display MERCEDES-BENZ GLS 2017 Service Manual

Problems with fuel and the fuel tank Problem
Possible causes/consequences and P Solutions
Fuel is leaking from the
vehicle.
G WARNING
The fuel line or the fuel tank is faulty.
Risk of explosion or fire. X
Apply the electric parking brake. X
Switch off the engine. X
Remove the SmartKey from the ignition lock.
or, on vehicles with KEYLESS ‑ GO:X
Open the driver's door.
The on-board electronics now have status 0 . This is the same as the
SmartKey having been removed. X
Do not restart the engine under any circumstances. X
Consult a qualified specialist workshop.
The engine does not
start. The fuel tank of a vehicle with a diesel engine has been run completely
dry. X
Refuel the vehicle with at least 5.3 US qt (5 liters) of diesel. X
Turn the ignition on for approximately ten seconds ( Y
page 138).X
Start the engine continuously for up to ten seconds until it runs
smoothly.
If the engine does not start: X
Turn the ignition on again for approximately ten seconds
( Y
page 138). X
Start the engine again continuously for up to ten seconds until it
runs smoothly.
If the engine does not start after three attempts: X
Consult a qualified specialist workshop.
The fuel filler flap cannot
be opened. The fuel filler flap is not unlocked. X
Unlock the vehicle ( Y
page 74).
The SmartKey battery is discharged or nearly discharged. X
Unlock the vehicle using the mechanical key ( Y
page 76).
The fuel filler flap is unlocked, but the opening mechanism is jammed. X
Consult 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 Manual
message is shown in the multifunction display.
If you drive the vehicle faster than 10 mph
(16 km/h), the Check Additive See Opera‐156
Refueling
Driving and parking

tor's Manual message 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 .X
Add at least 1 gal (3.8 l) of DEF.X
Switch on the ignition for at least 60 seconds. X
Start the engine.
i Have 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 ( Y
page 27).
If the outside temperature is below 12 ‡(

Opening/closing the DEF filler cap
The fuel filler flap is unlocked or locked auto-
matically when you open or close the vehicle
with the SmartKey or with KEYLESS-GO. X
To open: switch the ignition off.X
Press the fuel filler flap in the direction of
arrow C .
The fuel filler flap swings up. X
Turn blue DEF fuel filler cap D counter-clock-
wise and remove it.
DEF filler cap D is secured with a plastic
strip. X
To close: place DEF filler cap D on the filler
neck and turn it clockwise. X
To close the fuel filler flap, press it in the
direction of arrow C .X
Drive faster than 10 mph (16 km/h).
The Check Additive See Operator's
Manual message goes out after approx-
imately one minute.
i If the Check Additive See Operator's
Manual message continues to be shown in
the multifunction display, you must add more
DEF.
DEF refill canisters
! Do not screw the disposable hose on too
tight. The disposable hose could otherwise be
damaged and DEF may leak out. X
Unscrew the cap from the opening on top of
DEF refill canister D .X
Place disposable hose C on the opening of
DEF refill canister D and screw it on clock-
wise until hand-tight.
Disposable hose C remains closed until you
fasten disposable hose C to the DEF filler
neck of the vehicle.
X
Place disposable hose C on the filler neck on
the vehicle and screw it on clockwise until
hand-tight. When you feel resistance, dispos-
able hose C is sufficiently secured. X
Lift up and tip DEF refill canister D .
Filling stops when the DEF tank is completely
filled. Do not fill the DEF tank any further. DEF
refill canister D can be removed when it has
been only partially emptied. X
Turn disposable hose C on the filler neck of
the vehicle counter-clockwise and remove it. X
Turn disposable hose C on the opening of
DEF refill canister D counter-clockwise and
remove it. X
Reseal DEF refill canister D with the cap.
DEF refill canisters are available at many gas
stations or at a qualified specialist workshop.
DEF refill canisters are often sold with a filler
hose. A filler hose that does not exactly fit the
vehicle's DEF tank offers no protection against158
Refueling
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
G WARNING
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
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.
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.
C
Acceleration D
Coasting

