2001 bmw door locks open then automatically close what is the issue?

i have a 2001 bmw 330i when i press my unlock button they all go up but 3 seconds later they close automatically, sometimes they will not work at all. please help me, its all 4 doors.2001 bmw door locks open then automatically close what is the issue?i believe the car is made that way so when you get out you don,t have to lock it, it will lock by itself and i think if you left the key in the ignition it won,t do it. it is a security thing. if you want to try it with the key in the ign just make sure you leave a window open2001 bmw door locks open then automatically close what is the issue?Is the car running at this point or is it when you are trying to open the doors(like at the grocery store)?