rgonzal3

I have a 2005 AUDI A8 (D3) and the battery keeps draining. This only happens when I put the alarm system. if I leave the car in the garage without the alarm battery works fine. when this starting happening I just needed to give it a boost and started fine. After a while I replace replace the battery thinking it will fix the problem. no such luck. I try staying in the car and alarming it. after 30 seconds or so the system tries to go to sleep. (lights in the changing gear and little lights overhead would normally turn off) but now it looks like it tries and recycles and this stay-up all the time when the alarm is set. after 30 seconds i hear clicking sound from the trunk and the 30 second cycles starts all over again. I thinking it could be the battery management module. I'm not sure it is worth it to try that first.

also, since I have a new battery although it drains the battery to %5, all the systems shut down at this level and I can start the car. but I'm afraid that after a few month it will make the new battery bad as well.

Any advise would be helpful

ModestW12

Is your alarm a stock Audi system or an aftermarket alarm? (Do you use your Audi key to arm it?)

rgonzal3

The remote is the original. not an aftermarket.

rgonzal3

The car alarm system is the original, no aftermarket radio or anything like. It does not make a difference if I use the remote or the touch option to arm the alarm.

ModestW12

Got it. I have no clue what it could be but it's good to state that it's factory and that you do not have an after market radio in case and Audi expert scans this thread. Maybe someone has ran across as similar problem before.

If you (hopefully) eventually get help on this issue, this thread can be used to help people if they encounter this problem in the future.

rgonzal3

I think I found a solution. I was reading a post on an A6/Q7 regarding a TSB "Due to a software issue, the Radio R might not enter sleep mode if the ignition is turned off and the radio power
remains on". So I tried turning off the radio before putting the alarm and it seems to be working fine.....so far.
The only thing I can remember doing a few months ago was switching the navigation DVD for the original one when I received a message saying the disk was bad. Clean the disk and re-inserted it a few days later.

This is TSB
http://www.fileden.com/files/2007/3/...b.91-07-13.pdf