MFD -P0A80

I bought a high mileage 2006 base Prius for a song because it had the MFD out-then later the air bag light came on-I took it to the Oregon Coast Saturday put about 160 miles on it-perfect-when I ran the Dr. Prius app, I got a P0A80 error code signifying a weak #12 cell-the app said demo mode-so I need to clarify at Auto Zone to see if I have a real problem or not-hit the jackpot. Does anyone know if these are all related? Does anyone know of a good hybrid mechanic in the Salem Oregon area? Anyhow, thanks so much for the site and any help would be appreciated. Robertd