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Red Triangle after a freeze

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by laika108, Oct 16, 2024.

  1. laika108

    laika108 New Member

    Joined:
    Oct 23, 2023
    4
    1
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    Location:
    Columbus, OH
    Vehicle:
    2007 Prius
    Model:
    II
    I’m trying to diagnose a fault with my 2007 Prius. Here are the codes:


    I think P0AFA is related to the voltage in block 1 cycling between 15V and about -3V. An inverter issue?

    The car was working great even last night, but this morning after the first big freeze suddenly the issues popped up. Something very similar happened about a year ago exactly with the first freeze. I couldn’t drive it all winter, but when I went to fix it in the spring I didn’t have to do anything besides charge the 12V battery. Any clue what’s causing these winter woes?
     
    #1 laika108, Oct 16, 2024
  2. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    10,361
    1,790
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    Probably Original battery or rebuilt . And it's just time..
     
    #2 Tombukt2, Oct 16, 2024
  3. Brian1954

    Brian1954 Senior Member

    Joined:
    Jan 31, 2021
    1,105
    410
    0
    Location:
    South Central PA, USA
    Vehicle:
    2011 Prius
    Model:
    III
    You have a problem with corrosion on the voltage sensing wire harness where it connects to the HV battery ECU. This is the orange connector that plugs into the HV battery ECU. You will need to replace the voltage sensing wiring harness and/or the HV battery ECU. This is a common problem for a Gen 2 Prius because of water leaking into the trunk area of the car.

    Take a look at this thread:https://priuschat.com/index.php?posts/3437054
    and do a search in the Gen 2 forum for similar threads.
     
    #3 Brian1954, Oct 16, 2024
    Last edited: Oct 16, 2024
  4. laika108

    laika108 New Member

    Joined:
    Oct 23, 2023
    4
    1
    3
    Location:
    Columbus, OH
    Vehicle:
    2007 Prius
    Model:
    II
    I’m pretty sure I messed up that harness a couple years back when I first rebuilt the battery. No clue why it only gives fits when it’s cold: I’ll go ahead and rebuild it again though. Thanks for taking a look at it!
     
    #4 laika108, Oct 17, 2024
    Brian1954 likes this.
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