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U0100 culprit?

Discussion in 'Gen 2 Prius Technical Discussion' started by GhostmanOn3rd, Jan 25, 2022.

  1. GhostmanOn3rd

    GhostmanOn3rd Junior Member

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    I think I have a short somewhere. I have the following codes with both new Toyota hybrid and accessories battery.

    2009 Gen 2
    187k miles

    Poa60
    Poa63
    Poa72
    Poa75
    Poa78
    Poa7a
    P0A94
    Poaef
    P3222
    U0100
    Poa0d
    P3000

    Likely towing it to Toyota unless someone might have a little insight on what to check.

    I’ve visually checked about every wire I could find without taking dash apart.

    I have seen some nibbles on some wires so I’m thinking I have a short in the harness somewhere.

    I can get the car into neutral but not into drive or reverse.
     
  2. SFO

    SFO Senior Member

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    Which OBD2 scanner are you using to retrieve the above codes (DTCs) ?

    Did the above codes (DTCs) just happen out of the blue, or did something lead up to this event?

    If you recently installed the new toyota HV battery and have a DTC P0A0D, you should check the orange high voltage system interlock on the battery, is it properly installed and seated? Check if the internal fuse is good.
     
    #2 SFO, Jan 25, 2022
    Last edited: Jan 25, 2022
  3. GhostmanOn3rd

    GhostmanOn3rd Junior Member

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    I used Dr. Prius for this last reading but I also have used a Fancy Autel or snap-on. I don’t remember the brand. My neighbor is a mechanic and scanned it for me. It had page after page of errors which makes me think harness or maybe computer.
     
  4. SFO

    SFO Senior Member

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    First start with DTC P0A0D :

    [​IMG]
     
  5. SFO

    SFO Senior Member

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    If you tow it into the dealer, they will likely charge you $$$ to diagnose, then tell you they need more hours/$$$ of diagnostics to figure out what the problem is/isn't, then try to sell you a new harness or some other expensive fix, which may or not fix it, still costing you thousands.

    Do you have a DIY attitude and some basic tools, including a multimeter, or can the neighbor help at all?
     
  6. GhostmanOn3rd

    GhostmanOn3rd Junior Member

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    So the orange plug is locked properly. Would a bootleg techstream be able to diagnose?
     
  7. SFO

    SFO Senior Member

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    Unlikely that the orange plug has a bad fuse, but something to check. Who installed the new OEM battery?
    Couldn't hurt, as that is what the dealer technicians will use if you tow it into a dealership.
     
  8. GhostmanOn3rd

    GhostmanOn3rd Junior Member

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    They were there when I bought the car but my crap scanner I had with me didn’t see those codes.
     
  9. SFO

    SFO Senior Member

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    Is this the same vehicle with some (or all) of the same issues? : Fuel pressure zero | PriusChat

    In regards to another one of your lack of fuel posts, check the wiring on top of the gas tank, as @Dxta found a chewed up harness once.

    Given some of the above DTCs, have you also inspected under the hood for harness and wiring damage related to the nesting rodents?
     
  10. GhostmanOn3rd

    GhostmanOn3rd Junior Member

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    It is!

    i forgot I posted that. I did manage to check the fuel pump pressure and it’s perfect.
     
  11. SFO

    SFO Senior Member

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    Is it safe to say that you've never been able to start or drive the vehicle since purchasing as-is?

    Did you service the old HV battery and reinstall it yourself?

    Have you checked for 220V at the inverter already?

    Have you checked all of the fuses in the vehicle?

    Given the reported rodent nesting that was found, it would best to look everywhere for signs of wiring damage, not just the interior.

    Looking at the workups below, doing diagnostics on this vehicle will be far less time consuming if you have techstream or a device that can retrieve the related INFs (aka subcodes, secondary codes, detailed codes) for some of the reported DTCs. Not all DTCs have INFs.

    Here is the work up for DTC P0A60 and DTC P0A63, both with various INFs : https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/repair%20manual/04pruisr/05/21bpm/0a60288.pdf

    Here is the work up for DTC P0A72 and DTC P0A75, both with various INFs : https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/repair%20manual/04pruisr/05/21bpm/0a72326.pdf

    The workups for DTC P0A78, DTC P0A7A and DTC P0A94 are quite numerous, best if you retrieve the INFs and look for the needed workups here : share.qclt.com - /丰田普瑞斯原厂英文手册pdf格式/repair manual/04pruisr/05/21bpm/

    For that reported DTC P0AEF, could this be DTC P0A0F or another DTC?

    Here is the work up for DTC P3222 : https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/Prius%20Service%20Manuals%202004/%E4%BF%AE%E7%90%86%E6%89%8B%E5%86%8C/04pruisr/05/21bpm/3222313.pdf

    For DTC P0A0D we've address that already, though there could be a bad internal fuse.

    For DTC P3000 that points to the HV battery assembly, have you checked the connections for corrosion, including the HV battery ECU?

    [​IMG]

    [​IMG]

    Have you read this thread? : Help! Prius 2007 error with P0A78 P0A7A P0A94 PA040 PA041 | PriusChat

    If you have the back apart, check for corrosion at the HV battery fan connectors (and clean the fan if needed) :

    [​IMG]

    [​IMG]
     
  12. GhostmanOn3rd

    GhostmanOn3rd Junior Member

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    So this hybrid battery is literally 6 months old from Toyota. Terminals have been checked.

    ***This car will pop the 15 amp EFI fuse every time I start it up.
     
  13. ChapmanF

    ChapmanF Senior Member

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    When the Universe hands you a clue like that, you follow it. :)

    Have you looked in the wiring diagram (more info) to find what's downstream of that fuse, and started using your multimeter to chase that down?
     
  14. GhostmanOn3rd

    GhostmanOn3rd Junior Member

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    So I do not know how to do that.
     
  15. ChapmanF

    ChapmanF Senior Member

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    So, how much don't you know? Sometimes it's easier to help when we know where to start.

    Did you follow the link above and see how to get access to the wiring diagram?

    Have you looked at a wiring diagram before?

    Do you own a multimeter?

    What kind of work on 12 volt systems have you done before?
     
  16. GhostmanOn3rd

    GhostmanOn3rd Junior Member

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    I’ve looked at diagrams before and get intimidated. I do have a multimeter and understand how to check for continuity. I also have a test light that I think I know how to use. Haven’t had a chance to pull the link. Thanks for the support.
     
  17. ChapmanF

    ChapmanF Senior Member

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    Following that wiki link above, where it talks about the wiring diagram, there are also links to some other posts where examples were given of finding your way around it. You might find those helpful too.
     
  18. GhostmanOn3rd

    GhostmanOn3rd Junior Member

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    So I unplugged all 3 wires connections at the tank that connect the fuel tank and the 15 amp EFI FUSE blew.
     
  19. GhostmanOn3rd

    GhostmanOn3rd Junior Member

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    So I followed down the vsv, air ratio sensor, and MAF SENSOR and unplugged them all and it still blew fuse. Last thing is the ECM.

    how safe is it to swap a bad ecm into my hood car to test?
    I’m afraid to put the good ecm in the bad car because what if something shorts it out.
     
  20. ChapmanF

    ChapmanF Senior Member

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    Short could be in the wiring itself, not in any of the plugged-in components.

    Sometimes testing goes faster with something like a 12 volt test light installed in place of the fuse that keeps blowing. Then you can keep looking for what you have to disconnect for the light to go out, and you don't keep replacing dead fuses.