I have a 2004 Audi A4 3.0, with the Bose stereo, and while listening to the stereo at low volume, the volume fluctuates like mad. At higher volume it's fine.

There is a feature on the stereo called 'Speed Volume Control' (SVC) I thought was responsible for it. The original stereo my car came with was mysteriously missing this feature, despite it being in the manual. Naturally, I presumed this was the problem (that I couldn't turn the SVC off).

So, just last week Audi finally believed me (for 3 years they couldn't seem to duplicate the problem) and replaced my stereo. The feature is now available, but guess what? I turned it off, and the effing volume still fluctuates!! Just for fun, I set it to 5, then to 10, and everything else in between, and nothing works! I even played with the 'Max Volume' settings (the feature that comes after SVC) which shouldn't even have any bearing on it, and of course, it has no effect. This is driving me mad. Much appreciated if anyone can help. Audi sure as heck can't.

 

The SVC was my thought, but I don't have anything for you.
Here is a site that has all the little hidden tweaks for the radio, it might help.....

http://www.ibiblio.org/tkan/audi/radios/symphony.html

 

I'll check it out. Much appreciated!

 

Do you have volume control from the steering?

Could there be a wiring problem comign from there?