Didn't read the entire thread, but did you check the fuse?
If pump, fuse and relay are ok, the search for the cause starts to get complicated. Especially without SD2 which would help you to read error codes and view live data, such as hydraulic pressure. The pump relay is controlled by the TCU considering a few factors and parameters from other ECUs of the car. Probably wiring diagrams will be necessary for the further search.