2008 MERCEDES-BENZ SL55AMG TPMS

312 Operation
Tires and wheels
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
MOExtended system*
The MOExtended system allows you to
continue driving your vehicle even if there
is a total loss of pressure in one or more
tires.
You may only use the MOExtended system
in conjunction with the Run Flat Indicator*
(Canada vehicles) (
page 303), TPMS
(U.S. vehicles) (
page 305), or Advanced
TPMS* (Canada vehicles) (
page 308).
For information on driving in case of pres-
sure loss in one or more tires (emergency
mode), see the “Practical hints” section
(
page 425).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.

355 Practical hints
What to do if …
ProblemPossible cause/consequenceSuggested solution
HUSA only:
Combination low tire pressure/
TPMS malfunction telltale for
the TPMS illuminates continu-
ously.
Canada only:
Low tire pressure telltale for the
Advanced TPMS* illuminates
continuously.The TPMS (USA only) or Advanced TPMS*
(Canada only) detects a loss of pressure in
at least one tire.Carefully bring the vehicle to a halt,
avoiding abrupt steering and braking
maneuvers. Observe the traffic situation
around you.
Read and observe messages in the
multifunction display.
If the tire inflation pressure in the respec-
tive tire(s) has (have) been corrected,
the combination low tire pressure/TPMS
malfunction telltale goes out after a few
minutes of driving.
HUSA only:
Combination low tire pressure/
TPMS malfunction telltale for
the TPMS flashes for
60 seconds and then stays illu-
minated.There is a malfunction in the TPMS.Read and observe messages in the
multifunction display.
Have the TPMS checked by an
authorized Mercedes-Benz Center.
After the malfunction has been remedied,
the combination low tire pressure/TPMS
malfunction telltale goes out after a few
minutes of driving.
(Continued on next page)

356 Practical hints
What to do if …
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 (
page 294) or, if
available, the tire inflation pressure label on
the inside of the fuel filler flap (
page 279).
If your vehicle has tires of a different size
than the size indicated on the Tire and Load-
ing Information placard or, if available, the
tire inflation pressure label, you should de-
termine 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.
Accordingly, when the low tire pressure tell-
tale illuminates, you should stop and check
your tires as soon as possible, and inflate
them 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 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 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.USA only:
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
one minute and then remain continuously
illuminated. This sequence will continue
upon subsequent vehicle start-ups as long
as the malfunction exists. When the mal-
function indicator is illuminated, the system
may not be able to detect or signal low tire
pressure as intended.
TPMS malfunctions may occur for a variety
of reasons, including the installation of
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.

374 Practical hints
What to do if …
Left displayRight displayPossible cause/consequencePossible solution
Tire pressuredisplayed after
driving for
a few minutes.Vehicles with Advanced TPMS*:
The tire inflation pressure is being
checked.Drive the vehicle for a few minutes.
Tire Pressure MonitorInoperativeThe TPMS or Advanced TPMS* is
malfunctioning.Have the TPMS or Advanced TPMS*
checked by an authorized
Mercedes-Benz Center.
Tire Pressure MonitorInoperative
No Wheel SensorsThere are wheels without appropriate
wheel sensors mounted (e.g. winter
tires).Have the TPMS or Advanced TPMS*
checked by an authorized
Mercedes-Benz Center.
Have appropriate wheel sensors in-
stalled by an authorized Mercedes-Benz
Center.
Tire Pressure Monitor
Wheel Sensor MissingVehicles with Advanced TPMS*:
One or more sensors defect
(e.g. empty sensor battery).
The respective tire is indicated by
---
instead of the tire inflation pressure in
the multifunction display.
Have Advanced TPMS* checked by an
authorized Mercedes-Benz Center.
Have appropriate wheel sensors in-
stalled by an authorized Mercedes-Benz
Center.

375 Practical hints
What to do if …
Left displayRight displayPossible cause/consequencePossible solution
Tire Pressure Monitor
Wheel Sensor MissingVehicles with Advanced TPMS*:
One or more wheels without
appropriate wheel sensors
mounted (e.g. spare wheel).
The respective tire is indicated by
--- instead of the tire inflation
pressure in the multifunction
display.
Have the Advanced TPMS* checked by an
authorized Mercedes-Benz Center.
Have appropriate wheel sensors installed
by an authorized Mercedes-Benz Center.
Tire Pressure MonitorCurrently
UnavailableThe TPMS or Advanced TPMS* is
unable to monitor the tire pres-
sure due to a nearby radio interfer-
ence source.As soon as the causes for the malfunction
are no longer present, the TPMS or
Advanced TPMS* automatically becomes
active again after a few minutes driving.
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.
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 over-
heated.
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.

397 Practical hints
What to do if …
Left displayRight displayPossible cause/consequencePossible solution
HPlease correct
the tire pressure.The tire inflation pressure is too
low in one or more tires.Check and correct tire inflation pressure as required
(
page 302).
Tire Pressure
Caution
Tire DefectOne or more tires are deflating.Carefully bring the vehicle to a halt, avoiding abrupt
steering and braking maneuvers.
If necessary, change the wheel (page 417).
Caution
Tire defectOne or more tires are deflating.
Vehicles with Advanced TPMS*:
The respective tire is indicated in
the multifunction display.Carefully bring the vehicle to a halt, avoiding abrupt
steering and braking maneuvers.
If necessary, change the wheel (page 417).
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. Continued
driving with a flat tire will cause excessive
heat build-up and possibly a fire.
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 over-
heated.
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.

398 Practical hints
What to do if …
Left displayRight displayPossible cause/consequencePossible solution
HTire Pressure
Check TiresThe tire pressure in one or more
tires is already below the mini-
mum value.Carefully bring the vehicle to a halt, avoiding abrupt
steering and braking maneuvers.
Check and adjust tire pressure as required.
If necessary, change the wheel.
Check TiresThe tire pressure in one or more
tires is already below the mini-
mum value.
Vehicles with Advanced TPMS*:
The respective tire is indicated in
the multifunction display.Carefully bring the vehicle to a halt, avoiding abrupt
steering and braking maneuvers.
Check and adjust tire pressure as required.
If necessary, change the wheel (page 417).
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. Continued
driving with a flat tire will cause excessive
heat build-up and possibly a fire.
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 over-
heated.
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.

424 Practical hints
Flat tire
Detach the electric air pump.
Stow the electrical plug and the air
hose behind the flap and place the air
pump back in the trunk.
Lowering the vehicle
Lower vehicle by turning crank coun-
terclockwise until the full weight of the
vehicle is resting on the ground.
Pull the jack out of the jack support
tube.1 - 5 Wheel bolts
Tighten the five wheel bolts evenly,
following the diagonal sequence
illustrated (1 to 5), until all bolts
are tight. Observe a tightening torque
of 96 lb-ft (130 Nm).
Warning!G
Follow recommend inflation pressures.
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 load limit as indicated on the Tire
and Loading Information placard 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.
iThe flat tire may be transported in the trunk
when the retractable hardtop is raised. If avail-
able, use a protective sheet on the spare wheel.
Vehicles with TPMS or Advanced TPMS*:
Do not activate the tire inflation pressure moni-
tor until a full size wheel/tire with functioning
sensor has been placed back into service on the
vehicle.
Warning!G
Have the tightening torque checked after
changing a wheel. The wheels could come
loose if they are not tightened to a torque of
96 lb-ft (130 Nm).