2007 Lexus LX 470 Owners Manual - Page 310

4-3. Do-it-yourself maintenance n Selecting ID codes When replacing tires, make sure to select the ID code set that matches the new tire set. If the incorrect ID code is selected, the tire pressure warning system will not operate properly. "MAIN" "2nd" n When to replace your vehicle's tires Tires should be replaced if: l You have tire damage such as cuts, splits, cracks deep enough to expose the fabric or bulges indicating internal damage l A tire goes flat repeatedly or cannot be properly repaired due to the size or location of a cut or other damage If you are not sure, consult with your Lexus dealer. n Replacing tires and wheels If the ID code is not registered, the system will not work properly. After about 1 hour, the tire pressure warning light blinks to indicate a system malfunction. n Tire life Any tire over 6 years old must be checked by a qualified technician even if they have seldom or never been used or damage is not obvious. n If the tread wears down below 0.16 in. (4 mm) on snow tires The effectiveness of snow tires is lost. 296