The audio controls on the steering wheel remote stopped controlling the radio. All the buttons on the bottom half (mode, phone, etc..) do nothing now and the arrow buttons on the top part no longer control the volume or change track, station, etc... The arrows on the top do however work fine with controlling the menus and options in the IP interface. I have a GAP bluetooth tool and get fault code B1D21-13 (screenshot attached) but haven't been able to find out much on it. So I replaced the switch pack with a new one...same problem, same code with no changes. Anyone have any experience with this?