Starting to get this code on a regular basis. I reset and it's back in about 100km. Truck seems to run fine and is still doing the regen fine. I have 310K km on it and my mechanic, who I believe is very good, is suggesting a possible def pump and tank cleaning, although feels that at this level of km's, it would could be a waste of money as I will likely be soon forced to decide to replace the exhaust filter or do a delete. Based on the price comparisons - $6K replacement vs $1800K delete, it isn't a hard choice. Has anyone else had this code and what did you find was wrong?