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Unexpected shift into reverse 2006

Discussion in 'Gen 2 Prius Technical Discussion' started by dmann1, Oct 22, 2010.

  1. dmann1

    dmann1 New Member

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    I have a 2006 with 100,900 miles, original owner: Either no one else has had this problem, or I'm not using the correct words to find a thread, or anyone else who has had this problem is assuming driver error and is too embarassed to ask, but I'll throw out all effort to shield myself from distain and put myself at the mercy of the forum experts......I have had several (almost "many") occasions when I "know" I've shifted into "drive" and the car has instead gone in reverse. Because the shifter automatically goes back into the neutral position I can't confirm that I haven't made an error, but I can't imagine why I would be so brain-dead as to do so, especially repeatedly--I would guess it happens at least once a month. I don't know if sometimes I move the shifter too quickly, but if so, it seems it would do nothing in that case, not do the opposite of what I intend. So far I've been able to respond quickly enough to avoid disaster, although I did hit the car behind me recently--no damage to it (fortunately, since it was my mom's car,) but took the paint off my bumper where I hit the bolts holding its license plate. I've seen threads about the shifter sticking in various positions, etc., but I don't see anything about this problem. Has anyone else experienced this and think they too have lost their minds? Or can a more technical person offer some possible explanation other than that I should give up my license?? I'm about ready to install a camera so I can Monday-morning-quarterback the incidents.
     
    #1 dmann1, Oct 22, 2010
  2. krg03

    krg03 Not expert, just experienced

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    Vehicle:
    2007 Prius
    Model:
    II
    Have not seen this on my 06 nor remember reading any threads. Sounds like a trip to the dealer is advised since you can reproduce it.
     
    #2 krg03, Oct 22, 2010
  3. pEEf

    pEEf Engineer - EV nut

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    Vehicle:
    2008 Prius
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    N/A
    The shifter mechanism in the Gen2 is hall-effect, which means the electrical switches themselves have no moving parts and instead respond to a magnetic field. The magnetic field basically comes from a magnet that as attached to the mechanism that is part of the shift knob.

    It's a very reliable system, and has many self-checks and clearly Toyota wanted to make sure this kind of thing could never happen.

    Still, entropy exists in our world and it's possible it could fail in such a way as to cause undesired results.

    If this happened to me more than once, I'd probably add instrumentation to the wiring to confirm/deny it was a fault and not me losing my mind.

    Because this is a potential safety issue, My advice for you is to find a used shifter assembly (there should be plenty available in the salvage yards) and swap it. All it takes is about 5 minutes and a 10mm socket. If it continues to happen after this, then I would strongly suspect user error, as it's very unlikely it could be a fault elsewhere.

    Here's one for $25 on ebay. For that price, it's worth doing just to be sure.
     
    #3 pEEf, Oct 22, 2010
  4. pEEf

    pEEf Engineer - EV nut

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    Oh, and if you replace it and it fixes the problem, I'd love to do an expert teardown and failure analysis of the original one, maybe I can determine what happened!

    If you wanted to send it to me, I'd be happy to do this and post my results.
     
    #4 pEEf, Oct 22, 2010
    1 person likes this.
  5. Hal W

    Hal W New Member

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    Location:
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    Vehicle:
    2006 Prius
    Model:
    II
    I find myself going into D rather than reverse about 50% of the time. To my brain the reverse should be down. I would give it awhile. I have only had mine for a month, myself, and I'm hopeful I will get it:D.H
     
    #5 Hal W, Oct 22, 2010
  6. dmann1

    dmann1 New Member

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    Thanks for the technical info PeeF. I'll have my husband look at your answer and suggestions and see what he thinks (other than that I'm crazy-I do 99% of the driving in this car and it hasn't happened to him.) I had seen other comments about the positions of Drive and Reverse on the shifter, and I think the arguement has some validity, they do seem counter-intuitive, but I feel like if this was my problem it would be happening more often. I've had the car almost 5 years, so I should be "one" with it by now--you'd think!
     
    #6 dmann1, Oct 27, 2010
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