Traction control drops transmission out of gear

Discussion in 'Gen 3 Prius Main Forum' started by PriPriMan, Sep 17, 2010.

  1. PriPriMan

    PriPriMan New Member

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    I've had my 2010 Prius since June and it has a problem at very low speeds that seems to be getting worse. The problem is that if I'm driving very slowly, like when pulling into a parking space, and I brake gently, the traction control light starts flashing and the transmission drops into neutral. At that point I can't shift into any gear unless I put it into park first. This happens when moving very slowly in either forward or reverse and on completely dry pavement. I called the dealer and they hadn't heard about this. Has anyone here experienced this?
     
  2. tumbleweed

    tumbleweed Senior Member

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    I have not heard of anyone who has had that problem. Make sure you are not pushing the brake down to far because that activates the hill-start assist function, that will cause the traction control light to flash. Owner's Manual page 243.

    If it is not the hill-start assist and if it is repeatable you should have no problem getting the dealer or Toyota interested in fixing it. The biggest difficulty people have with warranty work seems to be problems the dealer's mechanics can't duplicate. If they can't see it happen they don't want to believe it happens.
     
  3. kithmo

    kithmo Couch Potato

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    PriPriman said he was braking gently, which wouldn't put the hill start assist into action and even if it was the hill start assist coming on then that wouldn't put the transmission into neutral.
    I'm thinking traction control sensor communication problem, probably the front wheels as it's related to the transmission.
    First thing I'd do is get underneath and check the connections to the front sensors, they should be on the hub carrier somewhere.
     
  4. PriPriMan

    PriPriMan New Member

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    I did some more testing on this and it seems the problem occurs if the car rocks back and forth even slightly while it's stopped in gear with the brake applied. For example, if someone gets out of the car while it's stopped in gear just the slight shaking of the car when they get out causes the problem to occur. It seems to happen more on an incline, even a slight one. It's still under warranty so I'm taking it to the dealer.
     
  5. That_Prius_Car

    That_Prius_Car Austin Kinser

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    Hmmm, I never had this problem when I had a 2010...
    I know in the Gen.II, the traction control is VERY aggressive. If I could rate the traction control on the Gen.II on a scale of 1-10, i'd rate it an 11. I thought traction control was one of the things they improved with the Gen.III...
     
  6. Skoorbmax

    Skoorbmax Senior Member

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    Haven't heard of this problem. TC _taking you out of gear_ and requiring you to stop to get it back in is definitely not cool.
     
  7. Airbalancer

    Airbalancer Active Member

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    I do not understand why people just call the dealer :confused:
    Take it in and show them
     
  8. PriPriMan

    PriPriMan New Member

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    I called the dealer because they are a ways from where I live and it's pointless to take it in unless I can demo the problem, otherwise it's just a waste of time. I called them to find out if this was a known problem and they had a fix. It wasn't so I needed to first figure out how to show them the problem, which isn't obvious.
     
  9. Bob Comer

    Bob Comer Active Member

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    I just got a new Gen3 Prius V last week and when parking the traction control light does come on occasionally, but it never kicks me out of gear. It does take hitting the accelerator a little harder to get moving again though...
     
  10. andino

    andino Senior Member

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    ^^ You're activating the Hill Start Assist

    To the OP, does it happen often? Maybe attempt to duplicate the situation and see if the problem arises again. If you can, take it to the dealer and replicate the same thing.
     
  11. Paradox

    Paradox Prius Enthusiast / Moderator
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    Ditto, you're pressing hard enough on the brake to activate the hill start assist feature. Look it up and read about it in your manual...
     
  12. jburns

    jburns Senior Senior Member

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    I don't think I've ever activated the hill assist. Don't even know if it works. Guess I should check although I doubt I would make a trip to the dealer if it didn't.
     
  13. Paradox

    Paradox Prius Enthusiast / Moderator
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    If when you brake you press hard enough at a low stopping speed, such as when parking, to make it beep and light up a yellow light on the dash and then you have to give it some bit of gas to make the car move, the hill start assist has been activated. You can easily try it out. Next time you are stopped, say at a light or a stop sign, press all the way down on the brake. You;ll hear the beep and see the yellow light. Then when you take your foot off the brake the car will not creep forward until you give a bit of throttle.
     
  14. jburns

    jburns Senior Senior Member

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    Thanks. I know how it works just never checked it or see the need for it. I guess I just press hard enough to stop. Maybe if I lived in San Francisco.

    In response to the bolded part why would you take your foot off the brake unless you were ready to move?
     
  15. Paradox

    Paradox Prius Enthusiast / Moderator
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    Sorry, I was explaining how it works and how to activate it. No harm, no foul, at least you know it's there in case you're on a hill and need it for some reason. I've used it maybe once because someone stopped quite close behind me on a moderate incline.

    I was describing testing it so you know how the system worked/felt if you were on say level ground. If on a hill you will not roll backward before having time to step on the gas. On level ground the car will not creep forward until you give it gas. Giving it gas is what deactivates the system; Well that or enough time off the brake and the system cancels out.

    Ok, I'm letting this thread get back on track now lol :focus:
     
  16. Bob Comer

    Bob Comer Active Member

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    It was once at a stoplght and twice in the same parking lot, I thought it was pretty light breaking but I'll watch fo it, thanks.
     
  17. Bob Comer

    Bob Comer Active Member

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    I tried what you said and I got it to go into hill start assist quite easily, but the traction control light blinks instead of being solid on like what I described before and I know I didn't press the brake that hard before.

    It hasn't happened again yet, so I'm not really worried about it anyway.

    It rained heavily today and not a peep from the traction control so I think everythings working as it should.
     
  18. Colonel Ronson

    Colonel Ronson New Member

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    ive never had the traction control turn on in me, even when i floor the car. the fact that there isn't even a switch to turn it off is mildly hilarious. id just take it to the dealer. i doubt you are activating hill start because that requires pressing the brake ALL THE WAY to the ground. and people dont do that hwen they are trying to park.
     
  19. 2k1Toaster

    2k1Toaster Brand New Prius Batteries

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    Could be a faulty sensor somewhere that is being over zealous. If you can honestly make it shift into nuetral by having someone jiggle your Prius while in Drive, then there is an issue. I don't know what, but it is there. Could be a sensor plug not mated the whole way or it could be a domokun stowed away inside your Prius on the boat ride over here and ate a wire, who knows.

    As for traction control, there is a super secret handshake type method to turn it off (at least in the Gen II) which is useful in heavy heavy ice/snow. But the big danger is that the combination of MG1/MG2/ICE can produce more power than the PSD can handle if it slips potentially causing damage. A little here and there, but if you had a switch and drove with it off, you could destroy your car in a year or two perhaps.

    My vote is for the domokun...
    [​IMG]
     
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