My car will start up/run fine, but occasionally when I shift out of park into drive or reverse for the first time, there will be a delay of 2-3 seconds, then a huge jolt as the car slams into gear. The cluster lights up PRNDS in solid red, which I'd guess is the tcu putting the car into limp mode?

It typically happens in the morning when leaving for work and the car has sat all night, but bit every time. I can shut the car off/on and usually everything is fine after that. A few times I had to restart the car 2 or 3 times.

I thought it was my tcu going bad so I swapped the stock one in for one with a. Giac chip, but still have the same issue occasionally. (No more/less frequent though)

No CEL or codes to be read when it happens. Any suggestions on where to start looking??

This is the second transmission, first was replaced at 50k by Audi and the car has 85k now.

Thanks for any ideas!