[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.)
Surprisingly, the bluetooth works fine and there is no SOS malfunction code thrown either.

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. Furthermore, when the system is not working the Map DVD won't eject. I press the eject button and nothing happens. However when the system is working it ejects normally.

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. I also reset my iDrive system multiple times by pressing the volume knob and both eject buttons simultaneously and it fixes nothing.
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. I could care less about the chimes and the outdated nav system but i really need my sound system to start working again. But I'm sure everything is connected so ideally everything works again.
Thanks!

[ctuna]

Always check for a strong battery and alternator voltage
before going further on Entertainment system problems.

The IBS system can cause you to chase your tail in these.

Second check for water on the amplifier.

When was the battery last changed what's it's resting voltage?
What is the alternator voltage.

electical e90 pdf
http://www.google.com/url?sa=t&rct=j...,d.cGU&cad=rja
http://www.google.com/url?sa=t&rct=j...85464276,d.cGU
http://www.google.com/url?sa=t&rct=j...85464276,d.cGU

[cooldude346]

Originally Posted by ctuna

Always check for a strong battery and alternator voltage
before going further on Entertainment system problems.

The IBS system can cause you to chase your tail in these.

Second check for water on the amplifier.

When was the battery last changed what's it's resting voltage?
What is the alternator voltage.

electical e90 pdf
http://www.google.com/url?sa=t&rct=j...,d.cGU&cad=rja
http://www.google.com/url?sa=t&rct=j...85464276,d.cGU
http://www.google.com/url?sa=t&rct=j...85464276,d.cGU

So I haven't checked the voltage output as I am not that technical myself. However, two weeks ago I got the alternator replaced because the voltage regulator was all messed up there was over voltage and my dash started to light up like a Christmas tree. Got the alternator replaced and everything back to normal. The mechanic who installed the alternator for me told me that the battery is perfectly fine (bought and installed new by the dealer two years ago).
Nonetheless, this problem started slightly before the alternator swap and has been present more since after the alternator swap. However sometimes it works randomly like i said. And the drive home from the mechanic after getting the alternator everything was working.

Could it still be the battery?

[ctuna]

Its a basic thing to check and easy to do .
If you ignore it you may go into a loop.
Also new does not always mean good.
Maybe you should just take it some place if you can't
do basic DIY .

New iDrive + Audio not working Problem (plz help)
(Why do you say New iDrive?)

Was this car subject to the Cabin Fuse Panel Cable recall and was it done?

[cooldude346]

Originally Posted by ctuna

Its a basic thing to check and easy to do .
If you ignore it you may go into a loop.
Also new does not always mean good.
Maybe you should just take it some place if you can't
do basic DIY .

New iDrive + Audio not working Problem (plz help)
(Why do you say New iDrive?)

Was this car subject to the Cabin Fuse Panel Cable recall and was it done?

Ok sounds good, I'll get the voltage output checked out someplace. The battery worked flawlessly for the past 2 years so it just doesn't make any sense.

I meant new as in this is a new problem that I have not seen anybody else encounter on these forums.
My car was not subject to that recall atleast in my 4 years of ownership.

[cooldude346]

So I got the battery voltage checked out earlier and it was completely normal: About 14.5-14.7v when car is on and about 12v when car is off.
The alternator seems to be working fine as well.

As of a few days ago everything is back to normal for the most part. The audio and the nav now work about 7/8 times on average whereas before it was 1/8 times.

Honestly its completely random. Sometimes when i fire up the car there is no sound. Most times I hear a bunch a chimes which means audio and nav will work and this makes me smile.

If the frequency stays like this I can live with it.

But honestly I think a wire is loose somewhere. I initially re-secured the amp connections and that didn't fix anything so its not that.
Any other wires I could tighten to permanently solve this issue?