Mercedes GT Roadster Power Window Failure

That sounds frustrating. I had something similar with my old Volvo, but the window only went down halfway. Did you check the wiring harness where it goes from the car to the door? That was my issue. Broken wires can cause electrical problems. Have you checked if power is getting to the window motor?

A broken wire? I didn't think about the wiring harness. When you checked the window motor, could you get to the connector easily, or did you have to take apart the door panel?

The harness was hard to figure out. On my Volvo, I had to take off part of the door panel to get to the connector. But before that, I used a multimeter at the switch and saw no power was getting through. With the error code you mentioned, should you start there? A bad switch could stop power from getting to the window motor or regulator motor. If it's not the switch, I'd suggest a workshop.

Your advice was helpful. I tested the switch, and that was the problem. A new one cost 200€. Thanks for pointing me in the right direction before I took apart the door panel and window mechanism. Thanks for your help.