Dead MMI

[Flying Scot]

Posted this in the A6 section, but in case it’s possibly a common issue I thought I’d try in here!

Been out in the car this morning and my entire MMI system is not working. When I hit the on/off button the screen displays the MMI logo, then disappears after about 20 seconds……….no phone/nav/cd/radio

I’ve had a look at every fuse I can find in the car (both ends of dashboard and also in the boot) and all seems to be Ok with them.

To get the car scanned, do I need to go to Audi, or can anyone with the know how do it?

If anyone in Glasgow area can help with this, I’ll more than happily furnish them with cash (or beer) for their troubles.

[a8 tech]

you need to run the optical bus test and its likely to be the phone control unit, bypassing the bt unit with a most repeater (gives a test mode optical signal)should see the mmi network re boot but i advise you visit the dealer instead of an indi due to past experience with indi workshops struggling with anything electrical.
The optic test will highlight the break in the optical circuit between control units and suggest which has failed, in most cases with this basic mmi 2g system its the phone prep or dsp amp/radio control units which fail
Another easy test for the inexperience is to see if address 77 can be accessed via vag com or vas, if not this is a sure sign the bt has failed

[Flying Scot]

Thanks for the prompt response on this.

Unfortunately I’m a complete novice when it comes to car electronics. I’m am an electrician and also a fibre (data networking) technician so having a look at it to try and identify/isolate the problem does not frighten me, but I have absolutely no idea where to find the relevant cables and components within the car.

Is there an idiot’s guide to having a look for the relevant bits & pieces?

I was planning to use the dealership rather than an independent, but would like to get an understanding of what the problem may be so that I’m not completely fleeced of all my cash (living on a tight budget at present!)