MMI Dead, Screen Black, A8L D3

My Audi A8L MMI was dead, stuck at open, black screen, doesn’t close, every time I push a device button or reset the MMI, MMI initialize screen would come  on, and went black, while it was on, I could hear the relay clicking in the trunk under the back seat. 

VCDS scan would come up with: No communication with Head Unit, Optical Bus: open.

The culprit was the 5A yellow fuse was blown, I might have shorted the line somehow while working in the trunk. It did give me a great scare.

5A Fuse

fuse blown

9 Comments

  • Had the same thing happen on my 2012 A7. The screen was working fine on Saturday night, but was blank on Sunday morning. The unit opened automatically but the screen was blank.
    Saw one post that would have required removing the whole unit from the dash to see if the power wires had been broken – but checked the fuse panel on the passenger side (#2 in the lower section) and found the blown 5 amp fuse. Replaced that and everything works perfectly.

    Occam’s razor…

    • Find out why the fuse was blown, it may blow again, hopefully it’s nothing and no wires are touching each other. Good job. The car doesn’t normally die, don’t ever open the dash.

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