2015 MERCEDES-BENZ GL-Class Workshop

Problems with fuel and the fuel tank
This section provides descriptions of and solutions to safety-relevant problems. Descriptions
of and solutions to further problems can be found in the Digital Operator's Manual. Problem
Possible causes/consequences and
0050
0050Solutions Fuel is leaking from the
vehicle. The fuel line or the fuel tank is faulty.
G WARNING
Risk of explosion or fire. X Turn the SmartKey to position 0in the ignition lock and remove
it immediately (Y page 167).
X Do not restart the engine under any circumstances.
X Consult a qualified specialist workshop. DEF (BlueTEC vehicles only)
Important notes on use To function properly, BlueTEC exhaust gas
aftertreatment must be operated with the
reducing agent DEF. Adding DEF is one of the
tasks performed 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
Check Additive
Additive See SeeOperator's
Operator's Manual
Manual
message is shown in the multifunction dis-
play.
If you drive the vehicle faster than 10 mph
(16 km/h), the Check
Check Additive Additive See
SeeOper‐
Oper‐
ator's Manual
ator's Manual message goes out after
approximately one minute.
When the supply of DEF is down to a reserve
of approximately 1 gal (3.8 l) the Refill Refill
AdBlue/DEF
AdBlue/DEF See
SeeOperator's
Operator's Manual
Manualmes-
sage is shown in the multifunction display.
When the DEF supply drops to a minimum, the Remaining Starts: 16
Remaining Starts: 16 message is shown
in the multifunction display.
If the Refill AdBlue/DEF No Start in Refill AdBlue/DEF No Start in
XXXX km XXXX km message is shown in the multifunc-
tion display, you can still drive the vehicle
over the distance shown. If DEF is not refilled,
you will subsequently be unable to start the
engine. If the Refill AdBlue/DEF Eng.
Refill AdBlue/DEF Eng. Start Not Poss Start Not Poss
message appears in the
multifunction display and the engine does not
start, you must add DEF.
X Add at least 1 gal (3.8 l)of DEF.
X Switch on the ignition for at least 60 sec-
onds.
X Start the engine.
i Have the DEF tank refilled at a qualified
specialist workshop.
Use the special DEF refill bottle when adding DEF between maintenance intervals. Contact
an authorized Mercedes-Benz Center with
any questions or, if necessary, contact Road-
side Assistance (Y page 26).
If the outside temperature is below 12 ‡
(00F811 †) it may be difficult to top up. If DEF is
frozen and there is an active warning indica-
tor, 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 spe-
cialist workshop.
Further information about BlueTEC exhaust
gas aftertreatment and DEF is available at any
authorized Mercedes-Benz Center. 188
RefuelingDriving and parking

Electric parking brake
General notes G
WARNING
If you leave children unsupervised in the vehi- cle, they could set it in motion by, for example:
R release the parking brake.
R shift the automatic transmission out of the
parking position P.
R start 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.
X If this is the case, only park the vehicle on
level ground and secure it to prevent it roll- ing away.
X Shift the automatic transmission to posi-
tion 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.
i The electric parking brake performs a
function test at regular intervals while the
engine is switched off. The sounds that can
be heard while this is occurring are normal. Applying/releasing manually X
To engage: push handle 0043.
When the electric parking brake is
engaged, the 0049(USA only) or 0024
(Canada only) red indicator lamp lights up
in the instrument cluster.
i The electric parking brake can also be
applied when the SmartKey is removed.
X To release: pull handle0043.
The red 0049(USA only) or 0024(Canada
only) indicator lamp in the instrument clus- ter goes out.
i The electric parking brake can only be
released:
R if the SmartKey is in position 1in the
ignition lock (Y page 167) or
R if the ignition was switched on using the
Start/Stop button.
To ensure that you do not roll backwards
when pulling away on an uphill slope, engage
the electric parking brake (Y page 171).
Applying automatically The electric parking brake is applied auto-
matically:
R if DISTRONIC PLUS brings the vehicle to a
standstill or
R if the HOLD function is keeping the vehicle
stationary 192
ParkingDriving and parking

