2005 Prius with P0AA6, Subcodes 526 and 613

Discussion in 'Gen 2 Prius Technical Discussion' started by pyromaster114, Jul 17, 2019.

  1. pyromaster114

    pyromaster114 New Member

    Joined:
    Jul 10, 2019
    4
    9
    0
    Location:
    USA
    Vehicle:
    2005 Prius
    Model:
    N/A
    Our 2005 Prius recently refused to start and gave a P0AA6 with Subcodes 526 and 613.

    Normally, this indicates that the transmission needs replacing according to Toyota's Service Bulletin.

    But here's the weird stuff:
    The thing will set this code when the transmission is cold (unusual according to LG).
    It has also never done this before, making it weird that we'd have a problem fairly consistently and, the code REAPPEARS when cleared with the car NOT attempting to be "Ready".
    The 'LG' test would suggest that the issue lies in the HV battery in the rear of the car, not the transmission.
    After all, how would the car detect a HV fault in the inverter, or MG1 or MG2, without any high voltage present?

    Is this a computer error? The car is getting up there in years, and we were not the first owners. :/ So unfortunately anything is possible.

    If I clear the codes and attempt to READY the car, it works, and you can drive it. Warning lights sometimes reappear, sometimes they don't. Almost invariably, the car will not enter ready mode again (even if no errors were displayed during the previous run) after shutting it off, until codes are cleared again.

    I feel weird proceeding either direction, as the Lucious Garage test is suggesting the fault is with the battery, but the Subcodes are suggesting transmission failure. In my previous experience, those tests always agreed with one another.
     
  2. ericbecky

    ericbecky Hybrid Battery Hero

    Joined:
    Mar 12, 2004
    4,358
    3,162
    1
    Location:
    Madison, Wisconsin
    Vehicle:
    2005 Prius
    Model:
    Two
    Start isolating components and use a megohmmeter to check for HV leaks. Buy/borrow/rent

    Once isolated (unhooked from other stuff)
    Check the battery and it's components.

    Check teansaxle and it's components.

    Check inverter and it's components.

    Very quickly you will find where the leak is located and be able to reproduce the issue in a measurable way.
     
Loading...