A8 2003 Battery/Energy Managment System

[Big Tall Paul]

Hi Guys, I'm new here and have a niggly problem with my A8.

Just wondering if any of you have had this issue (or similar) or can offer any help with solving it.

Battery level display on LCD screen never showed more than 60% so had battery replaced with a suitable equivalent (BIG) battery. Issue still the same.
Alternator always charges battery at 14.3-14.8v so no worries there.
Don't get me wrong, the car always starts first time, but as some of you will already know, when the (clever ?) energy management system (J644) detects a low battery condition it shuts down various circuits. These include the Audio system, LCD screen, Electric boot opening, interior lighting, heated seats and MOST IMPORTANTLY the remote unlocking facility.
I lock car with remote (or button on door handle) which always works fine.
When I return to the car 2-4 hours later the remote unlocking won't work, this means unlocking with the key in the lock which immediately sets of the alarm ! This is starting to really bug me (and my neighbours !)
Audi (Leicester) just seem intent on replacing the new battery with another new battery, but I think the issue is elsewhere.

Your thoughts would be most welcome.

Regards, Paul
P.S. I promise to buy beer for the man who helps me fix this.

[SneakyMcC]

I'd contact Paul Waterloo at www.audipages.com he may know. I'll pm you somewhere else that could prolly help?

[A6_JAck]

Do you have a volt metre?
You could try cheking that the alternator is charging the battery.

Jack

[J7KED]

Hi,
I had a similar problem with my 2004 A8. I just came back to the car one day and as you say some of the systems seemed to have shut down so checked the battery level and it was down to 20%. I drove around watching the MMI and waiting for it to charge and it never did.

Luckily it was still under warranty so took it into the dealers and they advised it was a software glitch that it was charging and battery was fine and fully charged only the car didn't realise it. They updated the software (seems like it was a known problem) and never had the problem since, may be worth popping into the dealer to see if they will do a free software upgrade.

God Luck
Jaime

[Big Tall Paul]

Guys, Thanks for your replies, they are much appreciated.

I think I've proved theres nothing wrong with the battery, but still have the problem.

J7KED I think I have the same problem, but its hard to tell.
Do you know which version of software you are/were running ?
What does your MMI Battery meter show since the update ?

Thanks again.

Paul

[anthonyg]

Hi guys
I have a similar problem with my 04 A8 3.0 tdi, its happened a few times and each time the garage tell me there is a 'glitch' within the management system.

What happens with mine though is for some unknown reason, the radio comes up as not being installed and does not work, everything else works fine, the cd player, sat nav, phone etc etc, including remote central locking, this goes on for a few days with the management system showing the battery at 100% charge, then i'll leave the car for a couple of hours and when i return I have complete electric faliure, the remote locking doesn't unlock, basically nothing electrical works.

Its just happened today, so I've hooked up a battery charger which tells me the battery is fully charged?? but when I check the battery level on the ms it tells me the battery is flat, wierd or what??

Anyone any ideas, as the garage don't seem to understand it either, they just keep hooking it up to the systems and ironing out the glitches

thanks

[beancounter]

Guy's sorry to hijack the thread but do you know how to get the battery level menu on the MMI?

I have an A8 2004 tdi, and it had a software upgrade recently to allow TMC on SAT NAV, but i can't seem to get to the battery level screen on MMI even though manual says i should?

thanks in advance.

[a8 tech]

tmc update wipes the adaption channel for battery display it can be retrevied in address 07 and reset the adaption channel to display on mmi.Battery display not showing 100% even though there is no issue can be rectified by software update.Battery drain can also be tested with amp meter (battery management by passed or after all bus networks shut down(2 hours)or via battery management itself which will check for closed circuit current via vag ***.When drains occur they can be as simple as tmc functions reciving traffic messages even when ignition off (turn the radio function for announcments of )or loop break on the most (faulty telephone control unit or gateway)Hope this helps and if you have vag *** ill tell you what adaption channels to change and check(i have never replaced a alternator on A8 and i have worked on them since Launch)battery management info.;
; VAG-COM Label File
;
; Audi A8 (4E)
;
; Component: J644 - Battery Regulation (#61)
;
; P/N: 4E0-910-181-???
;
;
;
; requires VAG-COM 405.0 or newer
;
;
;---------------------------------------------------
;
; measuring block informations
;
;---------------------------------------------------
;
;
001,0,General
001,1,Generator Voltage,(specified)
001,2,Battery Voltage,(actual)
001,3,Dynamic-Field,Signal
001,4,Load,Response Time,Display Range: 0...9 sec
;
002,0,Battery Tamperatures && Shut-Off Stages
002,1,Rail Temperature,(actual)
002,2,Battery Temperat.,(valuation)
002,3,Emergency,Shut-Off
002,4,Static-Current,Shut-Off Stage
;
003,0,Battery Status I
003,1,Battery Condition,,same as MMI
003,2,Internal Battery,Resistance
003,3,Qv,(Battery Aging)
;
004,0,Battery Status II
004,1,Current Value,from Battery,Display Range: -400...+100 A\n\npositive current = generator charges battery\nnegative current = battery not charged by generator
004,2,Static-Current,Mean Value,Display Range: 0.01...1.00 A (mean value of all statuc-current measurements)
004,3,Total Energy,Balance,Display Range: -10000...55025 Ah
004,4,Total Energy,Throuput,Display Range: 0...65025 Ah
;
005,0,Last Standing Time && Last Driving Cycle I
005,1,Static-Current,Mean Value
005,2,Total-Current,Mean Value
005,3,Duration last,Standing Time
005,4,Duration last,Driving Cycle
;
006,0,Last Standing Time && Last Driving Cycle II
006,1,Duration last,Standing Time,with increased static-current (higher than 20 mA)
006,2,Energy Balance,of last Drive,Display Range: -120.00...+120.00 Ah
006,3,Battery State,of Charge (SOC)
;
010,0,Generator
010,1,Generator Voltage,(specified)
010,2,Dynamic-Field,Signal
010,3,Generator,Interface,Display Range: OK/not OK
010,4,Generator,,Display Range: OK/not OK
To reinstall battery display goto address 07 adaption(10) then channel 02 and enter 32 and save,this will reset battery display on mmi screen.Regards A8

[beancounter]

Thanks A8 Tech - unfortunately i do not have VAG so not able to change, but it is not much of an issue at the moment as not having battery probs. It is just really annoying as per the manual i should be able to see this on mmi but i was not able to.

Your explanation at least identifies the cause which is good. Just disappointing that the the dealer clearly did not bother to restore the settings for me post the upgrade!

thanks mate

[a8 tech]

Return and ask them to reinstall,also check the set up function from heater controls works on the mmi also as this can be wiped off some times depending on how low your software on the mmi was(for tmc function you would have been quite low )and as meny as three cd rom updates may have been required to get you into the 5000 sw version of the latest a8.Also the latest sat nav disc now allows motorway symbols to be highlighted ie M6 where as before this function was not avaliable,but at £250 is it worth bothering.Regards a8