2008 MERCEDES-BENZ GL550 brakes

397 Operation
Tires and wheels
Restarting the Run Flat Indicator
The Run flat indicator must be restarted in
the following situations:

If you have changed the tire inflation
pressure

If you have replaced the wheels or tires

If you have installed new wheels or
tires
Using 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,
make sure the tire inflation pressure of
all four tires is correct.
Switch on the ignition (page 42).
Make sure the standard display menu
appears in the multifunction display
(
page 155).
Press buttonk orj repeatedly
until the following message appears in
the multifunction display:
Press the reset button on the instru-
ment cluster (
page 152).
The following message will appear in
the multifunction display:
Restart
Run Flat Indicator?
Yes
Cancel
Warning!G
The Run Flat Indicator does not provide a
warning for wrongly selected tire inflation
pressures. Always adjust tire inflation pres-
sure according to the Tire and Loading
Information placard on the driver’s door
B-pillar (
page 388) or, if available, on the
tire inflation pressure label located on the
inside of the fuel filler flap (
page 374).
The Run Flat Indicator does not replace
regular checks of the tire inflation pressures
since a gradual pressure loss in more than
one tire cannot be detected by the Run Flat
Indicator.
The Run Flat Indicator is not able to issue a
warning due to a sudden dramatic loss of
tire inflation pressure (e.g. tire blowout
caused by a foreign object). In this case
bring the vehicle to a halt by carefully apply-
ing the brakes and avoiding abrupt steering
maneuvers.
Warning!G
The Run Flat Indicator can only warn you in
a reliable manner if you have set the correct
tire inflation pressures for each tire.
If an incorrect tire inflation pressure was set,
the system will monitor the pressure ac-
cording to the incorrect value.
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399 Operation
Tires and wheels
Warning!G
The TPMS does not indicate a warning for
wrongly selected inflation pressures. Always
adjust tire inflation pressure according to
the Tire and Loading Information placard on
the driver’s door B-pillar or, if available, the
supplemental tire inflation pressure infor-
mation on the inside of the fuel filler flap.
The TPMS is not able to issue a warning due
to a sudden dramatic loss of pressure (e.g.
tire blowout caused by a foreign object). In
this case bring the vehicle to a halt by care-
fully applying the brakes and avoiding
abrupt steering maneuvers.
Warning!G
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recom-
mended 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 fuel filler flap.
If your vehicle has tires of a different size
than the size 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 monitor-
ing system (TPMS) that illuminates a low tire
pressure telltale when one or more of your
tires is significantly underinflated. Accord-
ingly, when the low tire pressure telltale illu-
minates, you should stop and check your
tires as soon as possible, and inflate them to
the proper pressure. Driving on a significant-
ly 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 vehi-
cle’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 telltale.
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 com-
bined with the low tire pressure telltale.
When the system detects a malfunction, the
telltale will flash for approximately 1 minute
and then remain continuously illuminated.
This sequence will continue upon subse-
quent vehicle start-ups as long as the
malfunction exists. When the malfunction
indicator is illuminated, the system may not
be able to detect or signal low tire pressure
as intended.

