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Inverter Coolant Issues?

Discussion in 'Gen 2 Prius Main Forum' started by jsinclair92, Jun 3, 2018.

  1. jsinclair92

    jsinclair92 Junior Member

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    I have had my 2008 Prius for 2 years without the first issue. A month or so ago I got a check engine light code, stating the inverter coolant 3 way valve was bad. I replaced it a few days ago and had no issues. The original code is gone .

    However, now I have two new codes (P0117 and P1116). I have spent the last few days reading every article on the internet trying to fix this new issue: I lost ~ 1 gallon of coolant when changing the valve . And have spent all weekend trying to purge the system of air. The coolant level in the reservoir was full when I replaced the valve, and is still full. I figured, like with any overflow reservoir, when the system is low, the tank empties. I have had no such luck.

    I have confirmed that the pump is running. With the car off, I pulled the pump relay and ran the pump in 20 second intervals . There was no turbulence in the reservoir. However, when I turn the ignition on and run the AC, I do see slight turbulence in the reservoir and feel the hoses coming off of the pump vibrating.

    When driving, I get the red triangle and a coolant temperature icon on the screen, which I assume means I'm overheated.

    What are my options? I have read horror stories on this forum of members getting in legal battles with Toyota over this very issue. What have I missed? What else can I try?
     

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  2. JC91006

    JC91006 Senior Member

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    There are 3 areas you'll need to check coolant levels.

    1. Engine side reservoir
    2. Radiator
    3. Inverter reservoir

    Make sure all 3 are full


    Did you by any chance disconnect the inverter pump when you replace the 3 way valve? And not connect it back?
     
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  3. Dxta

    Dxta Senior Member

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    +1 is either one of the cooling systems is clogged, causing the overheating symbol.
    Make sure no pipes, etc are kinked.
    In some cases I have worked on, the radiator might be clogged internally, or there could be a cylinder gasket problem.
     
  4. dolj

    dolj Senior Member

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    Make sure the CFCV is plumbed correctly. See attached picture. Some have crossed over the plumbing that comes off the top, which causes problems.

    Prius ICE cooling curcuit NA.png
     
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  5. jsinclair92

    jsinclair92 Junior Member

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    The engine side and inverter coolant reservoirs are full. I will check the radiator fluid level when I get home.

    I didn't disconnect the inverter pump, but I will be sure to double check. I marked the hoses prior to pulling them from the old 3-way valve, to ensure I didn't mix them up. I will certainly check to ensure all plumbing is correct.
     
  6. JC91006

    JC91006 Senior Member

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    It sounded to me from your post, you didn't fill the radiator after replacing the valve
     
  7. ChapmanF

    ChapmanF Senior Member

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    This sounds like some possible confusion. There isn't a three-way valve for the inverter cooling system.

    If you changed a three-way valve in a cooling system, the coolant that came out was from the engine. Did that get put back?

    -Chap
     
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  8. jsinclair92

    jsinclair92 Junior Member

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    Chap and JC - You are both correct. I read somewhere that the Prius had two separate cooling systems (one for the engine, and another for the inverter). Once I reviewed the diagram dolj shared I realized my assumption wasn't correct. Fingers crossed that the radiator is low on coolant and its a quick and easy fix.
     
    #8 jsinclair92, Jun 4, 2018
    Last edited: Jun 4, 2018
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  9. jerrymildred

    jerrymildred Senior Member

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    Your assumption was correct. Inverter cooling and engine cooling are totally separate systems. The diagram dolj shared doesn't show the inverter system.

    If you replaced the control valve, you need to bleed the engine cooling system, not the inverter cooling system.
     
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  10. ChapmanF

    ChapmanF Senior Member

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    Right, there's nothing wrong with what you read. The only trouble is you stopped reading before making sure which is which! :)

    -Chap
     
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  11. jsinclair92

    jsinclair92 Junior Member

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    Sometimes the simplest things throw us for a loop...

    It turns out the radiator was nearly bone dry. I will burp the system tonight and should be good to go. I will report back if this doesn't fix the issue.

    Thanks for the help guys!
     
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  12. jerrymildred

    jerrymildred Senior Member

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    YIKES!!! I assume you'll fill it this time? :)
    Hopefully, you caught it before the engine got too hot.
     
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