Bose (Navigation) No Sound But Head Working - Solved
 

Recently my 2009 Navigation/Radio suddenly had no sound but continued to display correctly (I blame it on my recent trip to Palm Springs where it was 120f at the peak of the day - I don't know for sure if the heat caused it, but that is freakin hot!).

I first checked all the in cabin fuses and nada. Then I googled with little results, but I did find my way here. Although there are plenty of threads here about door speakers and people having replaced their heads and amps without sound I could not find this specific scenario solved. So, here is my contribution to the subject.

The other threads touched on 12v switching to the amplifier power so this is where I started.

In the engine bay fuse box I found the "Head" relay to be dead. I replaced it temporarily with the ST (Stability Control) relay and all is well.

I ordered the replacement relay L110 67 730 on ebay for less than $8 shipped.

I have no idea what the S2 Navigation models look like. Can you take a picture of it and post it here?

Here's one I tracked down. Very nice looking IMO. My 2009 has intermittent sound outages. Was yours constant?

No, my experience was complete absence of sound, and if I toggled between audio sources the Navi unit would lock up.

So far with the relay replaced all is well.

Could it be the same thing for you? Maybe. If you swap the ST with the Head relay and the relay was bad then your Traction Control icon will flash with the same regularity as your sound cut. If it's not the relay then your guess is as good as mine.