Electrical Issues on A6 3.2 (Battery Regulator?)

[jdaudi]

Hi Everyone,

I am back with my electrical issues on my A6. I have never actually got this fixed so hopefully someone can help.

- Battery never holds a charge (or regulator doesn't allow it to be fully charged because of adaptation issue? See below). Have replaced battery it multiple times, never regulator.
- Has been at the dealer to look for parasitic drain. They removed the phone module, said that stayed on.

- Unable to code/adapt the battery regulator for a new battery. According to ECU, it seems to be coded for a 2004 battery. See in video
- Lights go oddly dim when turning on the headlights, all dash lights go out


It's so much to type i just made a video of it. Please see it:



If someone can point me in the right direction I would really appreciate it!

[jdaudi]

Can anyone point me in the right direction?

[mkv]

When my alternator regulator was on it's way out, I was getting very random voltage spikes and idle "pull-downs". The voltage was running away in the system, then the regulator would re-excite the alternator windings to compensate and this would pull down the idle. I could see the lights on the dash brightening slightly right before the pull down, and thus knew there was something up with voltage. When I got the old regulator out of the alternator the brushes were so short and had no spring force left that they were basically just gliding along the rings.

Have you checked the system voltage when the engine is running?
Have you checked the battery is in fact dead by placing a load tester on it?
Does the positive jumping terminal in the engine bay get very very hot after you've started the car? (the one under the red plastic cover on the right side of the engine bay)

[jdaudi]

@mkv - alternator regulator and battery regulator same thing? When the car is running I am getting about 14v.
- I have replaced the battery multiple times..
- The positive being hot I've never tested, but how long should the car run to feel hot in your opinion?

[mkv]

Hello,

There's only 1 regulator, it sits in the back of the alternator. The battery regulator you speak of may be the battery module? The fact that you keep replacing the battery points to a charging problem, which is usually the regulator in the alternator.

That terminal will get roasting hot within a minute or so. It's a common problem for it to develop high contact resistance on the crimped connections to it. Sometimes it melts the red plastic cover over it.

[jdaudi]

From what I was explained by the dealer is there is a "battery regulator" next to the battery in the truck (connected to the negative terminal) and needs coded when you replace the battery. If this doesn't happen, you can replace the battery all you want but the regulator won't allow it to charge, or think it's fully charged etc etc.. According to coding I could find (shown in my video above) I found that it seems to be coded for a 2004 (probably original battery)

I've let it run multiple times and got about 14v coming from the jump points in the hood with a multimeter.

[mkv]

They're mostly correct. The battery regulation module in the boot (trunk) does watch the charge level of the battery, but it also has input into the regulator in the alternator. That's how it limits the charge, by varying the output from the alternator. You can test if this system is all working by using the output tests in VCDS on the battery module. There are tests there for 20% excitation and 100% excitation. At the same time you can see the voltage. If the voltage rises to around 15V with 100% then the regulator in the alternator is working and so is the signal from the battery module.

What is the charge voltage across the battery terminals when the engine is running?

When you say you can't code a new battery, have you tried just coding any battery? Here's a screenshot of my coding, with a 95Ah battery. Try put this in: https://www.dropbox.com/s/vb54ukfvpe...ttery.png?dl=0

[jdaudi]

I will try that. I dont have VCDS I have a another coder (I have a schwaben which I read is about the same thing)

Coding isn't accepted for some reason, and I can't even read the current coding it seems. Not sure of the behavior of this on VCDS. Check this: https://youtu.be/jhBeAjyA0CU?t=514

Things I have done so far:

Car off (about 12 volts)
Car On (14.1 volts)
Touching terminals on battery while on 14 volts I believe.. I will try this again later to verify but pretty sure this is correct.
I don't remember terminals being hot ever.
I believe the last time this car at the dealer with the same problem they said the alternator was fine (probably based on the above)

Sometimes I can drive the car for hours and the battery meter on MMI won't move, or move one or two blocks and that's it. Others I can drive for 15-20 minutes and the battery meter shows (really fast?) charging.

I have also noticed this odd situation:

I've driven the car around for a few hours in attempts to charge the battery. It finally did fill up. I let the car sit for an hour as I walk around the park then come back, MMI says the battery is near dead (showing one block on juice on the MMI). It seems as if something is stuck on that's causing a drain, but a fully "charged" battery is draining in a hour to basiclally nothing from full according to MMI?

[mkv]

Yes, that is odd behaviour. Maybe you have a proper parasitic drain going on there, but that might not explain the erratic charging. Maybe though.

I think you have to ensure the coding to the battery module is fine first. Try and locate a VCDS.

Do you get quiescent current stage 1, 2, 3, etc. faults in your battery module?

[jdaudi]

Is that module 61? Then yes. It's sporadic though. Please watch the video I sent and it will show you a lot more than I can explain:

https://youtu.be/jhBeAjyA0CU?t=514

That is me in the video with my car

Also notice in the video it says Battery Regulator

[mkv]

Yes, that's module 61. Battery Regulator, battery module, it's all referring to the same thing. The actual regulator, the one in the alternator, is not a device you can scan or log into, it's the regulator that alternators have had for decades. Although the battery module (module 61) does influence it somewhat.

