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Problem with Engine Braking

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by EastR, Jan 28, 2011.

  1. EastR

    EastR Junior Member

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    Hello,
    I own a 2006 Prius. I love the engine braking feature ("B" on the shifter) and use it frequently instead of the regular brakes to slow down for red lights and on the highway. A week ago, the car started to act like it is in medium "B" mode when the car is in "D" drive. Instead of coasting after taking off the gas, the car slows down at a faster than normal rate. It also requires pushing the pedal farther down/more gas to keep the car moving at a consistent speed. I took it to my local Toyota dealership and they told me the car "operates as designed," did a fuel induction/coolant flush and the problem is still there. Any ideas from the prius experts? Thanks in advance.
     
    #1 EastR, Jan 28, 2011
  2. 2009Prius

    2009Prius A Wimpy DIYer

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    Not sure about your issue of car slowing down faster than usual but regarding the "B" mode unless you are going down a long hill and the HV battery is full it is normally better to just brake in the "D" mode and let the HV battery charge up for later use. Good luck and welcome to PriusChat! :)

    Do you apply parking brake? If so then in the winter it may stuck frozen. Just a thought.
     
    #2 2009Prius, Jan 28, 2011
  3. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    1) I have read up on Mt Greylock and if you live on top of it, you should be using B to get down it. Other than that, it is unlikely you ever should be using B. It is for those occasions when you need to waste energy as heat but do not want to over heat your brakes. You would never choose to use it for less than a 600 foot decent.

    2) If your Prius is operating correctly and D mode is acting like B mode, the HV Battery is so full there is nowhere to store more energy, so it has to waste it. Are all 8 bars full?

    3) one would think that if the Prius was misbehaving, there would be codes, and you say the dealer checked for codes.
     
    #3 JimboPalmer, Jan 28, 2011
  4. qbee42

    qbee42 My other car is a boat

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    You don't need B mode in Massachusetts. Using it only wastes gas.

    As for the feel of your Prius, does the indicator show that you are in D mode? If yes, then your car is okay.

    Tom
     
    #4 qbee42, Jan 28, 2011
  5. Jim Porta

    Jim Porta Junior Member

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    Someone will correct me if I'm wrong, but could the problem be low traction battery state of charge? The ICE has to do most or all the work at 2 purple bars. Traction battery not getting charged when in B mode. Stay in D unless you're coming down a mountain.
     
    #5 Jim Porta, Jan 29, 2011
  6. ursle

    ursle Gas miser

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    My car feels like it's in "B" mode when it's 10 degrees or below, and my mileage suffers, was your episode coincidently during a cold spell?
    I drop from 53 to 47 mpg during deep winter, as an outdoor enthusiast when my mileage starts to creep back up "winters over";)
     
    #6 ursle, Jan 29, 2011
  7. JimboK

    JimboK One owner, low mileage

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    As others suggest, it sounds like normal behavior if the battery is full ("full" actually being closer to 80%, though the MFD shows all green bars). The car puts itself into a variant of B mode to avoid overcharging the battery. Several of us have described this.

    And I also agree with the others that B mode is unnecessary -- and wasteful of energy -- unless descending a mountain or lonnngggg hill.
     
    #7 JimboK, Jan 29, 2011
  8. EastR

    EastR Junior Member

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    Thanks for the advice and good to meet other prius owners. I will lay off the "B" mode unless going down a big hill. Mileage is my other concern -- I'm down to 41.9 right now (on 260 mi.) when I usually run at 49-50mpg. It is a lot colder than usual ursle (about 10-15 deg F) during the commute so that can be a big factor.

    I don't think it's the battery being fully charged because it started happening two weeks ago and does it every time I drive the car.

    The dealership people said they did an "18 point" winter inspection but I'm not positive they plugged in the diagnostic computer... I'll have to call them back to check on that one. When I got the car back, the "maint req" light was on but I know the prius will do that automatically for oil changes and other minor things too.
     
    #8 EastR, Jan 31, 2011
  9. richard schumacher

    richard schumacher shortbus driver

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    If you can stand to leave the cabin heat off it will noticeably improve MPGs. Of course do always use the defrost as needed for safety.
     
    #9 richard schumacher, Jan 31, 2011
  10. kadeR

    kadeR Junior Member

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    Hi all, i'm sorry for the bump in this message, but this situation its hapening with my yaris HSD.
    When i get the foot out of the accel pedal i feel the engine reving up a litle bit before getting the revs down, the car its acting like its on B. I cant put it in EV mode and i dont get regenerative braking. The car its acting a little bit weird but it shows no errors on the dash. =X At first i thought that it was the warming up but after a 30km trip it was just the same. Any help?
     
    #10 kadeR, May 5, 2017
  11. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    How many kilometers?
     
    #11 Mendel Leisk, May 5, 2017
    kadeR likes this.
  12. kadeR

    kadeR Junior Member

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    75000km
     
    #12 kadeR, May 5, 2017
    Mendel Leisk likes this.
  13. bisco

    bisco cookie crumbler

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    12v okay?
     
    #13 bisco, May 5, 2017
  14. kadeR

    kadeR Junior Member

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    think so... the car starts up just right no light dimm.
     
    #14 kadeR, May 5, 2017
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