toymo

I completely forgot to mention the fact that prior to experiencing the OPs symptoms, the drivers-side door was open for 3 days, which left a few lights on, inevitably draining my 12v aux battery. When discovered on the 3rd day, I had to crawl into the trunk, access the 12v battery (a 5 year old OPTIMA yellow top), and connect it to a Schumacher Electric 1200 Amp Car Battery Jump Starter Charger where I was able to revive the Prius and get it to the Transmission P lock mechanism MFD message in order to re-engage the Transmission Control ECU back to normal driving.

If Syl had tightened all loose electrical connections to the 12v aux battery, turned-off all accessories, properly engaged and locked all electro-mechanical doors, and established the fact that there were no other sinks nor leakages present, then 4.8-8.3 volts would not be remaining on a brand new 12v battery.