MERCEDES-BENZ R500 2006 W251 Owner's Manual

370 OperationTires and wheels
Reactivating the 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 357) or, if avail-
able, the supplemental tire pressure
information on the inside of the fuel
filler flap (
page 342), make sure the
tire inflation pressure of all four tires is
correct.
TPMS malfunctions may occur for a variety
of reasons, including the installation of in-
compatible replacement or alternate tires or
wheels on the vehicle that prevent the TPMS
from functioning properly. Always check the
TPMS malfunction telltale 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.
iIf a condition causing the TPMS to mal-
function develops, it may take up to
10 minutes for the system to signal a
malfunction using the TPMS telltale
flashing and illumination sequence.
The telltale extinguishes after a few
minutes driving if the malfunction has
been corrected.iOperating radio transmission equip-
ment (e.g. wireless headsets, two-way
radios) in or near the vehicle could
cause the TPMS to malfunction.
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.


371 Operation
Tires and wheels

Press buttonè orÿ on the mul-
tifunction steering wheel repeatedly
until the standard display menu
appears in the multifunction display
(page 168).

Press thej or kbutton repeat-
edly until you see the following
message:Tire pressure monitor
active
Reactivation possible:
R-button

Press the reset button (
page 158).
The following message will appear in
the multifunction display:
Check current
tire pressure?

Press the æbutton.
The following message will appear in
the multifunction display:Tire pressure monitor
reactivatedThe TPMS will now monitor the tire in-
flation pressure values of all four tires.
If you wish to cancel activation:

Press the çbutton.Checking tire pressure electronically
with the Advanced Tire Pressure Moni-
toring System* (Advanced TPMS*),
(Canada only)
iReactivate the TPMS after adjusting
the tire inflation pressure to the infla-
tion pressure recommended for the
vehicle operating condition. Tire pres-
sure should only be adjusted on cold
tires. Observe the recommended tire
inflation pressure on the placard on the
driver’s door B-pillar (
page 357).
Some vehicles may have supplemental
tire pressure information for driving at
high speeds (
page 364) or for vehicle
loads less than the maximum loaded
vehicle condition (
page 364). If such
information is provided, it can be found
on the inside of the fuel filler flap.
iThe Advanced T
ire P
ressure M
onitoring
S
ystem* (Advanced TPMS*) is
equipped with a combination low tire
pressure/TPMS malfunction telltale in
the instrument cluster (
page 24). De-
pending on how the telltale illuminates,
it indicates a low tire pressure condi-
tion or a malfunction in the TPMS sys-
tem itself:


If the telltale illuminates continu-
ously, one or more of your tires is
significantly underinflated. There is
no malfunction in the TPMS.


If the telltale flashes for 60 seconds
and then stays illuminated, the
TPMS system itself is not operating
properly.

372 OperationTires and wheelsThe TPMS only functions on wheels that
are equipped with the proper electronic
sensors. It monitors the tire inflation pres-
sure, as selected by the driver, in all four
tires. A warning is issued to alert you to a
decrease in pressure in one or more of the
tires.
Tire pressure inquiries are made using the
multifunction display. The present inflation
pressures are displayed only after a few
minutes’ travel time.
Switch on the ignition (
page 38).

Press thej or kbutton until
the current inflation pressures for each
tire appear in the multifunction display.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.
Usually the readings issued by the con-
trol system are more precise.
iWhen the message
Tire pressure
displayed only after driving a few
minutes
appears in the multifunction
display, the individual inflation pres-
sure values are matched with the tires.
The individual values are displayed af-
ter a few minutes driving.
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 sen-
sor mounted, the system may still indi-
cate the tire inflation pressure of the
removed wheel for some minutes. If
this happens, keep in mind that the in-
dicated value where the spare wheel is
mounted 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 placard on the driver’s door B-pillar or, if
available, the supplemental tire pressure in-
formation 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.

