Welcome to the DPF failure club. The DPF failure might be more widespread than folks think, and not always easy to diagnose.
Mine had to be replaced at 12600 along with the EGR filter, and Catalytic Converter.
I bought the JSW 2010 certified preowned a the end of Jan 2011 with only 7500 miles on it. That very day, after pulling the trigger & signing on the old dotted line and driving it off the dealers lot the CEL came on.
After a few trial and error things were suggested by service, it wound up in limp mode, with CEL AND glow plug light on, and staying in the shop for a week. So for my first week of ownership, I had a loaner.
In that week, the EGR was replaced (fault returned), EGR boost pipe was found to be broken/cracked and that was replaced (fault returned) , central wiring harness was repaired (fault returned), wires were repinned at EGR connector (fault returned), techline involved, computer was reprogrammed and that seemed to fix the CEL illuminating for a short while.
Not long after, around March, the CEL would intermittantly come on go and then stay off for a while and then pretty much not go off.
I finally brought it back again in the middle of May which is when they determined the DPF was cracked. They gave me a loaner & kept the JSW for three days.
I can't say I know a lot about the ins and outs of these engines but it seems if you get the possible "faults" for EGR flow, CEL and replacing the EGR fails to fix the problem, it might be wise to point your service dept in the direction of the DPF........ especially while you are still under warranty as that can't be an inexpensive repair especially when they have to also replace the EGR filter, and catalytic converter as well.
The car runs fine since they replaced the DPF (except for that weird occasional downhill stutter thing around 1800k mostly in 5th or 6th, which I hvnt asked service to address yet -- and the air bag light staying on which required a pssngr front door sensor to be replaced). For the most part I pretty much stopped worrying that things, like HPFP failure, will happen and leave me stranded, --- drive more....worry less --- altho I do have the super triple A 200 mile towing package, just in case.
As you can see, I got off to a pretty rocky start with this car and most folks would have probably pulled the plug during that first week. Not eggsackly sure why I didn't; I like the ride, and for some strange reason I had confidence that the service department would finally get a handle on the CEL/DPF problem. Altho, it did cost me a ton of time and aggravation and I honestly don't know if I'll keep a car this complicated, sensor ridden, and prone to a possible $8k to $10k hpfp grenade repair in the offing, past the 60k VW certified pre-owned extended warranty.......anyway, FWIW, that's my DPF story.