I used an "Axxess" interface to connect my Kenwood DNX6980 to my 03. It has adjustable chime volumes :thumb:
:thumb:
(super low) and retained OnStar for the bush 911 just in case I'm going to die.
The Axxess ASWC plugs directly into their interface and is plug and play. It recognizes the vehicle and head unit and configures itself. It is also USB upgradable AND not expensive.
Everything works great; source, volume, seek, etc. Only thing is you need to double click it (hit volume up twice) each time you start the truck but its no big deal.