The reprogramming of the shutter speed is not a solution, since the tank lid remains open from the inside when locking up. Also with me the tank lid was open every time after the washing road visit. Finally I found a simple remedy. To do this one has to know that the tank lid is opened by the dry blower of the wash road and tears off in an unfavourable case. The air jet blows into the “finger arching” of the lid and creates an overpressure in the small volume between the lid and screw cap. This overpressure finally presses the tank lid on. Remedy: Glue a adhesive strip from the inside over the arch! This adhesive strip is not visible from the outside (if one does not take exactly white adhesive tape), but prevents the air from entering the small volume between the lid and screw cap. The adhesive strip is about 4 cm wide and 8 cm long. Since this small modification, the lid remains reliable with me (since 6 washings)! Please Volvo Grus!