Hello, my 221 550 4 matic of 2009, facelift, works perfectly, accelerates perfectly, no errors.

Sometimes when I start the car it starts turning off various modules. it gets better by itself. The engine is running, everything on the dashboard starts to light up. I am attaching a diagnosis protocol and a clip of how the car behaves.

Video file :
https://mega.nz/file/21RQlZSC#AFku5x...oZ4xaprtqHEWiY
https://mega.nz/file/bk5UxBLS#wyxm8C...UYEQea4QsJ9aag

The S Class is notoriously sensitive to low voltage. If your consumer battery is old and isn't storing a good charge, the car will selectively turn off various systems to preserve the voltage it has. When your alternator restores proper voltage, those systems previously turned off now return. Check your battery. If it is old, replace it.

the battery is in excellent condition. The AGM is charged on a charger and tested with a load with a fork, it holds perfectly. It performs perfectly on the tests.

Any codes?

I have attached a file with the diagnostics and a clip.

I would clear the codes, take her for a ride, and see if any or all of the codes return. My take is all of these codes are related to low voltage. I know you said the battery was good, but how old is it? Check the battery for a date.

The battery isn't too old, I'll try driving it next week and see if it shows the codes again.

Keep us posted. I would drive it daily for a week, let it sit overnight, check the voltage in the morning. If the resting voltage is not >12.0; I would think about a new battery. These cars are not happy with low voltage. After start and with engine running, voltage should be >14.0. There should be no codes.

The voltage with the engine running is 14-14.1

I will start taking measurements before starting the car.