X
Visit a qualified specialist workshop and
seek advice. Driving tips
General notes
Important safety notes 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 you operate mobile communication equip-
ment while driving, you will be distracted from traffic conditions. You could also lose controlof the vehicle. There is a risk of an accident.
Only operate this equipment when the vehicleis stationary.
Observe the legal requirements for the coun- try in which you are driving. Some jurisdic-
tions prohibit 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
second. Drive sensibly – save fuel Observe the following tips to save fuel:
X The tires should always be inflated to the
recommended tire pressure.
X Remove unnecessary loads.
X Remove roof carriers when they are not
needed.
X Warm up the engine at low engine speeds.
X Avoid frequent acceleration or braking.
X Have all maintenance work carried out as
indicated by the service intervals in the
Maintenance Booklet or by the service
interval display.
Fuel consumption also increases when driv-
ing in cold weather, in stop-start traffic and in
hilly terrain.
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. 194
Driving tipsDriving and parking

Servicing the brakes
!
If the red brake warning lamp lights up in
the instrument cluster and you hear a warn- ing tone while the engine is running, the
brake fluid level may be too low. Observe
additional warning messages in the multi-
function display.
The brake fluid level may be too low due to brake pad wear or leaking brake lines.
Have the brake system checked immedi-
ately. This work should be carried out at a
qualified specialist workshop.
! A function or performance test should
only be carried out on a 2-axle dynamom-
eter. If you are planning to have the vehicle tested on such a dynamometer, contact an
authorized Mercedes-Benz Center to
obtain further information first. Otherwise,
you could 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 parking brake is being tested on a
brake dynamometer (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 quali-
fied specialist workshop. Consult a qualified
specialist workshop to arrange this.
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 function- ality of your brakes at regular intervals. To doso, depress the brake pedal firmly when driv-
ing at a high speed. This improves the grip of
the brake pads.
You can find a description of Brake Assist
(BAS) on (Y page 69) 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 vehi-
cle'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 corresponds 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 for
AMG vehicles The high-performance brake system is only
available on 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 temper-
ature and humidity
The wear of individual components of the
brake system, such as the brake pads/linings
or brake discs, depends on the individual driv-
ing style and operating conditions.
For this reason, it is impossible to state a
mileage that will be valid under all circum-
stances. An aggressive driving style will lead
to high wear. You can obtain further informa- tion about this from your authorized
Mercedes-Benz Center.
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. Keep this in mind, and adapt Driving tips
197Driving and parking Z

Do not shift down for additional engine brak-
ing on a slippery road surface. G
DANGER
If the exhaust pipe is blocked or adequate
ventilation is not possible, poisonous gases
such as carbon monoxide (CO) may enter the vehicle. This is the case, e.g. if the vehicle
becomes trapped in snow. There is a risk of
fatal injury.
If you leave the engine or the auxiliary heating
running, make sure the exhaust pipe and area
around the vehicle are clear of snow. To
ensure an adequate supply of fresh air, open a window on the side of the vehicle that is not
facing into the wind.
Have your vehicle winter-proofed at a quali-
fied specialist workshop at the onset of win-
ter.
Drive particularly carefully on slippery road
surfaces. Avoid sudden acceleration, steering and braking maneuvers. Do not use the cruise
control or DISTRONIC PLUS.
If the vehicle threatens to skid or cannot be
stopped when moving at low speed:
X Shift the transmission to position N.
Vehicles with the ON&OFFROAD package:
if driving in snow or with snow chains, select
the snow program (Y page 256) with the off-
road program selector wheel in the center
console.
i Vehicles with a diesel engine:
do not
cover the radiator, e.g. with a protective
cover. The measuring function of the
onboard diagnosis system may otherwise
provide inaccurate values. Some of these
values are required by law and must there-
fore always be accurate.
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Changes in the outside temperature are dis-
played after a short delay. Indicated temperatures just above the freez-
ing point do not guarantee that the road sur-
face is free of ice. The road may still be icy,
especially in wooded areas or on bridges. You
should pay special attention to road condi-
tions when temperatures are around the
freezing point.
For more information on driving with snow
chains, see (Y page 409).
For more information on driving with summer
tires, see (Y page 408).
Observe the notes in the "Winter operation"
section (Y page 408). Off-road driving
Important safety notes G
WARNING
If you drive on a steep incline at an angle or
turn when driving on an incline, the vehicle
could slip sideways, tip and rollover. There is a risk of an accident.
Always drive on a steep incline in the line of
fall (straight up or down) and do not turn the
vehicle. G
WARNING
If the vehicle level is high, the vehicle center of gravity is raised. This could cause the vehicleto tip over more easily on uphill or downhill
gradients. There is a risk of an accident.
Select the lowest possible vehicle level.
When driving off-road, sand, mud and water,
possibly mixed with oil, for example, could get
into the brakes. This could result in a reduced braking effect or in total brake failure and also
in increased wear and tear. The braking char- acteristics change depending on the materialingressing the brakes. Clean the brakes after
driving off-road. If you detect a reduced brak- ing effect or grinding noises, have the brake
system checked in a qualified specialist work-shop as soon as possible. Adapt your driving
style to the different braking characteristics. Driving
tips
199Driving an d parking Z

