I know this is an older forum but I am hoping to still get some advice. My 2011 Prius III has been identified as having a faulty JBL Amplifier causing the 12v battery to drain when the car is not on. I've already replaced the 12v battery. I see there have been repeat problems with this dating back to 2005 and there was even a recall on it at that time. Has anyone had this issue with a Gen 3? Did Toyota correct it? My dealership says there's nothing they can do and I would need to pay for repairs myself ($700) so at this point I just asked for the amp to be disconnected while I contact Toyota Corporate. I would love advice if you were successful getting it replaced.
Turns out the first dealership didn't disconnect the amp to see if that stopped the drain. It did not so I went to a second dealership that went through circuit by circuit for 3.5 days and finally figured out it was the heat strip. $537 later and I am on my way again.