E90: Seat Belt/ PDC chime not working.

Hi,

I have a 2006 330i.

No Idrive. No front PDC. Just the basic rear PDC. No PDC "button" on
the dash.

I noticed recently that the PDC had apparently stopped working.

Took it to a local garage to check the system but they said PDC system
was actually OK. The sensors were working and detecting obstructions.
Just no sound was coming out.

At first I thought this would be straightforward but it seems from
looking at various forums that much depends on your package, whether
you have front PDC, and/or Idrive etc. Sometimes the sound is sent
through the stereo, or other times there's a separate speaker
somewhere.

Does anyone know where/how the PDC audio is handled on my particular
package (described briefly above)?

And who best to fix? BMW garage or is it a simple DIY task?

Many thanks.