Driving off-road increases the likelihood of
damage to the vehicle, which, in turn, can lead to failure of the mechanical assembly or sys-
tems. Adapt your driving style to suit the ter- rain conditions. Drive carefully. Have damage
to the vehicle rectified immediately at a quali-
fied specialist workshop.
Do not switch to transmission position N
when driving off-road. You could lose control
of the vehicle if you attempt to brake using
the service brake. If the gradient is too steep, drive backwards in reverse gear.
General notes Read this section carefully before driving your
vehicle off-road. Practice by driving over more gentle off-road terrain first.
Familiarize yourself with the characteristics
of your vehicle and the gear shift operation
before driving through difficult terrain.
The following driving systems are specially
adapted to off-road driving:
R Off-road program 1 and 2 (vehicles with the
ON&OFFROAD package) (Y page 259)
R LOW RANGE off-road gear (vehicles with
the ON&OFFROAD package)
(Y page 261)
R Differential lock (vehicles with the
ON&OFFROAD package) (Y page 260)
R Off-road ABS (Y page 69)
R Off-road 4ETS (Y page 73)
R AIRMATIC package (vehicle level)
(Y page 219)
R DSR (Downhill Speed Regulation)
(Y page 258)
Observe the following notes:
R Stop the vehicle before starting to drive
along an off-road route.
R For vehicles with the AIRMATIC pack-
age: select a vehicle level that is suitable
for the off-road terrain. To avoid damaging
the vehicle, make sure there is always suf-
ficient ground clearance. R
Check that items of luggage and loads are
stowed safely and are well secured
(Y page 347).
R Always keep the engine running and in gear
when driving on a downhill gradient. Acti-
vate DSR (Y page 258).
R Always keep the doors, tailgate, windows
and sliding sunroof closed while driving.
R Adapt your speed to the terrain. The
rougher, steeper or more ruts on the ter-
rain, the slower your speed should be.
R Drive slowly and at an even speed through
the water. Ensure that a bow wave does not
form as you drive.
R Drive with extreme care on unfamiliar off-
road routes where visibility is poor. For
safety reasons, 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 Check the depth of water before fording
rivers and streams.
R When fording, do not stop and do not
switch off the engine.
R On sand, drive quickly to overcome the roll-
ing resistance. Otherwise the vehicle's
wheels could become stuck in loose
ground.
R Do not jump with the vehicle as this will
interrupt the vehicle's propulsion.
R Always keep the engine running and in gear
when driving on a slope.
R Do not shift the automatic transmission to
transmission position N.
i Do not use the HOLD function when driv-
ing off-road, on steep uphill or downhill gra-
dients or on slippery or loose surfaces. The HOLD function cannot hold the vehicle on
such surfaces.
Checklist before driving off-road !
If the engine oil warning lamp lights up
while the vehicle is in motion, stop the vehi-
cle in a safe place as soon as possible. 200
Driving
tipsDriving an d parking

