Well my 09 Tahoe's were good to go until we took it to Chevy for a tire rotation. Two days later they were reading zero. Took it back and got it taken care of and was told that it probably would happen again because our tires were worn out. They still have thread on them about 40% left. So what happens 1 day later... zero's. So I was wondering if this is true or how I could fix it. I know about reseting the sensors but haven't tried it because chevy already did it and it zeroed out. Also I got a flat yesterday and when the tire shop removed the tire we realized that the sensor came loose and was rolling around inside the tire. Any ideas?