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Air Conditioning Problem?

Discussion in 'Prius c Care, Maintenance and Troubleshooting' started by Dathorese, May 4, 2018.

  1. Dathorese

    Dathorese New Member

    Joined:
    May 4, 2018
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    Location:
    Boston
    Vehicle:
    2016 Prius c
    Model:
    Two
    So I have a 2016 Prius C .... Everything worked perfectly in my vehicle until this winter.... I had my vehicle serviced, and they replaced my cabin air filter.... in the process. i believe that the service technician who did it, damaged the gears on the automatic selector switching unit that diverts the airflow from your defrost, floor, main vents etc... the only airflow i had was coming from the main vents.... Switching the airflow with the button didnt change anything...

    Took it to toyota, and had them fix it..
    Covered under warranty and fixed...

    Anyways.. Ever since the dealership fixed the issue with gears and such, ive felt like my aircondioning and climate control feature have not worked properly...

    Its always warm, so if you want to set the temp at 70, it doesnt necessarily cool down..

    Anyways.... Ive taken it to toyota again, and had them look at it about 2 weeks after the initial repair (in the winter time) telling him how it didnt feel like the Auto climate control was working properly..

    now that its getting hot (and weve had a few 90 degree days now) I find that my air conditioning doesnt work correctly.. (it did previous to any repair work)

    when i took it to the dealer about the automatic climate control and more specificly about the no cooling effect with it, they told me they tested it and it was working fine...

    So... Now that the warmer weather is here... Ive been doing some digging and testing of my own... Here is what ive come up with...

    My Air conditioning DOES WORK.... But only at very slow speeds, and only when running off Battery power. Once the Electric Engine kicks in and supports the air conditioning rapidly turns hot...

    I can physically hear the compressor kick in, and when feeling the low pressure vent, the AC tubing is in fact Cold.

    So my problem with my air conditioning is definitely related to the gas engine cycling on to support the speed and battery of the vehicle.

    Im guessing its possible that its electrical related and or that there is some switching mechanism that is flowing open so that when the engine starts, that hot antifreeze is then taking over and killing any cooling feature of the compressor..

    So... anyone have any ideas or hints?

    Ive got a few dealerships around, Im actually pretty dissatisfied with the one dealer i did take it to, But in hindsight, its a continuing problem from the original work done under warranty as far as im concerned, and taking it elsewhere wont potentially save me the costs if the dealership is going to cover it under that warranty claim.....
     
    #1 Dathorese, May 4, 2018
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    108,931
    49,507
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    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    welcome!
    have you tried running it manually?
     
    #2 bisco, May 4, 2018
    dubit likes this.
  3. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    24,046
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    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    Through much of your post (and I mean this in the gentlest way) there's an impression of very large rabbits of speculation being pulled from a very small hat of time spent learning how your car works, and if you were to spend a good quality hour or so with the New Car Features manual, you'd be able to pull out better rabbits.

    But in this one guess, you do seem to be near something that could be real. The movable dampers in the HVAC are controlled by electric servomotors, and there are three of them: one controlling where the air comes in from (outside, or recirculating from the cabin), and one controlling where it comes out (feet, face, defrost). You already reported there was some issue with that one after your past service.

    The remaining one (I promised there were three) is the one that controls the temperature of the delivered air, by controlling how much of the air goes through the heater core, and how much goes around it. The engine coolant passage to the heater core is always open, so the core is always hot when the engine runs, so the only control of delivered air temperature is effected by this "air mix" damper.

    Supposing it's possible there is also some issue in the positioning of the air mix servo, as you reported there had been for the outlet servo, you could be getting symptoms very similar to what you're describing.

    There's a good chance that a servo problem would be detected by the HVAC controller and reported as a trouble code. If you have Techstream, you can read the code that way. If you don't, for all the Prii I've known (Gen 1/2/3), there has been a way to get HVAC codes without Techstream: it's pretty much always to hold down AUTO and RECIRC together while turning the car on, and then you either count two digit codes from light blinks (Gen 1), or read them from the MFD (Gen 2) or the HVAC display (Gen 3). I do not know for sure whether the c also has that feature or exactly how it works, but you would find it described in the repair manual (or could just try the same trick and see what happens).

    There are also "active tests" in Techstream where you can tell each servo directly to move to various positions, and stick your head under the dash and see that it does. In Gen 1 there was also a way to do that without Techstream. I wouldn't be surprised if there is for the c, but the details would have to be looked up. That would be a pretty clear-cut way of demonstrating your problem, if that's what it is.

    -Chap
     
    #3 ChapmanF, May 4, 2018
    Leadfoot J. McCoalroller likes this.
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