AUTO mode blows only warm air, but Defrost mode works....

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Minty_Prius, Jul 10, 2015.

  1. Minty_Prius

    Minty_Prius New Member

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    Hello,
    On a recent 500 mile trip, I noticed the AUTO mode no longer triggered the cooling to work in my 2011 Prius. When I press AUTO and set the temp to a low temperature or LO, I only get warm air blowing out of the system (the AC button is lit when this happens). However, when I select the "defrost" button, very cold air comes out and the cooling seems to be working as usual. I've searched for quite a while on this topic, and can't find any similar situation described. Does anyone know how to fix this? My first thought would be a blown fuse, but I don't know which one I would check for this issue.

    Thanks for any ideas or leads!
     
    #1 Minty_Prius, Jul 10, 2015
  2. Tim Bender

    Tim Bender Member

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    One of the peculiar things about the A/C system (and you can confirm this with a scangauge or OBDII tool) is that the A/C compressor runs when defrost is on regardless of whether the A/C button is lit or not. I assume that you're getting cold air when you press the "Front" defrost button.

    Do you get cold air when you cycle the "mode" button to the defrost icon? IIRC that state also engages the A/C compressor.

    [​IMG]

    I have no idea how you're going to track down the problem but this might point you in a direction.
     
    #2 Tim Bender, Jul 10, 2015
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  3. Minty_Prius

    Minty_Prius New Member

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    Hello Tim,
    Thanks for responding! Yes, I am getting cold air when I press the "front" defrost button. I also get cold air when I cycble the "mode" button to defrost. I don't get cold air out of the main front vents when I press AUTO. I think this tells me the compressor is working fine, but something is wrong with the control. If you or anyone knows of any fuse to change or any test I can perform, it will be appreciated. Thank you!
     
    #3 Minty_Prius, Jul 10, 2015
  4. bisco

    bisco cookie crumbler

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    try turning everything off, then turn the fan on, then set the airflow to face, then press the a/c button.
     
    #4 bisco, Jul 10, 2015
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  5. Minty_Prius

    Minty_Prius New Member

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    Bisco. That worked! Thank you!
     
    #5 Minty_Prius, Jul 11, 2015
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  6. bisco

    bisco cookie crumbler

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    pleasure.
     
    #6 bisco, Jul 11, 2015
  7. Spooled

    Spooled Member

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    Wth? why doent the ac blow when on?
     
    #7 Spooled, Jul 11, 2015
  8. John Allen

    John Allen New Member

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    This doesn’t work for me, any other suggestion?
     
    #8 John Allen, Nov 4, 2020
  9. bisco

    bisco cookie crumbler

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    welcome!
    are you experiencing the exact same symptoms?
     
    #9 bisco, Nov 4, 2020
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