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Engine turning on and off rapidly when stopped

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Bonzocat, Dec 17, 2005.

  1. Bonzocat

    Bonzocat New Member

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    I've had a little oddity that I haven't seen on the forums... When my '05 is stopped on a hill, heading downhill only, the engine kicks on and off in rapid succession. If I put my foot down on the brake a little harder it seems to stop. Has anyone else had this happen? Any thoughts?

    One more thing that has bothered me...if I'm accelerating fairly rapidly while turning from a side street to a main street, the transmission seems to skip a beat...its like it completely loses power for a fraction of a second and then pops back in causing the car to jolt. Seems like that shouldn't be happening.

    Any input would be appreciated!
     
  2. efusco

    efusco Moderator Emeritus
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  3. prius04

    prius04 New Member

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    I've got nearly 22K on my 2004 Prius. My Prius has done this about once per month since the beginning. I stopped worrying about it at about 2K, that's not to say something isn't wrong tho. It's like the car can't be sure whether to shut off, or stay on. My daughter's Prius does this as well. I think she would say it happens more than once per month.

    As for the transmission hesitation, this sounds like the traction control has kicked in. Whenever the engine detects that one of the wheels might spin freely, the computer puts a stop on the whole thing. So there is no "laying rubber" with the Prius.

    On the other hand, ALL cars hesitate when you push on the gas. Since our car has a computer that has to make sense of what you want, using what you did to the gas pedal as a source of data, the computation also takes a split second.

    If I've got it wrong, others will come along as well.
     
  4. efusco

    efusco Moderator Emeritus
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    Sorry, didn't even notice that part of your question. That's the TRAC (traction control) kicking in. It'll do that as described by the answer above.
     
  5. DanMan32

    DanMan32 Senior Member

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    Was the battery SOC at 8 bars? If so, the computers were probably trying to bleed down the SOC a bit.
     
  6. Bonzocat

    Bonzocat New Member

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    Thanks, guys! The link Evan posted was very helpful. Eased my mind.

    And, Dan, I actually didn't look at the SOC bars, but I'm assuming that the energy bleed was the intention. I'm in LA, so freezing temperatures are not the answer.
     
  7. waldhorndude

    waldhorndude New Member

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    My Engine was doing this today and the SOC was ay 8 bars, is the above true?

    It was also somewhat cold.
     
  8. uart

    uart Senior Member

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    Yes it's true, it's happened to me several times, always at 8 bars. It happens quite often with people driving in hilly terrain.
     
  9. ahmeow

    ahmeow Prius Lover

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    I'm totallt agree with you. That's what happened. Nothing wrong with the transmission. The Op can enjoy the technology.