Lexus 2003 SC430 Owner's Manual page 238

If the warning light blinks and chimes sound every few
minutes, the tire pressure is very low.
Stop your vehicle at a safe place as soon as possible and
check that the tire pressure is as specified on the tire pressure
label. The air pressure gauge is located in the tool bag. Locate
the deflated tire and change to the spare tire. For the
procedure for changing the tire, see "If you have a flat tire
(Vehicles with standard tires)" on page 241.
The spare tire is not equipped with the tire pressure sensor.
So, the warning light remains on even if the spare tire is
mounted.
CAUTION
If the warning light blinks and chimes sound, observe
the following instructions:
D Decelerate as soon as possible to the most
appropriate speed that conditions permit.
D Avoid abrupt steering wheel maneuvering and
braking. If the vehicle tires deteriorate, you could
lose control of the steering wheel or the brakes,
causing death or serious injury.
D The warning system may not activate immediately if
bursts or sudden air leakage should occur.
NOTICE
D Do not use liquid sealants for a flat tire as air pressure
sensors will be damaged.
D When the tires must be repaired or replaced, have
them repaired or replaced by the nearest Lexus
dealer or authorized tire dealer. The tire pressure
sensors will be affected by the installation or removal
of tires.
D When the tires must be replaced, replace the
grommets for air pressure sensors as well.
System malfunction
The warning light comes on if the system does not work
properly.
The system will be disabled in the conditions below:
D Electric devices or facilities using similar radio wave
frequencies are nearby.
D If a radio set at similar frequencies is in use.
D Much snowflakes or ice gets on the vehicle, in particular,
around the wheels or wheel housings.
D The sensor battery is expired.
D The tires not equipped with air pressure sensor are used.
D Although the tires are equipped with air pressure sensors,
the selector switch (see page 224) is set to other tire setting.
2003 SC430 from May '03 Prod. (OM24449U)
STARTING AND DRIVING
221