My 2nd P0AA6-526 Hybrid Battery System Isolation Fault on Original Battery

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Lighthouse-Beacon, Nov 3, 2020.

  1. Lighthouse-Beacon

    Oct 24, 2018
    2009 Prius
    This is my second Hybrid Battery Voltage System Isolation Fault for this original battery pack on a 2009 Toyota Prius with 233k miles. It's a little different this time as I am not throwing a 612 subcode yet, just seeing the vehicle insolation resistance reduction cod. I did what I did last time, that thread is here:
    Help With Next Move: Code P0AA6 and Subcode 612 | PriusChat

    A good graph to have for identifying the subcode locations is:

    I did the test again to see if it was in the HV Battery Box (Most likely a leaky module like last time) That process is here:

    <iframe width="560" height="315" src="Gen 2 Prius P0AA6 battery leak confirmation - YouTube" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>


    The test did not confirm the leak was in the HV Battery area as I show 0.00V, which could mean one of the grounding modules is at the safety plug connection, if that's the case this test won't work. I've made it about 12 months since replacing a pair of modules, and 8 months prior to that before replacing a pair of modules.

    I am going to keep driving it and see if the ECU reports a bad mod soon. That's what I did last time. I took a lot of grief for installing this switch to reset the car and keeping driving with. But I am using it in the morning to get to work and I am glad I did. That thread is here:
    Installed a Switch to Keep Driving :) | PriusChat

    I am going to keep driving and watch for more detail codes then decide to 'wack a mole' a few mods or just buy the replacement pack here:
    New Prius Battery Kit (GEN2, 2004-2009) - New Prius Batteries LLC

    Which I would have done already had I not been 230K+ miles.
    tangerino likes this.