Switching between manual and auto gearbox while driving

Hi,

Chances are the tiptronic switch is bad. If you take a look at the attached pics, you will see a wiring schematic where I circled the tiptronic switch (pic 1), location of the switch circuit board in the shifter (pic 2), and the board itself (pic 3). Before replacing it, I would confirm if there are diagnostic trouble codes related to it and make sure all connections are tight. However, chances are one of the solder joints is likely cracked and causing it to shift between the two modes.

Let me know if this helps.

Take care,
Joe