2012 MERCEDES-BENZ GL-Class maintenance

use a sponge and cold water to clean it. DEF
residues crystallize after time and
contaminate the affected 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.
i If you are adding between maintenance
intervals, add approximately 1 gallon (3.8 l)
of DEF to the DEF tank. One gallon (3.8 l)
of DEF is approximately 2 DEF refill bottles.
For further information on DEF, see:
( Y page 374).
The DEF filler neck is under the cargo
compartment floor.XSwitch off the ignition.XOpen the tailgate.XLift up the trunk floor ( Y page 314).XTurn DEF cap : counter-clockwise and
remove it.XTurn DEF filler cap ; counter-clockwise
and open it.
Filler cap ; is secured with a plastic strap.XUnscrew the covering cap from DEF refill
bottle =.XPlace DEF refill bottle = on the filler neck
as shown and screw on clockwise hand-
tight.
! Only screw on the DEF refill bottle hand-
tight. It could otherwise be damaged.
XPress DEF refill bottle = down.
The DEF tank is filled. This may take up to
one minute.
i If the DEF refill bottle is no longer pressed
down, the filling process stops and the
partially emptied bottle can be removed.
XRelease DEF refill bottle =.XTurn DEF refill bottle = counter-clockwise
and remove it.XPlace DEF filler cap ; on the filler neck and
turn it clockwise.Refueling165Driving and parkingZ

Driving tips
General driving tips
Important safety notes
GWARNING
Always remember that you must concentrate
primarily on driving the vehicle. The driver's
concentration must always be directed
primarily at road traffic. For your own safety
and that of others, we recommend that you
stop the vehicle at a safe place and in
accordance with the traffic conditions before
making or accepting a phone call.
Comply with all legal requirements if you use
the telephone while driving. Use the hands-
free system and only use the telephone when
road, weather and traffic conditions permit. In
some jurisdictions, it is forbidden for drivers
to use mobile phones while driving.
Only operate COMAND (Cockpit Management
and Data System) in compliance with all legal
requirements and when the road, weather and
traffic conditions permit. You may otherwise
not be able to observe the traffic conditions,
endangering yourself and others.
Remember that your vehicle covers a distance
of 44 feet (approximately 14 m) a second
when it is traveling at only 30 mph
(approximately 50 km/h).
Drive sensibly – save fuel
Observe the following tips to save fuel:
XThe tires should always be inflated to the
recommended tire pressure.XRemove unnecessary loads.XRemove roof carriers when they are not
needed.XRemove basic carriers when they are not
needed.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 theService Booklet or by the service interval
display.
Fuel consumption also increases when
driving in cold weather, in stop-and-go traffic
and in mountainous terrain.
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
judgment.
The possibility of a serious or even fatal
accident are 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
taking drugs.
Pedals
GWARNING
Make sure absolutely no objects are
obstructing the pedals' range of movement.
Keep the driver's footwell clear of all
obstacles. If there are any floormats or
carpets in the footwell, make sure that the
pedals still have sufficient clearance.
During sudden driving or braking maneuvers,
the objects could get caught between the
pedals. You could then no longer brake or
accelerate. This could lead to accidents and
injury.
Rolling with the engine switched off
GWARNING
There is no power assistance for the steering
and the brake when the engine is not running.
Steering and braking requires significantly
more effort and you could lose control of the
vehicle and cause an accident as a result.
Do not turn off the engine while the vehicle is
in motion.
168Driving tipsDriving and parking

