1. Attachments are working again! Check out this thread for more details and to report any other bugs.

My AC just turns on Automaticly

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Fishcrab, Apr 26, 2015.

  1. Fishcrab

    Fishcrab Member

    Joined:
    Apr 3, 2015
    152
    29
    0
    Location:
    Florida
    Vehicle:
    2005 Prius
    Model:
    Two
    With my ac/ heating system set in the off position, my ac comes on all on its on with fan .
    This happens after I have been driving for awhile. Is this normal?
     
    #1 Fishcrab, Apr 26, 2015
  2. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,470
    8,383
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    Your climate controls shows everything off and air is blowing from your front vents? When stopped?
     
    #2 JC91006, Apr 26, 2015
  3. jdenenberg

    jdenenberg EE Professor

    Joined:
    Nov 21, 2005
    3,837
    1,827
    1
    Location:
    Trumbull, CT
    Vehicle:
    2020 Prius
    Model:
    LE AWD-e
    Turning off the AC via the MFD just turns off the AC compressor. The Fan/Heat/Defrost still functions when the thermostat requires it. You can also turn everything off via the steering wheel controls.

    JeffD
     
    #3 jdenenberg, Apr 26, 2015
  4. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,662
    38,207
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Toyota refers to the whole system as "air conditioning" (at least in 3rd gen Owners Manual), which is frustrating/confusing. Maybe OP can clarify, is it the cabin ventilation system's fan, or the air conditioning (ie Freon compressor, and so on) that's turning on.
     
    #4 Mendel Leisk, Apr 26, 2015
  5. Fishcrab

    Fishcrab Member

    Joined:
    Apr 3, 2015
    152
    29
    0
    Location:
    Florida
    Vehicle:
    2005 Prius
    Model:
    Two
    It's both the fan and the ac compressor turning on. The yellow ac light come on,on display.
    Yep, I think they refer to in The gen 2 as the whole system being ac too.
    Prior to the ac coming on, the ac system is in the off position.
     
    #5 Fishcrab, Apr 26, 2015
  6. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,693
    48,945
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    what is your thermostat set at?
     
    #6 bisco, Apr 26, 2015
  7. Fishcrab

    Fishcrab Member

    Joined:
    Apr 3, 2015
    152
    29
    0
    Location:
    Florida
    Vehicle:
    2005 Prius
    Model:
    Two
    It been around 77, usually not a really hot day.
    So are you saying if the thermostat is set low , the ac will come on? Even when unit is in off position.
     
    #7 Fishcrab, Apr 26, 2015
  8. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,693
    48,945
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    i'm not really sure, but what i am sure of is, the prius a/c seems to have a mind of its own sometimes:cool:
     
    #8 bisco, Apr 26, 2015
  9. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,693
    48,945
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    could you be unknowingly hitting the steering wheel button? i have done that while holding a coffee cup.
     
    #9 bisco, Apr 26, 2015
    Dino33ca likes this.
  10. Fishcrab

    Fishcrab Member

    Joined:
    Apr 3, 2015
    152
    29
    0
    Location:
    Florida
    Vehicle:
    2005 Prius
    Model:
    Two
    That's a good point Bisco, might be my wild driving.
     
    #10 Fishcrab, Apr 26, 2015
  11. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,693
    48,945
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    yeah, me too!:p every time i'd hit a steering wheel button by mistake, i'd be looking around for what caused the beep.o_O
     
    #11 bisco, Apr 26, 2015
  12. Easy Rider 2

    Easy Rider 2 Senior Member

    Joined:
    Aug 5, 2014
    1,584
    257
    0
    Location:
    Ocala, FL
    Vehicle:
    2013 Prius c
    Model:
    Three
    More likely it is a combination of the car's design and the very HIGH humidity if Florida much of the time.

    The fan never really shuts off completely; there is always a tiny air flow for safety reasons.

    I think that many recent models also never really turn of the auto climate control completely and will run the compressor at a low level to de-humidify the cabin when necessary. That is most likely to happen early in the mornings when the temps are down a bit but the humidity is up near 100%.

    This is my wild guess.
     
    #12 Easy Rider 2, Apr 26, 2015
  13. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,912
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    There are within Techstream various options for how the AC is controlled in the same way that seat belt and reverse warnings can be turned off.

    John (Britprius)
     
    #13 Britprius, Apr 27, 2015
    Fishcrab likes this.
  14. Fishcrab

    Fishcrab Member

    Joined:
    Apr 3, 2015
    152
    29
    0
    Location:
    Florida
    Vehicle:
    2005 Prius
    Model:
    Two
    That's good to know, will look into it.
    I did stop beeper for backup, what a relief, for a long driveway .
     
    #14 Fishcrab, Apr 27, 2015
(You must log in or sign up to post here.)