My check engine light has been on for 3 months on and off for the past 2 weeks hasn't went off. Had is in for a diagnostics and this code came up. 4 shops come up with same answer nothing wrong just keep wiping the code. The truck only has 55000 miles on it. This code is related to the def system and dealership said def system have been giving everyone problems. Has anyone else had this issue and what was the solution? The truck goes back in Tuesday to different dealership for another diagnostic and seeing if they can figure it out. Thank you