Please see hereby further proof why I came to this logical conclusion in the first place (I knew I had these photo's somewhere).

Old PSD-unit removed and measuring solenoid resistance (= fine):


Old PSD-unit removed and measuring pump resistance (short circuit = "fried" coil wiring):


The PSD fuse in the spare wheel well had of course also broken due to this short, so when the old PSD-unit was still in the car the only real connection to the combined ABS+PSD ECU was the solenoid one. Hence by me haven taken the old PSD-unit out, the only thing that changed was the PSD solenoid connection not longer being there. This problem did confuse me at the time for a little while as to why my ABS stopped working and the ABS warning light came on (and yes: I did then immediately checked the drivers rear side ABS sensor and it's wiring, and all was still fine with that of course).

New PDS-unit and measuring solenoid resistance (= fine):


New PSD-unit and measuring pump resistance (=fine):


With regards to your question of other ratings for the 2.7 ohm resistor: if there would be continuous battery voltage on it, then the wattage would have to be ~13V * (~13V/2.7) = 63 watt, which is a huge resistor size wise. However: as I'm rather sure that the ABS+PSD ECU only does a very short pulse kind of sensing as self-test during the starting of the car, I would think that a 5 to 10 watt 2.7 ohm resistor should be more than fine (I did bought a 2.7 ohm 5 watt resistor, and then forgot to test it at the time... ).