There is proof out there I've read technical bulletin that describes exactly how you explained above.

I've also lived it in real-time.

More than once.

I've driven an e53 with non working Alternator up to the point it stopped working and it will in-fact shut down systems that are not mission critical to keep the engine running right to the end.

When the computers decide you only get forth gear it's time to pull over.

First you'll see the bat light blink then go solid and very quickly after that no abs/DSC.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)