373 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
vehicle placard or the tire inflation pressure
label. (If your vehicle has tires of a different
size than the size indicated on the vehicle
placard or the tire inflation pressure label,
you should determine the proper tire infla-
tion 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 are significantly underinflated. Accord-
ingly, when the low tire pressure telltale illu-
minates, you should stop and check your
tires as soon as possible. Driving on a signif-
icantly 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 TPMS is not a substitute for
proper tire maintenance, and it is the driv-
er’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 mal-
function exists. When the malfunction
indicator is illuminated, the system may not
be able to detect or signal low tire pressure
as intended.
iIf a condition causing the TPMS to mal-
function develops, it may take up to
10 minutes for the system to signal a
malfunction using the TPMS telltale
flashing and illumination sequence.
The telltale extinguishes after a few
minutes driving if the malfunction has
been corrected.iOperating radio transmission equip-
ment (e.g. wireless headsets, two-way
radios) in or near the vehicle could
cause the TPMS to malfunction.

374 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 357) or, if avail-
able, the supplemental tire pressure
information on the inside of the fuel
filler flap (
page 342), make sure the
tire inflation pressure of all four tires is
correct.

Press buttonè orÿ on the mul-
tifunction steering wheel repeatedly
until the standard display menu
appears in the multifunction display
(page 168).

Press thej or kbutton repeat-
edly until you see the current inflation
pressures for each tire appear in the
display or the following message
appears in the multifunction display:Tire pressure displayed

only after driving
a few minutes

Press the reset button (
page 158).
The following message will appear in
the multifunction display:
Check current
tire pressure?

Press the æbutton.
The following message will appear in
the multifunction display:Tire pressure monitor
reactivatedThe TPMS will now monitor the tire in-
flation pressure values of all four tires.
If you wish to cancel activation:

Press the çbutton.
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.
iReactivate the TPMS after adjusting
the tire inflation pressure to the infla-
tion pressure recommended for the
vehicle operating condition. Tire pres-
sure should only be adjusted on cold
tires. Observe the recommended tire
inflation pressure on the placard on the
driver’s door B-pillar (
page 357).
Some vehicles may have supplemental
tire pressure information for driving at
high speeds (
page 364) or for vehicle
loads less than the maximum loaded
vehicle condition (
page 364). If such
information is provided, it can be found
on the inside of the fuel filler flap.

375 Operation
Tires and wheels
Potential problems associated with
underinflated and overinflated tires
Underinflated tire inflation pressure
Underinflated tires can

cause excessive and uneven tire wear


adversely affect fuel economy


lead to tire failure from being
overheated


adversely affect handling
characteristicsOverinflated tire inflation pressure
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
Tire 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:
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.

376 OperationTires and wheels1Uniform Quality Grading Standards
(
page 383)
2DOT, Tire Identification Number (TIN)
(page 380)
3Maximum tire load (
page 382)
4Maximum tire inflation pressure
(
page 382)
5Manufacturer
6Tire ply material (
page 385)
7Tire size designation, load and speed
rating (
page 376)
8Load identification (
page 380)
9Tire nameTire size designation, load and speed
rating
1Tire width
2Aspect ratio in %
3Radial tire code
4Rim diameter
5Tire load rating
6Tire speed ratingGeneral:
Depending on the design standards used,
the tire size molded into the sidewall may
have no letter or a letter preceding the tire
size designation.
No letter preceding the size designation
(as illustrated above): Passenger car tire
based on European design standards.
Letter “P” preceding the size designation:
Passenger car tire based on U.S. design
standards.
Letter “LT” preceding the size designation:
Light Truck tire based on U.S. design
standards.
Letter “T” preceding the size designation:
Temporary spare tires which are high
pressure compact spares designed for
temporary emergency use only.
Tire width
The tire width1 (
page 376) indicates
the nominal tire width in mm.
iFor illustration purposes only. Actual
data on tires are specific to each vehi-
cle and may vary from data shown in
above illustration.
For more information, see “Rims and
tires” (
page 514).
iFor illustration purposes only. Actual
data on tires are specific to each vehi-
cle and may vary from data shown in
above illustration.

