2008 Toyota Prius Owners Manual - Page 460

5-2. Steps to take in an emergency n Front passenger detection sensor and passenger seat belt reminder If luggage is placed on the front passenger seat, the front passenger detection sensor may cause the warning light to flash, even if a passenger is not sitting in the seat. n When the tire pressure warning light comes on Check the tire inflation pressure and adjust to the appropriate level. Pushing the tire pressure warning reset switch should not turn off the tire pressure warning light. 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 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 transmit- ters are used. l If the ID code on the tire pressure warning valves and transmitters is not registered. l If the tire inflation pressure is more than 73 psi (500 kPa, 5.1 kgf/cm2 or bar). The 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 wheel housings. l If non-genuine Toyota wheels are used. l If tire chains are used. 434 PRIUS_U_(L/O_0802)