1 hour ago, Danygeorge said:

@Mark2 Shaun Collins said in a video posted to me that . They had 2 cars with the same issues like mine and they couldn’t find the exact reason why was happening this thing with the battery not being charged. But it’s seems like that BSG it’s charging for the moment.

Some of the issues people have had with Audi dealers is exactly this, where the BSG has not totally failed. They are then instructed by Audi technical to do all sorts, including making up bypass wiring looms to prove the issue is with the BSG, checking earth connections, and with my car they wanted to dismantle half the car (with me underwriting the cost if it turned out to be a wiring fault, not BSG) which I declined. Hopefully you dealer looks to be one of the sensible ones.

@DieSel-Q yeah, but if they are doing what they’ve done with you , is like there’s nothing we can do about that, the only thing you can do is like , to prove you in person where is that bad wire that they found it. And about mine there’s nothing I can do right now because somehow they blame the adblue off tune is doing that even I know there’s nothing connection between that adblue tune and that 48v battery because I’ve asked someone from Audi Bucharest that there is no way that can affect the 48v battery not being charged properly and he’s not willing to send me anything in writing because he can lose he’s job, but he said when that alternator is failing there’s is no software that can fix it because it’s just a car part that you won’t fix it with an software or resetting the 48v battery, the only thing he said it might be it’s that alternator it’s not charging how it should, and you can see that with an vcds but mine doesn’t work on this car or measuring the BSG but why they would lie and saying that the BSG is fine it’s not like they are paying from there pocket no?

They get reimbursed by Audi UK if the BSG is proven faulty, who get reimbursed by Audi AG. 

They couldn't diagnose a faulty BSG on mine despite the 12v keeping losing charge , so wanted me to sign that I would cover the cost of 9 hours of Labour to strip the car to check the control modules (?£1500).

Then they said it they did all that and found faulty wiring rather than a control module, I would have to pay for that as well. Because - the Audi Used Warranty does not cover wiring issues! Farce.

 

I’ve just checked the battery level. It’s not fully charged and I think soon will be another breakdown. BTW @Mark2 I emailed Shaun Collins and I used your name , just to let you know. Thanks for that

I highly recommend one of those cheap LED voltage readers off eBay / Amazon that you plug into your 'cigarette lighter' socket.

I plug it in before I start and if it's less than 11 volts you won't be far off a yellow warning or it needs a run. Also you can see if the alternator is charging on the move as it will show 13-14 volts typically and 15 volts downhill. Really useful warning device. Eg.

https://www.ebay.co.uk/itm/305198934256?_skw=car+voltage+cigarette+socket&itmmeta=01K1EG6PRTFHKVRRYVPSSFT4WV&hash=item470f4628f0:g:vuQAAOSwObZgdAC7&itmprp=enc%3AAQAKAAABAFkggFvd1GGDu0w3yXCmi1ftSlxSw2tbuPleRnmKLfC5V%2FflulTWIHH2b1D3eQfYkMT1ROJyK87KR9PUYsjIkkOrWO7eEog%2B4EXVdBbTxw52gCKrQCF7AENWVZIJJ6EpvL%2B3R4GOSIhJhOC78fcVWC21%2FOwfLplr6o4lSpXc9b8cwRKr2cue9Q2%2FR2%2F33kPnQH29oU9kr0W9l%2B63DwCoZNA2SRd4WmG3UtCsMzKyj0LTpiOGwmc6%2F0rpMPN84fW5Raw7hVOuai0H3vKsVzVO6EMcFnk8K1Q%2FrmEq1LTowbG8LyRwm1j4S991LdGWCvpqD%2BefnCGKBWm64LxMlEmMjQ0%3D|tkp%3ABk9SR-DsmtCLZg

 

 

 

 

Edited July 30, 2025Jul 30 by DieSel-Q

Not a really bad idea, but I wanna find a way to replace that alternator in a way or other. 😅

Just a quick update on my case — I picked up the car on Tuesday. All the repairs, including diagnostics, were fully covered under the 7-year extended warranty. The newly installed BSG also comes with an additional 3-year warranty.

To my surprise, when I collected the car, I found a generous gift box from Audi in the boot. It included jackets, a hat, a bottle of Moët champagne, air fresheners, a backpack, a cup, a key ring, a cleaning kit, and a few other thoughtful extras.

