I have 2012 Doge Ram 1500 4x4 with 96,000+ miles. I am getting the SERV 4WD light on the dash when I first start and it stays on for awhile. It will eventually go off. I had the transfer case serviced back in December so I know it is not the reason for the light. This is not the quick flash of the light on startup but rather after the engine runs for a few minutes and sometimes while driving it comes on. How does this get reset.