I have a 2001 s500 with command unit , the unit powers on but I get no audio, it seems that the D2B is not waking up, I replaced the command still same problem so I replaced the amp and no luck,,, I get Fiber signal on the red side at the amp when it powers on but it stops there. Every once in a while it will just start working on its on. I have the phone module as well as the VR module insatlled. I believe this is a can bus problem but could be wrong,,,any ideas ? the dealer is completely lost and doesnt know where to start. this is driving me nuts PLEASE HELP