ngoncalo

hi, i have a audi q7 that dont start mmi, is always rebooting.
it turns displays on and then off and dont start.2
i change mmi unit hv video 4L0 910 731 but ists the same also change cd, dvd and same thing.
dont know what more to do.
some times when i disconnect and connect batery it works just ok. in one unit i try upgrade but dont read the cd, lcd is always on asking cd but dont read any. is possible to cancel it?
thanks

Jusforfun

What region are you in?
What model is your Q7?
Have you tried to manually reboot system?
you can reboot the MMI at any time by pressing and holding down 3 keys (upper right function + central **** + setup).
Have you connected to VCDS to see if there is any fault codes being generated?

ngoncalo

hi,
i try the reboot already, im in angola luanda but im portuguease.
its a q7 v8 4.2.
thanks

DieselDave

a constantly rebooting MMI is indicative of a break in the fibre optic loop. This may be a module not plugged in to the fibre loop, or not being powered up. Without power, the loop does not pass the module.

Or of course, the fibre optic cable could be broken. They are fairly fragile and bending them too much can break the fibre.

If the fibre loop is broken, a VCDS scan should tell you where the break is.

oaktreelimb

To isolate problem unit in the MMI MOST loop, i would buy an MMI optical loop (cheap). Remove one MMI component at a time then install the optical loop in its place. I would start with the telephone module next, then radio, amplifier, ...

Jusforfun

Was there any work done on the car? Have there been any aftermarket add ons like Dension for iPod or DVD player or tracker, something like that?
Has the problem existed from new? You say you replaced various parts but as the guys point out it is most likely a bad connection or fiber optic cable. any kink squash or pull on the end fitting can cause problems.
So far there have been 6 fiber optic cable fails reported including yours.

channelplus

Hi
my Q7 2007 premium 3.6 has same issued after rainy day while sunroof was open .
MMI didnot worked at all, changed the volume control board MMI logo appeared but after seconds gone. I removed battery overnight then MMI was working for day till I load sound then again MMI logo appearing and going , when i removing trunk radio fuses for minutes the MMI staring for a minute.
i don’t have the Audi scanner yet

doitall

Was there a fix?

'10Q7TDI_Prestige'

The fix is to buy a VCDS diagnostic scantool setup, scan your car fully for errors, and use that to guide further troubleshooting and testing with a fiber-optic loop bypass. You may need to purchase the fiber-optic bypass loop, if you don't see one in your car's tire change kit...easily overlooked piece of plastic loop that plugs into wire harness to 'bypass' the connected items...like the amplifier, etc., so you can determine which system element is really having issues and needs further attention. You can buy less expensive VAG-compatible scantools, but you'll regret doing so in the end game, as you really can't fix or correct problems with lesser scantools, but only observe them.