Mercedes-Benz 2008 S550 Operator's Manual page 566

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)
Warning!
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. Underinflation also reduces fuel effi-
ciency 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 infla-
tion pressure recommended by the vehicle
manufacturer on the vehicle placard or the
tire inflation pressure label.
G
Warning!
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 more than
one tire 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.
Operation
Tires and wheels
G
565