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Prius Help

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by awindhorst, Jun 1, 2014.

  1. awindhorst

    awindhorst Junior Member

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    Hello everyone. I am hoping that some of you smarter more experienced Prius owners/DIYers can help me out. I have been having some hybrid battery issues. My prius is a 2006 with 198,000 miles. The original battery was replaced at around 120,000 with a junk yard battery. About a year later that battery gave up the ghost and I decided to rebuild that battery. So far that has worked quite well until recently. My troubles started a couple weeks ago when I got the Red triangle and all the dash lights and the hybrid system icon on the MFD. Naturally I thought it was the battery again. Took it out and checked the voltages of the modules. All the modules where within tolerances. I grabbed a OBDII scanner and checked the code. It was telling me that the Hybrid current sensor was bad. I changed that out with the wiring harness from the old battery. That lasted for a few days before the red triangle came back. I checked the code and it was indicating one of the blocks was bad. I think P3019. So I took the battery back out and replaced that block with other modules. Almost instantaneously the red triangle came back with two more bad blocks. I think it was P3012 and P3022. So I took the battery out once more and tested all the voltages of all the modules. Everything was 7.86-7.9v. So I decided to start the rebalance of the existing modules in hopes to find some bad modules. I also bought a new 12v battery and installed that. I got everything back together and took it for a road test. It took about 30 mins before the triangle came back. I grabbed the codes and it was still indicating bad blocks. P3011 adn P3018. I am a little at a loss. Could the battery ECU be bad? How would I check if it was? Is there anything else that it could be? I have read that the inverter coolant pump could have stopped working or not enough coolant.

    Thank you in advance.
    Adam
     
    #1 awindhorst, Jun 1, 2014
  2. nh7o

    nh7o Off grid since 1980

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    Location:
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    Vehicle:
    2009 Prius
    Model:
    II
    I would start by taking a good look at the voltage sensing wires going to the ECU. If there are any corrosion issues that are hidden inside the crimp connectors or insulation, then flaky variable readings could result. Did you clean the connections well, all evenly torqued ? Bright shiny metal to bright shiny metal is necessary in this high current application.

    Checking the voltages at rest won't tell the whole story. You need to use Techstream via the mini VCI to see all the internal resistances of the blocks to get a better idea of what is happening.

    The battery ECU rarely goes bad, so it would be the last on the list. As for inverter coolant and pump, that is easy to see (look in the reservoir for turbulence indication fluid movement) and does not cause battery module imbalances. I would however check you battery cooling fan if you haven't done so.
     
    #2 nh7o, Jun 1, 2014
  3. awindhorst

    awindhorst Junior Member

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    I took out all the copper and cleaned them all up, removing all the old corrosion and buildup. Here is the freeze frame of the P3015. I will pull the battery agian tomorrow and see if I can see any corrosion on all the sensor wires.
    p3015 freeze frame.png
     
    #3 awindhorst, Jun 2, 2014
  4. ericbecky

    ericbecky Hybrid Battery Hero

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    Mar 12, 2004
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    Location:
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    Vehicle:
    2005 Prius
    Model:
    Two
    This sounds like a sensor wire issue. Probe each sensor wire aggressively where it transitions from wire to the crimped-on connector. Often there are breaks at that junction. If you probe while the pack is live in the car, you can watch for any voltage changes via Techstream.
     
    #4 ericbecky, Jun 3, 2014
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