I have a 2004 A8L with the MMI system. It seems to have started a problem with the computer. At first I thought it was loose contact with the dashboard, but now I am thinking it is an issue with the computer as it happens more frequent and it presents more issues. The symptoms are as follows:
- while driving, the dashboard turns off, usually for just about 5 seconds.
- Once in a while, it will turn off for 2 minutes, while clicking. As it clicks, the speedometer and the tach indicators are jumping just a bit (usually down)
- One the system comes back on, the average mileage and average speed indicator, plus the date and time are completely reset to 0.
- In addition, I can see that my mmi screen turns darker, almost if the backlight is off, but the mmi system keeps working.
- My turnsignal light on the dashboard is off as well, but the outside turn signals keep working.

Initially, I was not too worried, as it would just happen once in a week, but now it happens at least 10 - 20 times a day.
I have also noticed that it will reset, while the car is off without the key in the ignition.

It does not seem to throw any codes. No other error indicators (like engine light) are on.

Has anyone seen this before, and what, if anything, can be done about it.

Thank you,
Ronald

 

As was mentioned in another thread, the battery might be the culprit. I put the battery on a trickle charger overnight and the next day, it showed full. Unfortunately, the symptoms still exist.
I know this does not exactly rule out the fact that it still could be the battery, but it is less likely (in my opinion).
Anyone has any additional ideas what this could be?

Thank you,
Ronald

 

After replacing the battery, I still have the same issue.

 

I replaced the battery with a Bosch battery, that was supposed to be the correct replacement. I could not find a Varta quickly so I went this route. The issue seems to be getting worse. It resets almost every 3 minutes now.
I even tried the old battery but no difference.

Should I have ordered a Varta? Would that really made a difference? If so, what is the best place to get a Varta?

Or is it some bad power connection, maybe?
If it would be a power connection, where should I look? I am guessing somewhere behind the dashboard, but where?

Should I even look into a rebuild dashboard, would they be able to test, so I do not have to shell out a lot of money only to find out that it was not the problem.

Thank you for all your help,
Ronald

 

in pretty certain i saw an audi tsb a few days ago that describes this problem, i will see if i can find it again

 

I am still having the problem, and it is actually getting more frequent, so it would be great if you could find it.

Thank again,
Ronald

 

I cant find it, but i would take a guess that you have a break in the most circuit somewhere, while its not rebooting is there anything playing up

could be a faulty device or a cable loose

 

When it is not rebooting, everything is working fine, no issues. The car can sit idle, not even running and I can see it reboots. Some people have suggested a new battery, which I tried although I never got a Varta battery as I cannot find any).
I am still hoping once I find a Varta battery that this might go away, as I should be able to properly register the battery to the software.

Ronald

 

It is highly improbable the battery is causing the issue. It does sound like a sporadic power issue, same as if the battery was disconnected. With the engine running, battery wouldn't matter much since the alternator is providing power and the only symptom is the cluster. A battery/alternator fault would cause problems with other systems as well. First thing I'd do is go over the power circuts to the cluster from the cluster to where they begin. Easiest to attach a DVOM to each power wire( there will be at least 3 wires) and then wiggle the wire around to see if the voltage is sporadic. Do the same with grounds with the DVOM set to ohms. If no problems show, the next suspect would be the instrument cluster module itself. Pricey + it has to be adapted to the vehicle, miles programmed and the immobilizer adapted to the keys, etc.....
By the way, the battery gets adapted to the energy managment system. A non Audi battery will work, the energy managment system may not function correctly is all (might not do shut down stages to preserve starting power or show the true state of charge in the MMI, etc) Won't affect anything else in the vehicle directly.

 

when you put in the new battery, did you recode it to the car, even if your coding is just changing the serial number for battery it must be coded, as this resets the energy manager

not that i think this is the answer to your problems, battery problems cause a lot issues in these cars

it does sound like your dash insert has a problem, could be the insert or wiring to it

probably best way forward is to get a scan done by vcds or audi this will at least show what errors are coming up and give you a start to finding the problem.