'05 prius w/ red triangle, car w/! & main battery on MFD, codes P3000,P3030,C1241,C1259,C1310,C1378

Hi! Our 2005 Prius (1 of our 2), sat for longer than expected or desired after some tough financial times for our family. It also unknowingly sprung a water leak in the trunk leading to a small bit of corrosion and battery issues. Needless to say this is where we stand.

First off the 12v is currently dead but can be jumped. The car can turn on the computer system but not go into ready mode. I am given all the hazard lights but most importantly the red problem triangle and main battery symbols on the MFD. I have run a diagnostic check to find the following error codes._

P3000 Hv battery malfunction
P3030 high voltage sense wire broken
C1241 problem with 12v
C1259 regenerate malfunction skid control ECU
C1310 problem with Hv battery, Hv ecu dtc
C1378 -brake control power supply, skid control ecu, or wiring harness

My apologies as I realize after some research that I dont have subcodes.


I have read about people having issues with the hybrid battery wiring harness after experiencing rust, which brings me to my main question.

Does this seem like just a hybrid battery wiring harness issue? That is, if it were to be replaced, or possibly cleaned, would this solve the errors and get the car running? Or are there deeper issues and I'm looking at replacing other parts (skid control ecu or battery cells, etc)

Thanks for your time and expertise! We really appreciate any insightful info you could give. Cheers!