I have an 09 XB ...I purchased a full size spare and I was told that the XB computer would only monitor 4 tires ... is this correct or did they just not want to install the monitor? Since I always do a 5 tire rotation I'd sure like to have all the tires monitored.

 

it is real simple to put sensor in other tire when doing a rotation but is true car will only recognize the four because computer is set up that way. I do this for a living at Costco and for $17 we rotate and rebalance tires and for an extra $5 we could switch the sensor into other rim. Pain in the a** but can be done.

 

It is true that you can only program 4 sensors into the computer at one time. So your options is to move a sensor to the spare when rotating or purchasing a 5th sensor and have the dealer reprogram the computer each time (costly, my dealer charged me $50 to reprogram my sensors).

 

yes only 4 bummer

 

People really worry about their TPMS? I bought new wheels and never installed them from the factory steelies. Just check your tire pressure weekly and add as needed.

 

Sorry for jacking this thread, but how long are those TPMS last?

 

sheesh, new cars and their TPMS sensors. i'm soo happy the 05-06 tc's just use the ABS wheel speed sensors to monitor tire pressure. these TPMS sensors that are actually in the wheels make everything such a friggan PITA.

 

also...i'm reasearching this online alittle...what is the benefit of a 5 tire rotation pattern? seems like a waste of time/effort and money. buying a full size spare and adding it to the rotation. i mean, i suppose if one if your tires gets damaged, you can replace it with the full size spare that has been evenly worn down..but mainly it seems unnecessary.

 

While I disagree with the 5 tire rotation scheme, that's your choice. If you want a working TPMS in your spare the best option is to add one and get a Ateq Quickset TPMS tool so you can reprogram your ECU when you rotate tires. The TPMS will cost about $50 and the Quickset costs $135 at Tire Rack. In the long run it will be a lot cheaper than paying the dealer to do it.

 

OK, I'll bite ! How can an ABS sensor detect tire pressure?

 

i was told 3-4 years then the battries go out then you need to buy new ones .

 

the ABS wheel speed sensors on the 05-06 scion tc's monitor tire pressure by seeing how fast each wheel is spinning, and if there is a noticible enough discrepancy in the number of rotations between the wheels, it sets off the (!) warning light to let you know that one or more of the tires are not properly inflated.

you just have to re-initialize it every time you change wheels and tires so it learns what the new rotation rate should be and you're good to go. so people with 05-06 tc's can change wheels and tires all they want without having to reprogram or remove and reinstall TPMS sensors. we just have to reset it using the button in the glove box.