flat tire MERCEDES-BENZ S550 2007 W221 Owner's Guide

514 OperationTires and wheelsReactivating Advanced TPMS
The TPMS must be reactivated when you
have adjusted the tire inflation pressure to
a new level (e.g. because of different load
or driving conditions). The TPMS is then
recalibrated to the current tire inflation
pressures.
Using the tire placard on the driver’s
door B-pillar (
page 503) or, if avail-
able, the supplemental tire inflation
pressure information on the inside of
the fuel filler flap (page 489), make
sure the tire inflation pressure of all
four tires is correct.

Switch on the ignition (
page 315).

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 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.
i
Reactivate the TPMS after adjusting the tire
inflation pressure to the inflation pressure rec-
ommended for the vehicle operating condition.
Tire inflation pressure should only be adjusted
on cold tires. Observe the recommended tire in-
flation pressure on the placard on the driver’s
door B-pillar (
page 503). Some vehicles may
have supplemental tire inflation pressure infor-
mation for driving at high speeds (
page 510)
or for vehicle loads less than the maximum load-
ed vehicle condition. If such information is pro-
vided, it can be found on the inside of the fuel
filler flap (
page 489).
i
After wheel rotation or sensor replacement,
the vehicle must be parked for 20 minutes be-
fore attempting to reactivate the TPMS.
i
The menu overview can be found on
(
page 243).

515 Operation
Tires and wheels

Press#.
The message
Tire pressure monitor
reactivated
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.Run Flat Indicator (Canada only)
While the vehicle is being driven, the Run
Flat Indicator monitors the set tire inflation
pressures by evaluating each wheel’s rota-
tional speed. This allows the system to de-
tect a significant loss of pressure in a tire.
If a wheel’s rotational speed changes due
to falling tire inflation pressure, you will
see a corresponding warning message in
the multifunction display.
The Run Flat Indicator may function in a re-
stricted manner or with a delay if:


snow chains are mounted to the
vehicle


in presence of ice and snow


you are driving on a loose surface (e.g.
sand or gravel)


you are driving in a very sporty manner
(involving rapid acceleration or high
speeds in curves)
i
When 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
When the multifunction display shows the
message “Tire pressure Check tires”, one or
more of your tires is significantly under-in-
flated. You should stop and check your tires
as soon as possible, and inflate them to the
proper tire inflation pressure as indicated on
the vehicle’s tire information placard. Driv-
ing on a significantly underinflated tire caus-
es the tire to overheat and can lead to tire
failure. Under-inflation also reduces fuel ef-
ficiency and tire tread life, and may affect
the vehicle’s handling and stopping ability.
Each tire, including the spare, should be
checked monthly when cold and set to the
tire inflation pressure recommended by the
vehicle manufacturer on the vehicle placard
or the tire inflation pressure label.

516 OperationTires and wheels
Reactivating the Run Flat Indicator
The tire inflation pressure monitor must be
reactivated 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 placard on the driver’s
door B-pillar (
page 503) or, if avail-
able, the inside of the fuel filler flap
(
page 489), make sure the tire infla-
tion pressure of all four tires is correct.

Switch on the ignition (
page 315).

Press( or& to select the menu
“Service”.

Press$ or% to select “Tire
pressure”.

Press#.
The message
Run Flat Indicator
active
Reactivation possible: OK
appears in the multifunction display.

Press#.
The message
Tire pressure
now OK?
appears in the multifunction display.
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 placard on the driver’s
door B-pillar or fuel filler flap.
The Run Flat Indicator does not replace reg-
ular checks of the tire inflation pressures
since a gradual pressure loss in all four tires
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.
i
The menu overview can be found on
(
page 243).

517 Operation
Tires and wheels
If you wish to confirm activation:
Press$ or% to select “Yes”.

Press#.
The message
Run Flat Indicator
reactivated
appears in the multifunction display.
After a certain “learning phase”, the Run
Flat Indicator checks the set pressure val-
ues for all four tires.
If you wish to cancel activation:

PressL.
or
When the message
Tire pressure
now OK?
appears in the multifunction display:

Press$ or% to select “No”.

Press#.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
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.

