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

Need help information with brakes on my 2010 Prius V with the AT Package.

Discussion in 'Gen 3 Prius Technical Discussion' started by Hozz, Jun 28, 2009.

  1. Hozz

    Hozz New Member

    Joined:
    May 17, 2009
    32
    5
    0
    Location:
    Northern California
    Vehicle:
    2010 Prius
    Model:
    V
    Need help information with brakes on my 2010 Prius V with the AT Package. I have a slanted driveway ( about 4-5 degrees) and if I drive in and let the car sit for about 15 minutes and then back up with slight pressure on brakes they grab. Absolutely impossible to back out smoothly. What am I doing wrong and does anyone else have this problem?? Thanks in advance, Hozz
     
  2. HTMLSpinnr

    HTMLSpinnr Super Moderator
    Staff Member

    Joined:
    Dec 8, 2003
    5,339
    917
    251
    Location:
    Surprise, AZ (Phoenix)
    Vehicle:
    2018 Tesla Model 3
    Model:
    N/A
    Nothing to do w/ the package, mine are a tad grabbier and more difficult to modulate in my garage moving forward as well - I use a piece of carpet to judge my distance in the garage (when I feel the car bump over it, I stop). However w/ the brakes grabbing, it's difficult to perceive the carpet vs. grab. I'm getting better w/ them - and as they "break in" a bit, they may become a bit less grabby.
     
  3. shawnb2

    shawnb2 Active Member

    Joined:
    Mar 21, 2009
    533
    107
    22
    Location:
    Thousand Oaks, CA
    Vehicle:
    2010 Prius
    Model:
    V
    I am having the same issue pulling out of my in-laws driveway which is quite steep. I thought it was because of me putting it reverse was causing it to go faster than I wanted so I tried neutral and thought that fixed it. Next couple of times going over there and trying the same thing resulted in the same issue as you. Any help with this would be greatly appreciated. would be really nice to be able to pull out of the driveway with getting whiplash. Really weird feeling and probably my only real complaint about his car.
     
  4. RMulligan

    RMulligan Junior Member

    Joined:
    Jun 13, 2009
    41
    8
    0
    Location:
    Hawthorne, CA
    Vehicle:
    2016 Prius
    Model:
    Four Touring
    Just a guess on my part, but you might check out the Hill-start assist control feature (pg. 243 in the Owner's Manual). I've used it once or twice when starting from a stop light while on a hill. You press the brake pedal hard to engage the assist. There is a beep and the slip indicator will start flashing on the dash display. I don't think is matters if you are going forward or reverse, the brake releases when you step on the accelerator.

    I hope this helps.
     
  5. Gadgetdad

    Gadgetdad New Member

    Joined:
    Feb 10, 2007
    462
    53
    0
    Location:
    Modesto, California
    Vehicle:
    2010 Prius
    Model:
    IV
    :confused: I noticed this grabby brake thing while backing down a slightly sloped driveway. I was unable to find the sweet spot to gently slow the car and ease out backwards. My daughter thought I was playing a game we used to call "disco braking" where you would come to a stop pulsing the brake to the beat of the song on the radio! But this time there was no song, no radio but the brakes were grabbing!

    Lee
     
  6. RMulligan

    RMulligan Junior Member

    Joined:
    Jun 13, 2009
    41
    8
    0
    Location:
    Hawthorne, CA
    Vehicle:
    2016 Prius
    Model:
    Four Touring
    Second guess on my part. I was in a parking lot today and was backing out with my foot off the accelerator and covering the brake when I noticed the car moving at a speed much higher than I've ever experienced before (either going forward or backward). When I put on the brakes, they "grabbed" hard giving my wife and I the whiplash effect. When I released them, the car continued to speed backwards so I applied the brakes again, grabbing hard again. This repeated 4 or 5 times until I completed my maneuver. It reminded me of an old gasoline carburetor sticking at a fast idle. There was not way to "kick it down" to a lower idle because everything is electronic. I have not been able to repeat my experience (yet). But I do know the idle speed of the traction motor is nowhere near the speed I experienced today.

