I searched for C1392 and found a thread on another forum that solved the issue. I would not have found it without your help, thanks. The answer is in the attached image, it is a redundant plug for non memory seat models.
New to commenting here, but I have been using the information here for about a year.
I bought a 2002 L322 a year ago. Many things need fixing and I am doing them bit by bit. The previous owner had a habit of doing makeshift fixes that fail over...