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402 Operation
Tires and wheels
Switch on the ignition (page 42).
Press buttonj or k on the
multifunction steering wheel until the
current inflation pressures for each tire
appear in the multifunction display.
iPossible differences between the readings
of a tire pressure gauge of an air hose, e.g. gas
station equipment, and the vehicle’s control
system can occur. Usually the readings issued by
the control system are more precise.
iWhen the vehicle has been parked for longer
than 20 minutes, the message
Tire pressure
displayed after driving for a few
minutes.
appears in the multifunction display.
Warning!G
It is the driver’s responsibility to calibrate
the TPMS on the recommended cold infla-
tion pressure. Underinflated tires affect the
ability to steer or brake the vehicle. You
might lose control over the vehicle.
iWith a spare wheel without wheel sensor
mounted, the system may still indicate the tire
inflation pressure of the removed wheel for some
minutes. If this happens, keep in mind that the
indicated value where the spare wheel is mount-
ed does not reflect the actual spare tire inflation
pressure.
Warning!G
The TPMS does not indicate a warning for
wrongly selected inflation pressures. Always
adjust tire inflation pressure according to
the Tire and Loading Information placard on
the driver’s door B-pillar or, if available, the
supplemental tire inflation pressure infor-
mation on the inside of the fuel filler flap.
The TPMS is not able to issue a warning due
to a sudden dramatic loss of pressure (e.g.
tire blowout caused by a foreign object). In
this case bring the vehicle to a halt by care-
fully applying the brakes and avoiding
abrupt steering maneuvers.
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415 Operation
Tires and wheels
Tire ply material
1Plies in sidewall
2Plies under tread
This marking tells you about the type of
cord and number of plies in the sidewall
and under the tread.Tire and loading terminology
Accessory weight
The combined weight (in excess of those
standard items which may be replaced) of
automatic transmission, power steering,
power brakes, power windows, power
seats, radio, and heater, to the extent that
these items are available as
factory-installed equipment (whether
installed or not).
Air pressure
The amount of air inside the tire pressing
outward on each square inch of the tire.
Air pressure is expressed in pounds per
square inch (psi), or kilopascal (kPa) or
bars.
Aspect ratio
Dimensional relationship between tire
section height and section width
expressed in percentage.
Warning!G
The temperature grade for this tire is estab-
lished for a tire that is properly inflated and
not overloaded. Excessive speed, underin-
flation, or excessive loading, either sepa-
rately or in combination, can cause
excessive heat build-up and possible tire
failure.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
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417 Operation
Tires and wheels
Maximum load rating
The maximum load in kilograms and
pounds that can be carried by the tire.
Maximum loaded vehicle weight
The sum of curb weight, accessory weight,
total load limit and production options
weight.
Maximum tire inflation pressure
This number is the greatest amount of air
pressure that should ever be put in the tire
under normal driving conditions.
Normal occupant weight
The number of occupants the vehicle is
designed to seat, multiplied by
68 kilograms (150 lbs).
Occupant distribution
The distribution of occupants in a vehicle
at their designated seating positions.Production options weight
The combined weight of those installed
regular production options weighing over
5 lbs (2.3 kilograms) in excess of those
standard items which they replace, not
previously considered in curb weight or
accessory weight, including heavy duty
brakes, ride levelers, roof rack, heavy duty
battery, and special trim.
PSI (P
ounds per square inch)
A standard unit of measure for air pressure
-> bar, kilopascal (kPa).
Recommended tire inflation pressure
Recommended tire inflation pressure for
normal driving conditions is listed on the
Tire and Loading Information placard locat-
ed on driver’s door B-pillar. Provides best
handling, tread life and riding comfort. If so
equipped, supplemental information per-
taining to special driving situations can be
found on the tire inflation pressure label on
the inside of the fuel filler flap.Rim
A metal support for a tire or a tire and tube
assembly upon which the tire beads are
seated.
Sidewall
The portion of a tire between the tread and
the bead.
TIN (Tire Identification Number)
Unique identifier which facilitates efforts
by tire manufacturers to notify purchasers
in recall situations or other safety matters
concerning tires and gives purchases the
means to easily identify such tires. The TIN
is comprised of “Manufacturer’s identifica-
tion mark”, “Tire size”, “Tire type code”
and “Date of manufacture”.
Tire load rating
Numerical code associated with the
maximum load a tire can support.
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432 Operation
Vehicle care
Use a soft, clean cloth and a mild win-
dow cleaning solution on all outside
and inside glass surfaces.
An automotive glass cleaner is recom-
mended.Light alloy wheels
If possible, clean wheels once a week.
Use Mercedes-Benz approved Wheel
Care, a soft bristle brush and a strong
spray of water for cleaning the light al-
loy wheels.Plastic and rubber parts
Use a gentle dishwashing detergent or
mild detergent for delicate fabrics as a
washing solution.
Wipe with a cloth moistened in a
lukewarm solution.
The surface may temporarily change
color. If this is the case, wait for it to
dry.
!Fold the windshield wiper arms back onto
the windshield before turning the SmartKey in
the starter switch or pressing the KEYLESS-GO
start/stop button (vehicles with KEYLESS-GO*).
Hold on to the wiper when folding the wiper arm
back. If released, the force of the impact from
the tensioning spring could crack the windshield.
!To clean the window interior, do not use a
dry cloth, abrasives, solvents or cleaners con-
taining solvents. Do not touch the inside of the
front, rear or side windows and the power
tilt/sliding sunroof* or rear panorama roof with
hard objects such as an ice scraper or ring.
Doing so may damage the windows.
!Only use acid-free cleaning materials. Acid
may cause corrosion or damage the clear coat.
!The vehicle should not be parked for an ex-
tended period of time immediately after it has
been cleaned, especially not after the wheel rims
have been cleaned with wheel rim cleaner.
Wheel rim cleaners can lead to increased
corrosion of the brake disks and brake pads.
Non-approved wheel cleaners may also damage
the wheel paint if the car is not driven after
cleaning. Therefore, the vehicle’s brake system
should always be warmed-up before it is parked
after cleaning. To do so, please drive your vehicle
for several minutes to allow the brakes to dry.
When applying Mercedes-Benz approved Tire
Care and Mercedes-Benz approved Wheel Care
products, take care not to spray them on the
brake disks.
Warning!G
Do not use cleaners or cockpit care sprays
containing solvents to clean the cockpit or
the steering wheel. Cleaners containing sol-
vents will make the surface porous and vehi-
cle occupants could suffer serious injuries
from plastic parts coming loose in the event
of air bag deployment.

