The "code" error is saying it's confused usually from loss of voltage and you need to put in an anti theft code. Check the owners manual if p o put it there.

If the car died right away after alternator quit likely the battery is also shot. You may have been running on pure alternator and no battery headroom which matches your symptoms.

Did you get the car to start/run after charging up the battery?

Check and make sure the jump point terminal bolt is tight (not 100% sure that applies to v8 but I would check in case it does)

Alarm going off often from low battery as well have you checked the voltage when this happens?

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