2012 MERCEDES-BENZ GL-Class engine

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

XInsert DEF cap : as shown and turn it
clockwise as far as it will go.XFold the cargo compartment floor down.XClose the tailgate.XDrive at a speed above 10 mph (16 km/h).
The Check Additive See Operator's
Manual message goes out after
approximately one minute.
i If the Check Additive See
Operator's Manual message remains
shown in the multifunction display, add an
additional bottle of DEF.
i Then, have the DEF supply checked at a
qualified specialist workshop and
completely refilled if necessary.
Parking
Important safety notes
GWARNING
Do not park this vehicle in areas where
combustible materials can come into contact
with the hot exhaust system. Do not park the
vehicle on dry grassland or harvested grain
fields. Combustible materials, such as grass,
hay or leaves could be ignited by the hot
exhaust system and cause a vehicle fire.
Unintended vehicle movement can cause
serious personal injury or damage to the
vehicle or the vehicle drivetrain. To reduce
such risks, always do the following before
turning off the engine and leaving the vehicle:
R keep your right foot on the brake pedal.
R engage the parking brake.
R shift the automatic transmission to park
position P.
R slowly release the brake pedal.
R when parked on an incline, always turn the
front wheels towards the road curb.
R turn the SmartKey in the ignition lock to
position 0 and remove the SmartKey from
the ignition lock, or press the KEYLESS-GO
Start/Stop button.
R take the SmartKey with you and lock the
vehicle when leaving.
Switching off the engine
Important safety notes
GWARNING
Do not turn off the engine before the vehicle
has come to a complete stop. With the engine
not running, there is no power assistance for
the brake and steering systems. In this case,
it is important to keep in mind that a
considerably higher degree of effort is
necessary to brake and steer the vehicle.
GWARNING
Keep in mind that turning off the engine alone
only will shift the automatic transmission into
neutral position N automatically.
Always shift the automatic transmission into
park position P before turning off the engine.
Otherwise the vehicle could roll away which
could result in an accident and/or serious
personal injury.
i If you cannot turn off the engine as
described here, see "Engine emergency
stop" ( Y page 335).
Vehicles with automatic transmission
XApply the parking brake firmly.XShift the transmission to position P.
Using the SmartKey
XTurn the SmartKey to position 0 in the
ignition lock and remove it.
The immobilizer is activated.
i If you turn off the engine with the
SmartKey and then remove it from the
ignition lock or open a front door, the
automatic transmission shifts to P
automatically.
166ParkingDriving and parking

Using KEYLESS-GOXPress the Start/Stop button (Y page 149).
The engine stops and all the indicator
lamps in the instrument cluster go out.
i When the driver's door is closed, this
corresponds to SmartKey position 1. When
the driver's door is open, it corresponds to
SmartKey position 0 or "SmartKey
removed".
i If you use the Start/Stop button to switch
off the engine, the automatic transmission
shifts to N automatically. If you then open
the driver's or front-passenger door, the
automatic transmission shifts to P.
i In an emergency, the engine can be
turned off while the vehicle is in motion by
pressing and holding the Start/Stop button
for three seconds.
Parking brake
GWARNING
Engaging the parking brake while the vehicle
is in motion can cause the rear wheels to lock
up. You could lose control of the vehicle and
cause an accident. In addition, the vehicle's
brake lights do not light up when the parking
brake is engaged.
GWARNING
When leaving the vehicle, always remove the
SmartKey from the starter switch, take it with
you, and lock the vehicle. Do not leave
children unattended in the vehicle, or with
access to an unlocked vehicle. Children could
release the parking brake and/or shift the
automatic transmission out of park position
P , either of which could result in an accident
and/or serious personal injury.
XTo apply: depress parking brake ; firmly.
When the engine is running, the $ (USA
only) or J (Canada only) indicator lamp
lights up in the instrument cluster.XTo release: depress the brake pedal and
keep it depressed.XPull release handle :.
When the ignition is switched on or the
engine is running, the $ (USA only) or
J (Canada only) indicator lamp goes out
in the instrument cluster.
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 discharge.
XConnect a trickle charger.
i You can obtain information about trickle
chargers from a qualified specialist
workshop, e.g. an authorized Mercedes-
Benz Center.
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.Parking167Driving 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

