OBD codes 00293 and 00789 after leaving the shop
 

I took my 2006 Audi TT roadster (8N 1.8t, AWP) into the shop to have the condenser fan and relay swapped out. When I was leaving the shop I was shifting from reverse into drive and the car mad a really hard shift (klunk) and seemed to be stuck in 1st or 2nd gear. It is an automatic transmission. I made it home, topping out at about 45mph and ran an OBD on it. The errors from the transmission control module were as follows:I tried to diagnose it but ran out of steam, so I slept on it and went back to it the next morning. Low and behold, it was shifting like a dream again. I drove it for about 20 minutes and while stopped at a light. The PRNDL lights were all lit up, so I must be in limp mode. I took it back to the shop who went through some serious CYA maneuvers. I want to find out how to fix it, not who to blame. I will be picking up the car today, I assume in the same condition I left it with them. They are telling me to take it to a professional/dealership. This is a big chain shop... I learned my lesson taking it to them, but would like to not visit the dealer on it.

Does anyone have any tips on how to shortcut this saga and help me get to the root cause?

Any help would be greatly appreciated.

The switch that code is coming up with is the one on top of the box. Plenty of them online for around 30 bucks, here’s a link to the training manual
http://www.evosoft.dk/diagrams/DSG.pdf

page 38. Yeah the vws are all the same. Assuming your trans is the 09g.