Alicia Homburger

Welcome to the story of the possessed A5. My 2010 Cab MMI problems first began with signs from steering controls- voice command didn't work, then bluetooth kept dropping calls and the people I was talking to kept saying the sound was very distorted. Eventually all steering wheel controls stopped working, Soon after, MMI screen would blink out and reboot after a few seconds, but it was still working. Finally screen blinked out and no buttons on MMI controls would respond or light up, yet it will cycle through a process of trying to boot, won't go pass the initial screen, will play radio, but no controls will work to change station, adjust volume, etc., then it will keep blinking out, recycling back through the same thing again, and eventually will just go black on longer drives with no sound and no response. Audi dealer was no help- when I called stated it "probably" was the MMI controls and they would "start" with replacing that to see if it would fix it, but electronic parts are not returnable so if that was not at fault I was stuck with a new $700 part I didn't need and on to the next component. I found one on Ebay and replaced it myself but the same symptoms are occurring. Having read about the MOST system, and the fiber loop, I ordered a fiber loop to start bypassing components. So far I was only able to test the amp and it was not at fault. If I knew the location of all other components, and how to access them, I could continue the process, but I don't, and I'm a single mom so I definitely cannot afford the Audi dealer's solutions. Please HELP!!!

uberwgn

Alicia, how long have you owned the car?

Were beverages spilt?

Alicia Homburger

Hi, thank you for responding! I have owned it since 2015. And yes, there was a beverage spilled into the MMI Controls; hence my first impulse that I was suffering from "Pepsi syndrome" so before I ordered the new MMI Control, I disassembled and cleaned the buttons, and visually inspected the board. I assumed that to be my problem until replacing and experiencing the same symptoms. Might this still be my problem? The new part is from LKQ, so a fairly respectable company, if that helps.

uberwgn

I think you have to entertain the possibility that the spilled Pepsi is still having an impact. Many who have had similar spilled beverage incidents have found their repair costs running into many thousands of dollars...the most expensive Pepsi known to mankind

Alicia Homburger

Yes, I've seen the horror stories!!! If it's not the MMI controls themselves, though, what could it be? Any thoughts or knowledge on what components make up the fiber loop and where to find them?

uberwgn

Someone will pop it that can offer you some specific guidance on your model. I've never torn into such a repair and, frankly, the electronics/integration on these cars is a bit intimidating.

How long ago was the Pepsi accident? I always worry about the fluid continuing to migrate thru the wiring.

(About a year and a half ago the washer fluid hose failed in the rear of our 2006 wagon and doused the BOSE amp and receiver. The dealer quoted me nearly $4,000 on that without any guarantee that it would be working again after the expenditure. This was a minor repair compare to what you're dealing with. I was lucky and got all things working again for around $700. I would have never invested thousands into repairing the old car.)

Alicia Homburger

It was quite awhile back. Whatever the issue, it seems to at least be at its worst. I've read a lot on washer fluid lines causing the same type symptoms by ruining the amp; seems like you've experienced that.