P0A80 and P3000 error codes, but gas mileage still ok??

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Jonathan W, Apr 9, 2021.

  1. Jonathan W

    Jonathan W New Member

    Joined:
    Apr 9, 2021
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    Location:
    Akron, OH
    Vehicle:
    2007 Prius
    Model:
    Touring
    Hello! I am the second owner of a 2007 Prius with no previous accidents. It has about 103,000 miles. I've owned it for ~2 years and it has good maintenance records from before I owned it.

    I've had very few problems with it until earlier this week, when (outside temperature increased to ~80) the check engine light and red triangle appeared, accompanied by the yellow brake system warning light and the VSC light. Simultaneously, the charge of the hybrid battery was suddenly down to 1 or 2 bars. I pulled over and referred the manual to help me determine whether or not I could still drive it safely home. As I drove the rest of the way home, the battery charged back up to normal levels (blue and even green) and I didn't notice the car performing any differently. Diagnostics at an experienced, trusted shop found error codes P0A80 and P3000, telling me that the HV battery needs replaced and quoting $4,000 for the part(s) and labor (likely more than the value of the car!).

    I've now carefully driven it ~30 miles with the check engine light and red triangle still on, but the car's performance does not seem to be suffering - I'm still getting in the upper 40s for gas mileage and the battery seems to be charging/discharging as it has been in the past.

    Does anyone know of similar scenarios where the dreaded P0A80 code appears but there is no reduced performance? I'm trying to determine how soon I should take the HV battery out (after doing more research) and start some DIY work on it such as measuring voltages and seeing which cells/modules might need replaced or "reconditioned" with a charger/discharger system of some kind.

    Would cleaning the battery or battery fan make any difference?

    Would purchasing a refurbished HV battery as replacement (~$800 on Ebay, includes shipping and installation?! - probably too good to be true) be something I should consider at this time?

    Thanks for any help/guidance you can lend!
     
  2. palmatum

    palmatum New Member

    Joined:
    Mar 23, 2021
    8
    5
    5
    Location:
    Oakland
    Vehicle:
    2009 Prius
    Model:
    Two
    Hey I just delt with such an issue here: 2009 with P3000, P0A80, P0571 - intermitent 0% or 100% charge state and high/low voltage on a blade | PriusChat

    I think it's going out, and it may get suddenly worse. That happened to me, and it went into the battery protection mode I've heard about, where it cuts out the electric and just limps along at reduced power.

    I'd recommend getting a OBD2 reader and using the Dr Prius app on a smartphone to check out your battery. I bought the Panlong adapter for ~$12 or so. This will tell you how extensive the problem is, it gives you resolution down to every pair of modules. Pay attention and take screen shots when the pack is charging, discharging, and idle (parked with motor no longer idling). My bad module was high during charge, low on discharge and idle.

    If it's just one bad module, you can replace an individual module (~$50) with a few hours of work, a friend, and some sockets/torque-wrenches. So far (literally days ago so stay tuned) that's worked for me. I identified the module with the OBD2 data and then from resting voltage when pack was dissembled. However, I see stuff about how you're supposed to load test modules, so I may have just got lucky that it's easy to spot from resting voltage.

    I also did a battery reconditioning when it was assembled, since I installed a Prolong harness while I was putting it back together. But in retrospect it's not that hard to get back into the battery control box so you could just install that later.

    Others, is this good advice?
     
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  3. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
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    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    A module with one (or more) failed cells can easily be identified by it being 1.2V less than the other modules using just OCV (open circuit voltage). A load test will allow you to find other modules that have a lower capacity when compared to their peers. The lower capacity modules manifest by rising faster and to a higher voltage when charging and also discharging faster and going lower, again when compared to their peers. An alternative to load testing is observing the behavior of each block (pair of modules) when in the car under load i. e. braking (charge) and acceleration (discharge) using the handy apps Dr. Prius, Torque Pro, or Hybrid Assistant.

    The latter is what you did.
    Yes, a pretty accurate precise.
     
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