The problem is caused by malfunctioning passenger seat occupied sensor. It detects if somebody sits in it or baby seat is installed.
To cure the issue, this sensor must be replaced. It is mounted into the bottom part of the seat, under a seat cover. To do that seat must be almost completely disassembled.
Best Regards, Stan
ok I dont mind doing DIY is there a mercedes part or can it be obtained from a motor factor. Also any idea on cost?
Only original part is avaliable, but some parts stores might offer OEM parts as well. The cost is around 300 pounds.