Yes the ABS does different things on certain models, 16v and VR6 have a very basic form of traction control.
Be aware that the ECU is the part you need to match and has its own part number on the underside, not just the obvious number on the pump.
If you have a rear sensor fault that you can not fix despite replacing the sensor, sadly it is likely to be the ECU that is faulty. The problem is the solder goes dry on the terminals connecting the wheel sensor to the PCB of the ECU.
It is possible to open the case up and resolved the terminals, but you pretty much destroy the case getting into it & sealing the case back up is difficult.
A mate sent his ECU fixed by BA Raman, he is very happy with the result and it comes with warranty.
If you do replace your pump, ideally you need to bleed the brakes using vagcom to remove air fully.