377 Operation
Tires and wheels
Aspect ratio
The aspect ratio2 (
page 376) is the
dimensional relationship between tire
section height and section width and is
expressed in percentage. The aspect ratio
is arrived at by dividing section height by
section width.
Tire code
The tire code3 (
page 376) indicates
the tire construction type. The “R” stands
for radial tire type. Letter “D” means diag-
onal or bias ply construction; letter “B”
means belted-bias ply construction.
At the tire manufacturer’s option, any tire
with a speed capability above 149 mph
(240 km/h) can include a “ZR” in the size
designation (for example: 245/40 ZR 18).
For additional information, see “Tire speed
rating” (
page 378).Rim diameter
The rim diameter4 (
page 376) is the
diameter of the bead seat, not the
diameter of the rim edge. Rim diameter is
indicated in inches (in).
Tire load rating
The tire load rating5 (page 376) is a
numerical code associated with the
maximum load a tire can support.
For example, a load rating of 91 corre-
sponds to a maximum load of 1356 lbs
(615 kg) the tire is designed to support.
See also “Maximum tire load”
(
page 382) where the maximum load as-
sociated with the load index is indicated in
kilograms and lbs.
Warning!
G
The tire load rating must always be at least
half of the GAWR (
page 386) of your vehi-
cle. Otherwise, tire failure may be the result
which may cause an accident and/or seri-
ous personal injury to you or others.
Always replace rims and tires with the same
designation, manufacturer and type as
shown on the original part.
Warning!
G
Do not overload the tires by exceeding the
specified load limit as indicated on the plac-
ard located on the driver’s door B-pillar.
Overloading the tires can overheat them,
possibly causing a blowout. Overloading the
tires can also result in handling or steering
problems, or brake failure.

378 OperationTires and wheelsFor additional information on tire load
rating, see “Load identification”
(page 380).Tire speed rating
The tire speed rating6 (
page 376)
indicates the approved maximum speed
for the tire.Summer tires


At the tire manufacturer’s option, any
tire with a speed capability above
149 mph (240 km/h) can include a
“ZR” in the size designation (for exam-
ple: 245/40 ZR18). To determine the
maximum speed capability of the tire,
the service description for the tire must
be referred to. The service description
iTire load rating5 (
page 376) and
tire speed rating6 (page 376) are
also referred to as “service descrip-
tion”.
Warning!
G
Even when permitted by law, never operate
a vehicle at speeds greater than the
maximum speed rating of the tires.
Exceeding the maximum speed for which
tires are rated can lead to sudden tire
failure, causing loss of vehicle control and
possibly resulting in an accident and/or
personal injury and possible death, for you
and for others. iTire load rating5 (
page 376) and
tire speed rating6 (page 376) are
also referred to as “service descrip-
tion”.
Index
Speed rating
Q
up to 100 mph (160 km/h)
R
up to 106 mph (170 km/h)
S
up to 112 mph (180 km/h)
T
up to 118 mph (190 km/h)
H
up to 130 mph (210 km/h)
V
up to 149 mph (240 km/h)
W
up to 168 mph (270 km/h)
Y
up to 186 mph (300 km/h)
(Y)
above 186 mph (300 km/h)
ZR
above 149 mph (240 km/h)

379 Operation
Tires and wheels
is comprised of the tire load rating5
(page 376) and the tire speed
rating6 (
page 376).
If your tire includes “ZR” in the size
designation and no service
description5 and6 (
page 376) is
given, the tire manufacturer must be
consulted for the maximum speed ca-
pability.
If a service description5 and6
(
page 376) is given, the speed capa-
bility is limited by the speed symbol in
the service description.
Example: 245/40 ZR18 97Y.
In this example, “97Y” is the service
description. The letter “Y” designates
the speed rating and the speed capabil-
ity of the tire is limited to 186 mph
(300 km/h).


Any tire with a speed capability above
186 mph (300 km/h) must include a
“ZR” in the size designation AND the
service description must be placed in
parenthesis. Example: 275/40 ZR 18
(99Y). The “(Y)” speed rating in paren-
thesis designates the maximum speed
capability of the tire as being above
186 mph (300 km/h). Consult the tire
manufacturer for the actual maximum
permissible speed of the tire.All-season and winter tires
Index
Speed rating
QM+S
1
1or M+S
.
for winter tiresup to 100 mph (160 km/h)
TM+S
1
up to 118 mph (190 km/h)
HM+S
1
up to 130 mph (210 km/h)
VM+S
1
up to 149 mph (240 km/h)
iNot all M+S rated radial-ply tires pro-
vide special winter performance. Make
sure the tires you use show M+S and
the mountain/snowflake
marking.on the tire sidewall.
These tires meet specific snow traction
performance requirements of the Rub-
ber Manufacturers Association (RMA)
and the Rubber Association of Canada
(RAC) and have been designed specifi-
cally for use in snow conditions.