    Any comments? Does this kind of thing happen in other Prius models? This is my first Prius.
     
  7. tumbleweed

    tumbleweed Senior Member

    Joined:
    Oct 3, 2005
    4,067
    687
    0
    Location:
    Eastern Oregon
    Vehicle:
    2010 Prius
    Model:
    V
    It never happened with my GII.
     
  8. Paradox

    Paradox Prius Enthusiast / Moderator
    Staff Member

    Joined:
    Sep 22, 2005
    29,110
    8,589
    201
    Location:
    USA
    Vehicle:
    2014 Prius v wagon
    Model:
    Five

    Never had it happen on my Gen II and honestly have never noticed it on my Gen III either. My garage is a basement garage so I back into my garage down my driveway everyday... I'll pay more attention and see if I notice it the next few days.

    My first thought was the hillstart feature like someone else mentioned...
     
  9. going red baby!

    going red baby! still a n00b

    Joined:
    Jul 21, 2009
    610
    96
    0
    Location:
    Los Angeles
    Vehicle:
    2010 Prius
    Model:
    III
    I had this same thing happen to me when backing out of a parking space at a gas station. There was a slight slope down. I think the 3 guys standing near there thought I was a really bad driver with the car lurching like it was.

    I noticed that the icon for the Enhanced VSC/TRAC being in operation was on. From what I read on pg.246 of the manual I don't think it should have been on. I had been parked, talking and texting on my cell making plans and was only moving my car to the pump to fill up.

    I also noticed that light on twice before when I was just stopped at a red light. Am I doing something to make that happen? There's no way I was skidding or slipping or anything, just normal driving in sunny weather.

    (I swear I saw some more current threads on grabbing brakes but they didn't come up in my search, perhaps they are in another area, will search again.)
     
  10. spiderman

    spiderman wretched

    Joined:
    Jul 5, 2009
    7,543
    1,558
    0
    Location:
    Alaska
    Vehicle:
    2010 Prius
    Model:
    II
    Join the club with lots of members. One thing you mention that I don't think was noticed before is the indicator light. I did not notice that but I wasn't looking either (looking in the mirrors). There is at least a couple of threads though on the subject...
    Welcome to the club! :)
     
  11. Jabber

    Jabber Chicagoland Prius Guy

    Joined:
    Apr 23, 2009
    703
    213
    2
    Location:
    Chicago
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    The Hill-assist braking becomes engaged when you are stopped at a light with your foot on the brake pedal. If you let up on the brake pedal pressure and push it back down harder, it will engage. Hard to describe how to make it happen. I'll try this way using numbers to simulate the position of the brake pedal:

    Position 0 being no brake pedal pressure at all, position 4 all the way down, as hard as possible.

    Coming up to a stop light to slow down, position 2
    Come to a complete stop and let up a bit.. to position 1.
    Press down to position 3 and you will engage the hill assist. A couple of beeps and the VSC/Trac light will engage.
    When you remove your foot from the brake and apply gas pedal pressure, it will disengage.

    I don't know if this is what you are experiencing, but it sounds like it.
     
  12. going red baby!

    going red baby! still a n00b

    Joined:
    Jul 21, 2009
    610
    96
    0
    Location:
    Los Angeles
    Vehicle:
    2010 Prius
    Model:
    III
    I think you are right, thank you. I was just out running errands and while stopped I lifted my foot off the brake and pressed very hard on it and the VSC/Trac light came on. I may have inadvertently done that before I reversed on a slight incline the other night as well.

    But is that the hill assist thing? When reversing the VSC/Trac light was on, I don't remember if the brake held while I moved my foot to the accelerator, but the brakes were doing that grab thing and I looked like an idiot trying to back out of my spot. I've since found the brake grab poll thread where people said if you put it in park then back into reverse it goes away.