After returning from a 2 week vacation, the battery was flat on my Q7 2007. After a jump start the car was running great again. However, two days of city driving, the battery was flat once more. So I gave it an overnight charge.
I was informed after an earlier service, 5 months prior: battery diagnostic indicated "Not OK under VAS5051B reading battery control device". So I thought it was time for a battery change. After reading how potentially difficult it could be to change the battery on one of these motors, I booked the car in at the Audi garage. They informed me the Sound system: MMI was not working, and this was the cause that was draining the battery.
I just told them to replace the battery as this was the original fault, hopefully thinking the MMI system will fix it self. It didn’t. The display turns on, and after a couple of seconds its off again.
It can not be all of sudden working, then not working. There must a simpler answer instead of just replacing the MMI system at a cost of over $1100, part only. Any suggestions?

 

Regard yourself lucky with a quote of $1,100. I was quoted $2,400 here in Orange County California. The problem is with your Amplifier. It probably received water damage because of a leak from the Sunroof (see Leaking Audi for all information). I was able to located a new amplifier online for $399, cheaper would be to find one at a salvage yard. I have not replaced mine yet, because I actually have not figured out yet where the amplifier is located (you can not find anything in the owner manual). As soon as i figure it out, I will let you know. Have a look under "electrical problems". Somebody went through the same problems before.

 

the MMI system sucks for a lot of reasons, mainly it is just such a fragile system. I would pay an Audi technician to open the MMI console and check for residue from leaks (buttons are NOT gusseted to prevent spills from penetrating electronics- very common), and to also check the amplifier (I believe it is in the spare tire well). Should only cost the $150 diagnostics rate. Then I'd take it someplace cheaper to get the work done. I do that all the time and they HATE it...but it saves me a bundle and I'm out of warranty, so why pay 2X the labor rate?

Couple other thoughts- double check the fuses; amplifier swap out is supposed to be VERY easy. Audi technicians are not great- but they are familiar with the technology and are best at diagnosing. Anyone can turn a wrench.

 

Guys thanks for the replies. The problem is sorted. I had pulled the fuses to try and find the leak source and eventually discovered it was the amplifier in the trunk / boot which was causing the problem. This seems to a common problem, when you speak to the right Audi experts. The amplifier is easy to gain access, and easy to replace. The only thing is a new one will cost over $1200. Luckily I found a second hand one at a third of the price.

 

I am curious where you found a cheaper amp at. I am getting a quote of 2200.

 

I have a brand new Bose amp from the audi dealer that I'm currently not using and willing to sell for around $700 plus also have the mmi control brand new

 

Reviving old thread.

This is happening to my truck as well now, and i was wondering how to determine the amp is actually bad?

Need to find instructions on where the amp is too.

Thanks...

 

here you go,

 

I found that vid shortly after, thanks!

So i cracked open the old amp while waiting and found that there was much corrosion inside by the fibre op connector.. Tried cleaning it up with some clr and let it dry - looked pretty good to be honest, so i gave it a try.

Sound wouldn't work - speaker icon had a slash through, and cd was paused.

But it did stay on!


Anyhow, i bought a replacement unit myself and installed - right side speakers wouldn't work.


Apparently that's a component protection piece - if you don't put the exact same part into the car, it'll disable some of the funcitonality until you get Audi to update ... from reading apparently they enter it into the database, but to me, i'm more inclined to think they enable something on the device itself. It supposedly is to protect people from stealing from other cars and just installing. Paid 1.5hrs labour at audi to enable.

Mine was different since the amp part number has changed since 07.

But everythign is gravy now...

 

Does anyone know the part number to the fiber optic loop used in the video and where I can purchase one in the states. I live in Los Angeles. Thanks!