You say the steering wheel volume controls "no longer work". Can I take that to mean they worked at one time and stopped working? If so, did you do anything with the Fusion between the working and not-working period, like upgrade the firmware? Speaking of which, have you upgraded your unit to the latest revision (3.1, just came out 3 days ago!!!)?
Re. not working with the phone, silly question but is your phone connected via Bluetooth and if so, when you go into the Fusion Settings menu for Bluetooth and select your phone, does it show two Bluetooth profiles or just one? It should say that it has Hands Free and one other, I think it's Audio, or Multimedia, I can't remember exactly. The important one for the phone is Hands Free.
P.S. You can find the latest Fusion firmware here:
https://fusionentertainment.com/life...upport/updates