2003 MERCEDES-BENZ S CLASS tire pressure

272 OperationTires and wheels
Tires and wheelsSee your authorized Mercedes-Benz Cen-
ter for information on tested and recom-
mended rims and tires for summer and
winter operation. They can also offer ad-
vice concerning tire service and purchase.
Retreaded tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on
retreads. Mercedes-Benz can therefore
not assure the operating safety of the vehi-
cle when such tires are used.
Important guidelines

Use only sets of tires and rims of the
same type and make.


Tires must be of the correct size for the
rim.


Break in new tires for approximately
60 miles (100 km) at moderate
speeds.


Regularly check the tires and rims for
damage.


If vehicle is heavily loaded, check tire
pressure and correct as required.


Do not allow your tires to wear down
too far. Adhesion properties on wet
roads are sharply reduced at tread
depths under
1/8in (3 mm).


When replacing individual tires, you
should mount new tires on the front
wheels first (on vehicles with
same-sized wheels all around).
Warning!
G
Replace rims or tires with the same designa-
tion, manufacturer and type as shown on the
original part. See your authorized
Mercedes-Benz Center for further informa-
tion. If incorrectly sized rims and tires are
mounted:

The wheel brakes or suspension compo-
nents can be damaged.


The correct operating clearance of the
wheels and the tires are no longer guar-
anteed.
Warning!
G
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires have
sustained damage, replace them.
When replacing rims, use only genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can re-
sult in the bolts loosening and possibly an
accident.

273 Operation
Tires and wheels
Life of tires
The service life of a tire is dependent upon
varying factors including but not limited to:

driving style


tire pressure


distance driven
Direction of rotation
Unidirectional tires offer added advantag-
es, such as better hydroplaning perfor-
mance. To benefit, however, you must
ensure that the tires rotate in the direction
specified.
An arrow on the sidewall indicates the in-
tended direction of tire rotation.
Checking tire inflation pressure
Correct the tire pressure only when tires
are cold.
Regularly check your tire pressure at inter-
vals of no more than 14 days.
If the tires are warm, you should only cor-
rect the tire pressure if it is too low for cur-
rent operating conditions.
A table on the fuel filler flap lists the spec-
ified tire inflation pressures for warm and
cold tires as well as for various operating
conditions.
Warning!
G
Tires and spare tire should be replaced after
six years, regardless of the remaining tread.!Keep unmounted tires in a cool, dry
place with as little exposure to light as
possible. Protect tires from contact
with oil, grease and gasoline.
Warning!
G
If the tire pressure repeatedly drops:

Check the tires for punctures from
foreign objects.


Check to see whether air is leaking from
the valves or from around the rim.

274 OperationTires and wheelsTire pressure changes by approximately
1.5 psi (0.1 bar) per 18°F (10°C) of air
temperature change. Keep this in mind
when checking tire pressure where the
temperature is different from the outside
temperature.
Tire temperature and tire pressure also in-
crease while driving, depending on the
driving speed and the tire load.Check the spare tire periodically for condi-
tion and inflation pressure. Spare tires will
age and become worn over time even if
never used, and thus should be inspected
and replaced when necessary or after a
maximum of six years.
Checking tire pressure electronically*
The tire inflation pressure monitor only
functions on wheels that are equipped with
the proper electronic sensors. It monitors
the tire inflation pressure, as selected by
the driver, in all four tires. A warning is is-
sued to alert you to a decrease in pressure
in one or more of the tires.
Tire pressure inquiries are made using the
multifunction display (
page 130). The in-
flation pressures are displayed only after a
few minutes travel time.
You can select the unit of measure used for
the tire inflation pressure by changing the
setting in the control system (
page 130).
iThe pressures listed for light loads are
minimum values offering high driving
comfort.
Increased inflation pressures listed for
heavier loads may also be used for light
loads. These higher pressures produce
favorable handling characteristics. The
ride of the vehicle, however, will be
somewhat harder. Never exceed the
max. values or inflate tires below the
min. values listed on the fuel filler flap.
Warning!
G
Follow recommended tire inflation pres-
sures.
Do not overinflate tires. Overinflating tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.
Do not overload the tires by exceeding the
specified vehicle capacity weight (as indicat-
ed by the label on the pillar in the driver’s
door opening). Overloading the tires can
overheat them, possibly causing a blowout.

275 Operation
Tires and wheels

Switch on ignition.

Press button
è
or
ÿ
on the mul-
tifunction steering wheel repeatedly
until the standard display menu ap-
pears in the multifunction display
(
page 130).

Press button
k
or
j
repeatedly
until you see the current inflation pres-
sures for each tire appear in the dis-
play.
iPossible differences between the read-
ings of a tire pressure gauge of an air
hose, e.g. gas station equipment, and
the vehicle’s control system can occur.
The readings issued by the control sys-
tem are more precise.
Warning!
G
The tire inflation pressure monitor does not
indicate a warning for wrongly selected in-
flation pressures. Always adjust tire inflation
pressure according to the label on the fuel
filler flap.
The tire inflation pressure monitor is not
able to issue a warning due to a sudden loss
of pressure (e.g. tire puncture caused by a
foreign object). In the event of a sudden loss
of pressure, bring the vehicle to a halt by
carefully applying the brakes and avoiding
abrupt steering maneuvers.iOperating radio transmission equip-
ment (e.g. wireless headsets, two-way
radios) in or near the vehicle could
cause the tire inflation pressure moni-
tor to malfunction.
Warning!
G
Follow recommended tire inflation pres-
sures.
Do not overinflate tires. Overinflating tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.
Do not overload the tires by exceeding the
specified vehicle capacity weight (as indicat-
ed by the label on the pillar in the driver’s
door opening). Overloading the tires can
overheat them, possibly causing a blowout.

