Changed my tires over for winter, and after the TPS sensor was telling me I had a flat. Checked the air pressure and it was good. went back to the dealer and they re-calibrated the TPS. Then a few days later a different tire showed flat, checked the air pressure and it was good. Went back to the dealer and they re-calibrated the TPS for a second time. Then a third time a third different tire the TPS showed flat, repeated the same steps for a third time. Its been good since, but going to GM to reset the TPS is a pain.