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Help! My 2004 prius is having issues: Brakes and Pack Battery

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Seth A. Hargis, Aug 12, 2023.

  1. Seth A. Hargis

    Seth A. Hargis New Member

    Joined:
    Aug 12, 2023
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    Location:
    Knoxville, TN
    Vehicle:
    2004 Prius
    Model:
    N/A
    Hello everyone, I am going to try and jump straight to the point. The other day, went to drive my prius and when I went to back up, the brakes hardly worked and the pedal was not sensitive and hardly worked as well. My car also was running and trying to charge the battery at a high rate, and could not keep the charge on the battery. I ran a scanner and it produced a few codes-P3015, P0A80. I found these relate to the Pack battery, so being a college student and not able to afford a new battery, I decided to take everything out and test the volts in each module. I found that 1 of my modules, #9, was running at 6.7 instead of 7.9. I replaced it, now runs at 7.9. After turning my car back on, the brakes are still not functioning at all. Now is running code P3056 since i changed the module. Any tips on anything? not really sure what the breaks are doing. All the brake error lights are on, and the emergency brake light as well, even though it is not engaged.
    I have pictures if someone is interested.
    Thanks everyone,
    Seth
     
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
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    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
  3. mr_guy_mann

    mr_guy_mann Senior Member

    Joined:
    Sep 3, 2020
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    Location:
    NJ-USA
    Vehicle:
    2006 Prius
    Model:
    Four
    What are you using to check codes? You might need something more capable to "talk" to all the systems on a Gen2 Prius.

    Here's a thread that reviews several scantool apps and devices.
    https://priuschat.com/index.php?posts/3290690

    P3056 is for the HV battery current sensor. It's the white plastic ring that the big orange negative HV battery cable goes through - near the contactor relays. You want to make sure you plugged the little 3-wire connector into the sensor and the other end into the ecu (& that none of the wiring is damaged).

    Posted via the PriusChat mobile app.
     
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