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Replaced hybrid battery - car won’t start

Discussion in 'Gen 2 Prius Technical Discussion' started by paryzekaj, Jul 21, 2024.

  1. paryzekaj

    paryzekaj New Member

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    I replaced the hybrid battery in my 2004 Prius yesterday using a reconditioned battery. Now the car won’t go into gear. I have read through many similar posts online but so far haven’t found a solution. The car does start but that is it. I have no battery or engine codes. When using the Dr Prius app the new battery looks good with good voltage and resistance reading in each module.
    What am I missing? The orange interlock switch on the battery is in place and locked down (I have gone through that one numerous times). The 12v battery is strong and connected well. I feel like I must be missing something? TIA
     
    #1 paryzekaj, Jul 21, 2024
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  2. bisco

    bisco cookie crumbler

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    'the car does start' means you have the ready light?
    have you double checked all the connectors?
     
    #2 bisco, Jul 21, 2024
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  3. ChapmanF

    ChapmanF Senior Member

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    Are there any warning lights on the dash?
     
    #3 ChapmanF, Jul 21, 2024
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  4. paryzekaj

    paryzekaj New Member

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    Yes - Every light is lit up. No codes though, either battery or engine codes.
     
    #4 paryzekaj, Jul 22, 2024
  5. paryzekaj

    paryzekaj New Member

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    I have reseated the orange interlock switch a half dozen time. The car does turn on but it doesn’t shift into gear - just park and neutral. I guess I start some disassembly and reseat all electrical connections. I was going to attach a video but it appears to involved to be worth it. All warning light light up when I start the car and the Red triangle gets added to the mix when I try to shift into gear.
     
    #5 paryzekaj, Jul 22, 2024
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  6. paryzekaj

    paryzekaj New Member

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    Just to close this up the car is running now. I took the brackets and trim off the electrical connections side of the battery. Checks all connections and reseated everything on that side. There was a small white wire that goes to the vehicle side of the orange wire connections that was not in position. Put that one back where it belongs and inserted the interlock, connected the 12v battery negative and tried to start the vehicle. It worked so disconnected the negative and interlock and reassembled everything. Reconnected and started the vehicle again. No codes, no warning lights, and drives fine. All’s good now.
     
    #6 paryzekaj, Jul 22, 2024
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  7. ChapmanF

    ChapmanF Senior Member

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    As always, that means the scan tool being used isn't able to show what the codes are.

    We have a thread here that reviews scan tools and apps and identifies some good choices capable of retrieving the codes.

    Gen2 OBD2 app review | PriusChat

    Good find. If a better code reader had been at hand, it would have shown the P0A0D code that might have steered you more quickly in that direction.
     
    #7 ChapmanF, Jul 22, 2024
  8. JohnnyPR

    JohnnyPR Member

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    Great to hear you made it work! Well done
    There's a neat 2007 Prius that could worth saving and might need a new battery. The previous owner had the brake job done and new tires from 4Wheelonline installed earlier this year. We'll take a look at it tomorrow.
     
    #8 JohnnyPR, Jul 22, 2024
  9. avoice217

    avoice217 Member

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    Hey all, so someone shared this thread in my post in hopes that it might help me as well. So I just purchased a brand new battery and have the P0A0D code on mine (sub code is 350). To paryzekaj, is it possible to take a photo of the area/spot where you found the white wire loose by chance? I know that all of my connectors should be in place, so if that's good on mine then I'll have to look at the ECU on the passenger side because I honestly can't think of any other ideas on what my issue might be.
     
    #9 avoice217, Jul 24, 2024
  10. ChapmanF

    ChapmanF Senior Member

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    The issue is probably an open in the safety interlock circuit somewhere. It is a dead-simple series DC circuit that pulls the HV control ECU's ILK pin to ground when all of the interlocks are made. An open circuit is reported as P0A0D.

    Troubleshooting that kind of a circuit with a multimeter is a very basic exercise. The wiring diagram shows how it is routed. I would definitely do that troubleshooting before I would start to think the ECU had gone bad.
     
    #10 ChapmanF, Jul 24, 2024
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