2010 Prius Check Hybrid System Warning - Need Help

Discussion in 'Gen 3 Prius Technical Discussion' started by Michael Short, Jul 10, 2019.

  1. Michael Short

    Michael Short New Member

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    Jul 10, 2019
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    Location:
    Phoenix AZ
    Vehicle:
    2010 Prius
    Model:
    N/A
    I have a 2010 Prius with 160k miles. I was driving on the freeway on cruise control at 70mph a few nights ago and the "Check Hybrid System" warning appeared on the LED display. There didn't seem to be anything wrong with the car so I drove it home and then drove it to the dealership the following afternoon.

    The dealership came back with the following codes: P0AA6 with an information code of 526. They told me that I needed to start by replacing the hybrid battery. After pressing them for details, I was told the codes were ultimately inconclusive and the problem could be coming from the hybrid battery, the intelligence power module, or the "trans axel".

    I didn't feel comfortable "starting out" with a $3,500 repair in hopes that it'd solve the problem, so I decided to drive the car home and get a second opinion.

    Tonight, a hybrid battery specialist came out and took a look at the car. He ran a few basic voltage tests on the hybrid battery case and on a few of the orange "high voltage plugs" near the engine (I don't know what these are called). None of his tests identified a "voltage leak" and he felt like we should reset the codes to see if the "Check Hybrid System" warning persisted. So he disconnected the 12V battery (which apparently resets the codes), put everything back together, and the "Check Hybrid System" warning was gone when we turned on the car.

    I was told to just drive the car and see if the "Check Hybrid System" warning reappears. If it does, then get the car looked at again as it's likely I have a real problem. If not, then maybe it was just a transient glitch and there was never a real problem in the first place. Sounds reasonable to me, but I'm inexperienced with this kind of situation so I wanted to get some outside perspective.

    What would you guys do if you were in my situation? Just keep driving the car? Have it checked out by someone else? Other?

    Thanks!
     
  2. PriusCamper

    PriusCamper Senior Member

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    Hopefully it goes well for you and lights don't come back, but that's rare... Now's the time to get educated on preventative maintenance to your hybrid system though. If I were you I'd be suspicious of corrosion in the bus bars and voltage sensing wires. Getting that cleaned up, as well as maintenance like cleaning the battery cooling fan and making sure your 12v battery is strong will help eliminate those issues so you can focus on the more expensive stuff once it comes up. Also learn all you can about the lifespan of your hybrid battery and what you can do to prolong it here: FAQ
     
  3. 4shizzel

    4shizzel Junior Member

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    Location:
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    Vehicle:
    2010 Prius
    Model:
    III
    Wow...I got a 2010 Prius with P0AA6 with an information code of 526 also. The dealer told me I'd have to start the repair by replacing the HV battery and it still might not be the problem. How is yours holding out? Did your light ever come back on?

    Thanks
     
  4. PriusCamper

    PriusCamper Senior Member

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    Never underestimate even the most talented mechanic to be so scared of High Voltage work to the point they don't know where to begin in a way that's affordable and maintains customer loyalty. If I lived near you, I'd charge you an hour to put in a loaner hybrid pack to determine if this problem is coming from the pack or elsewhere in the system. Then once the results of that are known, you can narrow it down to more specific diagnosis. Hope you can find someone who's willing to do that?
     
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