I have had the following problem with my transit since last week: When I brake and/or flash the control lamp for the rear fog lamp lights. The vehicle has NO trailer coupling and no filament lamp has been replaced and/or something has been changed on the vehicle electronics. All lamps on the vehicle work. From time to time the error is also gone I have already removed both rear lights and checked for ground errors, but found nothing. Also the 3rd brake lamp is OK. If I turn on the warning flashing system and step on the brake without ignition, flash all indicator lights in the AI and the KM indicator also flashes. Who can possibly give a hint where I can look for???