Diagnosing Inverter Coolant Pump Issue

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by newpain01, Apr 30, 2025 at 8:57 PM.

  1. newpain01

    newpain01 New Member

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    Vehicle:
    2013 Prius
    Model:
    Three
    Hey everyone!

    I have a 2013 Prius getting a code P314A, replaced the Inverter Coolant Pump with a brand new Aisin pump, checked the IGCT fuse which was fine and also replaced the IGCT Relay and I'm still getting "Check Hybrid System" error on the dash, a P314A code and the radiator fans are running at all times. I have tried disconnecting the batteries and charging the 12V battery as well.

    I also unhooked the upper hose going into the inverter radiator and confirmed that no coolant is running, the pump doesn't seem to turn on. I unhooked the connector on the pump and tried measuring voltage on the blue and white wires and was reading 0V, so I am assuming no power is going into the pump.

    Scanned it with Techstream and that's all it shows. When trying to do an Active test on the pump, Techstream throws a fatal error.

    What can I do to test and diagnose this?
     
    #1 newpain01, Apr 30, 2025 at 8:57 PM
  2. PriusCamper

    PriusCamper Senior Member

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    Pacific Northwest, USA
    Vehicle:
    2007 Prius
    Model:
    Two
    Perhaps @ChapmanF or @SFO or @Mendel Leisk could help yo go further down the Toyota techstream rabbit hole with this? Seems like you've done everything right so far and that getting more options / expertise in Techstream is what's going to help you figure this out. Or at least that's my impression after taking a look at the links:

    upload_2025-5-1_13-10-23.png
     
    #2 PriusCamper, May 1, 2025 at 4:10 PM
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