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I think my CVT is failing, what do you think?

Discussion in 'Gen 2 Prius Main Forum' started by desertrider2215, Oct 17, 2009.

  1. desertrider2215

    desertrider2215 Member

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    This has happened about 5 times now. I have 118,000 miles on my '04 and I think the transmission is failing on me.

    About 3 seconds after I push on the gas pretty hard out of nowhere (usually when I'm already going from anywhere from 20-80 mph) it will give up and stop "revving" and go to low rpms. It basically refuses to go full throttle when I have the pedal pushed down. It revs up to the normal grunting sound for a couple seconds then gives up and goes back down.

    Another thing it does: I'll have the pedal down half way or so and let go almost all the way and the car is still revving high then slowly goes back down after i completely let go of the pedal.

    One last one. In the mornings when I start up my car sometimes the whole car shakes now and it moves back and forth after the engine has started until the engine shuts off and switches to electric. I've driven this car many miles and this isn't normal behavior...should I sell the car before I get hit with a $5,000 repair bill for a new transmission? Or is there nothing to be worried about.

    Thanks!:)
     
    #1 desertrider2215, Oct 17, 2009
  2. statultra

    statultra uber-Senior Member

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    it sounds like traction control activated. either that or your emergency brake is stuck, also that shakign back and forth happens when my e-brake is on in park
     
    #2 statultra, Oct 17, 2009
  3. desertrider2215

    desertrider2215 Member

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    I know what the traction control feels like, i could see how it could be similar but its a different feeling. ive hit many potholes and slid out a little and this wasn't the traction. especially when im going up a hill on the freeway doing 80 the traction wouldn't come on. hope i figure out what it is
     
    #3 desertrider2215, Oct 17, 2009
  4. brick

    brick Active Member

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    How old is the 12V battery? Original?
     
    #4 brick, Oct 17, 2009
  5. toxicity

    toxicity A/C Hog

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    Check your tires. One of my tires has been low on air recently and traction control kicks in non-stop after 30mph, its really weird.
     
    #5 toxicity, Oct 17, 2009
  6. qbee42

    qbee42 My other car is a boat

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    I suspect it's not your CVT since the Prius doesn't have one. The HSD on the Prius acts like a virtual CVT, so many people refer to the Prius CVT, but there is no such animal inside the Prius. All the Prius has is a set of fixed planetary gears and two motor-generators. They are always engaged: nothing shifts or clutches, ever.

    It is possible to have mechanical problems with the transaxle, or electronic problems with an ECU. Either of these should throw diagnostic codes.

    Tom
     
    #6 qbee42, Oct 17, 2009
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Just for fun, I'd suggest that you disconnect the 12V auxiliary battery negative terminal for several minutes, then reconnect. The point of this is to let the hybrid vehicle and engine ECUs reset.

    See if that helps, it can't hurt.

    I would be more inclined to believe that you have an ECU glitch instead of a transaxle problem. I haven't noticed other complaints that are similar to yours.

    If disconnecting/reconnecting the 12V battery doesn't help your driveability issues, another suggestion would be to ask your dealer to reflash the engine and hybrid vehicle ECUs (the equivalent of SSC 50P being performed on your car, except for lubricating the transaxle wiring harness connector with dielectric grease.) This reflash would update the engine and hybrid vehicle ECUs to the latest firmware revision.
     
    #7 Patrick Wong, Oct 17, 2009
  8. edthefox5

    edthefox5 Senior Member

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    The first one sounds like an engine issue and none sound like a "trans" issue. The first one might be a bad throttle motor or a severly gunked up throttle butterfly a known issue. Take the air cleaner assy off and with car off and using a flashlight look down the throttle bore. Twist the throttle butterfly open and look deep into the intake. Should be nice & clean in there and no soot at all. If sooty the Auto stores sell specific throttle body cleaner spray but I just use spray carb cleaner. Flush it & clean the bore & butterfly good and allow it to dry before re-starting. Easy place to start.
     
    #8 edthefox5, Oct 18, 2009
  9. Sandy

    Sandy Hippi Chick

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    I know we were botht having that problem with lack of power when I changed my 12V it never happened again:)
     
    #9 Sandy, Oct 18, 2009
  10. northwichita

    northwichita .

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    I had brief acceleration loss on heavy acceleration that was due to old spark plugs, changing them also help smooth out engine stops, similar to your problem. The intake system could also be a problem.
    Have your plugs been changed?
     
    #10 northwichita, Oct 18, 2009
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