Post by DaveSmith on Dec 9, 2009 13:13:18 GMT -5
From 2007 & up models, FEDERAL regulation requires that ALL manufacturers to equip their vehicles with a DIRECT TPMS system.
On most Lexus, if it's a full size spare, the spare tire does have a sensor in it, and ALL 5 pressures must be very close to each other or it'll trip the tire light to come on.
If the tire light is staying on steady = tire pressure difference
If the tire light is blinking = you have 1 or more sensors aren't working correctly
Prior to 2007 - some Lexus models used the indirect system that uses the speed sensor on each wheel to measure difference in rotational speed. Where you have to manually reset the tire light every time changing tires, adjusting pressures, etc..
Things you should know about your TPMS unit
-Each sensor has an internal battery designed for up to 10 years of service. TPMS sensor requires replacement when the battery life expires.
-Pressure build up or pressure loss may trigger a warning that is not a result of tire damage. Stable air pressure can reduce false warnings. (Consider Nitrogen Tire Inflation to overcome heating and cooling inflation warnings)
-Pressure sensors can require unique internal component replacement that may include rubber seals, valve cores and valve caps that should be replaced if damaged. The process of replacement of these components can extend the life of your TPMS system.
What you should know about TPMS
-TPMS systems have been mandated by the Transportation Recall Enhancement Accountability Documentation (TREAD) Act.
-It is against the law to disable a TPMS system in any vehicle equipped with federally required and factory installed TPMS items.
-TPMS systems are already present in some new and late models, but will be implemented in mostly all vehicles.