I had purchased a 2016 VW Passat S, 1.8L TSI with the 6 speed automatic transmission as my work vehicle. The car had only 14k miles on it when I purchased it. I put around 3k miles on it in a month, and noticed that the transmission started to downshift hard on deceleration when shifting from 5th to 4th gear. When upshifting through the gears on normal driving, it would drop RPM drastically between gears, which caused my fuel consumption to drop from 36 mpg to 29 mpg. I took the car to my local VW dealer, (where I purchased it) and was advised to bring it in a week later for them to diagnose the problem. Within that week all gear changes became very hard, especially when downshifting to pass another car. Also in all this, the car would change gears quickly like it was trying to catch up with itself. I took the car in when they had an opening to give me a loaner car, and was told by the service writer that this would take a few days. Three days had gone by and I was told that they were still running diagnostics on the car. a week later, I was told that they had located the problem, and had to replace the transmission controller/ ECU and reprogram it. I got the car back, and it drives like new again. I hope this helps anyone else having this issue with this type vehicle. Love the car, and my local dealer took very good care of me, They kept me up to date anytime they had any info on my car.