[cooldude346]

Hey everyone. Firstly, I'm thankful for all of you guys here who are always willing to share information and expertise with everybody! This problem has been driving me crazy. Ive done alot of research and ive realized that I haven't been able to find anybody else with the exact same problem. I'll lay it out as best I can:

The Car:
2007 335i E90. It has the cold weather package and the sports package. Build date 10/2006.
It has the Logic7 sound system and it has the iDrive system.
Just under 120k miles but its maintenance and upkeep has been tight.

The Problem:
Upon starting the car, there is no audio whatsoever. No door open chime, no seatbelt chime, and worst yet - the sound system does not work. In iDrive all the audio options (FM, AM Radio, Sat, CD, and Aux) are greyed out. Furthermore, the Navigation side also does not work. All the options regarding that are also greyed out. The only thing it allows me to actually select is "Onboard Info" and "Trip Computer" on the right side of the screen. The rest of the iDrive system works fine. Just having issues with the "Navigation" and the "Entertainment".
(I have pictures showing the greyed out options but not quite sure how to upload them here. I think people who have the pre-lci iDrive unit will best be able to relate to what I'm talking about as I know the newer systems are totally different.)

Why this problem is different than most other sound related problems:
Whenever the audio goes out the Nav goes out with it. They are linked together. For other people as far as I have read, just their audio goes out and they have no chimes along with no radio.

What I have tried:
This problem came up like a year ago. Back then all I did was pull out the 3 fuses for the radio and reinsert them and it fixed everything.
The problem has reappeared as of 3 weeks ago.
However, I tried the same thing this time and even checked/swapped the fuses and made sure they were working but no luck. I disconnected and reconnected the battery multiple times to no avail. Lastly, upon reading other threads and similar problems that people were having I suspected my satellite module had gone bad and it was messing with everything. In order to fix that I ordered the termination loop hardware and did that bypassing the satellite module. Still no chimes and no sound. The car throws absolutely no codes either.

The weird part:
So 3 weeks ago both the audio and the nav stopped working. However, about 4 times since then everything started working perfectly. Sound is there and the nav works too. 2 of these times were back to back in the course of one day. And the other two occurrences were random.
Furthermore, to make things weirder, two times, I was driving along and I hear a a random chime with no warning (like you know the chime you hear when gas is low or something). After hearing that chime for the rest of the drive the audio comes back and the nav suddenly starts working again. However, upon restarting the car everything is gone yet again.
All in all, out of the about 25 short trips that I've had in the past 3 weeks the sound and nav worked 6 times.

Please Help
I was suspecting the satellite module but I bypassed that and the audio still doesn't work. Im also suspecting the amp but how come sometimes it works perfectly and other times not at all? I checked to see if the area where the amp is was damp or wet or anything but it seems perfectly normal.

Please give me some suggestions as to what else I can try to do before taking it to the dealership. Thanks!

[Estoril_AJ]

Did you ever resolve your issues? I am having similar problems in my F30 (I know it is a different headunit, but you are experiencing a very similar situation to mine)

[cooldude346]

Originally Posted by Estoril_AJ

Did you ever resolve your issues? I am having similar problems in my F30 (I know it is a different headunit, but you are experiencing a very similar situation to mine)

Hi, first of all sorry to be replying so late. So I had the above described problem ongoing for like 2 years. The unit would cut out sound and I wouldn't be able to listen to music and then randomly out of the blue it would start working again and be fine for months!

However, earlier this summer the headunit just died completely. Like I had a black iDrive screen that would occasionally flash. Furthermore, there was absolutely no sound (no music, no chimes). This problem was ongoing, like it would never work. So after a month of just driving around like that I decided to buy a replacement screen from a local salvage junkyard. I plugged in the new screen myself but it was giving me the same issue so I returned the screen.

I assumed it was a faulty headunit then.
So I bought a used headunit from a local junkyard for about $300 and proceeded to install that. I didn't want to do that myself as it seemed kind of complicated so I took it to a shop. They installed it for me and everything was working (including nav) but it had no sound or chimes. The shop told me the unit needs to be reprogrammed for the car and then I will get my sound back. However, they said they cant do it there as they dont have the right equipment and that I need to get it done by the dealership. So I took the car to the dealership and they did it but also charged me $460. So all in all, everything works perfectly now but it cost me around $850 to get it fixed.

Its been 3 months since I got it fixed and not once has the sound cut or chimes cut out so I think the intermittent problems I was having over the past 2 years were related to a faulty headunit itself.

Hope this helps.