276 OperationTires and wheelsActivating the tire inflation pressure
monitor
You must activate the tire inflation pres-
sure monitor in the following cases:

If you have changed the tire pressure


If you have replaced the wheels or tires


If you have installed new wheels or
tires

Make sure that the tire pressure is cor-
rectly set.

Press button
è
or
ÿ
on the mul-
tifunction steering wheel repeatedly
until the standard display menu appear
in the in the multifunction display
(
page 135).

Press the
j
or
k
button repeat-
edly until you see the current inflation
pressures for each tire appear in the
display
or the following message appears in
the display
TIRE PRES. MONITOR

PRES. DISPLAY AFTER DRIVING A FEW
MINS. REACTIVATE USING R BUTTON

Press the reset button
J
(page 22).
The following message will appear in
the multifunction display:
CHECK CURRENT TIRE PRES.?


Press the
æ
button.
The following message will appear in
the multifunction display field:
TIRE PRES. MONITOR ACTIVATED

The tire inflation pressure monitor will
now monitor the tire inflation pressure
values of all four tires.
The following message will appear in
the multifunction display field:
TIRE PRES. MONITOR

PRES. DISPLAY AFTER DRIVING A FEW
MINS. REACTIVATE USING R BUTTONThis display appears until the individual
inflation pressure values are matched
with the tires. The individual values are
then displayed (
page 274).
iIf transporting a deflated road wheel or
additional wheel sensors in the vehicle,
the tire inflation pressure monitor
should not be reactivated until the de-
flated wheel or additional wheel sen-
sors have been removed from the
vehicle. Otherwise, the deflated wheel
or additional sensors could cause the
tire inflation pressure monitor system
to malfunction.

277 Operation
Tires and wheels
If you wish to cancel activation:
Press the
ç
button.
If the following message appears in the
multifunction display field:
REACTIVATE TIRE

PRES. MONITOR

or
TIRE PRES.

CHECK TIRES!


Check the tire inflation pressures and
correct them if necessary.

Reactivate the tire inflation pressure
monitor.
Rotating wheels
On vehicles with the same wheel size all
around, wheels can be rotated every 3 000
to 6 000 miles (5 000 to 10 000 km), or
sooner if necessary, according to the de-
gree of tire wear. The same direction of tire
rotation must be retained.
Rotate the wheels before the characteris-
tic tire wear pattern becomes visible
(shoulder wear on front wheels and tread
center wear on rear wheels).
Thoroughly clean the inner side of the
wheels after each rotation. Check and en-
sure proper tire inflation pressure. If nec-
essary, activate the tire inflation pressure
monitor*.Warning!
G
Rotate front and rear wheels only if they are
of the same size.
!If your vehicle is equipped with a tire in-
flation pressure monitor*, there are
electronic components built into the
wheel.
Do not use mounting tools in the area
of the valve as they could damage the
electronic components.
To prevent damage or incorrect instal-
lation, have the tires changed at an au-
thorized Mercedes-Benz Center.Warning!
G
Have the tightening torque checked after
changing a wheel. Wheels could become
loose if not tightened with a torque of
110 ft.lb. (150 Nm).
Use only genuine Mercedes-Benz wheel
bolts specified for your vehicle's rims.

316 Practical hintsWhat to do if …?<
SEAT BELT SYSTEM
VISIT WORKSHOP!
The seat belt system is malfunctioning.

Visit an authorized Mercedes-Benz
Center as soon as possible.
H
TIRE PRES. MONITOR

PRES. DISPLAY AFTER
DRIVING A FEW MINS. RE-
ACTIVATE USING R BUTTON
The tire pressure is being checked.
TIRE PRES. MONITOR
REACTIVATE!
The tire inflation pressure monitor* is de-
activated.

Activate the tire inflation pressure moni-
tor* (
page 276).
Display
Possible cause
Suggested solution
Warning!
G
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. Contin-
ued driving with a flat tire will cause exces-
sive heat build-up and possibly a fire.

317 Practical hints
What to do if …?
Display
Possible cause
Suggested solution
H
TIRE PRES. MONITOR
NOT ACTIVE
The tire inflation pressure monitor* is un-
able to monitor the tire pressure due to

the presence of several wheel sensors
in the vehicle.


excessive wheel sensor temperatures.


a nearby radio interference source.


unrecognized wheel sensors mounted.

Check the tire pressure at the next ser-
vice station.
TIRE PRES. MONITOR
VISIT WORKSHOP!
The tire inflation pressure monitor* is mal-
functioning.

Have the tire inflation pressure monitor*
checked by an authorized Mercedes-Benz
Center.

Change the wheel (
page 339).
A wheel without proper sensor was in-
stalled.

Check and correct tire pressure as re-
quired (
page 273).
Warning!
G
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. Contin-
ued driving with a flat tire will cause exces-
sive heat build-up and possibly a fire.