mine just turned on the other day. ive had 19 inch aftermarket wheels on for over 6 months and everything was good. we had a chilly day here in so cal last week and they turned out. went to americas tire and they check the pressure and put air into all of them for free, and my light went off

 

my TPMS went out when I got my 18's put on... but i think it came on 'cause the place that put on my wheels messed up one of the sensors...