Electric Motor Starts When Driver Side Door Handle Touched?

Discussion in 'Gen III 2010+ Prius Technical Discussion' started by eadams44, Jul 31, 2011.

  1. eadams44

    eadams44 New Member

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    After the car is parked for a while, when you open the driver side door or just touch the door handle an electric motor starts running. After several seconds it stops. Sounds as though it is running a pump and building pressure or vacuum. Just wondering exactly what it is? Thanks.
     
  2. jdcollins5

    jdcollins5 Senior Member

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    I believe that is going to be your brake hydraulic system building pressure, as you suspected.
     
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  3. macmaster05

    macmaster05 Senor Member

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    It's getting ready to OWN.
     
  4. eadams44

    eadams44 New Member

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    own???
     
  5. V8Cobrakid

    V8Cobrakid Green Handyman

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    own = do it's work ( i assume )

    they're getting ready to put a mad beat-down on those brake calipers if necessary... so to speak
     
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  6. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
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    The typical conventional car waits to be driven and only reacts when needed. The Prius, and I'm not making this up, actually anticipates and begins the preparation cycle before you even start the car.

    There's also a pump the moves pre-heated fluids from a thermos to the engine block in order to bring the engine up to temp faster. I often wondered if that was what the "open the door" noise was.

    But yes, when you open the driver's door the Prius thinks, "I'm about to get driven; I'd better get ready."
     
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  7. Teakwood

    Teakwood Member

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    Yep;)
     
  8. eadams44

    eadams44 New Member

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    Thanks all. I do appreciate the replies!
     
  9. fuzzy1

    fuzzy1 Senior Member

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    Not on the Gen3, that thermos was abolished with the 2010 redesign.
     
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  10. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
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    Good call. I wasn't paying attention and was talking GenII.
     
  11. qbee42

    qbee42 My other car is a boat

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    On the Gen III it is the brake accumulator pump building hydraulic pressure.

    Tom
     
  12. Mendel Leisk

    Mendel Leisk Senior Member

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    The few times I'm opening the door just to pop the hood, and this motor is still starting up, Ii kind of gets to me: wish Toyota would have chose something else as instigator for this pump, maybe: starting the car?
     
  13. macman408

    macman408 Electron Guidance Counselor

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    But by the time you start the car, your foot is already on the brake pedal, and that pressure is already being used. So opening the door is really the right time to do it. Next time you open the door to pop the hood, lean over from the passenger side to do it. ;)
     
  14. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
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    NOOOOooooooo :eek:

    Okay, so I over-react. But this very thing killed my 12v battery.
    Twice. (I'm not that bright.)

    Two things you need to know:
    1) I keep my headlights on as pseudo-daytime running lights.
    2) On the Gen2, the "turn off the lights" is triggered ONLY by the driver's door. Seriously.

    So I opened the passenger door to roll up the windows. On another occasion, I opened the passenger door to plug in my air pump. Both times it was the middle of a sunny day and I didn't notice that the headlights came on when I powered up the car. And both times, since I never opened the driver's door, the lights stayed on even after I powered down.

    But again, we're talking Gen3 in this thread and since I don't have a Gen3 someone else will need to test this.
     
  15. Teakwood

    Teakwood Member

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    So stop making erroneous statements.
     
  16. J5A

    J5A Active Member

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    As in pwned?
     
  17. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah, I think I'm going to start doing that. I already do that if I want to for instance check the gauges, but was thinking it would be hard to reach the hood release, but believe you're right: it's not that much of a stretch.
     
  18. fuzzy1

    fuzzy1 Senior Member

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    Despite not owning the generation in question, I think Tony got this one right.
     
  19. qbee42

    qbee42 My other car is a boat

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    That's how it works for the Gen II. Toyota changed the initiator with the Gen III. The intention is to make sure brake boost is available when the driver first steps on the pedal.

    Tom
     
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  20. Ffejrobins30

    Ffejrobins30 New Member

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    The noiswe you are hearing is the brake pump running. The reason that they do it when you open the door is because it actually builds pressure and MEASURES where the pads are so it knows how much pressure to apply based on the throw of the pedal.