ZhaoningSong

Yesterday I went to MB Roanoke for my 90K B service and airbag replacement for recall. After they finished, I picked up my car and connect my phone via bluetooth for some music, however, there is no sound at all. I drove back to dealership and let them check again. they told me it might because they disconnected the battery and it may cause the amplifer malfunction. They told me there are two possible problems which either antenna or COMMAND system. Because I didn't do anything and it worked perfectly before I brought to MB dealer, and they didn't told me they need to disconnect the battery and what may happen once it disconnected, I think it should be their responability to solve this problem. However they refused to cover the repair cost saying my car is already our of warrenty that's why they wil not cover it. But I think they at least should tell me the potential danger to disconnect the battery and now they just refused to take responability. I don't know what I can do right now, can anyone give me some advice? Thank you guys.

Alfadude

Have you tried to pair your phone with the car again? Maybe it doesn't recognize it?
Is there no sound with any inputs or just with your phone?

ZhaoningSong

It should not my phone's problem, because I tried radio as well, there is no sound as well.

gamma300C

Does the radio light up at night with the headlights on ? I see they changed your cabin filter too so they were in behind that part of the dash also. I'm sure you checked the radio fuse but , if they shorted something else, there is a fuse in the back of the radio itself that can blow.

file:///C:/Users/Owner/Downloads/w204FuseDiagram[1].pdf

ZhaoningSong

I'm not sure what you mean about radio light up? I always keep COMMAND system on when I was driving