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2004 Prius 2 will not start after changing one battery.

Discussion in 'Gen 2 Prius Technical Discussion' started by joyongsuk, Sep 29, 2019.

  1. joyongsuk

    joyongsuk New Member

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    I was driving my Prius with the AC on for at least 30 mins.
    The Red Triangle appeared along with all other warning lights. I noticed that I suddenly lost power.
    So I turned AC off and drove home with no battery engine power.
    I noticed that the charge level on the battery was acting eractically. It would charge quickly and go down quickly.
    I ran some tests using Torque Pro and it said that the first bank of batteries were a little less than voltage.
    I was able to turn off and on the engine at this point and ride without any power.
    Then I removed the battery unit.
    I isolated the bad module using voltage measuring tool and having a light bulb connected at the same time. One of the units measured 6.5 volts. All the others ranged from 7.4 to 7.6.
    I replaced it with a unit I got from Electron Automotive in Orange, CA for about $60.
    After putting everything back, I tried starting the engine. All the warnings light still came on and the car would not start this time.
    I checked 12 volt battery. I charged it up to full capacity. But still did not help.
    I'm thinking just get a full set of battery pack for about $1500 from Electron Automotive.
    Any ideas why after I replaced that one battery, it would not start?
     
    #1 joyongsuk, Sep 29, 2019
  2. Raytheeagle

    Raytheeagle Senior Member

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    Welcome to Prius Chat (y).

    Some questions:

    • How many miles on your Prius?
    • Is there movement in the inverter coolant reservoir?
    • Did you install the orange plug correctly (lock it into place)?
    • Did you load balance the cell and pack?
    Good luck and keep us posted (y).
     
    #2 Raytheeagle, Sep 29, 2019
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  3. joyongsuk

    joyongsuk New Member

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    • 197000 miles
    • there was movement in the coolant. Now I can't start it, so I can't check.
    • The safety plug was plugged in correctly.
    • I did not load balance the cell and pack. I will work on that then. Thank you.
     
    #3 joyongsuk, Sep 29, 2019
  4. TMR-JWAP

    TMR-JWAP Senior Member

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    This is a very common cause of your symptoms....3 steps...many people forget step 3, which is the step that tells the ecu the safety switch is completely inserted. Without step 3, the car thinks the safety switch is still removed and will keep the dashboard lit with alarms.

    Safety Disconnect Installation Procedure.jpg
     
    #4 TMR-JWAP, Sep 29, 2019
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  5. joyongsuk

    joyongsuk New Member

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    ok. I will double check.
    Thank you.
     
    #5 joyongsuk, Sep 29, 2019
  6. joyongsuk

    joyongsuk New Member

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    I checked the safety switch. It is locked in.
    When I try to start the engine, it turns on the monitor only with power switch showing green light. The hybrid battery shows 0 bars.
    Then when I start the engine the second time, the power switch shows red. All the warning lights are on. The bar level on monitor shows like 6 bars charged then every like 10 second increments the bar goes down. But when I start it again, the bars are back up. When I try to switch gears, only park and neutral works.
     
    #6 joyongsuk, Sep 29, 2019
  7. SFO

    SFO Senior Member

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    Please don't waste $1500 on a frankenbattery that only has a 15k mile / 1 yr warranty.

    Buy a new OEM battery, there are a handful of dealers in the LA basin that sell OTC for not much over 1500.
     
    #7 SFO, Sep 30, 2019
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  8. TMR-JWAP

    TMR-JWAP Senior Member

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    OK, your car is still acting like it thinks the safety disconnect is not installed. As I mentioned previously, the third step of the procedure is what actually activates the interlock. If the safety switch is properly installed, you may have forgotten to connect the interlock wire at the bottom of the disconnect.

    There are three plugs that connect from the car harness to the HV battery. A big one, a medium one and a small one.

    The big one goes to the ecu.
    The medium one goes to the relays for control power.
    The small one goes to a wire that snakes behind the safety disconnect and into a plug socket under the disconnect. This is the actual interlock terminals. If you forgot to plug that back in after disassembling/assembling your battery, the interlock will not work.
     
    #8 TMR-JWAP, Sep 30, 2019
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  9. joyongsuk

    joyongsuk New Member

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    I will check those cables too. Thank you.
     
    #9 joyongsuk, Sep 30, 2019
  10. joyongsuk

    joyongsuk New Member

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    Thank you for you help. After going over the cables, the one that was still not plugged was the cable that fits into the air vent piece. That was kinda of hard to find since it was attached to the side and hidden.
    Again, thank you for your help. Prius is now running again.
     
    #10 joyongsuk, Oct 1, 2019
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