[335dye]

I have a 2008 BMW 335xi. It has the HiFi System Professional DSP. I had replaced the stock headunit about a year ago with an Eonon unit. No issues whatsoever up until a couple weeks ago aside from the SOS message staying on due to aftermarket headunit and not coding it.

I have this issue in another thread but not sure if connected. So a few weeks ago, I was in the drive thru of a coffee shop when the car started to throw on a couple warning lights. Random like 4x4 and others. Then it died on me and would not start. Luckily I had my son with me and we pushed it out the way and had it towed to the house.

The next morning I decided to check it out and it started right up. Took it for a test drive and it started to throw warning lights again and I could see the voltage dropping on my headunit. When going around a traffic circle, the radio stopped working. As in no sound but I still had a display. I was able to make it back home before it died in my driveway. I started troubleshooting by checking battery terminals and voltage checks in the trunk and under the hood and then would test drive it again. I eventually replaced the voltage regulator on the alternator and it has not shut off on me yet. But the radio still does not have sound.

When troubleshooting the sound issue, I do have radio controls and lights, I can hear when connected to bluetooth, and I have all of the chimes. Just no sound when in radio mode. I checked fuses, I checked the fiber optic connectors and even bought the loop connector to bypass the units in the trunk. I also reinstalled the stock head unit to rule out the Eonon and still no radio either way. I do see a steady yellow light on the amplifier and all of the fiber optic connectors in the trunk, under the dash by the OBD II port and behind the radio have their blinking lights. I have been thinking of selling the car but can’t in good faith sell it with this issue. Any suggestions? Not sure if something got fried during the initial fault or just happened by chance? Thanks for any help or input.

[ctuna]

https://www.bimmerfest.com/threads/n...#post-13794101

Did you also mean no sound without a CD and through the Aux?

Always check for water on the Amp it's a common problem.

[335dye]

Originally Posted by ctuna

https://www.bimmerfest.com/threads/n...#post-13794101

Did you also mean no sound without a CD and through the Aux?

Always check for water on the Amp it's a common problem.

I did look for water and it is dry in that area. Also, I can here/play music when using bluetooth and CDs. Have not tried an aux cord yet.

I did notice that there is no light coming from the fiber optic line coming from the vehicle side but there is a red light on the head unit side. Not sure if thats an issue or not.

[ctuna]

If your head unit plays cd's that indicates the audio system is OK.
If it's only the radio it could be the antenna's or the head unit itself.

Look at the third link down for some info about the antenna's and the diversity antenna

BMW stereo types
http://www.e90post.com/forums/showthread.php?t=352586
http://www.e90post.com/forums/attach...2&d=1266451970
http://www.e90post.com/forums/attach...2&d=1260829447
http://www.e90post.com/forums/attach...1&d=1209780865
http://bmwcoders.com/forum/3-er-8/bm...1-e92-e93-291/
http://technicpnp.com/menuDiagrams/d...e90_92_93.html
http://www.musicarnw.com/page-2/
http://www.e90post.com/forums/attach...3&d=1169133185
http://www.e90post.com/forums/attach...1&d=1209780605
http://www.e90post.com/forums/showthread.php?t=641323
http://www.e90post.com/forums/attach...4&d=1278871872
http://www.e90post.com/forums/showthread.php?t=343673
https://www.bimmerfest.com/threads/e...n-752.1275694/
base system wiring pre/post 3/09
https://www.google.com/url?sa=t&rct=...tDpLJPcGkw_ui_
Base System Guide
http://www.e90post.com/forums/attach...5&d=1493273253

[335dye]

UPDATE:

I appreciate the help ctuna. After trying to reinstall the factory headunit, I realized that I was not connecting the fiber optical connector correctly. Once I figured that out, the radio works and I can hear AM/FM. So I know the problem is not on the BMW side. The Eonon head unit has an issue so I emailed the company.