Overall, Audi really stepped up and handled the issue to the standard I expected. I've learned my lesson and decided to take out the extended warranty plan with Audi — better safe than sorry!

All in all, I’m pleased with how everything was resolved and back on the road with renewed confidence.

I have had the same problem occur just this month. Audi RS7 2021.  Similar scenario had a load of warning lamps come on - mechanical fault, slip diff and start/stop malfunction. I called Audi assist even though i have the extended warranty i  couldn't use them as i don't have the breakdown cover. I had to use admiral. Car was looked at and the alternator wasn't charging the battery advised to take it to Audi. Car was drivable. 

As i prepared for the journey not less than 5 min all sorts of warning lights came up and power just went into limp mode. I was able to park up and avoided an accident. Today i  have had it towed to West london audi. Nice chap service - said they would look at the car next week but for now i am without a car. 

Fine print - if you have audi extended warranty but not roadside they can't help but if you have both you are eligible for a courtesy car - what nonsense is this.

As this is a known issue should audi provide a courtesy car as i am unsure how long this will take ? I have two small kids and its the summer holiday so not great to be without a car. 

From speaking to the service chap the work should be covered but at this stage they have to run the diagnostics to confirm. 

Any help ? Those that have been through it did they provide a car while work was carried out? 

 

 

 

 

 

I was offered a courtesy car before mine had even been diagnosed but declined it as fortunately I have access to a second vehicle.

I'm guessing the offer of a courtesy car will vary from dealer group to dealer group and on a car being physically available. That said, I'm still surprised at Audi leaving you without transport.Maybe they will offer a courtesy car after yours is proven to be the fault covered by warranty?

 

 

I can’t remember the exact conversation and don’t want to be inaccurate.

However, I got the distinct impression that i would have been a car offered had there been one available. 
 

The lack of a loan car availability seemed reasonable in the circumstances as i had to just dump the car with the Audi dealership without any kind of appointment.

When i picked up the car, it had been beautifully cleaned (including the application of tyre black). In addition, they invited me to pick some gifts free of charge. I was given an Audi umbrella, Quattro Mug, Key Ring and an Audi metal thermos flask.

I did not expect this, but was very pleased and impressed by what Audi had done to correct the BSG failure and to retain my trust.

I just wish everyone was similarly treated.

I was told the replacement alternator was on back order in Germany and could literally take months to come through. I would not be provided with a courtesy car. At this point I went out and bought another vehicle as it was unclear whether hiring was financially viable. Anyone being provided with a car should think themselves lucky.

If anyone is desperate I for have a spare Audi BSG sitting on a shelf in my garage, I am happy to sell it to anyone as long as they pay the shipping cost and replace it with their new one when it arrives 

Update:

Car went into Glasgow Audi last Thursday for a diagnostic. After an anxious weekend and a few phone calls to them, I finally got an acknowledgment from them on Tuesday regarding their awareness of the extended warranty, (which was a relief as I was foreseeing a conversation with them regarding what I found on here and where it would go) however I got a call on Wednesday that they were awaiting approval from Audi UK ensuring the failed part no matched the faulty BSG and got told yesterday it was and that it would all be paid free of charge under the warranty. Thank goodness.

Thank you soooo much to everyone on this forum and in particular to Mark2 for his contribution and making people aware of the warranty otherwise this could have been a costly repair at my local garage with a 2nd hand or reconditioned part. The power of forums like this is brilliant. Thanks again everyone. 

Hi Gary

Great to hear about this good outcome.

However, it seems the responses from dealers are not in sync. IMHO, it should not be like pulling teeth to get to the correct result and customers should certainly not have to educate some dealers about the 7 year warranty.

 

Totally agree Alex, in an ideal world yes 😂 however the power of the internet and forums like this are invaluable for people, and the main reason I didn’t automatically book my car into my normal independent mechanic. The thought of paying for this repair to then discover afterwards its warranty would have been a catastrophe! 
 

I do take your point re the dealerships though, they should all be advised directly from Audi UK of the fault and offer customers immediate peace of mind. 

Hi Gary

My car is working perfectly now, and have decided to always turn off the Stop/Start function every time I drive to try and take the wear and tear off the system. The Stop/Start function must put one heck of a strain on the BGS.

