The TPMS light has been on since we bought our 09. I wanted to make sure the sensors were actually bad before I committed to paying to replace them. I say that because I had the body control module (home of the tire sensor receiver) out of the truck when I had the dash out to replace the evaporator core. The back of it looked like it may have gotten wet at some point. It was either that or just solder flux residue from when it was made. I couldn't be sure.
So I picked up a potentially broken GM tire sensor tool on eBay. It was cheap enough and I had a good guess what was wrong with it. Turns out I was right. The rechargable battery packs were terminally dead, and the kit didn't include a charging cradle. The terminal inside the device was damaged due to the dead pack corroding it.
Fortunately you can use generic C batteries with these things. So I took the back off, removed the ruined battery pack, fixed the terminal and dropped in some recharagable C-cells from Amazon. It fired right up.
All four of the sensors are bad. The spare tire seems ok though.
The other cool thing about this is it has a simulation mode. You can basically put it in reverse and have it pretend to be each wheel, to see if the BCM can successfully do a sensor relearn. It did. The BCM is ok.
I don't know yet if I'm going to try to replace them myself, or just live with it until we make a decision on replacing or refinishing the wheels.