Unfortunately I will also be guessing but I am pretty sure that I know what this is. It is talking about the detection of fingers in the top part of an electric window to prevent pinching of said fingers (laymen's terms, I love them). So in measuring the highest limit of detection the theoretical value "corresponds to the window position where the opening from the point where the window is at its widest is 4mm"...It's rather confusing though, as French manuals can often be, so I'm not putting my confidence level very high. I hope only that this helps you process a little. I also included a renault manual I find helpful for automotive vocabulary, because it has pictures.