thehedge

This one has me stumped (and yes, I have searched the forums and came up empty).

I have a 2005 A6 with 40K on it. Since the weather turned cold up here in the midwest, occasionally in the morning, the interior lights won't come on when I open the doors. Looking at the battery meter, shows the batter almost dead (less than 10%).

I took it to the dealer and they came it is the "battery maintainer" gone bad and have to order a part from Germany. They reprogrammed the MMI to a later rev and told me not to worry about the battery while the part is on order. State that the "maintainer" trickels charges out to all the various components when the car is not running.

The part comes in and they replace it (but won't give me any details of where it actually is on the car). This is all covered under warranty.

Anyone know what this part is, where it's located and if they tend to be problematic?

By the way, this is not a "maintainer" that I plug into AC to keep the battery charged.

JerryS4

.....Or a board that distributes / allocates out electrical power carefully to systems that need backup power when the car is shut down. These systems tend to be reliable but somewhat complex with micro-controllers running specific code for that vehicle. In any case, not something that us users can ever play with.

gk1

I could see how if it went bad then the battery would drain, but not if it was functioning properly.

BTW it's in the trunk with the battery. It's a small black box. I'll see if I can find a picture/diagram.

gk1

It's in the trunk bolted to the "bumper" area. The diagram is from the viewpoint of if you were sitting in the trunk facing backwards. The number "5" is on top of the battery on the left in the diagram.

<img src="http://pictureposter.audiworld.com/14154/energy_management_module.jpg">

jefman

seems like we may have the same issue, I will keep you updated

thehedge

Yep. I have one right there. My service tech said that he had never seen reports from one going bad before but had to order it all the way from Germany. While it was in the shop, they also said that they updated the MMI (to version 4140?) which should address the issues as well. He said that the version I had sometimes left parts of the radio controller powered on after the key was removed which could also drain the battery.

He did "re-enable" the battery display without my asking him even though their procedures state not to do so. I guess there were a number of owners misreading the battery meter so Audi thought it was best to hide that display.

(I have an older Ford F150 where the oil pressure gauge is just a dummy gauge since the first few years the truck had it, too many people brought the trucks in for service since the gauge kept moving (as the engine warmed/cooled/etc.)

Thanks.

PFL1011

say what the problem is. They were going to give me the car back today until another 05 with the same problem got towed in.

thehedge

They replaced the battery controller in mine last week. Tonight, I unlocked the car and opened the driver door to go home from work.... no interior lights again. Checking the battery controller .... back down to 10%.

I'll be back on the phone to reschedule again with Audi tomorrow.

Has anyone seen this and had a real fix yet? I just know one of these day it'll be down below 10% and I'll be stuck.

hrc4u

i had the same issue when i bought my 05-3.2l car...
the issue dissapered when i put in a new battery!
probably the old battery had a bad cell...