The ECO display consists of three sections, with
an inner and outer area. The sections corre-
spond to the following three categories:
C
Acceleration (evaluation of all accel-
eration processes): R
the outer area fills up and the inner
area lights up green: moderate
acceleration, especially at higher
speeds R
the outer area empties and the
inner area is gray: sporty acceler-
ation
D
Coasting (evaluation of all decelera-
tion processes): R
the 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. R
the outer area empties and the
inner area is gray: frequent heavy
braking

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
G WARNING
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. R
Brake occasionally to remove any possible
salt residue. Make sure that you do not
endanger other road users when doing so. R
Carefully depress the brake pedal and the
beginning and end of a journey. R
Maintain a greater distance to the vehicle
ahead.
Servicing the brakes
! The brake fluid level may be too low, if: R
if the red brake warning lamp lights up in
the instrument cluster and R
you 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 0 or 1 or Start/Stop
button in position 0 or 1 ) when the electricDriving tips 165
Driving and parking Z

parking brake is being tested on a brake dyna-
mometer (maximum 10 seconds).
Braking triggered automatically by ESP ®
may
seriously damage the brake system.
All checks and maintenance work on the brake
system must be carried out at a qualified spe-
cialist workshop.
Have brake pads installed and brake fluid
replaced at a qualified specialist workshop.
If the brake system has only been subject to
moderate loads, you should test the functional-
ity of your brakes at regular intervals. To do so,
depress the brake pedal firmly when driving at a
high speed. This improves the grip of the brake
pads.
You can find a description of Brake Assist (BAS)
on ( Y
page 64) or of BAS PLUS on ( Y
page 69).
Mercedes-Benz recommends that you only have
brake pads/linings installed on your vehicle
which have been approved for Mercedes-Benz
vehicles or which correspond to an equivalent
quality standard. Brake pads/linings which have
not been approved for Mercedes-Benz vehicles
or which are not of an equivalent quality could
affect your vehicle's operating safety.
Mercedes-Benz recommends that you only use
brake fluid that has been specially approved for
your vehicle by Mercedes-Benz, or which corre-
sponds to an equivalent quality standard. Brake
fluid which has not been approved for
Mercedes-Benz vehicles or which is not of an
equivalent quality could affect your vehicle's
operating safety.
High-performance brake system
(Mercedes-AMG vehicles) The high-performance brake system is designed
for heavy loads. This may lead to noise when
braking. This will depend on: R
Speed R
Braking force R
Environmental conditions, such as tempera-
ture and humidity
The wear of individual components of the brake
system, such as the brake pads/linings or brake
discs, depends on the individual driving style
and operating conditions.
For this reason, it is impossible to state a mile-
age that will be valid under all circumstances. An
aggressive driving style will lead to high wear. You can obtain further information about this
from your authorized Mercedes-Benz Center.
New and replaced brake pads and discs only
reach their optimum braking effect after several
hundred kilometers of driving. Compensate for
this by applying greater force to the brake pedal.
Keep this in mind, and adapt your driving and
braking accordingly during this break-in period.
Excessive heavy braking results in correspond-
ingly high brake wear. Observe the & brake
wear warning lamp in the instrument cluster and
note any brake status messages in the multi-
function display. Especially for high perform-
ance driving, it is important to maintain and have
the brake system checked regularly.
Driving on wet roads
Hydroplaning If water has accumulated to a certain depth on
the road surface, there is a danger of hydro-
planing occurring, even if: R
you drive at low speeds. R
the tires have adequate tread depth.
For this reason, in the event of heavy rain or in
conditions in which hydroplaning may occur,
you must drive in the following manner: R
lower your speed. R
avoid ruts. R
avoid sudden steering movements. R
brake carefully.
Driving on flooded roads
! Do not drive through flooded areas. Check
the depth of any water before driving through
it. Drive slowly through standing water. Oth-
erwise, water may enter the vehicle interior or
the engine compartment. This can damage
the electronic components in the engine or
the automatic transmission. Water can also
be drawn in by the engine's air suction nozzles
and this can cause engine damage.
i Vehicles with the AIRMATIC package:
select the raised vehicle level before driving
through a body of water.166
Driving tips
Driving and parking

