date & time keeps resetting
 

my date and time keeps resetting itself, no idea why its happening.
During the reset I lose speedo & rev counter info, fuel & Temp info and all illumination behind the dials, once date & time defaults back to original factory setting, all dial info returns.

A8 2005 model before facelift

Often the sign of a battery going bad...check voltage at battery running and off. Running, it should be getting a charge over 13.5V. If it drops to 12V or less shortly after shutting engine off, battery is weak.
Also check that fuse for instrument cluster is seated well...should be labeled on fuse box cover...#1 in 3rd row on a D2...don't know about your D3.

Did you ever determine what the problem was? I have the exact same problems with my 2004 A8.

Thanks,
Ronald

Sorry ,

No I never did get to the bottom of it, my best guess was it had something to do with the original battery being on its way out. I eventually part exed the car for the newer shape A8.

this use to happen to me,, i was going crazy but one day my car just didnt turn on and once i changed the battery everything was alll gooood....

That's worth the try
 

I am going to try the new battery route. Thank you for the replies. I will post my findings so anyone that encounters this issue will know (or not) what to do.

I replaced the battery, to no avail
 

I did replace the battery, but purchased a Bosch replacement. This made no difference. Maybe I should have replaced it with a Varta? I am not sure that would be the issue, but i am willing to try.
What is the best place to get a Varta battery?

Thanks,
Ronald

BOSCH and Varta are owned by Johnson Controls and are essential the same batteries repackaged accordingly.

the plot thickens, but there is a light at the end (I think)
 

Thanks for the reply

I realized after reading some more forums that I need to register the new battery. Unfortunately, the Bosch battery does not have the proper amount of numbers for serial and product number (10-12), nor can I select Bosch in my list of manufacturers in the VCDS software.
I could keep all the Varta info and change one number on the serial, but I am afraid that might not work.

Should I go for it (has anyone tried it) or should I look for a different battery. The brand choices I have are: Varta, Moll, Banner, Exide and JFF/Boading

Thanks,
Ronald

Tried to change numbers, no luck
 

I tried to change some numbers on the serial number, but that gave me an error of invalid code(s).

So it looks like my only option here is to get a battery on the list, or deal with the dashboard flashing and everything resetting.

Can anyone tell me where to get an Exide or Varta brand battery for my
2004 A8L?

Ronald