The TCM isn't your problem then. Even if the TCM was not even plugged in, the transmission will move forward and backward, because it would revert to just a simple hydromechanical unit. Limp mode is just a fixed gear, 3rd I think, and reverse will still work, it will just engage a bit harsh since the line pressure will not be regulated.
You have an internal trans problem.
Just FYI, the only VAG autobox sold here that I am aware of that is 100% totally dependent on the electronics to work correctly in order to move the car is the 02E (DSG). Because its 'limp mode' is neutral.