Problems with PARKTRONIC
Problem
Possible causes/consequences and
0050
0050Solutions Only the red segments
in the PARKTRONIC
warning displays are lit.
You also hear a warning
tone for approximately
two seconds.
PARKTRONIC is deacti-
vated after approx-
imately five seconds,
and the indicator lamp
in the PARKTRONIC
button lights up. PARKTRONIC has malfunctioned and has switched off.
X If problems persist, have PARKTRONIC checked at a qualified
specialist workshop. Only the red segments
in the PARKTRONIC
warning displays are lit.
PARKTRONIC is deacti-
vated after approx-
imately five seconds. The PARKTRONIC sensors are dirty or there is interference.
X Clean the PARKTRONIC sensors (Y page 381).
X Switch the ignition back on. The problem may be caused by an external source of radio or
ultrasound waves.
X See if PARKTRONIC functions in a different location. Active Parking Assist
General notes Active Parking Assist is an electronic parking
aid with ultrasound. It measures the road on
both sides of the vehicle. A parking symbol
indicates a suitable parking space. Active
steering intervention can assist you during
parking.
You may also use PARKTRONIC (Y page 225).
Important safety notes Active Parking Assist is merely an aid. It is not
a replacement for your attention to your
immediate surroundings. You are always
responsible for safe maneuvering, parking
and exiting a parking space. When maneu-
vering, parking or pulling out of a parking
space, make sure that there are no persons,
animals or objects in the area in which you are maneuvering. When PARKTRONIC is switched off, Active
Parking Assist is also unavailable. G
WARNING
While parking or pulling out of a parking
space, the vehicle swings out and can drive
onto areas of the oncoming lane. This could
result in a collision with another road user.
There is a risk of an accident.
Pay attention to other road users. Stop the
vehicle if necessary or cancel the Active Park- ing Assist parking procedure.
! If unavoidable, you should drive over
obstacles such as curbs slowly and not at a sharp angle. Otherwise, you may damage
the wheels or tires. 228
Driving systemsDriving and parking

Under the following circumstances, the rear
view camera will not function, or will function
in a limited manner:
R if the tailgate is open
R in heavy rain, snow or fog
R at night or in very dark places
R if the camera is exposed to very bright light
R if the area is lit by fluorescent bulbs or LED
lighting (the display may flicker)
R if there is a sudden change in temperature,
e.g. when driving into a heated garage in
winter
R if the camera lens is dirty or obstructed
R if the rear of your vehicle is damaged. In this
event, have the camera position and setting checked at a qualified specialist workshop
The field of vision and other functions of the
rear view camera may be restricted due to
additional accessories on the rear of the vehi-
cle (e.g. license plate holder, bicycle rack).
Activating/deactivating the rear view
camera X
To activate: make sure that the SmartKey
is in position 2in the ignition lock.
X Make sure that the function "show rear
view camera display" is selected in
COMAND.
X Engage reverse gear.
The area behind the vehicle is shown in the
COMAND display with guide lines.
X To change the function mode for vehi-
cles with trailer tow hitch: using theCOMAND controller, select symbol
0043for
the "Reverse parking" function or sym-
bol 0044for "Coupling up a trailer" (see the
separate COMAND operating instructions). The symbol of the selected function is high- lighted.
To deactivate: the rear view camera deacti-
vates if you shift the transmission to Por after
driving forwards a short distance.
Displays in the COMAND display The rear view camera may show a distorted
view of obstacles, show them incorrectly or
not at all. The rear view camera does not show
objects in the following positions:
R very close to the rear bumper
R under the rear bumper
R in the area immediately above the tailgate
handle
! Objects not at ground level may appear to
be further away than they actually are, e.g.:
R the bumper of a parked vehicle
R the drawbar of a trailer
R the ball coupling of a trailer tow hitch
R the rear section of an HGV
R a slanted post
Use the guidelines only for orientation.
Approach objects no further than the bot-
tom-most guideline. Driving systems
233Driving and parking Z