drive on for a short while. This allows the
airflow to cool the brakes more quickly.
Wet roadsGWARNING
After driving in heavy rain for some time
without applying the brakes or through water
deep enough to wet brake components, the
first braking action may be somewhat
reduced. You have to depress the brake pedal
more firmly. Maintain a safe distance from
vehicles 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
GWARNING
The layer of salt on the brake discs and the
brake pads/linings may cause a delay in the
braking effect, resulting in a significantly
longer braking distance, which could lead to
an accident.
To avoid this danger, you should:
R occasionally brake carefully, without
putting other road users at risk, when you
are driving on salted roads. This helps to
remove any salt that may have started to
build up on the brake discs and the brake
pads/linings.
R maintain a greater distance to the vehicle
ahead and drive with particular care.
R carefully apply the brakes at the end of a
trip and immediately after commencing a
new trip, so that salt residues are removed
from the brake discs.
Servicing the brakes
! If the brake warning lamp lights up in the
instrument cluster and you hear a warning
tone even though the parking brake has
been released, the brake fluid level may be
too low. 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. Have this work carried out at
an authorized Mercedes-Benz Center.
All checks and maintenance work on the
brake system must be carried out at a
qualified specialist workshop. This work
should be carried out at an authorized
Mercedes-Benz Center.
Have the brake pads and brake fluid installed
or replaced at a qualified specialist workshop,
e.g. an authorized Mercedes-Benz Center.
GWARNING
If other than recommended brake pads are
installed, or other than recommended brake
fluid is used, the braking properties of the
vehicle can be degraded to an extent that safe
braking is substantially impaired. This could
result in an accident.
! A function or performance test should
only be carried out on a 2-axle
dynamometer. 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.
! As the ESP ®
system operates
automatically, the engine and the ignition
must be switched off (SmartKey in position
0 or 1 in the ignition lock or Start/Stop
button in position 0 or 1) while the parking
brake is being tested on a brake
dynamometer (maximum 10 seconds).
170Driving tipsDriving and parking

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment 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.
i Please read the information on qualified
specialist workshops ( Y page 24).
Important safety notes
You will find an illustration of the instrument
cluster in the "At a glance" section
( Y page 29).
GWARNING
A driver's attention to the road and traffic
conditions must always be his/her primary
focus when driving.
For your safety and the safety of others,
selecting features through the multifunction
steering wheel should only be done by the
driver when traffic and road conditions permit
it to be done safely.
Bear in mind that at a speed of just 30 mph
(approximately 50 km/h ), your vehicle is
covering a distance of 44 feet (approximately
14 m) every second.
GWARNING
No messages will be displayed if either the
instrument cluster or the multifunction
display is inoperative.
As a result, you will not be able to see
information about your driving conditions,
such as
R speed
R outside temperature
R warning/indicator lamps
Rmalfunction/warning messages
R failure of any systems
Driving characteristics may be impaired.
If you must continue to drive, do so with added
caution. Contact an authorized Mercedes-
Benz Center as soon as possible.GWARNING
Malfunction and warning messages are only
indicated for certain systems and are
intentionally not very detailed. The
malfunction and warning messages are
simply a reminder with respect to the
operation of certain systems. They do not
replace the owner's and/or driver's
responsibility to maintain the vehicle's
operating safety. Have all required
maintenance and safety checks performed on
the vehicle. Bring the vehicle to an authorized
Mercedes-Benz Center to address the
malfunction and warning messages.
Displays and operation
Tachometer
The red band in the tachometer indicates the
engine's overrevving range.
! Do not drive in the overrevving range, as
this could damage the engine.
The fuel supply is interrupted to protect the
engine when the red band is reached.
Outside temperature display
The outside temperature display is in the
multifunction display ( Y page 218).
GWARNING
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Indicated temperatures just above the
freezing point do not guarantee that the road
216Displays and operationOn-board computer and displays

indicated on the Tire and Loading Information placard or, if available, the tire inflation pressure
label, you should determine the proper tire inflation pressure for those tires.
As an added safety feature, your vehicle has been equipped with a tire pressure monitoring
system (TPMS) that illuminates a low tire pressure warning lamp when one or more of your tires
are significantly underinflated. Accordingly, when the low tire pressure warning lamp illuminates,
you should stop and check your tires as soon as possible, and inflate them to the proper pressure.
Driving on a significantly underinflated tire causes the tire to overheat and can lead to tire failure.
Underinflation also reduces fuel efficiency and tire tread life, and may affect the vehicle's handling
and stopping ability. Please note that the TPMS is not a substitute for proper tire maintenance,
and it is the driver's responsibility to maintain correct tire pressure, even if underinflation has
not reached the level to trigger illumination of the TPMS low tire pressure warning lamp.
Your vehicle has also been equipped with a TPMS malfunction indicator to indicate when the
system is not operating properly. The TPMS malfunction indicator is combined with the low tire
pressure warning lamp. When the system detects a malfunction, the warning lamp will flash for
approximately one minute and then remain continuously illuminated. This sequence will continue
upon subsequent vehicle start-ups as long as the malfunction exists. When the malfunction
indicator is lit, the system may not be able to detect or signal low tire pressure as intended.
TPMS malfunctions may occur for a variety of reasons, including the installation of incompatible
replacement or alternate tires or wheels on the vehicle that prevent the TPMS from functioning
properly. Always check the TPMS malfunction warning lamp after replacing one or more tires or
wheels on your vehicle to ensure that the replacement or alternate tires and wheels allow the
TPMS to continue to function properly.266Warning and indicator lamps in the instrument clusterOn-board computer and displays

