2007 Lexus GX 470 Owners Manual - Page 368

5-2. Steps to take in an emergency n When the tire pressure warning light comes on Check the tire inflation pressure and adjust to the appropriate level. n The tire pressure warning light may turn on due to natural causes The tire pressure warning 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 warning light. n When a tire is replaced with a spare tire The spare tire is also equipped with the tire pressure warning valve and transmitter. The tire pressure warning light will turn on if the tire inflation pressure of the spare tire is low. If a tire goes flat, even though the flat tire is replaced with the spare tire, the warning light does not turn off. Replace the spare tire with the repaired tire and adjust the proper tire inflation pressure. The warning light will turn off after a few minutes. n If the tire pressure warning system is inoperative The tire pressure warning system may become inoperative in the following conditions: (When the condition becomes normal, the system will work properly.) l If tires not equipped with tire pressure warning valves and transmitters are used. l If the ID code on the tire pressure warning valves and transmitters is not regis- tered. l If electronic devices or facilities using similar radio wave frequencies are nearby. l If a radio set at similar frequencies is in use in the vehicle. l If a window tint that affects the radio wave signals is installed. l If the tire pressure warning select switch is set to a different tire setting. l If there is a lot of snow or ice on the vehicle, in particular around the wheels or 5 When trouble arises wheel housings. l If non-genuine Lexus wheels are used. l If tire chains are used. l If the tire inflation pressure is 73 psi (500 kPa, 5.1 kgf/cm2 or bar) or higher. l If the tire is in a location subject to poor radio wave signal reception. 353