Aux-In Volume Stuck at 0 - S752A Individual

[svenchen]

Have done a bunch of searching with not a lot of valuable answers.

After a TON of debugging while installing the AVIN unit last night I got to the issue of it possibly being the car. Before I reverse the install back to stock would love to know if anyone has a solid answer.

E90 M3 with S752A Individual Audio

When I plug the AVIN output in to a random portable speaker via 3.5mm it plays fine to the portable speaker.

I plugged my Macbook Pro in to the center console Aux-In jack to test and had no sound and when accessing the factory Aux Volume level it is stuck at full negative (have used all volume controls and pressed the iDrive button in the screen to _actually_ get to the adjustment). My theory is that the car is not detecting that there's anything on the other end of the Aux or perhaps there is something at the plug. USB power works as does the cigarette lighter and all fuses are fine (13, 59(?)).

1. is the Y-cable actually the solution? shouldn't the aux just work if 3.5mm audio from a laptop is plugged in?
2. any other ways to debug?

TIA!

[6ixSpd]

It is not uncommon for the Aux/USB port housing in the armrest to stop functioning. I had the exact same thing happen in my 328i, I replaced the port with another OEM one and all has been well since.

https://www.ecstuning.com/b-genuine-...t/84109237653/

[MJBO]

Auxilary port failure...

These cars really do have some special faults

[svenchen]

lol.

thanks for the link 6ixSpd. going to go see if there's anything to be gleaned from pulling the original socket out and probably just order the new boondoggle.

[VtecforV8]

I just replaced my port with a new OEM part for the same reason--the USB component works fine, but no sound will play when i try to play through Aux. Two different cables, one android phone, one iPhone. Nothing. If i crank the volume ine car, i just get static.

Replacing the part did nothing, it seems, so i am wondering if there is some computer gremlin causing the issue. Any more ideas?

[VtecforV8]

Bump. Anyone having aux port issues (or better yet, had them and fixed them)? Replacing the part didn't help, but the USB port in the same module works fine. Thanks!

[VtecforV8]

Trying to bump this up again. I can't figure out why there's no AUX sound (android or iphone) but the USB works fine. Replaced the whole part and everything--same situation. It's not a "the volume is too low" isuse.

Thanks!

[Scrippy]

Combox or MulfII issue depending on which you have. These would be found under the rear trunk carpet. The aux in port terminates to these guys.