2010 silverado dpms system
 

I just bought a 2010 silverado 1500 yesterday and everything ran beautifully. When i checked the dash, all 4 tires indicated proper pressure and no lights on the dash.
Today, the "check the tire pressure system" symbol came on and will not go away. Also, it does not show the tire pressures like it did yesterday. I checked all four tires and they are all 35psi-35.5. Within operating standards.
What gives. I put my obdii reader on and it doesn't say anything is wrong, but the low tire symbol will not go away.
Help !!!!!!