Happened to me too. When it gets colder the air pressure in the tire drops. I took me two trips to the gas station last time to get it right. I put in 32 in the front, 33 in the back got in the car and the light was still on and sure enough somebody pulls up behind me to check their tires. Being a nice guy I came back later. It is kind of a PIA but I'd rather have it than not.

Pat