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Low voltage to traction battery relays. (11.2) , inverter pump doesn't run

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by tallman, Jan 18, 2020.

  1. tallman

    tallman Junior Member

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    Red triangle car doesn't run

    Posted via the PriusChat mobile app.
     
  2. SFO

    SFO Senior Member

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    The vehicle is trying to tell you something is wrong, best to scan it with an OBD2 device so as to retrieve the stored DTCs.

    Might also consider testing the 12v battery health.
     
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  3. tallman

    tallman Junior Member

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    Snap on scanned poa63,poa72,poa75,poa78,poa7a,power. Bought Car not running on a trip from NC to Canada, towed to Toyota dealership, they said it needed a new wireing harnes $5000 , I bought as is inverter pump does not run , it was replaced 20 k ago by Toyota

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  4. jerrymildred

    jerrymildred Senior Member

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    Are you saying the 12V battery only has 11.2 volts? If so, that the first thing to address. Many, if not all, the other issues will likely disappear once there's enough voltage to close the relays and run the computers.
     
  5. tallman

    tallman Junior Member

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    12 volt was down when I got charged up fine, left booster hooked to back,and shows good voltage ( 12.8 - 13.5) but at fuse box up front only shows 11.2 , same as at traction battery relays with start button pushed,, wondering if inverter pump is pulling voltage down,,,, or could cable going from back 12 volt to front have a problem

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  6. tallman

    tallman Junior Member

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    I did check amp draw at back , there is a 10.5 draw off battery in back with start button pushed

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  7. davecook89t

    davecook89t Senior Member

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    You could try disconnecting the inverter pump to see if that is drawing down the voltage. The plug is located next to the fusebox near the firewall on the driver's side. That is the recommended procedure if the inverter pump keeps blowing the AM2 fuse. The car can run for short periods without the inverter pump operating.
     
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  8. tallman

    tallman Junior Member

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    Thanks , I was trying to get to the plug on the pump ,was about ready to start pulling things,

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  9. tallman

    tallman Junior Member

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    Checked what think is the am fuse , 2nd one of four on the driver's side of fuse box it's good

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  10. tallman

    tallman Junior Member

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    This car has probably been run until it quit . I didn't have it when the problem started

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  11. davecook89t

    davecook89t Senior Member

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    Right, I would expect that the AM2 fuse would be good if the inverter pump is still drawing power. Also, you would have no dash lights if the AM2 fuse is blown, since most of them are on the same circuit. My advice was to disconnect the plug that supplies power to the inverter pump, as shown in the picture supplied by @JC91006 in #4 of this thread: HELP PLEASE!! Triangle of Death w/check engine, VSC & Brake control lights.CAR NOT DRIVING! NO CODES | PriusChat.

    You should be able to compare your voltage at the front jump points with the power to the inverter pump disconnected to the voltage when it is connected to see if that is what is drawing down your battery's power.
     
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  12. jerrymildred

    jerrymildred Senior Member

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    Sounds like a loose connection. Sometimes the ground connection to the car's body will corrode and/or come loose. Also the terminal clamps themselves can be loose. That would explain the normal voltage at the battery and the low voltage up front. It's extremely unlikely to be a fuse.
     
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  13. SFO

    SFO Senior Member

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    Here is the workup for DTC P0A63 (with an unknown INF or subcode) : 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 workup for DTC P0A72 and DTC P0A75 (both with unknown INFs or subcodes) : 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 workup for DTC P0A78 has far too many INFs or sub codes (aka detail code) to list them all, you will need a scanner that will offer appropriate subcode.

    The workup for DTC P0A7A also has far too many INFs or sub codes (detail codes) to list them all, you will need a scanner that will offer the appropriate subcode.
     
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  14. tallman

    tallman Junior Member

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    Unplugged the connection in the picture ,no change or noise from the pump, no power at either side of the plug that i unconnected, I do have 12.2 volts at jump terminal at fuse box
    Posted via the PriusChat mobile app.
     
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  15. TMR-JWAP

    TMR-JWAP Senior Member

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    You may also want to take a very careful look at the main fusible link on the passenger side of the engine compartment fusebox. If anyone tried to jump the car and connected backwards, it will blow the portion at the upper right corner of the link, along with a few fuses in that fusebox. This will NOT kill all functions of the car, but it will cause the ABS system to have a non-stop high draw from the battery, which may be what you have going on. Speaking from experience when I recently helped a young lady across town that had similar symptoms as you.

    If you have verified the fusible link: What happens if you connect the jump pack to the underhood jump point and a good engine compartment ground point? You've got to have good connections because you'll have a heck of a draw when the brake pump turns on.

    Connect it there.
    Then....
    With all the doors closed and the key FOB away from the car, is the security light on the dash flashing every couple seconds?

    Get the fob, open the door. Does the door ajar light come on?

    Press the power button one time (no foot on brake) the MFD should turn on.
    Press the power button again, the dash should come alive.
    Press power button one more time, everything should turn off.

    Now put your foot on the brake and press power one time, the car should turn on and go ready.

    If something above does not happen, tell me where it fails to happen and we'll go from there.
     
    #15 TMR-JWAP, Jan 20, 2020
    Last edited: Jan 20, 2020
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  16. TMR-JWAP

    TMR-JWAP Senior Member

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    This is the portion of the fusible link that usually blows. This photo is with the plastic cover removed. The stud is the underhood jump point, also where the main power cable from the 12v battery connects. And yes, if that is blown, as soon as you press the power button, the ABS system will put a large current draw on the 12v system and draw the voltage way down. I initially pulled the 2 ABS relays to get the current draw to stop while I was troubleshooting. It was the first time I had worked on a car with this problem.

    There were two or three other small fuses blown in that box, but I don't remember exactly which ones. If you find the fusible link blown, you may want to check every fuse in that box.

    Fusible Link.JPG
     
    #16 TMR-JWAP, Jan 20, 2020
    Last edited: Jan 20, 2020
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  17. Priuslover09

    Priuslover09 Member

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    Where are you in West Virginia what were the codes like? Did you test the 12v?
     
  18. tallman

    tallman Junior Member

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    30 miles north of Beckley near rt 19 Fayetteville
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  19. tallman

    tallman Junior Member

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    I checked all fuse with a test light , they are ok , I'll check it the link tomorrow and do the other and jump box , inverter pump is not running, I unplugged at firewall near fuse box , no change, appreciate your help

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  20. tallman

    tallman Junior Member

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