My check engine light came on on my 2011 F350 so I brought it to the dealer (which is supposed to be a reputable one). They told me it was code "P20BA" which is a redundant heater code that means its either something to do with the glow plugs or a heater that is inside my heater core but either way it would take a couple of days to fix. I left it and on the second day they called to tell me that Ford tech had them go through a series of tests and at the end of the tests if the light went out to ship the truck. So of course the light turned off. They told me this with a smile and said they know it will come back on and to call as soon as it did. Sure enough, i didnt make it out of the parking lot and the light came back on. I made another appointment, brought it in and again on the second day they called to tell me they had to do the same thing and the light went back off but this time they "think" they traced it back to the DEF tank heater but were also waiting for a call back from ford tech. Of course this part is not covered under warranty (53k miles on the truck) and the part is $250 plus labor. I told them to figure it out with ford tech and to call me when they have a definitive answer and not just a guess and I will bring it back in. Has anyone else had this code or know anything about it?