I'm having the exact same problem. Thank you wispassat for starting this thread. My version of this still-ongoing debacle is as follows:
2013 Passat 2.0 TDI. Original owner, always serviced at VW dealership. Prior to the software update the vehicle was amazingly reliable. Aside from replacing 2 heater cores and various recall items, we've had no issues what so ever, love the car. Which is why we opted for the restitution payment + fix option.
June 2017, mileage 102,916.
Dealership performed the "software update". From that point forward, it's been nothing but problems.
Nov 2017, mileage 109,699
1st occurrence of this CEL with adblue no-start 200 mi warning. Got it to our home dealership quickly who "Ran test and found adblue injector putting too much adblue into the system at 180 ml and spec is 170 and no pressure buildup in injector." Their fix was "a reductive agent injector remove and re-install". Basically they replaced the adblue injector and cleared the codes / reset the computer. Returned the vehicle to us.
Dec 2017, mileage 112,184
2nd occurrence of CEL and adblue no-start 200 mi warning. Was returning home from an 8 hour drive, still had about 280 miles to home and knew I wouldn't make it before I reached 0 on the countdown meter so coordinated with home dealership and drove it straight there without shutting it off. Left it there for repair. They found fault P204F and this time their fix was to replace the NOx sensor. They let me pick it back up and take it. Service Advisor informed us they're starting to see a trend and have "2 customers with this exact same issue after having received the software update."
Dec 2017, mileage 113,242
3rd occurrence of CEL and adblue no-start 200 mi warning. Christmas weekend, was traveling out of state when this happened and there was a record-setting cold snap across the country. Light came on again just over 300 miles from home, with over 300 miles remaining to our final destination. We had no choice but to turn around and go backwards an hour and a half to the nearest VW dealership and leave it with them (Lincoln, NE). Picked up a rental car (good luck trying to get one on Christmas weekend with no reservations). Left our Passat at that dealership and continued our trip. A few days later on the way back through we picked our car back up from the VW dealership in Lincoln. All they did was a code reset. Interestingly, the Service Manager at this dealership also informed me she has "2 or 3 customers with the exact same symptoms after updating the software". This is now the 2nd VW dealership that has told me this. Minutes after leaving the dealership on our way home we noticed it wasn't blowing hot air. The heater core had failed. This was the 3rd heater core to have gone out in 113K miles. So the remainder of our trip home was in -10 degree record breaking cold, we struggled to keep it in the high 20's inside the car even under blankets. Everyone was frozen by the time we got home.
Dec 2017, mileage 113,694
Once home, we had our home dealership replace the heater core, somehow it was still under warranty and they didn't charge us for it. I suspect because maybe the replacements they keep putting in it won't last more than 12 months, but I can't confirm that. Maybe it's because I'm still under 120K miles.
Jan 2017, mileage 114,551
4th occurrence of CEL and adblue no start 200 mi warning. This time we were 2 ½ hours from home traveling to a sports tournament for my daughter. Had to miss that and sit in yet another (now my 3rd) VW dealership service department while they run diagnostics on it. To no surprise, they got the exact same code, "P204F Reductant Performance code stored. Completed adblue level reset procedure and cleared faults". I was very fortunate this dealership had a service department even open on a Saturday, and on top of that were able to get me into their already full schedule. They released the vehicle to me and we made it home ok later that day. What's crazy is the service advisor at this dealership (now the 3rd one I've talked to at this point) also told me, and I quote: "We have 2 customers in this exact same situation as you, they've replaced everything and we still don't know what causes it. What we can tell you is that VW acknowledges there's bug in the TDI software fix that was applied recently and they are working on an update for it but we don't have an ETA. One of my two customers' car is so bad, I've had them in a loaner for over a month."
Common trends we've observed:
1. As others have noticed, it's always happened when on long trips of over 200 miles or more. Never happens when doing short trips or in-town driving. This is horrible because when you get stranded like that long ways from home, you've basically got 200 miles to find a VW dealership near you and pray that they'll even be able to help you. I refuse to let any other shop touch this Passat, given this crap going on with the software. Don't want to give them a reason to not warrantee it.
2. So far, has always happened when it's cold. But that could just be coincidence / timing. It will be interesting to see if it continues into this spring when things warm back up.
3. Every VW service department we've talked to (and that's been 3 as of this writing) has independently told us that they have at least 2 customers with this exact same issue where they've replaced everything (NOx sensor, injector, adblue tank heater, etc) and at this point there's nothing left to replace, yet the customers keep getting these CEL's with adblue no start in 200mi. warnings, and VW corporate is "working on it".
So the million dollar question is… When is VW going to come out with a revised version of their software fix? A version 2.0, or fix to the fix, basically.
It's also very concerning, as others have posted, that VW is directing dealerships to park customers' cars and hand out loaners. So far this hasn't happened to me, but then again, we travel long distances with our Passat and two of the four times this issue came up we went to foreign / non-home dealerships that viewed us as "just passing through".
If every VW dealership across the country is averaging 2 or 3 customers with this problem, then that's a LOT of cases. As one of the earlier posters commented about their car being the canary, I've heard the exact same thing "we're not sure why, but you guys are the rare 1%. Everyone else's TDI that received the update is just fine". At first that seemed plausible, but now I have to call BS on that, because I've now personally spoke with 3 different VW service departments each telling me they have at least 2 customers with this exact same problem. I'm no rocket scientist, but from where I come from we call that a trend.
I'm also not a litigious person, but one might consider this a "class" of people that need some serious representation. For those of us that opted to keep our TDI's by taking the "settlement + fix" option, I'm still waiting on VW to follow through with their end of the deal. A fix means fix. Not this mess. Sure we received our settlement check, but the time, energy, money, and distress caused by dealing with this debacle far exceeds that amount. It's painfully clear the fix isn't a viable or acceptable fix. So VW needs to either make that right, or buy these cars back.
Still undecided what we're going to do in this situation. Sucks all the way around.