2011 Lexus RX 450h Owners Manual - Page 661

5-2. Steps to take in an emergency n The tire pressure warning light may come on due to natural causes The tire pressure warning light may come on due to natural causes such as natural air leaks and tire inflation pressure changes caused by temperature. In this case, adjusting the tire inflation pressure will turn off the warning light (after a few minutes). n When a tire is replaced with a spare tire The compact spare tire is not equipped with a tire pressure warning valve and transmitter. If a tire goes flat, the tire pressure warning light will not turn off even though the flat tire has been replaced with the spare tire. Replace the spare tire with the repaired tire and adjust the tire inflation pressure. The tire pressure warning light will go off after a few minutes. n If the tire pressure warning system is not functioning The tire pressure warning system will be disabled 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 in the tire pressure warning computer l If the tire pressure warning select switch is set to a different tire setting l If the tire inflation pressure is 73 psi (500 kPa, 5.1 kgf/cm2 or bar) or higher The tire pressure warning system may be disabled in the following conditions: (When the condition becomes normal, the system will work properly.) 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 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 (Even if you use Lexus wheels, the tire pressure warning system may not work properly with some types of tires.) l If tire chains are used l Vehicles with a full-size spare tire: If the spare tire is in a location subject to poor radio wave signal reception l Vehicles with a full-size spare tire: If a large metallic object which can interfere with signal reception is put in the luggage compartment 581