayed reac-
tion from the brakes when braking for the first time. This may also occur after the vehicle has
been washed or driven through deep water.
You then have to depress the brake pedal more
firmly. Maintain a greater distance from the
vehicle in front.
After driving on a wet road or having the vehicle
washed, brake firmly while paying attention to
the traffic conditions. This will warm up the
brake discs, thereby drying them more quickly
and protecting them against corrosion.
Limited braking performance on salt-
treated roads
If you drive on salted roads, a layer of salt resi-
due may form on the brake discs and brake
pads. This can result in a significantly longer
braking distance.
RBrake occasionally to remove any possible
salt residue. Make sure that you do not
endanger other road users when doing so.
RCarefully depress the brake pedal and the
beginning and end of a journey.
RMaintain a greater distance to the vehicle
ahead.
Servicing the brakes
!The brake fluid level may be too low, if:
Rif the red brake warning lamp lights up in
the instrument cluster and
Ryou hear a warning tone while the engine is
running
Observe additional warning messages in the
multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked immediately.
Consult a qualified specialist workshop to
arrange this.
!A function or performance test should only
be carried out on a 2-axle dynamometer. If
you wish to operate the vehicle on such a
dynamometer, please consult a qualified spe-
cialist workshop in advance. You could oth-
erwise damage the drive train or the brake
system.
!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
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