[TJBentley]

Hey guys. So I recently got an audio system installed. It's been in there for about two weeks everything has been fine. Yesterday I decided to tweak the settings a bit on the audiocontrol lvq-1 unit. System started sounding a little better and SLIGHTLY louder. When I went to my car this morning I got a message saying electronics were shut off because battery was discharging?? I'm guessing it has to do with the system somehow and something that I touched, which is weird because all I did was play with the equalizer settings. Then I come out the gym two hours later and see a check engine light come on. I go to autozone and they pull this code:

U0079
Control module
Communication Bus
"G" off

Can anyone help me?? I tried looking up that code on Google but want successful. What could this be?

[ezmaass]

Can't help you on the code - but I'd probably suggest having the audio installer look at it, or BMW preferably. There's a chance the audio system was installed incorrectly, draining the battery.

[TJBentley]

UPDATE: Okay so things have gotten worse. Still getting increased battery discharge message upon every startup after not turning the car on for a few hours. Took the car back to installer who installed a cut off switch because according to him this car has no ignition. The cutoff switch he put under the dash had to manually be shut off everytime I exited the car, which I didn't like. Took it to another installer who was able to eliminate the cut off switch and "find" the ignition so it seems as if everything shuts off. However I still am getting the battery message, along with check engine light, and passenger restraint malfunction message!! I am going insane here I don't know what else to do. Also noticed my headlights won't automatically turn on anymore when in auto and I have to manually switch it off. Don't think my car shuts off at red lights neither. I think this has to do with some type of voltage issue. Please anyone have any insight as to what it can be or what I can do? I'm stuck here I can't bring it to BMW neither as it would void warranty

[SonicEndeavor]

Nothing you did to the equalizer settings caused this problem. The installation caused the problem.
Take the car to an independent BMW specialist to have it checked out. Since the problem is getting worse, you need to get this resolved soon before something more serious happens.

[TJBentley]

yeah I agree, tomorrow I am going to do exactly that. I just noticed as well that my automatic headlights wont go on in the auto position at night when the car first starts, and after manually putting them on and going back into auto mode they will turn back off. however, after about 20 minutes and switching the lights back to auto mode, they will stay on. Sort of like the battery needed to charge up or electronics needed to warm up or something.?

[SonicEndeavor]

Yeah, if the battery is seriously discharged you can loose certain functionality and settings. You should have the battery checked out as well to make sure it's not dying.

[E90Fleet]

Whats the voltage on your battery ?
Sounds like its very low

Auto stop start wont operate if your battery is low and you will get the discharge warning.

[TJBentley]

Going now to autozone to check on that. I'll probably stop by an Indy bmw shop to check it there also. I'll update you guys.

[Sunny 528i]

honeslty i would have the cutoff switch installed, that would eliminate your battery drain issues. My E60 went through the same thing your going through. High battery drain message everytime i got in the car. So i finally went to auto zone and had them fully charge my battery and installed it back in the car after adding in a cutoff switch, no battery drain after that point on. Keep in mind i had a JL W7 with a 1000w amp, tore my e60 to hell. now it rattles over every bump --____--

[TJBentley]

So in the morning I checked the battery at Autozone. They said the battery was 40% charged and couldn't charge it for me because they don't charge BMW batteries anymore being that they don't have a certain device that would save the memory that the battery stores. Drove more and a couple hours later checked at another autozone, battery was reading 85% charged and they also said the same thing about not being able to charge the battery (although I did see him enter 800cc instead of 850cc). After this i decided to go to the BMW indy mechanic, he basically said Autozone guys have no idea what they're talking about because the car would charge the battery on its own, and ran a diagnostic for me. I seen tons of codes come up which he said I can go to the dealership to get fixed such as the passenger restraint system and check engine light. He also said that it showed something was waking the system up when it's parked over night. I told him about my new audio system in the trunk and he said these cars are very sensitive electronically and come with tons of electronics that use the battery, and advised me if I wanted to keep the system I would have to install another battery or capacitor in the trunk. He then went on to say when I take it to BMW I don't have to uninstall anything in the trunk and just bring it in like that and not mention anything about a battery, just call BMW and tell them my passenger restraint malfunction light is on along with check engine light and have them find the problems on their own and fix them. Keep in mind, this mechanic used to work as a service tech at a BMW dealership for ten years before opening up his own place. what scares me is that some of the problems are directly related to the extra load on the electrical system, wouldn't BMW open my trunk when they decide to check out the battery and see the audio equipment?? therefore using that as an excuse not to cover anything? The airbag warning is probably just a coincidence but not related to the electrical stuff going on. Anybody with an audio system installed have a problem with BMW dealerships not fulfilling the warranty?? My car is a 2012 that just passed the 50k mark but I bought it as a CPO so it's got warranty until 100k miles.

