Help with red triangle and hidden code P3009-526

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by dpeverhart, Jun 9, 2014.

  1. dpeverhart

    dpeverhart Member

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    I picked up a 2004 Prius with 150k. It has no check engine light and no codes with a scangauge. I hooked it up to a mini-vci with techstream and found the following: P3009-526, C1310 and B1421. The car will only start if you reset codes, then after a few minutes of running the red triangle comes back.

    The car runs perfect with absolutely no shuddering and gas mileage is normal.

    So far here is what I've done:

    -Tested all 28 modules. First test was immediately after running they were between 7.96 and 7.99, then after leaving it sit for 5 days and again very consistent between 7.69 and 7.71.
    -Replaced 12 volt battery with new from Toyota.
    -Replaced HV battery wire frame and bus bar (both sides)
    -Changed oil and filter, transmission drain and fill, checked coolant levels-good.
    -Changed air filter. It was on backwards when I picked up this car with dirty side up and it was very dirty.

    Any suggestions on what I should check next?
    Thanks
     
    #1 dpeverhart, Jun 9, 2014
    Last edited: Jun 9, 2014
  2. JC91006

    JC91006 Senior Member

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    the dirty side of the air filter is suppose to be "up" when you open the housing.

    I believe last time I had p3009-526, it was my transaxle that I had to replace.
     
    #2 JC91006, Jun 9, 2014
  3. nh7o

    nh7o Off grid since 1980

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    #3 nh7o, Jun 10, 2014
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    P3009 means that your car has a high voltage ground fault. That ground fault could be at any system in contact with high voltage: traction battery, traction battery ECU, battery cable to inverter, inverter, transaxle, or air conditioning compressor. Usually a megger is used to determine the ground fault, along with disconnecting portions of the system for testing.

    You are correct that the old engine air filter was installed backwards if the dirty side was up, and that is indicative of very poor prior maintenance. The dirty side should be down in 2G models.
     
    #4 Patrick Wong, Jun 10, 2014
  5. dpeverhart

    dpeverhart Member

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    I drove the car to Taylor Automotive in Sanford to see if they could pinpoint the issue with this HV leak code I'm getting. They just called and said I need a new hybrid battery which left me somewhat confused since the code P3009 is for a high voltage ground fault. I asked him how it could be the HV Battery when I have tested it several times in various states of charge and the modules always tested very close in voltage. His response was there was lots of corrosion. Now I'm not sure if we're talking about the same battery because I replaced the wiring harness and buss bar on both sides with new ones so there is no corrosion visible. Finally he said to come down and the tech can show me. Now I wish I would have replaced the HV battery with one from a good working Prius before taking it down but my understanding of the P3009 was the ground fault leak was elsewhere in the system (battery cable, inverter, AC, Trans etc.)
     
    #5 dpeverhart, Jun 16, 2014
  6. JC91006

    JC91006 Senior Member

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    The diagnosis is a bad battery, it doesn't mean you can't replace it yourself.
     
    #6 JC91006, Jun 16, 2014
  7. dpeverhart

    dpeverhart Member

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    Of course and that's what I plan on doing, I only mentioned it as I was surprised and somewhat skeptical of this diagnosis.

     
    #7 dpeverhart, Jun 16, 2014
  8. Patrick Wong

    Patrick Wong DIY Enthusiast

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    No, a ground fault can occur at any place where high voltage is present including the traction battery and the traction battery ECU.
     
    #8 Patrick Wong, Jun 16, 2014
  9. dpeverhart

    dpeverhart Member

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    So in this case how do you pinpoint where the leak is within the traction battery? I've already swapped out the ECU with another known good one so that can be ruled out. I also changed the frame/wire on both sides with new.

    When I bought this car, the traction battery case was off, so somebody was inside. Now I'm wondering if they could have omitted wire or connection. Hopefully Taylor Automotive can show me where within the traction battery the ground fault occurs.
     
    #9 dpeverhart, Jun 17, 2014
  10. Patrick Wong

    Patrick Wong DIY Enthusiast

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    1. Look for an electrolyte leak from a module to the sheet metal battery case.
    2. Disconnect the battery cable leading to the inverter, at the traction battery. Using a digital multimeter, measure voltage from any module to the sheet metal case. If you can measure voltage then there is a leak somewhere.
    3. In that case, remove the orange busbars and see which module still shows a voltage to the sheet metal case. Measure from both the + and - terminals of each module to the sheet metal. There should be zero voltage - if you can find any non-zero reading, that module has a problem.
    4. If you don't find a problem with any of the 28 modules, inspect the wiring to the traction battery ECU as there may be a problem with the wiring.
     
    #10 Patrick Wong, Jun 17, 2014
  11. dpeverhart

    dpeverhart Member

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    Thanks Patrick,
    I followed these instructions and found cell block 11 with a module leaking electrolyte onto the case. I removed all the modules in that area, cleaned it up real good, replaced the leaky module with a good one, reinstalled the pack and everything is working great! I appreciate all the help.
     
    #11 dpeverhart, Jun 18, 2014
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