Prius 1.8 2011 warning sign p lock

Classic 12V battery failure shenanigans. The codes may or may not be representative of actual problems. Low battery capacity will cause all those computers (ECU'S) to have a boot failure. Have your auxiliary battery load tested.

 

Hey I had this happen recently, and I went here to check on what I could do to fix it.
The dash lights up like crazy, the transmission area of the display shows all the gears flashing. Turn off does not work, and car stays in aux mode powering the radio and alarms when you close the door.

I went on disconnecting the 12v battery that is in the trunk at the negative end and left the car DC'd (disconnected) for 5 mins. Plugged it back in and the car had the same problem, it actually turned the radio on to a random song and started blasting it, pretty scary. Tried the DC of the 12v at the negative end two more times and I didn't fix it. The tow truck was already on the way, and I then tried removing the positive end of the 12v battery connection. It was maybe, barely, slightly loose, and I didn't leave it DC'd I connected it back up after removing it for a second to adjust. Once I reaffirmed the connections to + & -, THE CAR WORKED! YAY Called off the tow truck and powered up just fine.

Before this problem I had just visited a car wash, and I was worried I broke the car driving it through the tunnel. It seems that the + connection had been loose (probably because of dirt roads) for a while, and I poked around the car cleaning the inside with a vacuum which affected it. Once it didn't have the proper connection it couldn't draw enough Amps to properly power the car.

Thanks
AzWxGuy because I focused on the 12v problem instead of getting lost in the wide world of code-problems.