I have had my truck to the dealer many times about this message on the DIC. I have heard about the EPROD, bad switch and bad ground on more than one occasion. It only comes on when I travel with my fifth wheel camper attached after about 75 to 100 miles. Total weight of truck and trailer averages 16,800 lbs. Would be very much appreciated if you can relay knowledge about this problem. Truck now has 19,700 miles.