Glad to see this thread is not dead - TPMS is, IMHO, one of the dumbest things ever foisted upon people. First, people don't check their tires any more, which means they don't know what is happening. Second, these things are prone to failure at around 100K and are VERY expensive to replace (around $150-$200 on Subaru/Nissan/etc - I know, I've done both via company and 3rd party sales). They are incredibly inaccurate in the winter. Yes, tire pressure will drop - but the sensor should not trigger at 3% of the value. And they do. So now everyone drives around with their tires hyper-inflated, which makes them prone to skids. But, the reason I'm posting here is that the 2008 Subaru TPMS is useless. Even 2 dealers have had to admit they don't know why it comes on in my Impreza when it goes below 40 degrees (tires as high as 40 psi - reliably - by dealer measure). The dealers (3 so far) don't know how to turn it off. They don't know what's wrong since it sets NO code. And they don't know how to fix it. So we drive around for 6 months of the year with the light on. Been driving for over 40 years and have never been unable to maintain tire pressure adequately. It's another attempt to fix society with technology, and it never works. [I've seen the future, and it's still broken]. Yes, there was a problem with Ford Explorers, but now the rest of us are paying an incredibly high price for something of questionable benefit.