Audi Repair: 2004 S4 Avant gearbox issue, automatic transmission problem, uphill slope

Question
I have 2004 S4 Avant which has a weird automatic transmission problem. Sometime when I start the car, all the gear indicator are flashing. Whenever they flash and if the car still moves, the gearbox does not seem to be "clicking" correctly because whenever I slow down or stop on an uphill slope, the transmission will shake and the car will shut down. In another instant, even when the indicator does not flash, the car does not move as if the gear is not engaged.

In essence, it is quite temperamental because there could be days that the indicator lights up correctly and the car behaves as if nothing is wrong.

My mechanic told me that I have to replace the computer altogether and would not be so sure if the problem could go away.

I am wondering if this is just a gearbox issue or really a computer control issue.


Answer
The computer is indicating a fault in the transmission by flashing all the gear selections.  This fault is either in the sensors, in the computer, or in the connections.  Most of the time it is in the connections.  Changing the computer is the lazy mechanic's way to diagnose; I would not start there.  Good luck,  Jan