My A4 1.8T has this fuel meter that will work when it wants to and shows low sometimes. It will work when the tank is full or above 3/4. After 3/4 it will some how drop a lot quicker and then go to near empty and start dropping, even though I have near half a tank (200 miles with average 20MPG)

I assume there is something wrong with signal from the tank being weak or the receiving end getting weak signals.

Any ideas where I can start looking to fix this? Thanks