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AC now working(B1442/42 Air Inlet Damper Control Servo Motor Circuit)

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Chen_N, Jun 18, 2019.

  1. Chen_N

    Chen_N New Member

    Joined:
    Jun 18, 2019
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    Location:
    Phoenix
    Vehicle:
    2007 Prius
    Model:
    Four Touring
    Hi folks,

    I have a 2nd Gen 07 Prius, and the A/C suddenly stop working recently. The AC is blowing ambient temperature. I Checked A/C fault codes (hold recirc/auto buttons on steering wheel at the same time, press power button twice while holding those, see what codes flash on the screen). The code displayed on the screen is 42(Air Inlet Damper Control Servo Motor Circuit).

    I did a bit research, and here is explain of this code:
    The air inlet control servomotor switches between ”RECIRCULATION” and ”FRESH” by rotating the motor (normal, reverse) with electrical power from the A/C amplifier. This controls intake air and switches ”RECIRCULATION”, ”FRESH” and ”HALF–RECIRCULATION”.

    It doesn't sounds like a failure Inlet Servo Motor will cause A/C blowing ambient temperature air. How should I start trouble shooting?
     
  2. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
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    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    If you take out your cabin air filter and look in through that opening, you should be able to see if the air inlet damper is swinging properly when you select fresh and recirc. That could help confirm if there's a problem there.

    A lot of cars have a "Max A/C" mode that selects recirc, because if the outdoor conditions are brutal enough, it is easier to cool down some air inside the cabin and keep it cool, than it is to continuously cool down an incoming stream of outside air.

    In my part of the country, most of the time, my Prius A/C is able to keep up in fresh mode with no problem. But I can imagine other places (Phoenix maybe?) where inability to control the air inlet could put the A/C at a noticeable disadvantage.
     
    Sue Ellen likes this.
  3. Newstarr

    Newstarr New Member

    Joined:
    Aug 18, 2019
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    Location:
    Bay Area, California
    Vehicle:
    2007 Prius
    Model:
    Five
    I'm having the same problem. How did you remedy the problem?