518 OperationTires and wheelsTire labeling
Besides tire name (sales designation) and
manufacturer name, a number of markings
can be found on a tire.
Following are some explanations for the
markings on your vehicle’s tires:1Uniform Quality Grading Standards
(
page 524)
2DOT, Tire Identification Number (TIN)
(page 522)
3Maximum tire load (
page 523)
4Maximum tire inflation pressure
(
page 523)
5Manufacturer
6Tire ply material (
page 525)
7Tire size designation, load and speed
rating (
page 518)
8Load identification (
page 521)
9Tire nameTire size designation, load and speed
rating
1Tire width
2Aspect ratio in %
3Radial tire code
4Rim diameter
5Tire load rating
6Tire speed rating
i
For illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
For more information, see “Rims and tires”
(
page 655).
i
For illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.

523 Operation
Tires and wheels
Date of manufacture
The date of manufacture5 (
page 522)
identifies the week and year of manufac-
ture.
The first two figures identify the week,
starting with “01” to represent the first full
week of the calendar year. The second two
figures represent the year.
For example, “3202” represents the 32nd
week of 2002.
Maximum tire load
1Maximum tire load ratingThe maximum tire load is the maximum
weight the tires are designed to support.
For more information on tire load rating
(
page 519).
For information on calculating total and
cargo load capacities (
page 505).
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 509) for proper
tire inflation.
i
For illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.Warning!
G
Do not overload the tires by exceeding the
specified load limit or vehicle capacity
weight as indicated on the placard located
on the driver’s door B-pillar (
page 503).
Overloading the tires can overheat them,
possibly causing a blowout. Overloading the
tires can also result in handling or steering
problems, or brake failure.
i
For illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.

524 OperationTires and wheelsUniform 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
Quality grades can be found, where appli-
cable, on the tire sidewall between tread
shoulder and maximum section width. For
example:All passenger car tires must conform to
federal safety requirements in addition to
these grades.
Treadwear
The treadwear grade is a comparative rat-
ing based on the wear rate of the tire when
tested under controlled conditions on a
specified government test course. For ex-
ample, a tire graded 150 would wear one
and one-half (1
1/2) times as well on the
government course as a tire graded 100.
The relative performance of tires depends
upon the actual conditions of their use,
however, and may depart significantly
from the norm due to variations in driving
habits, service practices and differences in
road characteristics and climate.
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, 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.
i
For illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
Treadwear
Traction
Temperature
200
AA
A

525 Operation
Tires and wheels
Traction
The traction grades, from highest to low-
est, are AA, A, B, and C. Those grades rep-
resent the tire’s ability to stop on wet
pavement as measured under controlled
conditions on specified government test
surfaces of asphalt and concrete. A tire
marked C may have poor traction perfor-
mance.
Temperature
The temperature grades are A (the high-
est), B, and C, representing the tire’s resis-
tance to the generation of heat and its
ability to dissipate heat when tested under
controlled conditions on a specified indoor
laboratory test wheel. Sustained high tem-perature can cause the material of the tire
to degenerate and reduce tire life, and ex-
cessive temperature can lead to sudden
tire failure. The grade C corresponds to the
minimum level of performance which all
passenger car tires must meet under the
Federal Motor Vehicle Safety Standard
No. 109. Grades B and A represent higher
levels of performance on the laboratory
test wheel than the minimum required by
law.
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.
Warning!
G
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration,
cornering, hydroplaning, or peak traction
characteristics.
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.
i
For illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.

526 OperationTires and wheelsTire 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.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 driv-
en 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 (D
epartment o
f T
ransportation)
A tire branding symbol which denotes the
tire meets requirements of the
U.S. Department of Transportation.
GAWR (G
ross A
xle W
eight R
ating)
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 V
ehicle W
eight)
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.

527 Operation
Tires and wheels
GVWR (G
ross V
ehicle W
eight R
ating)
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
Certification 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,
vehicle capacity weight 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 s
quare i
nch)
A standard unit of measure for air pressure
-> bar, kilopascal (kPa).
Recommended tire inflation pressure
Recommended tire inflation pressure
listed on placard located on driver’s door
B-pillar for normal driving conditions.
Provides best handling, tread life and
riding comfort.
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 (T
ire I
dentification N
umber)
Unique identifier which facilitates efforts
by tire manufacturers to notify purchasers
in recall situations or other safety matters