respectively it does not work when someone tries to start the car.
Have you tried to enter date and time on the BC? Maybe then the PPPP is gone.
On the E32 there is a 'secret' fuse for the anti theft system and it is also connected to the BC. If the BC does not show any power, look for this fuse under the rear seat.
It's from the German 7er.com, so language is German, but pics will do
click here