Please explain this error code and how to fix it: P20EE00

Question

The engine light is on. I already chaged the diesel filter. there is white smoke coming from the exhaust and I really need some help to get my car repaired.
it was a brand new 2013 audi TDI. After 10 months it started smoking and the engine light came on. The mecanic suspected the diesel fuel at the pump station which was of poor quality. Please help. When he installed the computer on the suv he got this code P20EE00