This screw plug (arrow) is used to check the oil level in the main gear of the automatic transmission. The photo shows a five-speed automatic transmission.
Unfortunately, checking the oil level in the final drive of an automatic transmission is often neglected, although in this place the danger due to insufficient lubrication is much higher than, for example, in a manual transmission.
The oil added is not the same as that used in the manual transmission. Audi prescribes the use of transmission oil G 052 145 S2 (synthetic oil) from Audi warehouse.
Oil change is not provided. Oil level is checked. The photo above shows the threaded plug of the inspection/filler hole.
(The original material is located on the website: AUDImanual.ru)