Inverter pump not pumping

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Dummy, Oct 8, 2022.

  1. Dummy

    Dummy Member

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    My dash lit up like a Christmas tree and the code says it’s the inverter pump. I opened the reservoir and the coolant isn’t moving. I would like to rule out any fuse or relay issues before I swap the pump. Can you tell me all of the things to check?

    The lights that come at the same time are the red triangle, check engine, yellow circle with !, and VSC
     
    #1 Dummy, Oct 8, 2022
    Last edited: Oct 9, 2022
  2. JC91006

    JC91006 Senior Member

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    From my experience with the pump failure, it would only light up the red triangle. If you have a bunch of lights that turned on, you may have additional problems. But I would first start with the pump if you are getting the code P0a93 and notice no movement in the coolant.
     
  3. wjtracy

    wjtracy Senior Member

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    Those pumps seems to last 80-90k miles
     
  4. mr_guy_mann

    mr_guy_mann Senior Member

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    Well, you could unplug the connector at the pump, power up the car, and test for power and ground. The white wire with black stripe in the connector should be ground, and the other wire should 12V.

    Posted via the PriusChat mobile app.
     
  5. Dummy

    Dummy Member

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    yep that’s the code and I have no movement. Why wouldn’t I check fuses/relays first?
     
  6. Dummy

    Dummy Member

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    I’ll try that. If there’s no power what should I check?
     
  7. ChapmanF

    ChapmanF Senior Member

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    In the unlikely event you find no power, you can check with us and we'll go from there. In the likely event that power is ok, you already know what comes next.
     
  8. SFO

    SFO Senior Member

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    Inverter coolant pumps don't last forever; when was the last time it was changed, and did you use an OEM pump?
     
  9. TMR-JWAP

    TMR-JWAP Senior Member

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    The Inverter Cooling Water Pump receives power through the AM2 fuse. If the AM2 fuse were blown, the entire car would be dead.
     
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  10. ChapmanF

    ChapmanF Senior Member

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    Well, parts of the car would power up and work—those on other fuses—but it definitely wouldn't be taking you anywhere.
     
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  11. Dummy

    Dummy Member

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    The pump has started pumping again. I turned the car on and removed the coolant cap. I then squeezed the hose to see if I could feel movement. When I let go I could see movement in the reservoir. Is this a freak occurrence?
     
  12. SFO

    SFO Senior Member

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    @Dummy - just be patient, and wait for the pump to finally fail, and if lucky it will blow the AM2 fuse first.
     
  13. Dummy

    Dummy Member

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    I don’t know when it was changed last. I bought it at 180k and it has about 210k now.
     
  14. wjtracy

    wjtracy Senior Member

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    Well, a lot of us had a recall on it inverter pump replacement at the ~50-80k mark. So somewhere around 170k I had to replace again on my own nickel. If this is only your second pump, you are probably overdue.

    These are amazing 12v pumps, some find other non-car uses. But they do not last forever.
     
  15. mr_guy_mann

    mr_guy_mann Senior Member

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    It's a not unheard of failure mode (esp for aftermarket pumps). I would replace the pump ASAP.

    I did mine last year (just because) and used a Toyota part. More expensive than AM units but to me the difference in price isn't worth the possible problems of it failing sooner.

    YMMV

    Posted via the PriusChat mobile app.