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AC not working with Error codes 23, 42, 72. How do I fix this?

Discussion in 'Gen 2 Prius Technical Discussion' started by NotEvenThatsOdd, Jul 15, 2019.

  1. NotEvenThatsOdd

    NotEvenThatsOdd New Member

    Joined:
    Jul 15, 2019
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    Location:
    W. Massachusetts
    Vehicle:
    2008 Prius
    Model:
    Two
    Hi all,
    I’m not mechanic but I’m fairly handy when it comes to cars. I’ve successfully changed the head gaskets in my 2009 Subaru. On my 2008 Prius, I’ve changed the oil, front brake pads, rotors, front struts, both tie rods on both sides, sway bar links, wheel bearings, axle, etc.

    So now it’s time to tackle the AC that doesn’t work. The fans blow in the cabin but only not-cool air. I bought this car in the winter a few years ago and didn’t bother to check the AC until last summer and now I’m trying to fix it.

    I bought gauges and both high and low say 25 psi. I discovered the error codes by pressing the buttons on the steering wheel and came up with codes 23, 42, and 72.

    I am not gonna take this into a shop so please don’t suggest I do so. I would like to learn how to fix this myself. If anybody has any leads on where to start, I would love to hear suggestions.
     
  2. Dr_DLH

    Dr_DLH Member

    Joined:
    Apr 9, 2012
    106
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    Location:
    California
    Vehicle:
    2011 Prius
    Model:
    III
    Did you ever get this resolved? We have a 2005 Prius that is showing codes 21 and 23. Seems to blow cold for a bit and then stop. We had it serviced and the AC guy is puzzled. The hi side line is not getting hot. Normally they are too hot to touch. Pressure is normal for hi (200)and low(35) side. The fan is still blowing but just goes to humid. Has anyone experienced the code 23 and how to fix it?
     
  3. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
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    8,382
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    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    The ac normally shuts down when it detects an overheating situation.

    Most of the time people experience this when their inverter pump fails. But this should light up your red triangle when you drive for longer periods
     
    Raytheeagle likes this.
  4. Dr_DLH

    Dr_DLH Member

    Joined:
    Apr 9, 2012
    106
    19
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    Location:
    California
    Vehicle:
    2011 Prius
    Model:
    III
    Replaced the inverter pump last week because of another issue. The AC has not worked correctly for over a month. I may have found the issue as last night it started working perfectly.. Will update what I find.
     
    Sue Ellen likes this.
  5. Shawn W.

    Shawn W. Junior Member

    Joined:
    Jun 8, 2022
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    Location:
    Niagara Falls
    Vehicle:
    2004 Prius
    Model:
    N/A
    It's been almost three years. What did you find?