My son used the dieselgate rebate from VW to pay for the fluid change.
They give you $1000 but you can only spend it at VW.
They charged over $700 for the 40,000 service!!!
I believe it does the reset and is used for checking the oil temperature.IRC also shows trans oil level on some models?
There appear to be a few OBD readers for the car, but not all work with the TDI VW. A dieselhead friend recommends this one.
http://www.ross-tech.com/index.html
We drove a Suburban over 125k; a starter, brakes,heater core, most of the exhaust system,fluids...
Doubt if I spent $700 on ALL the parts.
Here is the D I Y info.
http://www.myturbodiesel.com/wiki/dsg-fluid-drain-and-replacement-service-vw-and-audi-stronic-oil-flush/
Looked up the DSG service kit, even on Amazon 6 quarts of fluid and the small filter are 125 bucks. Assuming the filter is worth 5 bucks, that means 20/qt for the oil...so awesome profit margin there even before labor charge.
But German stuff has always been pricey, even back to the 70s when I was young.