2007 MERCEDES-BENZ CL500 fuel pressure

530 Operation
Tires and wheels
Tire inflation pressure changes by approxi-
mately 1.5 psi (0.1 bar) per 18°F (10°C) of
air temperature change. Keep this in mind
when checking tire inflation pressure
where the temperature is different from
the outside temperature.
Checking tire inflation pressure
Regularly check your tire inflation pressure
at least once a month.
Check and adjust the tire inflation
pressure when the tires are cold. The tires
can be considered cold if the vehicle has
been parked for at least 3 hours or driven
less than 1 mile (1.6 km).
If you check the tire inflation pressure
when the tires are warm (the vehicle has
been driven for several miles or sitting less
than 3 hours), the reading will be
approximately 4 psi (0.3 bar) higher than
the cold reading. This is normal. Do not let
air out to match the specified cold tire in-
flation pressure. Otherwise, the tire will be
underinflated.Checking tire inflation pressure
manually
Follow the steps below to achieve correct
tire inflation pressure:
Remove the cap from the valve on one
tire.
Firmly press a tire gauge onto the
valve.
Read tire inflation pressure on tire
gauge and check against the recom-
mended tire inflation pressure on the
Tire and Loading Information placard
on the driver’s door B-pillar
(
page 523). If necessary, add air to
achieve the recommended tire inflation
pressure.
Install the valve cap.
Repeat this procedure for each tire.
Warning!G
Follow recommend tire inflation pressures.
Do not underinflate tires. Underinflated tires
wear excessively and/or unevenly, adverse-
ly 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 com-
fort, wear unevenly, increase stopping dis-
tance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road de-
bris, potholes etc.
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard on the driv-
er’s door B-pillar. Overloading the tires can
overheat them, possibly causing a blowout.
Overloading the tires can also result in han-
dling or steering problems, or brake failure.
iIf you have overfilled the tire, release tire in-
flation pressure by pushing the metal stem of the
valve with e.g. a tip of a pen. Then recheck the
tire inflation pressure with the tire gauge.

532 Operation
Tires and wheels
Switch on the ignition (page 336).
Press( or& to select the menu
“Service”.
Press$ or% to select “Tire
pressure”.
Press#.
iWhen the message “Tire pressures dis-
played after driving a few minutes” appears in
the display, the individual inflation pressure val-
ues are matched with the tires. The individual
values are displayed after a few minutes driving.
Warning!G
It is the driver’s responsibility to calibrate
the Advanced TPMS on the recommended
cold inflation pressure. Underinflated tires
affect the ability to steer or brake the vehi-
cle. 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 Advanced TPMS does not indicate a
warning for wrongly selected inflation pres-
sures. Always adjust tire inflation pressure
according to the Tire and Loading Informa-
tion placard on the driver’s door B-pillar or,
if available, the supplemental tire inflation
pressure information on the inside of the
fuel filler flap.
The Advanced TPMS is not able to issue a
warning due to a sudden dramatic loss of
pressure (e.g. tire blowout caused by a for-
eign object). In this case bring the vehicle to
a halt by carefully applying the brakes and
avoiding abrupt steering maneuvers.


533 Operation
Tires and wheels
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 an advanced tire pres-
sure monitoring system (Advanced TPMS)
that illuminates a low tire pressure telltale
when one or more of your tires is significant-
ly underinflated. Accordingly, when the low
tire pressure telltale illuminates, you should
stop and check your tires as soon as possi-
ble, and inflate then 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 effect the vehi-
cle’s handling and stopping ability. Please
note that the Advanced TPMS is not a sub-
stitute for proper tire maintenance, and it is
the driver’s responsibility to maintain cor-
rect tire pressure, even if underinflation has
not reached the level to trigger illumination
of the Advanced TPMS low tire pressure tell-
tale.
Your vehicle has also been equipped with an
Advanced TPMS malfunction indicator to in-
dicate when the system is not operating
properly. The Advanced TPMS malfunction
indicator is combined with the low tire pres-
sure telltale. When the system detects a
malfunction, the telltale will flash for approx-
imately one minute and then remain contin-
uously illuminated. This sequence will
continue upon subsequent vehicle start-ups
as long as the malfunction exists. When the
malfunction indicator is illuminated,the system may not be able to detect or sig-
nal low tire pressure as intended.
Advanced TPMS malfunctions may occur for
a variety of reasons, including the installa-
tion of replacement or alternate tires or
wheels on the vehicle that prevent the Ad-
vanced TPMS from functioning properly. Al-
ways check the Advanced TPMS
malfunction telltale after replacing one or
more tires or wheels on your vehicle to en-
sure that the replacement or alternate tires
and wheels allow the Advanced TPMS to
continue to function properly.
iIf a condition causing the Advanced TPMS to
malfunction develops, it may take up to
10 minutes for the system to signal a malfunc-
tion using the Advanced TPMS telltale flashing
and illumination sequence.
The telltale extinguishes after a few minutes driv-
ing if the malfunction has been corrected.
iOperating radio transmission equipment
(e.g. wireless headsets, two-way radios) in or
near the vehicle could cause the Advanced TPMS
to malfunction.

