Hello, thanks for the replies zip and doc. i have a small update. i bought a new Varta 77AH 780A Battery to be 100% sure its not that. it didnt change anything. i also got my drb3 emulator which i think i managed to setup right. im not able to connect to the body control module or the central locking pump. i am getting "NO Response from BCM pin 1" and "NO Response from CLP pin 1". i recorded a short video of the emulator.

i am able to connect and read parts of the car like the engine but other parts fail. is it possible to screw up the setup that only half of the functions work? how should i proceed now?
@zip: the wing parts/gears look all good to me. there is also no visible water residue in the trunk area. but i have to say that i still have not unplugged the locking pump and opened it up.