R
LOW RANGE offroad gear (vehicles with the
Offroad Engineering package) ( Y
page 219)R
Differential lock (vehicles with the Off-Road
Engineering package) ( Y
page 218)R
Off-road ABS ( Y
page 64)R
Off-road 4ETS ( Y
page 67)R
Off-road ESP ®
( Y
page 68)R
AIRMATIC package (vehicle level)
( Y
page 186) R
DSR (Downhill Speed Regulation)
( Y
page 216)
Observe the following notes: R
Stop the vehicle before starting to drive along
an off-road route. If necessary, select the off-
road program ( Y
page 218) or shift to the
LOW RANGE off-road gear ( Y
page 219).R
Select a vehicle level that is suitable for the
terrain. To avoid damaging the vehicle, make
sure there is always sufficient ground clear-
ance. R
Check that items of luggage and loads are
stowed safely and are well secured
( Y
page 299). R
Always keep the engine running and in gear
when driving on a downhill gradient. Activate
DSR ( Y
page 216).R
Always keep the engine running and in gear
when driving on a slope. R
Adapt your speed to the terrain. The rougher,
steeper or more ruts on the terrain, the slower
your speed should be. R
Do not jump with the vehicle as this will inter-
rupt the vehicle's propulsion. R
Drive with extreme care on unfamiliar off-road
routes where visibility is poor. For safety rea-
sons, get out of the vehicle first and survey
the off-road route. R
Look out for obstacles, such as rocks, holes,
tree stumps and furrows. R
Always keep the doors, the tailgate, the side
windows and the sliding sunroof closed while
the vehicle is in motion. R
Do not shift the automatic transmission to
transmission position N .R
Observe the notes on off-road fording
( Y
page 167).
i Do not use the HOLD function when driving
off-road, on steep uphill or downhill gradients
or on slippery or loose surfaces. The HOLD function cannot hold the vehicle on such sur-
faces.
Checklist before driving off-road
! If the engine oil warning lamp lights up while
the vehicle is in motion, stop the vehicle in a
safe place as soon as possible. Check the
engine oil level. The engine oil warning lamp
warning must not be ignored. Continuing the
journey while the symbol is displayed could
lead to engine damage. X
Engine oil level: check the engine oil level
and add oil if necessary.
When driving on steep gradients, the engine
oil level must be sufficiently high to ensure a
correct oil supply in the vehicle. X
DEF tank (BlueTEC vehicles): check the
level and add if necessary ( Y
page 156).X
Tire-changing tool kit: check that the jack is
working and make sure you have the lug
wrench, a robust tow cable and a folding
spade in the vehicle. X
Wheels and tires: check the tire tread depth
and tire pressure. X
Check for damage and remove any foreign
objects, e.g. small stones, from the wheels/
tires. X
Replace any missing valve caps. X
Replace dented or damaged wheels. X
Rims: dented or bent rims can result in a loss
of tire pressure and damage the tire bead.
Before driving off-road, check the wheels and
replace them if necessary.
Checklist after driving off-road
! If you detect damage to the vehicle after
driving off-road, have the vehicle checked
immediately at a qualified specialist work-
shop.
Driving over rough terrain places greater
demands on your vehicle than driving on normal
roads. After driving off-road, check the vehicle.
This allows you to detect damage promptly and
reduce the risk of an accident to yourself and
other road users. X
If the Offroad or Offroad Plus drive program
is selected: select the Individual , Sport ,Driving tips 169
Driving and parking Z

When you activate cruise control, the stored
speed is shown in the multifunction display for
five seconds.
Activation conditions To activate cruise control, all of the following
activation conditions must be fulfilled: R
the electric parking brake must be released. R
you are driving faster than 20 mph (30 km/h). R
ESP ®
must be active, but not intervening.R
the transmission must be in position D .R
DSR must be deactivated. R
the Offroad Plus drive program must be deac-
tivated (vehicles with the Off-Road Engineer-
ing package).
Storing, maintaining and calling up a
speed
Storing and maintaining a speed X
Accelerate the vehicle to the desired speed. X
Briefly press the cruise control lever up C or
down

