1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Electric Motor Starts When Driver Side Door Handle Touched?

Discussion in 'Gen 3 Prius Technical Discussion' started by eadams44, Jul 31, 2011.

  1. eadams44

    eadams44 New Member

    Joined:
    Jun 2, 2011
    17
    1
    0
    Location:
    Jonesville, SC
    Vehicle:
    2011 Prius
    Model:
    Three
    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

    Joined:
    Aug 30, 2009
    5,131
    1,338
    0
    Location:
    Wilmington, NC
    Vehicle:
    2010 Prius
    Model:
    III
    I believe that is going to be your brake hydraulic system building pressure, as you suspected.
     
    1 person likes this.
  3. macmaster05

    macmaster05 Senor Member

    Joined:
    Sep 27, 2009
    4,050
    727
    5
    Location:
    USA
    Vehicle:
    2010 Prius
    Model:
    Two
    It's getting ready to OWN.
     
  4. eadams44

    eadams44 New Member

    Joined:
    Jun 2, 2011
    17
    1
    0
    Location:
    Jonesville, SC
    Vehicle:
    2011 Prius
    Model:
    Three
    own???
     
  5. V8Cobrakid

    V8Cobrakid Green Handyman

    Joined:
    Jun 6, 2004
    3,790
    152
    0
    Location:
    Park View, Los Angeles, CA. U.S.A
    Vehicle:
    2004 Prius
    Model:
    N/A
    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
     
    1 person likes this.
  6. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
    Staff Member

    Joined:
    May 11, 2004
    14,816
    2,496
    66
    Location:
    Far-North Chicagoland
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    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."
     
    1 person likes this.
  7. Teakwood

    Teakwood Member

    Joined:
    Jun 23, 2010
    491
    73
    0
    Location:
    New Mexico
    Vehicle:
    2010 Prius
    Model:
    II
    Yep;)
     
  8. eadams44

    eadams44 New Member

    Joined:
    Jun 2, 2011
    17
    1
    0
    Location:
    Jonesville, SC
    Vehicle:
    2011 Prius
    Model:
    Three
    Thanks all. I do appreciate the replies!
     
  9. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,035
    10,010
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    Not on the Gen3, that thermos was abolished with the 2010 redesign.
     
    1 person likes this.
  10. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
    Staff Member

    Joined:
    May 11, 2004
    14,816
    2,496
    66
    Location:
    Far-North Chicagoland
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    Good call. I wasn't paying attention and was talking GenII.
     
  11. qbee42

    qbee42 My other car is a boat

    Joined:
    Mar 2, 2006
    18,058
    3,073
    7
    Location:
    Northern Michigan
    Vehicle:
    2006 Prius
    On the Gen III it is the brake accumulator pump building hydraulic pressure.

    Tom
     
  12. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,463
    38,101
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    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

    Joined:
    Mar 21, 2010
    1,179
    365
    1
    Location:
    California
    Vehicle:
    2010 Prius
    Model:
    V
    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
    Staff Member

    Joined:
    May 11, 2004
    14,816
    2,496
    66
    Location:
    Far-North Chicagoland
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    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

    Joined:
    Jun 23, 2010
    491
    73
    0
    Location:
    New Mexico
    Vehicle:
    2010 Prius
    Model:
    II
    So stop making erroneous statements.
     
  16. J5A

    J5A Active Member

    Joined:
    Jan 7, 2011
    592
    83
    0
    Location:
    Severna Park, MD
    Vehicle:
    2010 Prius
    Model:
    IV
    As in pwned?
     
  17. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,463
    38,101
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    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

    Joined:
    Feb 26, 2009
    17,035
    10,010
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    Despite not owning the generation in question, I think Tony got this one right.
     
  19. qbee42

    qbee42 My other car is a boat

    Joined:
    Mar 2, 2006
    18,058
    3,073
    7
    Location:
    Northern Michigan
    Vehicle:
    2006 Prius
    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
     
    1 person likes this.
  20. Ffejrobins30

    Ffejrobins30 New Member

    Joined:
    May 22, 2011
    23
    1
    0
    Location:
    Santa Clarita, CA
    Vehicle:
    2011 Prius
    Model:
    III
    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.