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A/C blowing hot air while vehicle is in motion

Discussion in 'Gen 3 Prius Technical Discussion' started by willie1154, Jul 19, 2024.

  1. willie1154

    willie1154 New Member

    Joined:
    Jul 19, 2024
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    Location:
    San Antonio, Texas
    Vehicle:
    2011 Prius
    Model:
    Three
    Hello,
    My 2011 Prius A/C started blowing cold air as usual when I turned on the car. When the car is in motion, the air goes from cold to hot. I saw a thread on this which said it was most likely one or any of the three actuators in the HVAC box that is possibly stuck. My thought is that the thermostat may be stuck. Well, yesterday I reset the hybrid system, and everything is back to normal. A/C is blowing cold air again. Any ideas?
     
  2. ForestBeekeeper

    ForestBeekeeper Active Member

    Joined:
    Sep 19, 2011
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    Location:
    Maine
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    When you say, "I reset the hybrid system".

    Do you mean you shut the car off, waited a minute and restarted it?

    I once had an issue with the HUD screen, a shutdown and restart fixed it.

    Another couple of times my cruise control went on the blink. A shutdown and restart fixed it each time.



    Or do you mean, shut down, disconnect the 12vdc battery for a minute, re-connect and restart?
     
  3. willie1154

    willie1154 New Member

    Joined:
    Jul 19, 2024
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    Location:
    San Antonio, Texas
    Vehicle:
    2011 Prius
    Model:
    Three
    I unplugged the hybrid and the 12V battery for 10 minutes, then reconnected and turned on vehicle.
     
    ForestBeekeeper likes this.
  4. ForestBeekeeper

    ForestBeekeeper Active Member

    Joined:
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    Location:
    Maine
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    When I first bought our 2011, the dealership Service Manager warned me about voltage spikes on the 12vdc battery terminal as responsible for burning out computer chips in the vehicle.

    According to him, anytime you jump the vehicle or disconnect/re-connect the 12vdc terminals you risk frying chips.
     
    #4 ForestBeekeeper, Jul 20, 2024
    Last edited: Jul 20, 2024
  5. ChapmanF

    ChapmanF Senior Member

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    Vehicle:
    2010 Prius
    Model:
    IV
    I don't think I worry about that as much as that dealership Service Manager does.
     
    bbrages likes this.
  6. BlainesGarage

    BlainesGarage New Member

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    Jul 10, 2024
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    Location:
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    Vehicle:
    2012 Prius
    Model:
    Four
    Most dealership service managers have the same skill set as a grocery store manager.