534 Operation
Tires and wheels
Reactivating Advanced TPMS
The Advanced TPMS must be reactivated
when you have adjusted the tire inflation
pressure to a new level (e.g. because of dif-
ferent load or driving conditions). The Ad-
vanced TPMS is then recalibrated to the
current tire inflation pressures.
Using the Tire and Loading Information
placard on the driver’s door B-pillar
(
page 523) or, if available, the sup-
plemental tire inflation pressure
information on the inside of the fuel fill-
er flap (
page 509), make sure the tire
inflation pressure of all four tires is
correct.
Switch on the ignition (page 336).
Press( or& to select the menu
“Service”.
Press$ or% to select
“Tire pressure”.
Press#.
You will see

the current inflation pressures for
each tire
or

the message
“Tire pressures
displayed after driving
a few minutes”
appear in the multifunction display.
Press%.
The message
“Use current pressure
values as new
reference values
To confirm press "OK"”
appears in the multifunction display.
Warning!G
It is the driver’s responsibility to calibrate
the Advanced TPMS on the recommended
cold inflation pressure. Underinflated tires
affect the ability to steer or brake the vehi-
cle. You might lose control over the vehicle.
iReactivate the Advanced TPMS after adjust-
ing the tire inflation pressure to the inflation
pressure recommended for the vehicle operating
condition. Tire inflation pressure should only be
adjusted on cold tires. Observe the recommend-
ed tire inflation pressure on the Tire and Loading
Information placard on the driver’s door B-pillar
(
page 523). Some vehicles may have supple-
mental tire inflation pressure information for
driving at high speeds (
page 529) or for vehi-
cle loads less than the maximum loaded vehicle
condition. If such information is provided, it can
be found on the inside of the fuel filler flap
(
page 509).
iAfter wheel rotation or sensor replacement,
the vehicle must be parked for 20 minutes be-
fore attempting to reactivate the Advanced
TPMS.
iThe menu overview can be found on
(
page 258).

535 Operation
Tires and wheels
Press#.
The message
“Tire pressure monitor
restarted”
appears in the multifunction display.
After a few minutes driving, the current
tire inflation pressure values are ac-
cepted as reference values and then
monitored.
If you wish to cancel activation:
PressL.
or
Press$ to exit menu screen.Potential problems associated with
underinflated and overinflated tires
Underinflated tires
Underinflated tires can:

cause excessive and uneven tire wear

adversely affect fuel economy

lead to tire failure from being
overheated

adversely affect handling
characteristicsOverinflated tires
Overinflated tires can:

adversely affect handling
characteristics

cause uneven tire wear

be more prone to damage from road
hazards

adversely affect ride comfort

increase stopping distance
iWhen the wheel positions are changed on
the vehicle, it is possible that the air pressure is
temporarily displayed for the wrong position.
This will be corrected after driving for several
minutes, and the air pressure will be shown for
the correct position.
Warning!G
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.
Warning!G
Follow recommended tire inflation
pressures.
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.

542 Operation
Tires and wheels
Maximum tire inflation pressure
1Maximum permissible tire inflation
pressure
This is the maximum permissible tire
inflation pressure for the tire.
Always follow the recommended tire
inflation pressure (
page 528) for proper
tire inflation. Uniform Tire Quality Grading Standards
(U.S. vehicles)
Tire manufacturers are required to grade
tires based on three performance
factors: treadwear, traction and
temperature resistance.
1Treadwear
2Traction
3Temperature resistance
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
Warning!G
Never exceed the max. tire inflation
pressure. 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 over-
heated.
Do not overinflate tires. Overinflated tires
can adversely affect handling and ride com-
fort, wear unevenly, increase stopping dis-
tance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road de-
bris, potholes etc.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.

545 Operation
Tires and wheels
Bar
Another metric unit for air pressure. There
are 14.5038 pounds per square inch (psi)
to 1 bar; there are 100 kilopascals (kPa)
to 1 bar.
Bead
The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the
rim.
Cold tire inflation pressure
Tire inflation pressure when your vehicle
has been sitting for at least 3 hours or
driven no more than 1 mile (1.6 km).
Curb weight
The weight of a motor vehicle with stan-
dard equipment including the maximum
capacity of fuel, oil, and coolant, and, if so
equipped, air conditioning and additional
optional equipment, but without passen-
gers and cargo.DOT (Department of Transportation)
A tire branding symbol which denotes the
tire meets requirements of the
U.S. Department of Transportation.
GAWR (G
ross Axle Weight Rating)
The GAWR is the maximum permissible
axle weight. The gross vehicle weight on
each axle must never exceed the GAWR for
the front and rear axle indicated on the
certification label located on the driver’s
door B-pillar.
GVW (G
ross Vehicle Weight)
The GVW comprises the weight of the
vehicle including fuel, tools, spare wheel,
installed accessories, passengers and
cargo and, if applicable, trailer tongue
load. The GVW must never exceed the
GVWR indicated on the certification label
located on the driver’s door B-pillar.GVWR (G
ross Vehicle Weight Rating)
This is the maximum permissible vehicle
weight of the fully loaded vehicle (weight of
the vehicle including all options, passen-
gers, fuel, and cargo and, if applicable,
trailer tongue load). It is indicated on certi-
fication label located on the driver’s door
B-pillar.
Kilopascal (kPa)
The metric unit for air pressure. There are
6.9 kilopascals (kPa) to 1 psi; another
metric unit for air pressure is bars. There
are 100 kilopascals (kPa) to 1 bar.
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.

546 Operation
Tires and wheels
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.