This warning drove us crazy in my wife's 2008 Pontiac G6. The pressure was set to the tire maximum, and every once in a while it would say low pressure and wouldn't go off. Then, it started saying we had a defective airbag sensor. Then other items started giving warnings. To make a long story short, it wound up being the car battery!
One day it wouldn't start. So we put in a new battery and all the warning lights went off and never came back. I mentioned the problems I had been having to my GM service manager, and before I could even tell him about the battery, he said "did you replace the battery?" Evidently, the GM vehicles are very sensitive to having the proper battery voltage.
This may or may not be your issue, but I'd sure check on the battery especially if it's a two year old original GM battery. That's about how long they last.