Codes P3030, P3106, C1259...2001 won't start.

I get these three codes using my scanner and I get the two P codes when I use the Techstream software. They come back after I clear them. Here's some background.

I own two gen 1 Priuses(Priui?), a 2002 with more than 350k miles on it and a recently acquired 2001 with only 220k miles on it. I had rebuilt the 2002 hybrid battery, so I installed the rebuilt battery into the 2001 and I attempted to start it. I got just a short crank and then nothing. I assumed it was the 12 volt battery so I took it to be tested at Autozone and they said that the battery was good. I went home and trickle charged the battery on my bench in the garage and it showed 13.4 volts the next morning. I re-installed it in the car and attempted to start it again. Nothing.

My 2002 has been configured to receive a Miata battery, so I figured I could take the battery leads and the Miata battery from the now donor car, install them in the 2001 and see if the car would start. It didn't. It cranked briefly once, then nothing when I turned it over. I decided to add my Centech battery charger
to boost the Miata battery to see if that would improve my chances of starting the car. No luck.

Then I started to wonder if there was something in addition to the battery leads that needed to be done to configure the 2001 to receive the Miata battery...so I switched the 2001 back to the original configuration with the original battery, which still showed 13.4 volts. I attached the Centech and attempted to start it and nothing. I then decided to test the load on the battery using a multi meter and when I turned the ignition, the 13.4v went down to 10.8v. I re-attached the Centech and the battery read .5v. I assumed the battery was damaged so I bought a new one. It arrived yesterday and I installed it this morning. I turned it over, I got the abbreviated crank, as usual, and then nothing when I turned the key.
I'm not interested in damaging the new battery so I need some direction.

I've literally never heard the 2001 run, even when I bought it. It was only $400 and it cranked, but didn't start when I went to look at it, but it had no codes, so what I paid was worth the parts. I know the battery I installed is good. Could I have done something wrong? I did the immobilizer fix(the ignition turn to the on position for 20-30 minutes, then, off. Key removed, door opened, then closed, etc...) and it didn't work. I checked the leads on the ECM. I've checked them visually. Nothing seems loose or frayed. What is my next step?

Any help offered would be greatly appreciated.

 

I bought the manual and still this is all way over my head. Got some studying to do. Great time for it...