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Pedal Entrapment Recall

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by davidj08, Feb 2, 2010.

  1. davidj08

    davidj08 Junior Member

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    My concern centers on the difference between the fix for Camry, Lexus, and Avalon compared to the fix for Prius. The fix for the Camry, etc. includes software modifications to ensure that the brake overrides the accelerator in the event both brake and accelerator pedals are applied. The fix for the Prius does not include any software modification. When I called Toyota to ask why, I was told because Prius has traction control, the software modification isn't necessary. They said that when wheelspin occurs the traction control shuts down the engine. However, my view is that sudden unintended acceleration could occur without wheelspin. Moreover, the Camry, etc. have traction control as well. In fact the Avalons, 2009 and 2010 have traction control and vehicle stability control standard. My question is why doesn't Prius get the software modification? I'd appreciate any comments.
     
    #1 davidj08, Feb 2, 2010
  2. Jabber

    Jabber Chicagoland Prius Guy

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    Nothing is getting the software modification as part of either recall. The Camrys are getting a shim put in place. The other vehicles are getting either the pedal itself replaced or modified.

    The software upgrade will be done over time on the different models, but it is NOT part of any recall as of this moment.
     
    #2 Jabber, Feb 2, 2010
  3. davidj08

    davidj08 Junior Member

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    Jeff, Thanks for input. NHTSA website says Camry, Lexus and Avalon will get the softweare mod. When I called Toyota, they confirmed software mod would be done with those vehicles. davidj08
     
    #3 davidj08, Feb 2, 2010
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    That's my question as well.

    When the hybrid vehicle ECU is working properly, then you will find that the brake pedal always dominates the accelerator pedal. Try it for yourself to see: Get up to freeway speed where no one is behind you, floor the accelerator pedal, then depress the brake pedal. You'll find the car will quickly slow down.

    There have been a few Prius unintended acceleration incidents which don't seem to be explained by a floor mat or an accelerator pedal problem. According to the news accounts of those incidents, skid marks were left by the tires and brake system heat damage was evident, which implies the brake pedal was depressed hard. You are left concluding that some weird software glitch happened.

    I think it would be nice for Prius to have a redundant, failsafe method where engine power will be cut when the brake pedal is applied, in addition to the control logic that already exists.
     
    #4 Patrick Wong, Feb 2, 2010
  5. Jabber

    Jabber Chicagoland Prius Guy

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    I owe you an apology David. I reread your post and thought you were asking about a software mod being part of the recall. Nowhere did you mention the recall, so I apologize.. Just a fail-safe item that Toyota is going to do in the near future.
     
    #5 Jabber, Feb 2, 2010
  6. davidj08

    davidj08 Junior Member

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    Jabber, Thanks for all your help. I've got some friends in Chicagoland. I'll be sure to send them your way. David
     
    #6 davidj08, Feb 2, 2010
  7. davidj08

    davidj08 Junior Member

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    Patrick, Thank you. I went out on the freeway, did exactly as you suggested and it's quite obvious the brake overrides the accelerator. The car slowed as if no gas was being applied. While having a second system to override the accelerator would be nice and give us a fail-safe method to preclude unintended acceleration, I can readily understand why we won't get the software modification. The engineers behind the decision are saying we have one system and it should be expected to work.

    If you can, this novice has two more questions for you: 1) What does ECU stand for? 2) Do you know what characteristics cause this override to engage? By this I mean, that I have at speeds <15 employed the gas and brake pedals and have never experienced this override. I have done this to dry out the brakes after washing the vehicle. Is the override a function of speed or the degree of acceleration being applied?? Thanks again. You've been of extraordinary help. davidj08
     
    #7 davidj08, Feb 2, 2010
  8. Patrick Wong

    Patrick Wong DIY Enthusiast

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    1) ECU: electronic control unit

    2) No. When I want to dry the brakes, I will get up to speed (like 30-40 mph), shift to N, then brake gently. If you apply the accelerator and brake pedal at the same time while the car is in D, the braking may be regen, not friction.
     
    #8 Patrick Wong, Feb 2, 2010
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