cabin heat too warm with outside temp<35

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by jvanandel, Dec 21, 2005.

  1. jvanandel

    jvanandel New Member

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    May 29, 2005
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    The temperature control in my 2005 Prius doesn't always work. If the outside temperature is below about 35 degrees, once the heater starts producing heat, I can't control it. That is, if I set the cabin temperature at 66, it still seems like the heater is set at 75-80 degrees. It doesn't matter if I set the climate control to re-circulate or not. If I set the temperature control to "Max Cold", the temperature gets way too cold.

    Aftter 30 minutes or so, the problem seems to correct itself. If the outside temperature is about 40 degrees, the heater works just fine.

    Has anyone else experienced this?

    Any idea if a dealer can fix this?

    (The dealer who does my service claims that all software updates have been done on this car.)
     
    #1 jvanandel, Dec 21, 2005
  2. Technogeek

    Technogeek New Member

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    Just curious, are you manually adjusting the fan speed to arrive at a comfortable temperature or are you using the automatic climate control?

    If you are using the automatic climate control, just turn the temp down a degree or two and the climate system will automatically lower the fan speed.
     
    #2 Technogeek, Dec 21, 2005
  3. jeromep

    jeromep Member

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    Location:
    Eastern Washington State
    Vehicle:
    2005 Prius
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    N/A
    The auto climate operates as such.

    Assuming that the system is in full auto and the auto a/c light is iluminated on the dash (best way to run the system) this is what you should experience in the winter.

    When you first start the vehicle you will not have any fan, unless you put the system in defrost.

    After the vehicle has warmed up a little the fan will start out very slowly and as heat provided by the ICE becomes more plentiful the fan speed will gradually increase until it is max or near max.

    The fan will operate at higher speeds until the cabin set temp is reached.

    As the cabin reaches the set temp the fan will continue to slow and the air output position will also change, usually going from floor-defrost to floor and then to floor-dash. Rarely will it go to dash only when significant heat is being pumped into the cabin.

    You can tell when the cabin has reached the setpoint because the fan speed will be much lower than earlier and air will be coming out of all dash vents and the floor vents.

    Because the vehicle is working to get your cabin from a cold temperature to a much warmer temperature it will see like it is not responding to your wishes, but it certainly is. It is pumping as much hot air into the vehicle as possible until it gets to the setpoint and then it will only provide enough heat to maintain the setpoint.
     
    #3 jeromep, Dec 21, 2005
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