I would get on occasion, very quick error beep (Check charging system), usually after I start my car after sitting overnight. I had to record a video to catch the error. The error wouldn't stay on. Sometimes it will last the whole day without the error, but everytime I start the car, after 5 min, it would very quickly pop up. I had my MPI changed last year. They have a service bulletin about it. I don't see/feel anything wrong on my car otherwise.

What do you think this is? Thanks in advance.