2010 Warm Air When Engine Runs/On (AC Heater Servo Regulator 063800-1100)

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by kilimar, Jun 30, 2021.

  1. kilimar

    kilimar Junior Member

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    So the AC blows cold air when it's on the HV but as soon as the engine kicks in, the cold air becomes warm (not hot) air. Doesn't matter if the car is moving or stationary. Web searches reveals that it could be the A/C Blend Door and/or Blend Motor. I removed the glove compartment and can see the motor. It looks like maybe a teeth is missing (the gear moves). The part number on the motor is 063800-1100. I can find the part number on eBay but that's about it. I can't seem to find it at parts.toyota.com. I tried looking at the diagrams on parts.toyota.com but I can't seem to locate the motors. At rockauto.com, I found the item but the part number doesn't match -- it also doesn't include the gear....


    • Can someone help me find the parts (motor and/or gear) on parts.toyota.com or rockauto.com (or some other site that sells them new vs used on eBay)?
    • Also, any hints on a guide to removal (esp, the bottom half of the dash to get to the motor) -- I can only see 1 of the 3 or 4 screws?

    Thanks!

    P.S. The other two motors works fine. The recirculate door moves properly (I can see the flap move with the filter door removed). As does the direct air foot well -- that motor also turns and air does flow to the foot well.

    IMG_20210628_182129959.jpg
     
    #1 kilimar, Jun 30, 2021
    Last edited: Jun 30, 2021
  2. JC91006

    JC91006 Senior Member

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    When you first start the car in the morning, when the engine is on and warming up, does the AC work?
     
  3. kilimar

    kilimar Junior Member

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    If I don't move the car, the engine runs for a short time (30 seconds?) unless the battery is low. And as this is a new problem (I replaced my '08 with this 2010 five days ago), but from what it seems like, yes, the AC works for the first minute of the day while the engine is running.
     
  4. JC91006

    JC91006 Senior Member

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    So this really doesn't have anything to do with the engine running or not. I think you should read the codes on the car. The car most likely is detecting a failure in it's ECU and shutting down systems that can harm the car (your AC)
     
  5. kilimar

    kilimar Junior Member

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    So you're thinking that the engine running for 30 seconds in the morning creates enough heat to overcome the cold A/C air to become warm air? Hmm.... not being a mechanic, I can't disagree.

    As part of the troubleshooting process, I did use an OBDII and using Torque both and Car Scanner, neither shows any codes. I had driven ~300 miles before reading the code. I don't have techstream so there are things that neither Torque nor Car Scanner can read...

    So while on the highway from Orlando to Tampa, when the engine turns off during a coast or what not, the AC would run cold but when the engine kicks in, less cool air .. throughout the whole trip. Unfortunately, driving at high speeds, the engine doesn't turn too often, so it was a less than cool trip but the system wasn't blowing high heat so it was tolerable without having to turn off the AC and/or open the windows, even during the 3-6 PM heat. It was about 89-92 outside, so it wasn't too bad with the cold/warm cycle of AC but with the windows close and no AC, it would of been deadly.
     
  6. JC91006

    JC91006 Senior Member

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    If your car is not showing any failure codes I would just check if the refrigerant level is full
     
  7. ChapmanF

    ChapmanF Senior Member

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    You're confirming here that the other two actuators work, but I'm not getting from your post whether you've also confirmed that the air mix actuator doesn't work (as opposed to thinking it looks like a tooth might be missing). Have you watched it while changing your temperature setpoint above and below cabin temp and seen any actual problem in how it moves?

    This is the animal if it's truly what you need, but I wonder if that decision could still be a bit premature.
     