Happy motoring Sir!

On 8/9/2025 at 11:51 AM, AlexR said:

Hi Gary

My car is working perfectly now, and have decided to always turn off the Stop/Start function every time I drive to try and take the wear and tear off the system. The Stop/Start function must put one heck of a strain on the BGS.

Happy motoring Sir!

Yes, mine has been turned off every time since I bought my car used in 2023!

Make sure that your Eco coasting is turned off as well.

 

Thanks Gary - I’ll do that. 
 

Interesting (positive) experience with my car following a service.

Background:

My car was in the Audi dealer for a month earlier in the year due to constant Low battery issues, despite the 12v being replaced. To cut a long story short, they didn't know what they were doing, but I suspected that the BSG was not charging the 12v properly, and because it hadn't failed, I was being strung along. I ended up replacing the 12v again at an Audi specialist ...

So - serviced last week:-

I have a plug in voltage reader that goes into the 12v 'cigarette lighter' socket (bought in case my BSG was imminently going to die). Once on the move, it is now constantly showing 14.6 volts of charge, whereas it used to vary depending on braking, going downhill, lifting off the throttle etc between 12.4 and 15.2 volts.

That seems to suggest that either they've replaced a part without telling me at the service, or Audi have released a software update. I can't think of another explanation, but it's got to be good that the voltage is reading what it is now.

Any thoughts or experience 're the software update theory !?

 

 

Hi DieSel

Glad things are looking up. 
Sometime before my BSG failed, I was getting battery and Drive Train messages. This was traced to the spring loaded pulley wheel that holds the belt taught on the BSG wheel. In essence, the car would not auto start all the time in start/stop mode so it rolled to a halt. 😳 Cost me a few hundred quid at Audi. Subsequently and probably unrelated, the BSG properly failed. All fixed now free of charge.😊

Edited August 22, 2025Aug 22 by AlexR

Hi everyone.

I am an owner of A6 C8 3.0 diesel with a motorcode DDVE. In February 2025 had the same problem with starter-generator as it was here in topic described. Audi Germany replaced starter-generator and NOX-sensor (the cause of failure) free of charge stating that SG is under extended 7 years warranty.

Since then no sounds or failure codes on starter-generator. For 5 or 6 days I do have the following situation with voltage. Previously my onboard voltage was 13,3 volts at idle and up to 15,3 during recuperation. Now I have only 12V and rear 13,2 at idle and up to 15,3 at recuperation. Using OBD11 software have checked starter-generator, converter - no fault code, nothing at all. 12V battery does not drain and in the morning it has 12,5-12,4 V.

Has anybody had such experience of dealing with the issue? Thanks.

My car has always showed a voltage of 12 volts or less with ignition 'on', but engine off. I have had 2x new starter batteries due to 'yellow' warnings. When driving, my maximum voltage was 15.3 like you, and typically 12.5 - 13.3 (?)

My car was serviced again by Audi in July, and it now shows 14.6 volts when driving, constantly.

If you live in Kassel, you know where you can find Audi parts.....

 

 

 

47 minutes ago, DieSel-Q said:

My car has always showed a voltage of 12 volts or less with ignition 'on', but engine off. I have had 2x new starter batteries due to 'yellow' warnings. When driving, my maximum voltage was 15.3 like you, and typically 12.5 - 13.3 (?)

My car was serviced again by Audi in July, and it now shows 14.6 volts when driving, constantly.

If you live in Kassel, you know where you can find Audi parts.....

Thanks for a feedback. Do you know what exectly has been done to have 14,6V constantly? Battery management  module software update? Mein says version 0108. Or Gateway 19? Software version 0036? Can you check the versions of software? 

47 minutes ago, DieSel-Q said:

 

 

 

 

Edited September 2, 2025Sep 2 by Roman_DE

By the way, what type of 12V battery is installed in your case, AGM or EFB+?

Edited September 2, 2025Sep 2 by Roman_DE

No as I don't have the software/reader - I just have a plug in LED next to the year selector. Battery is AGM (OEM battery - third one in 40000 m / 60km.

If you find out more about software updates, post on here.

You could almost walk to Baunatal and ask someone !?

Edited September 2, 2025Sep 2 by DieSel-Q