Mercedes Benz C320 shuts off by itself while in idle?

I currently have the car in storage because it's my summer car, and it has been in the garage since early October. Today, i decided to start it up because the last time i did so was 2 months ago, and i added a fuel stabilizer designed for stored vehicles and i wanted it to circulate. The battery was weak due to the extremely cold weather (-13C outside and a lot of -40C temperatures in the past few weeks) so i had to jump it but that's normal procedure for me because every time i have to warm it up it needed a boost. I just let the car run for around 15-20 minutes then all of a sudden it just completely turned off by itself, as if you turned it off manually. No warning lights or error codes prior to that. I did not drive the car, i just left it on idle. Why so?

hi, i dont know, a weak battery can cause many failure in electronic système , i think you must have a good battery fully charged and you must remove the default message on the OBD with a Stardiag and watch if some of them return or not.