a75

Perhaps this is due to the region for which the car is delivered?

ThomasWShea

my current logic

On the alternator:
I don’t know what this means worldwide, but I scrolled back up to the post where I provided a screen shot of the air cooled alternator on audi’s USA website and it says that same alternator is used for the SQ7 and SQ8 2020 through 2022. We know mrclopec‘s 2023 SQ8 has this same alternator too, so the audi usa part page probably just hasn’t been updated yet. As far as other markets I think people would need to check, maybe they have an air cooled alternator, maybe they have the BSG. All we know is if they have an SQ7 or SQ8, they may not have the BSG and therefore would not affected by the TSB.

On the capacitor:
We have only confirmed this on @Mrclopec 2023 SQ8. Since his 2023 SQ8 has the same alternator the SQ8 has had since 2020, at least here in the US, I don’t feel like I would draw a conclusion around the capacitor solving anything, or being related to the exploding continental/vitesco liquid cooled BSGs. I would love to know why they are putting capacitors in vs batts, but I don’t think we are going to learn that easily.

Researching capacitors doesn’t gain us anything on the BSG issue because the capacitor showed up in a car unaffected by the BSG issue.

RSQ8:
i agree this is intriguing. why is the SQ8 different? I have read and read about mild hybrids. the only components required are a 48 volt power source, and a dc to dc converter. start stop or bsg are not required to call a car mild hybrid. so the sq8 is still a mild hybrid without a bsg, technically. the bsg adds the ability to do the advanced start stop, and propel the car using the bsg as a motor - but even if a car has a bsg, it doesn’t need to use the bsg as a motor, or be used for the start stop. audi could be using the bsg just because they are 48 volt vs 14 volt. Do we know for sure that the start stop is implemented using the bsg? it could still be using the starter for some models.

retom

BSG in Audi does not support engine operation. This is a different type of MHEV, not like in the MB or X5 LCI, where an additional, electric motor is installed to support the engine with additional power and also acts as a second starter. In the Audi MHEV BSG is only an additional starter that starts the engine when the engine is warm and the 48V battery is properly charged. A standard 12V starter is used when the engine is cold.
Some Audi cars with BSG also have a coasting function with the engine completely switched off. Cars without BSG may have this coasting function as well but they do not shut down the engine but only switch the transmission on Neutral and disengage the drive. This was in my previous Q7.
BTW, SQ8 own by a75 is European MY2022 and has no BSG.
Many secrets but we will get to the truth!

ThomasWShea

Just to clarify - I am stating this but also asking - because I am not 100%. Not specific to Audi, I thought there were 3 methods of supporting engine propulsion: bsg which produces rather anemic amount of motor power, but it can still boost the engine AND then crankshaft starter generator, or driveline starter generator which go between the engine and the transmission.

The coasting bsg, and transmission to neutral you mention - I assume these are two different ways to achieve "advanced stop/start".

Yes i remember @a75 - he is in the Ukraine right? I was surprised he didn't have the bsg because I assumed europe was all one region for Audi, but maybe they segment off some eastern countries for some reason, or non EU countries?

It sounds like you are saying in Audi, the BSG propulsion isn't used at all in the Q8 cars - and this was my understanding as well, because it is not mentioned in any of their materials.

Mrclopec

Dont forget the RS model cars are "technically" a different company. They are produced by Audi Sport GMBH, not Audi AG. Says so right on the vin label in the door. This is also why in ETKA, the RS models are in their own separate category and not commingled with the standard and S model variants. I would think internal logistics and contracting would have something to do with it. It really may just be that simple...

Could be...

Thomas... :-) ..... Please go read my post #'s 534 and 561 again.

I would love to see an Autoscan of that vehicle. Im sure there is a logical explanation. Being that it is a 2022, I wonder what build week it was produced...

retom

RSQ8 is produced in Bratislava in the same factory as other Q8, Q7 models, Cayenne, Touareg and partly Bentayga and Urus. It may be signed by Audi Sport Gmbh but I don't think that logistics matters in this case.
a75 posted in #554 the scan of his module 21. There is hardware number 4M0915169G which is the part number for capacitor. The same as in your car as I remember well.
I am sure that a75 will be able to post the scan of other modules but for me data in module 21 explains his 48V system.

Mrclopec

No doubt at all that he has the SCAP, and thanks for his contribution and sharing helping further continue our dialogue. I know all variants are produced in the same factory, with the same people, and the same parts bins, but money and budgeting drives every company. The truth is - is it is another company and their budgeting is handled separately right down to every bolt put in their RS cars...Look at my PR Sheet at option S3G. (S-codes are Exclusive PR Codes by the way and do not show up in the master PR code list). It shows that all customization was performed by Audi Sport GMBH on a separate invoice. Here is an example of one company invoicing another company, both of which are owned by mom. Very common in the business world and so this can most definitely have something to do with money. Just my opinion though so I don't want to throw it out there as fact.

retom

We are not alone with our 48V system issues. It's a poor consolation, but it looks like these systems are underdeveloped. If not the alternator then the battery.
https://www.classaction.org/mercedes...ttery-lawsuits

ThomasWShea

Should we look at the part numbers for the batteries for the mercedes vehicles they describe, to see if LG Chem is also the supplier? I posted that video in post #537 that describes how the audi 48 volt batteries die.
EDIT: The batteries are ACCUmotive, their own subsidiary: https://group.mercedes-benz.com/care...066.html?r=dai

@Mrclopec I re-read the posts you mentioned. I *think* we are concluding the same thing - you have more concrete technical depth and coding knowledge in your answers. But I think we are both saying the SQ7 and SQ8 can have an air cooled alternator. I agree, SCAP is new for 2023. I was just saying I don't think we know if it is related to the failing BSG issue. (that isn't to say the batteries don't have their own set of issues that audi may be trying to improve.)

campingmanbc

2019 Q8 Prestige 40,000kms in Canada. Driving home tonight from a Mercedes electric car test drive event and my girl threw the Elecronic system malfunction warning. As we were driving my buddy searched this thread and read these horror stories. I said “it’s fine, those are just the worst stories”… 5 mins later the car’s throwing errors all over the place and dash lights up like a Christmas tree. Then the car dies on us in a busy road (very dangerous). Managed to get it started and safely to a friends house. Called roadside and told up to 6 hours for a tow. 2.5 hours later got towed to dealer. Will talk to them in the morning. Moral of the story..1. Don’t test drive Mercedes 2. As soon as you get this warning, pull over somewhere safe and get it towed. I absolutely love my Q8 and hope she comes back to life soon. BTW Audi way better than Mercedes IMHO