I watched the video, I have never worked with that scan tool so I can't comment on why it goes back to the main screen and doesn't seem to offer any battery info or adaptions.

[jdaudi]

So can we agree that if I am getting 14.1 volts with car running (from posts in trunk and touching direct to battery) my alternator is fine, correct? No need to replace alt or alt regulator

So that leaves us with battery regulator/module next. Would you suggest replacing this guy? Is there a way to test the battery regulator? (Other than you saying the live data with VCDS, which I dont know if I can do right now) but nothing with a multimeter?

[mkv]

So can we agree that if I am getting 14.1 volts with car running (from posts in trunk and touching direct to battery) my alternator is fine, correct? No need to replace alt or alt regulator

So that leaves us with battery regulator/module next. Would you suggest replacing this guy? Is there a way to test the battery regulator? (Other than you saying the live data with VCDS, which I dont know if I can do right now) but nothing with a multimeter?

I guess so, but then that doesn't explain why your batteries are dying. Unless there is a problem with the battery module, which doesn't mean it's broken, it could just need coding.

I would still try and code it with VCDS before getting a replacement. Unless getting a replacement is easy, which you still have to code anyway.

[jdaudi]

I'll have to try. Do you know the ground points on the car that I could check for corrosion? (I can't seem to find anywhere online)

[mkv]

There are many many ground points on the vehicle. But the most important ones are the one by the battery module, where the negative terminal connects to the body, as well as the main connection to the engine block, which on my vehicle at least is from the front right chassis rail to the block. Get at the second one from underneath the vehicle.

[G-Can]

Was this ever solved?

My car started showing low battery levels and in mmi battery is at 40%

Battery was replaced few months back. Wasn't coded as far as I know as it was done by local mechanic and he had no clue of "coding"

I do have multiple errors for battery regulator and quiscenet current errors.

[jdaudi]

Was this ever solved?

My car started showing low battery levels and in mmi battery is at 40%

Battery was replaced few months back. Wasn't coded as far as I know as it was done by local mechanic and he had no clue of "coding"

I do have multiple errors for battery regulator and quiscenet current errors.

hey there, sure was. I replaced my battery, again, and it fixed everything. I still get odd reg codes on the vagcom but otherwise she's fine. replace your battery!

[G-Can]

hey there, sure was. I replaced my battery, again, and it fixed everything. I still get odd reg codes on the vagcom but otherwise she's fine. replace your battery!

Fck, my mechanic will be thrilled, he's gonna be with did you do to it

Hopefully that's it.

But why do I keep having battery quiscenet errors under battery regulator, this 2as prior to replacing the battery and even worse now lol

[jdaudi]

Fck, my mechanic will be thrilled, he's gonna be with did you do to it

Hopefully that's it.

But why do I keep having battery quiscenet errors under battery regulator, this 2as prior to replacing the battery and even worse now lol

What codes are you getting?

[G-Can]

What codes are you getting?

This
Other codes are some crap for infotainment, etc. Nothing engine related

[jdaudi]

This

What is your current charge level when you get these codes? (go to settings in the UI)

Does the battery level ever go up?

Alternator was tested?

Does it start pretty easy? (CCA was checked? If you have same car as me it should be I think 700 CCAs or higher.. 700 is on the low side im pretty sure though)

[G-Can]

What is your current charge level when you get these codes? (go to settings in the UI)

Does the battery level ever go up?

Alternator was tested?

Does it start pretty easy? (CCA was checked? If you have same car as me it should be I think 700 CCAs or higher.. 700 is on the low side im pretty sure though)

So when I started it an hour ago, it gave me a warning on dash, i instantly checked and it was at about 40%, now after driving for 25min, it's at 80%

How do I check other values you mention, I do have vcds, but need to know where to look

[jdaudi]

So when I started it an hour ago, it gave me a warning on dash, i instantly checked and it was at about 40%, now after driving for 25min, it's at 80%

How do I check other values you mention, I do have vcds, but need to know where to look

It's definitely the battery man. I didn't want to believe it either but basically when you get different "quiescent stages" it basically means your battery is having a hard time keeping energy stored and it's loosing it quickly and the regulator believes there is something electrical wrong (it detects the ultra fast voltage drop if that makes sense?)

[G-Can]

It's definitely the battery man. I didn't want to believe it either but basically when you get different "quiescent stages" it basically means your battery is having a hard time keeping energy stored and it's loosing it quickly and the regulator believes there is something electrical wrong (it detects the ultra fast voltage drop if that makes sense?)

Just to confirm, it was the battery. It was out of warranty for 1 month.
mechanic managed to get the supplier to honour the warranty. Garbage lasted 2 years.
Original was in the car for 14 years and I never should of replaced it at first place, it would.of probably outlived these 2 new ones.

[Avantly]

This
Other codes are some crap for infotainment, etc. Nothing engine related

Do you have codes in other modules regarding the CAN bus being in 1 wire mode? IIRC when in 1 wire mode (due to one of the common faults like the door harness) some modules don't go fully to sleep and trip the quiescent current fault.