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{Solved} 2006 Gen II HV battery change now showing P0AA6 code

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by phlarz, Aug 17, 2015.

  1. phlarz

    phlarz New Member

    Joined:
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    Location:
    SE USA
    Vehicle:
    2006 Prius
    Model:
    Two
    Gen II Prius, 151000 miles, HV battery died (rapid charging / discharging, cooling fan on high constantly, etc)
    Installed remanufactured HV battery from Dorman.
    Connect it all back up, test drive, get the triangle of death, VSC, amber (!), and MIL on MFD...car continues to drive normally until shutdown, upon next startup lights still present and won't shift into D or R only N. Pull codes, P0AA6 is showing. Don't have the information codes, so follow Luscious Garage's You Tube video for trouble shooting HV Leak. Code doesn't reset with car in ign on (not ready) after 60 seconds, make car ready and shift immediately to N...code resets after 30 sec. Have done this trouble shooting 4 times and code always resets with ready on and in N. This points to the HV 'leak' being either in the wiring harness or the inverter.
    Any ideas on what I can do next in order to figure out which one?
    Thanks
     
  2. bisco

    bisco cookie crumbler

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    welcome! try toyotatechinfo.com for a troubleshooting tree. all the best.(y)
     
  3. dat2109

    dat2109 Junior Member

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    Location:
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    Vehicle:
    2006 Prius
    Model:
    II
    I just went through the same code issue on the same year Prius with the same number of miles. If you have a techstream you can read the subcodes to see where the car is telling you the leak is. You will want to use an insulation tester / megger to verify, then you can fix the problem.

    For me it was MG2, I replaced it.

    Where in the SE are you??
     
  4. phlarz

    phlarz New Member

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    Vehicle:
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    Two
    dat2109,
    west TN
    Thanks for the help
    Don't have a techstream, thus the reason for the Luscious Garage test.
    Will work on getting hold of a techstream.
    I initially thought it was the MG2 based on research but, assuming I'm doing the troubleshooting correctly, it appears to be between the HV battery and the output of the Inverter.
    Did you replace just the MG2 or the whole transaxel?
     
  5. dat2109

    dat2109 Junior Member

    Joined:
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    Location:
    Carolinas
    Vehicle:
    2006 Prius
    Model:
    II
    I replaced only the MG2 in my case, and I was able to diagnose / trace the issue to the MG2 specifically. From the inverter you could isolate the issue pretty quickly with an insulation tester, there are 4 high voltage paths into or out of the invertor. battery, mg1, mg2, and a/c. Add the inverter itself as a leak possibility and ofcourse, the interconnect wiring. Let me know if you want more details about this.

    Using a techstream you can get subcodes for a P0AA6 that helps point you to the problem.
     
  6. phlarz

    phlarz New Member

    Joined:
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    Location:
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    Vehicle:
    2006 Prius
    Model:
    Two
    Appears to be fixed.....
    Old battery did not have isolator strap on wires on the car side of the HV relay, so when the refurbished battery was installed the strap was left off....found the strap tucked up inside of the case of the old battery (evidently the old battery had been taken out of the car before by the previous owner)...additionally the grounding wire from the car side, right hand (as you look at the battery in the car from the driver's side) HV post was found on the refurbished battery not to have a nut on the end under the battery case...installed nut and isolator strap and viola, car is functioning as normal....
    So recommendations for installing refurbished battery....ensure that you have all the parts you need off of the old battery and ensure that the new battery has all obvious wiring hooked up properly (had to take the case off the battery to find the nut missing off the ground wire)....
    Only reason for looking back into the battery installation was that it was the only thing changed prior to getting the P0AA6 code and the trouble shooting in the Luscious Garage video pointed to the wiring from the battery to the inverter or the inverter itself....
    Happy to be up and running again, just hope this refurbished battery lasts for a while :)
     
    Piroshka likes this.