Replaced Brake Actuator, now have P0AA6. ?

So I had the brake actuator go bad on this 2005 Prius. Got a used one, owner claimed no codes on used unit, so went ahead with repair. After buttoning everything up, hooked up scan tool,(xtool D7) and pushed the button. All the lights were still there, abs vsc etc. car started, seemed like it would be ready for bleeding.
Then the red triangle appeared, p0aa6. removed the 12 volt ground to start over, and when putting the ground back on, got a pretty good spark when connecting it back.
Went through the process again, even trying to relearn the linear valve. Same red triangle, p0aa6.
Anyone ever have this happen, and get it fixed?

 

Thank you for the reply. I agree, and when connecting back the 12V battery, it sparked at the ground like there was a short or something.
I removed the inverter cover 3 times double checking my work, and can't seem to find anything that seems different. Hooked all the wires, connectors as they were. Really frustrating.
Is there a meter or electronic testing device I could check for that issue?

PS: Edit-I had the car on 4 jack stands to get ready to do the brake bleed. Just took the car off the jack stands, cleared the codes, and the red trianglle went away. CAme back after a few minutes, cleared again, and went away. Got the c1203 and c1345 plus the other brake codes for limear etc. OK< guess tomorrow is another day!!