  8. kilimar

    kilimar Junior Member

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    Sorry, so a little history.
    • Day 1 -- Dealer detailed the car and turned the HEAT on high to "dry out" the carpet and seats. Drove home; ~20 miles and did not notice issue.
    • Day 2 -- drove to Tampa -- notice the problem -- stopped at Pepboys and they did a VERY quick visual said maybe freon was low. Picked up a freon can with analog gauge for $60. Attached to the low port and the needle on the gauge is in the green zone (~40). There was some bubbles in the inline visual thingy -- I 'added' (pressed the handle) freon anyway -- the bubbles are gone and the needle moved a tiny little bit, maybe ~41. Drove back home in the afternoon in cooler than outside temperature but not cool enough to be comfortable. At home, web researched the issue, found similar issue on priuschat and priusforum.
    • Day 3 -- Drove the car to and from work and the issue was still present (~40 miles round trip). Looked at the motors for the first time, I only checked the two (recirc & floor) -- I did not change the temperature to see if the blend door gear turned -- brain fart. However, I did tried to turn each of the visible gears by the teeth, including the blend door gear, they moved from none to less than a millimeter.
    • Day 5 - This morning, my brain did re-engage and I had my son change all three settings (recirc, floor, and temp). All three gears move. When changing the temperature between hot/cold, the blend door actuator motor gear does move. The gear (white) on the blend door actuator motor seems to turn in sync with a black gear. And they 'seem' like they might fit together but I can't tell since it's behind things -- I see only the top of both gears and they are close to each other. It is the black gear that looks like it is missing a tooth ... I can't tell from the parts diagrams the location of the black gear. One kicker ... the AC seem to be fine this morning on the way to work, including while the engine is running.
     
    #8 kilimar, Jun 30, 2021
    Last edited: Jun 30, 2021
  9. kilimar

    kilimar Junior Member

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    I did check and it's fine :)) see Day 2 above).
     
  10. JC91006

    JC91006 Senior Member

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    Did this all happen after the dealer detailed the car? Did they detail the engine too?

    I'm still suspecting the car disabled the AC. This can happen for a number of reasons, one of the reasons would be a failed inverter pump (which would throw a code). That is why the AC works fine in the morning, the car is cool and everything is not hot.

    You would need to go through the complete diagnostic steps for AC repair. Techinfo.toyota.com will have all the information, you can get a 2 days subscription and try to figure this out on your own. But if this occurred after the dealer detailed the car (engine compartment), I would bring it back to them to sort it out.
     
  11. Mendel Leisk

    Mendel Leisk Sand Pounder

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    Post a pic of the can, with the labels legible? Prius AC is finicky, especially the oil needed. And the pressure.

    If what you added has the wrong oil, it’d be best to leave the AC off, have the system evacuated and recharged. Safest bet would be dealership.
     
  12. ChapmanF

    ChapmanF Senior Member

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    The thing about refrigerants is that they are chemicals usually chosen to have a liquid/vapor transition ("boil") temperature not far from people's happy place, at the pressures used in the system. So as long as there is any amount of refrigerant in there sufficient for some of it to be liquid, and the system is off and sitting quietly, the pressure you're going to see will be the pressure from a saturation pressure/temperature chart for R134a at whatever temperature it's currently at. Add some and it will still be around 40. Remove some and it will still be around 40. Check on a warmer day and it will be higher, or colder and it will be lower. :)

    So that pressure really doesn't tell you much at all about how much is in there. It's more useful as a sort of thermometer. If you ever saw it lower than the expected saturation pressure, that would have to mean it wasn't merely low but pretty much gone. (Unexpected readings can also result if it was serviced improperly at some point and there are foreign substances like air or water in there.)
     
  13. kilimar

    kilimar Junior Member

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  14. kilimar

    kilimar Junior Member

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    They did detail the engine ... probably with a pressure washer. If the inverter pump failed, it threw a code and the dealer cleared the code; would the code come back? I have driven the car over 200 miles since the detailing ...
     
  15. JC91006

    JC91006 Senior Member

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    I was just giving you an example of a possible failure part, it could be a number of things. Since they did detail the engine and this happened right after they did so, I would bring it to the dealer and let them sort it out.
     
  16. JC91006

    JC91006 Senior Member

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    I remember a mechanic was doing a 2010 water pump change for the first time. He changed out the water pump and afterwards realized the AC stopped working. He looked again and noticed the AC compressor (I think that's what he said) was located under the water pump. When the water pump was removed, coolant got everywhere on there and somehow broke that compressor.

    So when detailing an engine with so many electronic parts, you have to be very careful not to get the wrong areas wet.
     
  17. Grit

    Grit Senior Member

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    o_O
     
  18. kilimar

    kilimar Junior Member

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    It was a large green zone... and the needle was in the middle. It can't hurt for the needle to be in the higher 1/3 of the green zone, right? :rolleyes:

    IMG_E9675_700x700.jpg
     
    #18 kilimar, Jun 30, 2021
    Last edited: Jun 30, 2021
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