Since between Christmas and New Years I've had the CEL in my 2012 350 with 6.7 . I pulled the code, P20BE, and called the dealer. They got me in, verified it, cleaned the nozzle for the DEF and checked the connections but didn't find a problem so drive it. Code is for the reductant heater. Drove it home and parked outside for 2 hrs. When I started it to pull it in garage CEL on. I called service the next day and asked them to order whatever was needed to fix. Called a couple weeks later and was told parts were on national backorder. I let it go a month and still backorder maybe shipped by 3/28. All this time I drove it a limited amount but you can't leave a $60,000 truck sit all the time. I finally said enough is enough and called Customer Service and surprisingly enough they agreed with me and were very helpful. I got my truck fixed today-2 weeks after calling. I read on FTE of many others having this problem so don't be afraid to call! Dealer was happy I got the ball rolling, especially when CS told them I wasn't unhappy with them, just Ford.