2012 MERCEDES-BENZ GL-Class flat tire

or be fully raised. Observe the instructions
for towing the vehicle with all wheels in full
contact with the ground.
i In wintry driving conditions, the maximum
effect of 4MATIC can only be achieved if
you use winter tires ( M+S tires), with snow
chains if necessary.
! When testing the parking brake, operate
the vehicle only briefly (for a maximum of
ten seconds) on a brake test dynamometer.
When doing this, turn the key to position
0 or 1 in the ignition. Failure to do this can
cause damage to the drive train or the
brake system.
! Function or performance tests may only
be performed on a 2-axle dynamometer. If
you wish to operate the vehicle on such a
dynamometer, please consult an
authorized Mercedes-Benz Center
beforehand. You could otherwise damage
the drive train or the brake system.
For information about driving off-road, see
( Y page 174).
DSR (Downhill Speed Regulation)
Important safety notes
DSR is an aid to assist you when driving
downhill. It keeps the speed of travel at the
speed selected on the on-board computer.
The steeper the downhill gradient, the greater
the DSR braking effect on the vehicle. When
driving on flat stretches of road or on an uphill
gradient, the DSR braking effect is minimal or
non-existent.
The set speed is set to 4 mph (6 km/h) at the
factory; this can be adjusted using the on-
board computer ( Y page 228).
GWARNING
Downhill Speed Regulation (DSR) is a
convenience system designed to assist the
driver during vehicle operation. The system
setting must be appropriate to the
topographical and weather conditions
encountered, which can change quickly. The
driver is responsible for the vehicle speed and
for safe brake operation at all times.
Depending on the programmed speed, actual
vehicle speed and gradient, switching on DSR
while driving can cause the vehicle to slow
down rapidly, and you may hear a sound,
caused by the activation of the vehicle's brake
system through DSR. Sudden and unexpected
deceleration can result in loss of vehicle
control, causing an accident and/or serious
personal injury to you and others. Do not
switch on DSR in a situation where rapid
deceleration could result in a loss of vehicle
control.
DSR controls the set speed when it is active
and the automatic transmission is in the D,
R or N position. You can drive at a higher or
a lower speed than that set on the on-board
computer at any time by accelerating or
braking.GWARNING
If you depress the accelerator pedal with DSR
activated, the vehicle can drive faster than the
programmed set speed. You should therefore
drive downhill with particular caution as it
could lead to an accident and/or serious
injury to you or others. Keep in mind that as
soon as you remove your foot from the
accelerator pedal with DSR switched on, DSR
will start regulating the vehicle's speed
including use of brakes if required. Depending
on the programmed set speed, actual vehicle
speed and gradient, DSR can cause the
vehicle to slow down rapidly. Sudden and
unexpected deceleration can result in loss of
vehicle control, causing an accident and/or
serious personal injury to you and others.
For information about driving off-road, see
( Y page 174).
204Off-road driving systemsDriving and parking

TiresGWARNING
Do not drive with a flat tire. A flat tire affects the ability to steer or brake the vehicle. You may
lose control of the vehicle. Continued driving with a flat tire will cause excessive heat build-up
and possibly a fire.
GWARNING
Follow recommended tire inflation pressures.
Do not underinflate tires. Underinflated tires wear excessively and/or unevenly, adversely affect
handling and fuel economy, and are more likely to fail from being overheated.
Do not overinflate tires. Overinflated tires can adversely affect handling and ride comfort, wear
unevenly, increase stopping distance, and result in sudden deflation (blowout) because they are
more likely to become punctured or damaged by road debris, potholes etc.
Display messagesPossible causes/consequences and M SolutionsTire Pressure
Check TiresGRisk of accident
The tire pressure loss warning system has detected a significant
loss in pressure.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XCheck the tires and, if necessary, change the wheel
( Y page 362).XCheck the tire pressures and, if necessary, set to the correct
tire pressure.XRestart the tire pressure loss warning system when the tire
pressure is correct ( Y page 345).Check tires,
then restart Run
Flat IndicatorThe tire pressure loss warning system generated a display
message and has not been restarted since.XSet the correct tire pressure in all four tires.XRestart the tire pressure loss warning system ( Y page 345).Run Flat Indicator
InoperativeThe tire pressure loss warning system is defective.XVisit a qualified specialist workshop.Tire pressure
displayed after
driving for a few
minutesThe tire pressure monitor is measuring the tire pressure.XDrive on.
The tire pressures appear in the multifunction display after you
have been driving for a few minutes.Tire Pressure
Monitor
InoperativeThe tire pressure monitor is defective.XVisit a qualified specialist workshop.252Display messagesOn-board computer and displays

Driving systemsProblemPossible causes/consequences and M Solutions·
The red distance
warning lamp lights up
while the vehicle is in
motion. A warning tone
also sounds.GRisk of accident
The warning is issued if you approach a stationary vehicle or a
vehicle driving ahead of you at too high a speed.
XBe prepared to brake immediately.XPay careful attention to the traffic situation. You may have to
brake or take evasive action.
More information about DISTRONIC (Y page 182) and the distance
warning signal ( Y page 72).
Tires
ProblemPossible causes/consequences and M Solutionsh
USA only:
The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) is lit.GRisk of accident
The tire pressure monitor has detected a loss of pressure in at
least one of the tires.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XObserve the additional display messages in the multifunction
display.XCheck the tire pressure. If necessary, correct the tire pressure
( Y page 347).XIf necessary, change a wheel ( Y page 362).h
USA only:
The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) flashes for
60 seconds and then
remains lit.The tire pressure monitor is defective.XObserve the additional display messages in the multifunction
display.XVisit a qualified specialist workshop.GWARNING
Each tire, including the spare (if provided), should be checked every other week when cold and
inflated to the inflation pressure recommended by the vehicle manufacturer on the Tire and
Loading Information placard on the driver's door B-pillar or, if available, the tire inflation pressure
label on the inside of the fuel filler flap. If your vehicle has tires of a different size than the size
Warning and indicator lamps in the instrument cluster265On-board computer and displaysZ

