I just replaced the ABS actuator with a good used one. Triangle warning w/!, brake, ABS appeared on the screen. I wouldn’t found any helpful to troubleshoot it. It turned out the rear orange plugs were not pushed in all the way. Fix it!
The helpful way to troubleshoot it would have been to read the trouble codes from the car. There would have been P0A0D, which tells you your orange plugs are not pushed in all the way, and you would have immediately known what was needed.