How to reset MMI (by LoCal)
8.7.2009 - Instructions on how to reset MMI, applies at least to MMI 2G cars and maybe MMI 3G cars. This means the full MMI systems with controls below the gear-lever, not in-dash Concert/Symphony III radios or RNS-E/BNS 5.0 navigators that look like MMI, but are not.
To restart the Audi Multi-media Interface, aka MMI, system (radio, navigation, TV, telephone etc.) there is a ctrl-alt-del-like three finger salute available. This might be useful after making system changes or when experiencing problems with MMI, try it at least.
For A4/A5/A6/Q5/Q7, press SETUP, BIG **** and top right soft button together.
For A8, apparently, press TEL, BIG **** and the top right soft button together.
(For right-hand vehicles apparently the mirror-image combination should be applied.)
Make sure you press them simultaneously. When done right, the MMI screen will go blank, then show the MMI booting logo and return to the menu finally.
Pictures of the buttons to press:
This link suggests the same is true for MMI 3G:
MMI 3g reset
This link mentions a VAG COM adaptation that will also restart MMI 2G (controller 07, channel 111, input a value of 1):
Starting MMI system reset