2006 Lexus GS 300 Owners Manual - Page 458

STARTING AND DRIVING If the low tire pressure warning light does not go off or comes on during driving, it indicates that tire inflation pressure is low. Make sure there is no flat tire. If the light comes on again even after tire inflation pressure adjustment, you may have a flat tire. If there is not adequate air pressure in the tires, the light will not go off. The light may turn on due to natural causes such as natural air leaks or tire inflation pressure changes caused by temperature. In this case, adjusting the tire inflation pressure will turn off the light. The tire pressure warning system is not a substitute for checking tire inflation pressure. For details about adjusting the tire inflation pressure, see "Checking tire inflation pressure" on page 539. If the low tire pressure warning light comes on, the action you must take is different depending on the type of tires used. Vehicles with run−flat tires: Stop your vehicle at a safe place as soon as possible and check that the tire inflation pressure is as specified on the tire and loading information label. If the low tire pressure warning light comes on even after tire inflation pressure adjustment, it is probable that you have a flat tire. If you cannot verify the tire inflation pressure soon, go to the nearest Lexus dealer or authorized tire dealer at the moderate speed and do not ever exceed 90 km/h (55 mph) and have all your vehicle's tires checked and adjusted. And whether there is a flat tire or not should be also checked at this time. If any tire must be replaced, see "If you have a flat tire" on page 468. If your vehicle is equipped with spare tire, the spare is not equipped with the tire pressure sensor. So, the low tire pressure warning light remains on even if the spare tire is mounted. The light goes off a few minutes after air is put into the deflated tire. 434