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negative block voltage? Please help!!! *Added Photo

Discussion in 'Gen 2 Prius Technical Discussion' started by redsokfan7, Jan 1, 2021.

  1. redsokfan7

    redsokfan7 New Member

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    Location:
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    Vehicle:
    2004 Prius
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    ----USA----
    I am using torque app, I have gotten P0A80
    and the car is still drivable. But on blocks 12,13,and14 intermittently those block flash to negative voltage then back to normal voltage. All other blocks are normal as well as those three until the dial swings back and forth from negative to normal. I have moved the 3 blocks to the front of pack and the issue did no move.
    I have cleaned all bus bars completely, changed all sensing wires, cleaned all contacts and connectors with no burning or corroded connections. Might it be the hybrid battery ecu? I know that would have another code but I dont know what else to check?

    *If you look at photo last 3 blocks read 16 but the min and mx value is normal and either negative or something weird.
     

    Attached Files:

    #1 redsokfan7, Jan 1, 2021
  2. SFO

    SFO Senior Member

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    Welcome to PriusChat!!

    If you haven't already, check the ECU voltage sensor connector and plug :

    [​IMG]

    [​IMG]

    If those look good, then take a peak inside the ECU and look for internal corrosion or whiskers :

    [​IMG]

    This thread has more images that may be helpful : The battery fires at ECU sense connector thread | PriusChat
     
    #2 SFO, Jan 2, 2021
    landspeed and donbright like this.
  3. PriusCamper

    PriusCamper Senior Member

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    Wow... Ordinarily replacing voltage sensing wires is the fix for this problem? Was there any sign of corrosion where voltage sensing wires plug into the ECU? Also taking the cover off the ECU and making sure that plug is still connecting to circuit board is essential if there was signs of corrosion in that plug socket.

    But I suspect the main source of your problem is Torque app, which wasn't built for hybrid cars and doesn't work as well as Dr. Prius app or Toyota techstream. The P0A80 that Torque app is reading has sub-codes to point you in the right direction but Torque app can't read sub-codes.

    So if everything in the pack checks out and it sounds like it does, I'd blame it on torque app... I just went and looked at the latest comments on Torque App Pro and there's plenty of unhappy people and not many who are happy.
     
    #3 PriusCamper, Jan 2, 2021
  4. TMR-JWAP

    TMR-JWAP Senior Member

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    Moving the modules from one area of the pack to another will change nothing. A module cannot just flip its voltage. Your problem is the sensing harness or the ecu. If this is the original harness, you probably have small fractures in the crimp where the tab connects to the wire, or you have corrosion issues at the plug/socket junction (as mentioned earlier). Or, possibly loose connections at the studs or you just have an ecu issue.
     
    #4 TMR-JWAP, Jan 2, 2021
    landspeed likes this.
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