R
you activat e th e Offroad Plus progra m (vehi-
cle s wit h th e Off-Road Engineerin g package)R
you shift th e transmission to position N while
drivin g
If cruise control is deactivated, you will hear a
warnin g tone . You will see th e Cruise Con ‐
tro l Off message in th e multifunction display
for approximately fiv e seconds.
i Whe n you switch off th e engine, th e last
speed store d is cleared .
Distance Pilot DISTRONIC
Gene ra l notesDistanc e Pilo t DISTRONI C regulates th e speed
and automatically help s you maintai n th e dis-
tance to th e vehicl e detecte d in front. Vehicles
are detecte d wit h th e aid of th e rada r sensor
system. Distanc e Pilo t DISTRONI C brakes auto-
matically so that th e set speed is no t exceeded .
You mus t select a lower gear in goo d time on
lon g and steep downhill gradients , especially if
th e vehicl e is laden or towin g a trailer . By doin g
so, you will mak e use of th e brakin g effec t of th e
engine. This relieves th e load on th e brak e sys-
te m and prevents th e brakes from overheating
and wearin g to o quickly.
If Distanc e Pilo t DISTRONI C detects that there is
a ris k of a collision , you will be warned visually
and acoustically. Without your intervention , Dis-
tance Pilo t DISTRONI C canno t preven t a colli-
sion . An intermittent warnin g tone will then
soun d and th e distanc e warnin g lamp will ligh t
up in th e instrumen t cluster. Brake immediately
in order to increase th e distanc e to th e vehicl e in
fron t or tak e evasive action provided it is saf e to
do so.
Fo r Distanc e Pilo t DISTRONI C to assist you
when driving, th e rada r sensor system mus t be
operational.
Dis tanc e P
ilo t DISTRONI C operate s in th e range
between 0 mph (0 km/h) and 12 0 mph
(20 0 km/h).
Do no t use Distanc e Pilo t DISTRONI C while driv-
in g on roads wit h steep gradients .
Since Distanc e Pilo t DISTRONI C transmit s rada r
waves, it can resemble th e rada r detectors of
th e responsibl e authorities. You can refer to th e
relevan t chapter in th e Operator' s Manual if
question s are asked about this. i US A only:
This device has been approve d by th e FCC as
a "Vehicular Radar System". The rada r sensor
is intended for use in an automotive rada r
system only. Removing, tamperin g with, or
altering th e device will voi d any warranties,
and is no t permitte d by th e FCC. Do no t tam -
per with, alter, or use in any non-approve d
way.
An y unauthorize d modification to this device
could voi d th e user’s authorit y to operate th e
equipment.
i Canada only: This device complies wit h
RSS-210 of Industry Canada. Operation is
subjec t to th e followin g tw o conditions:
1. This device may no t caus e harmful inter-
ference , and
2. This device mus t accept any interferenc e
received, includin g interferenc e that may
caus e undesired operation of th e device .
Removal, tampering, or altering of th e d evice
w
ill voi d any warranties, and is no t permitted.
Do no t tamper with, alter, or use in any non-
approve d way.
An y unauthorize d modification to this device
could voi d th e user's authorit y to operate th e
equipment.
Imp or tant safety notes
G WARNIN G
Distanc e Pilo t DISTRONI C does no t reac t to :R
people or animals R
stationary objects on th e road, e.g. stoppe d
or parked vehicles R
oncomin g vehicles and crossin g traffic
As a result , Distanc e Pilo t DISTRONI C may
neither giv e warnings no r interven e in suc h
situations. There is a ris k of an accident.
Always pay careful attention to th e traffic sit -
uation and be read y to brake.
G WARNIN G
Distanc e Pilo t DISTRONI C canno t always
clearly identify other roa d user s and complex
traffic situations.174
Driving systems
Driving and parking