I have 2007 with 278k on original 12 volt and hybrid batteries. The car sat for 2.5 weeks over the recent holidays. During first drive after the holidays I received triangle of death . Checked codes and received P3000 and P0A80. I also checked the the 12 volt battery using the display with the display diagnostics. I received 11.7 with no load, and 10.8 volts with the headlights and brake lights on. Is it worth it to replacing the original 12 volt battery in hopes that solves the hybrid battery pack codes? This car owes me nothing. A family member gave it to me for free at about 200k and other than brakes, wheel bearing, spark plugs trans fluid change it has been great and i really like it. I want to make sure I am not junking a "free"car that may just need a new 12 volt battery. I look forward to advice!
The 12 although toast is no big deal throw a desulphating charger on it to get you thru the trials and tribs of or repairing the hybrid battery. Since no money in the car try to find a guy to rebuild it or buy a used hybrid battery. Not sure where u are but if near San Francisco there's the premier hybrid specialist there Luscious garage Lots of hybrid peeps in that area that can rebuild the battery.
With that many miles on the odometer, the P0A80 isn't likely to be an erroneous fault due to the 12V aux battery. What might have happened during the 2.5 weeks of idle time is that the modules self discharged to the point that one of the six cells in a module failed due to an internal short rendering that module beyond repair and needing replacement. One sure way to determine if a module failed is to measure the block voltages with Techstream or the Torque app for Android. If it turns out that the HV pack does need repair then you have a decision ahead of you that no Prius owner ever looks forward to. I hope you get lucky and it isn't the pack.