Exhaust checkGWARNING
Inhalation of exhaust gas is hazardous to your
health. All exhaust gas contains carbon
monoxide (CO), and inhaling it can cause
unconsciousness and possible death.
Do not run the engine in confined areas (such
as a garage) which are not properly ventilated.
If you think that exhaust gas fumes are
entering the vehicle while driving, have the
cause determined and corrected
immediately. If you must drive under these
conditions, drive only with at least one
window fully open at all times.
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
when they are maintained exactly in
accordance with the manufacturer's
specifications. For this reason, all work on the
engine must be carried out only by qualified
and authorized Mercedes-Benz technicians.
The engine settings must not be changed in
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 Service Booklet.
Engine oil
! Vehicles with a diesel particle filter:
If the vehicle is mostly driven for short
distances, it is possible that malfunctions
may occur during the automatic cleaning of
the diesel particle filter. This can lead to
engine damage. Therefore, if you frequently
drive short distances, make sure to drive
on highways or inter-urban roads for 20
minutes at least every 310 miles (500 km).
Brakes
Important safety notesGWARNING
On slippery road surfaces, never downshift in
order to obtain braking action. This could
result in drive wheel slip and reduced vehicle
control. Your vehicle's ABS will not prevent
this type of control loss.
Do not engage the transfer case in position
LOW when driving on ice or packed snow. At
speeds below 18 mph (30 km/h) vehicle
steering is adversely affected by the Off-road
ABS.
GWARNING
Make sure that you do not endanger other
road users when you apply the brakes.
Downhill gradients
! On long and steep gradients, you must
reduce the load on the brakes by shifting
early to a lower gear. This allows you to take
advantage of the engine braking effect and
helps avoid overheating and excessive
wear of the brakes.
When you take advantage of the engine
braking effect, 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 warranty.
Heavy and light loads
GWARNING
Depressing the brake pedal constantly results
in excessive and premature wear to the brake
pads.
It may also cause the brakes to overheat,
seriously impairing their effectiveness. It may
then not be possible to stop the vehicle in
sufficient time to avoid an accident.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately, but
Driving tips169Driving and parkingZ

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

Braking maneuvers triggered automatically
by ESP ®
may seriously damage the brake
system.
If your brake system is subject only to
moderate loads, you should test the
functionality of your brakes at regular
intervals by pressing firmly on the brake pedal
at high speeds. This improves the grip of the
brake pads.GWARNING
Make sure that you do not endanger other
road users when you apply the brakes.
You can find a description of Brake Assist
(BAS) on ( Y page 69).
Parking brake
If you drive on wet roads or dirt-covered
surfaces, road salt and/or dirt could get into
the parking brake.
In order to prevent corrosion and a reduction
in the braking power of the parking brake,
observe the following:
R Gently depress the parking brake from time
to time before beginning the journey.
R Drive a distance of approximately 110 yds
(100 m) with a maximum speed of 12 mph
(20 km/h).
GWARNING
While performing this procedure please
assure that the vehicle is stopped before
applying the parking brake. Otherwise the
rear wheels could lock up. You could lose
control of the vehicle and cause an accident.
In addition, the vehicle's brake lights do not
light up when the parking brake is engaged.
Make sure not to endanger any other road
users when you engage the parking brake.
Driving on wet roads
Hydroplaning
If water has accumulated to a certain depth
on the road surface, there is a danger of
hydroplaning 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 can occur
you must drive in the following manner:
R reduce your speed
R avoid ruts
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. Otherwise, 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 Set the raised level before driving through
a stretch of standing water.
Off-road fording
:Fording depthDriving tips171Driving and parkingZ

FordingdepthVehicles with the AIRMATIC
packageRaised level20 inches (50 cm)Vehicles with the Off-Road
Pro engineering packageOff-road level 320 inches (50 cm)Off-road level 220 inches(50 cm)Off-road level 123.6 inches (60 cm)
R Establish how deep the water is and the
characteristics of the body of water before
fording.
R Select the highest possible vehicle level.
R Select the off-road drive program
( Y page 206) or the LOW RANGE off-road
gear ( Y page 206).
R Select the off-road drive program
( Y page 206).
R Restrict the shift range to 1 or 2.
R Avoid high engine speeds.
R Enter and exit the water at a flat place and
at a steady walking pace.
! Under no circumstances should you
accelerate before entering the water. The
bow wave could cause water to enter and
damage the engine and other assemblies.
R Drive slowly and at an even speed through
the water.
R Do not stop.
! Do not open any of the vehicle's doors
while fording. Otherwise, water could get
into the vehicle interior and damage the
vehicle's electronics and interior
equipment.
R Water offers a high degree of resistance,
and the ground is slippery and in some
cases unstable. Therefore, it is difficult and
dangerous to pull away in the water.
R Ensure that a bow wave does not form as
you drive.
R Clean any mud from the tire tread after
fording.
R Apply the brakes to dry them after fording.
Winter driving
Important safety notes
GWARNING
If the vehicle becomes trapped in snow,
ensure that snow is kept away from the
exhaust pipe and from around the vehicle as
long as the engine is running. Otherwise,
poisonous carbon monoxide (CO) may enter
the vehicle, resulting in loss of consciousness
and even death.
To assure sufficient fresh air ventilation, open
a window slightly on the side of the vehicle
not facing the wind.
At the onset of winter, have your vehicle
winterproofed at a qualified specialist
workshop, e.g. at an authorized Mercedes-
Benz Center.
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
therefore always be accurate.
Winter tires
At temperatures below 45 ‡(+7 †), use
winter tires or all-season tires. Both types of
tire are identified by the M+S marking.
Only winter tires bearing the i snowflake
symbol in addition to the M+S marking
provide the best possible grip in wintry road
172Driving tipsDriving and parking