You could probably replace the solenoids with resistors around 7.5 Ohms. They will dissipate around 25 W if they operate. That may only be for short periods, so you may get away with smaller resistors but I would suggest wirewound resistors of at least 5 W continuous rating.
The pump will take far less current when running than would be calculated by the supply voltage divided by the resistance, which is around 10 A. It will probably take 2 - 4 A. You could try using the same resistors.
It's difficult to know what would simulate the pressure transducer. The electronics may expect to see a change in reading when the pump runs or the brakes operate. Simulating that could be difficult.
ABS modulators on cars often have quite extensive electronics inside them. Is that the part that you want to keep?
Thanks for the advice on resistors! I'll give them a try, very helpful.
I had been looking at much larger ones for the pump, because the circuit has a 30 amp fuse, but resistors for that would've been huge.
I would think the pressure transducer will be used by the computer for diagnostics, but I'm not sure. It will be an experiment replacing this. I was hoping to try taking a fixed atmospheric reading from the sensor to use. But, I'm not sure how to test this for a suitable replacement, there are 4 terminals but no indication of what each is? Although, there is a split between the top and bottom terminals in the picture below.
I would probably keep the transducer, but I don't think I can remove it from the block without destroying it.
Yes, I want to keep the electronics as they share wheel speed etc. with the engine control unit. There are commercially available ABS delete plugs to replace the whole ABS unit, I'm not sure how they simulate the pressure, or if they do, but they seem to work without creating fault codes. None in stock at the moment, and pretty expensive.