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

Do not expose the child restraint system to
direct sunlight. The child restraint system's
metal parts, for example, could become very
hot, and the child could be burned on these
parts.GWARNING
Never touch the heating element or sides of
the lighter; they are extremely hot. Hold the
knob only.
Make sure any children traveling with you do
not injure themselves or start a fire with the
hot cigarette lighter.
! The 12 V socket in the cigarette lighter
can be used for accessories (up to a
maximum of 180 W) as long as they have
the standard socket type for cigarette
lighters. Note that the socket in the
cigarette lighter can be damaged when
connecting accessories, for example by
frequent insertion and removal or by
sockets that do not fit correctly. A damaged
socket can cause the cigarette lighter to
stop working.
! The cigarette lighter in the center console
in the front compartment is not intended
for operating the tire inflation compressor.
XTurn the SmartKey to position 2 in the
ignition lock.XTo open: briefly press marking =.
Stowage compartment : opens.XPress in cigarette lighter ;.
Cigarette lighter ; will pop out
automatically when the heating element is
red-hot.
12 V sockets
Points to observe before use
! The socket in the center console and the
socket in the cargo compartment are not
intended for operating the tire inflation
compressor.
The sockets can be used for accessories, e.
g. lamps or mobile phone chargers with a
maximum current draw of 180 W (15 A).
If you use the sockets for long periods when
the engine is switched off, the battery may
discharge.
XTurn the SmartKey to position 2 in the
ignition lock.
i You can also use the power sockets when
the SmartKey is in position 1 in the ignition
lock.
An emergency cut-out ensures that the on-
board voltage does not drop too low. If the
on-board voltage is too low, the power to
the sockets is automatically cut. This
ensures that there is sufficient power to
start the engine.
Features285Stowing and featuresZ

Socket in the front-passenger footwellXLift up the cover of socket :.
Socket in the front-compartment center
console
! If accessories are connected, make sure
that a maximum current draw of 15 A is not
exceeded. Otherwise, you will overload the
fuse.
! The socket is not suitable for operating
the tire inflation compressor.
XTo open: briefly press marking =.
Stowage compartment : opens.XRemove cover from socket ;.
i
On vehicles with an ashtray and cigarette
lighter, you must remove the cigarette
lighter ( Y page 284) in order to use the
socket.
Socket in the rear-compartment center
consoleXLift up the cover of socket :.
Socket in the cargo compartment
!
The socket is not suitable for operating
the tire inflation compressor.
XLift up the cover of socket :.
115 V power socket
GWARNING
The 115V AC socket operates at high voltage.
Use the 115V AC socket in the vehicle with
the same caution and prudence that you
exercise when using power outlets at home.
Keep any fluids away from the 115V AC
socket. Do not clean the socket with fluids or
tapered objects. Keep the 115V AC socket
cover in the closed position, when not in use.
Otherwise, you could suffer an electric shock
and be seriously or even fatally injured.
286FeaturesStowing and features

Useful information ............................314
Where will I find...? ...........................314
Flat tire .............................................. 316
Battery ............................................... 326
Jump-starting .................................... 329
Towing and tow-starting ..................331
Fuses .................................................. 333313Breakdown assistance

XTurn emergency spare wheel retainer :
counter-clockwise and remove it.XRemove insert =.XRemove "Minispare" emergency spare
wheel ;.
For further information on changing a wheel
and mounting the spare wheel, see
( Y page 316).
Flat tire
Preparing the vehicle
Your vehicle may be equipped with a
"Minispare" emergency spare wheel or
MOExtended tires (tires with run-flat
properties) ( Y page 325).
i Vehicle preparation is not necessary on
vehicles with MOExtended tires.
i Vehicles equipped with MOExtended tires
are not equipped with a TIREFIT kit at the
factory. It is therefore recommended that
you additionally equip your vehicle with a
TIREFIT kit if you mount tires that do not
feature run-flat properties, e.g. winter tires.
A TIREFIT kit can be obtained from an
authorized Mercedes-Benz Center.
XMake sure that highway level is
selected 36
(Y page 189).XStop the vehicle as far away as possible
from traffic on solid, non-slippery and level
ground.XSwitch on the hazard warning lamps.XFirmly depress the parking brake.XBring the front wheels into the straight-
ahead position.XMove the DIRECT SELECT lever to P.XSwitch off the engine.XVehicles without KEYLESS-GO: remove
the SmartKey from the ignition lock.XVehicles with KEYLESS-GO: open the
driver's door.
The on-board electronics have status 0,
which is the same as the SmartKey having
been removed.XVehicles with KEYLESS-GO: remove the
Start/Stop button from the ignition lock
( Y page 149).XAll occupants must get out of the vehicle.
Make sure that they are not endangered as
they do so.XMake sure that no one is near the danger
area while a wheel is being changed.
Anyone who is not directly assisting in the
wheel change should, for example, stand
behind the barrier.XGet out of the vehicle. Pay attention to
traffic conditions when doing so.XClose the driver's door.
i Only operate the tire inflation compressor
using the socket in the footwell of the
second row of seats ( Y page 286), even if
the ignition is turned off.
An emergency cut-off ensures that the on-
board electrical system voltage does not
drop too low. If the on-board electrical
system voltage is too low, power to the
sockets is automatically cut off. This
ensures that there is sufficient power to
start the engine.
36 Vehicles with air suspension.316Flat tireBreakdown assistance