Useful information ............................300
Engine compartment ........................300
Maintenance ...................................... 305
Care .................................................... 305299Maintenance and care

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment 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.
i Please read the information on qualified
specialist workshops ( Y page 24).
Engine compartment
Hood
Opening the hood
GWARNING
Do not pull the release lever while the vehicle
is in motion. Otherwise, the hood could be
forced open by passing air flow.
This could cause the hood to come loose and
injure you and/or others.
GWARNING
Do not open the hood when the engine is
overheated. You could be seriously injured.
Observe the coolant temperature display to
determine whether the engine may be
overheated. If you see flames or smoke
coming from the engine compartment, move
away from the vehicle. Wait until the engine
has cooled. If necessary, call the fire
department.
GWARNING
There is a risk of injury if the hood is open,
even if the engine is not running.
Some engine components can become very
hot.
To avoid the risk of burns, only touch those
components described in the Operator's
Manual and observe the relevant safety notes.
GWARNING
To help prevent personal injury, stay clear of
moving parts when the hood is open and the
engine is running.
The radiator fan may continue to run for
approximately 30 seconds or may even
restart after the engine has been turned off.
Stay clear of fan blades.
GWARNING
Vehicles with gasoline engine:
The engine is equipped with a transistorized
ignition system. Because of the high voltage
it is dangerous to touch any components
(ignition coils, spark plug sockets, diagnostic
socket) of the ignition system
R with the engine running
R while starting the engine
R when the ignition is switched on and the
engine is turned manually
GWARNING
Vehicles with diesel engine:
The engine is equipped with a high-voltage
electronic control unit for the injection
system. Because of the high voltage it is
dangerous to touch any components of the
injection system (injectors, electrical wires)
R with the engine running
R while starting the engine
R when the ignition is switched on
XMake sure that the windshield wipers are
switched off.GWARNING
The windshield wipers and wiper linkage
could be set in motion.
When the hood is open, you or others could
be injured by the wiper linkage.
Make sure that the windshield wipers are
switched off. Remove the SmartKey or make
sure that no ignition position has been
selected with KEYLESS-GO. All indicator
lamps must be off in the instrument cluster.
300Engine compartmentMaintenance and care

XPull release lever : on the hood.
The hood is released.
! Make sure that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield
wipers or the hood.
XReach into the gap, pull hood catch
handle ; up and lift the hood.
Once you have lifted the hood about
15 inches (40 cm), it is automatically
opened the rest of the way and held open
by the gas-filled struts.
Closing the hood
GWARNING
When closing the hood, use extreme caution
not to catch hands or fingers. Be careful that
you do not close the hood on anyone.
Make sure the hood is securely engaged
before driving off. Do not continue driving if
the hood can no longer engage after an
accident, for example. The hood could
otherwise come loose while the vehicle is in
motion and injure you and/or others.XLower the hood and let it fall from a height
of approximately 8 inches (20 cm).XCheck that the hood has engaged properly.
If the hood can be raised slightly, it is not
properly engaged. Open it again and close
it with a little more force.
Radiator
i Vehicles with a diesel engine: do not
cover the radiator, for example with a
winter front or bug cover. Otherwise, the
readings of the on-board-diagnostic
system may be inaccurate. Some of these
readings are required by law and must be
accurate at all times.
Engine oil
Notes on the oil level
Depending on the driving style, the vehicle
consumes up to 0.9 US qts. (0.8 l) of oil over
a distance of 600 miles (1000 km). The oil
consumption may be higher than this when
the vehicle is new or if you frequently drive at
high engine speeds.
Checking the oil level using the oil
dipstick
When checking the oil level:
R park the vehicle on a level surface.
R the engine should be switched off for
approximately five minutes if the engine is
at normal operating temperature.
Engine compartment301Maintenance and careZ