Problem after replacing the high voltage battery

Discussion in 'Gen 2 Prius Technical Discussion' started by LinuxOID, Jun 24, 2026 at 10:51 AM.

  1. LinuxOID

    LinuxOID New Member

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    Location:
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    Vehicle:
    2003 Prius
    Model:
    II
    Toyota prius NHW20 (JDM) 2003 year (pre-restyling)

    Hello everyone. So, I replaced the high-voltage battery with a used original one.

    I started getting errors P3140 and P3143 intermittently (I can't find any information about the second one anywhere). This all happened while driving, so I can't tell you the error codes because I reset the ELM.

    How I solve this problem: I simply remove and reinsert the orange pin... I insert it correctly, pushing it down at the end. After that, the problem goes away again after 30-50 km. Can you tell me what could be the cause? upload_2026-6-24_17-50-16.png

    upload_2026-6-24_17-49-55.png
    I pulled the pin intentionally to provoke the error p3143 and read its subcode when I already had the TechStream in hand, but only p3140 appeared and p3143 did not.

    I disassembled the pin itself and everything is clean. I also tested the connector that connects to the pin and it's fine. The problem is most likely somewhere in the high-voltage battery, not in the inverter (which is what some people mention). I draw this conclusion because the error disappears after I remove the pin. Or am I wrong?
     
    #1 LinuxOID, Jun 24, 2026 at 10:51 AM
  2. Brian1954

    Brian1954 Senior Member

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    III
    #2 Brian1954, Jun 24, 2026 at 11:18 PM
    Last edited: Jun 25, 2026 at 8:45 AM
  3. Hayslayer

    Hayslayer Active Member

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    Location:
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    Vehicle:
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    Touring
    Since the last place you worked was the HV battery I would start with that. The socket where the safety plug inserts has a plug at the bottom which is the interlock. Maybe you didn't plug the wire in all the way at the bottom. This is the short wire that's about 6 inches long and goes from the bottom of the socket to the top, where it then connects to the car harness. You could also have damaged or poor condition pin connectors in any of those connectors creating an intermittent connection.
     
    #3 Hayslayer, Jun 25, 2026 at 9:13 PM
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