[TJBentley]

Originally Posted by Sunny 528i

honeslty i would have the cutoff switch installed, that would eliminate your battery drain issues. My E60 went through the same thing your going through. High battery drain message everytime i got in the car. So i finally went to auto zone and had them fully charge my battery and installed it back in the car after adding in a cutoff switch, no battery drain after that point on. Keep in mind i had a JL W7 with a 1000w amp, tore my e60 to hell. now it rattles over every bump --____--

Yeah man thats an option I'm going to have to consider if I keep everything. What's funny is that in my e60 I had this same system installed (1500 watt amp powering two subs and 800 watt powering highs) and it never gave problems like this. I did however have a cutoff switch installed from the beginning but I didn't mind it at all because I didn't have to manually shut it off every day. I guess it did its thing all on its own. I wonder how Autozone charged your battery being that they told me today they aren't able to charge BMW batteries for fear of something going wrong and them being held responsible.

[Sunny 528i]

Originally Posted by TJBentley

Yeah man thats an option I'm going to have to consider if I keep everything. What's funny is that in my e60 I had this same system installed (1500 watt amp powering two subs and 800 watt powering highs) and it never gave problems like this. I did however have a cutoff switch installed from the beginning but I didn't mind it at all because I didn't have to manually shut it off every day. I guess it did its thing all on its own. I wonder how Autozone charged your battery being that they told me today they aren't able to charge BMW batteries for fear of something going wrong and them being held responsible.

Well the battery they charged for me was for the E60, not 100% sure but the F10 battery may have issues if it's over charged due to all the electrical components that’s regulated by it, that’s probably why they are afraid to charge it

[TJBentley]

Originally Posted by Sunny 528i

Well the battery they charged for me was for the E60, not 100% sure but the F10 battery may have issues if it's over charged due to all the electrical components thats regulated by it, thats probably why they are afraid to charge it

Yeah that would make sense.. I'm stressed man I don't know what to do lol decisions decisions... Anybody else considering an audio install please learn from my headache! That's for sure

[Sunny 528i]

Originally Posted by TJBentley

Yeah that would make sense.. I'm stressed man I don't know what to do lol decisions decisions... Anybody else considering an audio install please learn from my headache! That's for sure

I would take it back to the place that installed it and have them remove EVERYTHING and i mean everything. Then i would PM Technic and buy the harness he sell's based off the last 7 numbers of your VIN your current factory audio system, hi-fi, top hi-fi, HK, etc...His harness provids a plug & play setup that plugs into your oem amp with oem connecters. His harness will provide your RCA's and your remote wire. Thats all you need from the car itself, whats left is to power the aftermarkt amp from the battery and grounding it, connect the remote and RCA wires, plug in the subs and BOOM your good to go!

I have personally bought his harness in the pass and its truely a plug & play device. I installed my whole system in 15 mins! Awesome product

here is Technic's direct link, this should solve your problems

http://f10.5post.com/forums/member.php?u=1065

[TJBentley]

Originally Posted by Sunny 528i

I would take it back to the place that installed it and have them remove EVERYTHING and i mean everything. Then i would PM Technic and buy the harness he sell's based off the last 7 numbers of your VIN your current factory audio system, hi-fi, top hi-fi, HK, etc...His harness provids a plug & play setup that plugs into your oem amp with oem connecters. His harness will provide your RCA's and your remote wire. Thats all you need from the car itself, whats left is to power the aftermarkt amp from the battery and grounding it, connect the remote and RCA wires, plug in the subs and BOOM your good to go!

I have personally bought his harness in the pass and its truely a plug & play device. I installed my whole system in 15 mins! Awesome product

here is Technic's direct link, this should solve your problems

http://f10.5post.com/forums/member.php?u=1065

Yeah man honestly you're right I should have gone this route. I was so torn between just getting BSW stage one with an aftermarket amp for them but I wanted to re use some of my old stuff from the e60. I'm going to be taking everything out in about a week or so when I get time from work. Only thing I wouldn't know what to do is how to install more than one amp. I bought an audio control lcq-1 to add to the two amps so I figured hey let a shop install this who knows what they are doing (apparently not lol) so yeah man, I'm probably going to go the technic route once I recover from all of this. I miss having no check engine light

[Slickrick2]

You might just need a new battery. The old battery won't hold the charge anymore.

[mjatta1983]

Hey, do you mind telling me what it ended been? I am having the same check engine light, as you . I also got an audio system installed, but i started removing everything so see if i can find the source, but still nothing. I used carly am getting
U0079
Control module
Communication Bus
"G" off

I didn't have any battery drainage though, just a check engine light, when ever
I clear it, it comes right back on again after I restart the car. My car is due for state emissions inspections, so I need to get this fix fast, I NEED HELP

[parmarharsh]

did anyone ever find a fix to this code?

[TJBentley]

It’s been so long since I posted this so it’s hard to remember exactly, but I took the car to an audio guy that specialized in bmws and he redid my entire system using the bimmertech amp. I didn’t install any other amps or subs. Fixed all problems. Huge difference in sound quality just with the bimmertech amp and all stock speakers. Got a boost in overall volume as well.