Here is a wiring diagram for the ABS (BELOW) to figure out which wires are for each solenoid, then apply 12 volts and ground to apply them, then do the normal bleeding. YOU might be smart enough to figure out how to make that work, but I'm not. In normal operation during a skid, the computer pulses the various solenoids on and off very quickly, and for only a few seconds. With a scanner, the bleeding process is over almost as fast as you can push the buttons. If you were to apply 12 volts, I'd be concerned a solenoid could become overheated if it is kept applied too long.
Also be aware some solenoid-controlled valves are normally open, and they block fluid flow when applied, ("block" valves), and some are normally closed, and open to pass fluid when turned on, ("dump" valves). We don't know which valves to apply power to or if multiple valves have to be energized at the same time. Some engineer much smarter than us figured that out, then programmed their scanners to do it.
What you might consider is turning the ignition switch on while you're in the middle of bleeding. Most ABS Computers exercise the valves during the six-second self-test process when the yellow warning light is on. I could envision doing that two or three times, and that might be enough to expel air from the chambers. The self-test might be aborted if the computer sees you have the brake pedal applied, so consider pushing the brake pedal two or three seconds after you turn on the ignition switch. That might be enough to push any released air bubbles further down the line, then they can be bled out the rest of the way like normal. Have the bleeder screws open so fluid and air can flow down the lines and away from the valves.
Remember to never push the brake pedal over half way to the floor. Crud and corrosion build up in the lower halves of the bores where the pistons in the master cylinder don't normally travel. Pushing the pedal over half way runs the rubber lip seal over that crud and can rip them. That can result in a slowly-sinking brake pedal, and that often doesn't show up until two or three days later.
Images (Click to enlarge)
Sunday, August 9th, 2020 AT 12:50 PM