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440 Practical hints
What to do if …
ProblemPossible cause/conse-
quenceSuggested solution
?(USA only)
±(Canada only)
The yellow engine malfunction
indicator lamp comes on while
driving.A loss of pressure has been
detected in the fuel system.
The fuel cap may not be closed
properly or the fuel system
may be leaky.Check the fuel cap (page 374).
If it is not closed properly:
Close the fuel cap.
If it is closed properly:
Have the fuel system checked by an
authorized Mercedes-Benz Light Truck
Center.
Vehicles with diesel engine:
Your fuel tank is empty.After refueling start, turn off and
restart the engine three or four times in
succession.
The limp-home mode is canceled. You do
not need to have your vehicle checked.
lThe red distance warning lamp comes on
while driving and you hear a warning sound.You are gaining too rapidly on
the vehicle ahead of you.Apply the brakes immediately.
Carefully observe the traffic situation.
You may need to brake or maneuver to
avoid hitting an obstacle.
The Distronic* has recognized
a stationary obstacle on your
probable line of travel.
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458 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
ESPUnavailable
See Operator’s ManualThe ESP® was deactivated because
of insufficient power supply. The
charging voltage has fallen below
10 volts.
The brake system is still functioning
normally but without the ESP
®
available.
When the voltage is above this value again, the
ESP® is operational again and the message in
the multifunction display should disappear.
If the message in the multifunction display does
not disappear:
Have the generator (alternator) and the
battery checked.
Have the system checked at an authorized
Mercedes-Benz Light Truck Center as soon
as possible.
If the yellow ESP® warning
lampv flashes while driving and
this message appears, the 4-ETS has
switched off to prevent overheating
of the drive wheel brakes.As soon as the brakes have cooled off, the
4-ETS switches on again.
The message in the multifunction display disap-
pears and the ESP
® warning lampv goes
out.
The self-diagnosis has not been
completed yet.The display will clear after driving a short
distance at a vehicle speed of above
12 mph (20 km/h).
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