Our fuel gauge quit working a couple of weeks ago. It died in an interesting way. First, it went from about half to about an eighth over a day or 2. We thought we were imagining things, so I filled it and it took 10.8 gal, so it really was that low. But then it didn't budge off of 1/8th. To make life more interesting, it continued to work it's way to 0, as if there really was only an eighth tank. The range went from 30 miles to 20 to 10 and down to 0...this over the next couple of days.
Made an appt, and the dealer ordered a new tank unit.
A couple of weeks later, I had my appt for the repair. The day before, I put 4 gal in, to make sure I didn't run out on my way home. The gauge came back to life right after I added fuel. Then the little triangle (look at your instrument panel) light flashed, and I noticed the "dpf plugged" light was on. I suspect (but have no proof) that the car will not do a regen if the fuel gauge is not registering any fuel. I had a perfect trip for a regen, so I let it do it's thing (per service manual) and the lights were off before I got home.
Dealer put the tank unit in the next day and "fixed" the car. Actually, they said even though the gauge was working again, it wasn't reading the level correctly.
Since I knew that the service adviser wouldn't have a clue about the dpf light (I was correct), I left a note with her about it asking the tech to verify that no damage was done to the dpf. What a waste of time that was. When I asked about the results of that, on the phone, she said she didn't know and would find out. When I picked the car up, she looked at me clueless, when I asked again. The VW service manager, at least knew what I was talking about, but just tried to convince me it must be a coincidence, and told me that if there were any issues, the tech would have seen a code. Sheesh, at this point they wore me down and I said "thank you" and left.
Full disclosure. I was an auto tech in several dealerships (Chrysler, Cadillac /Toyota, Mercedes / VW) in a previous life. We used to care, even when warranty wasn't paying, so it's an eye opener to see life in the new giant dealerships. It's not helping customer service.
Done whining...love the car.