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Decelerates downhill

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by PeterPrius, Apr 7, 2010.

  1. PeterPrius

    PeterPrius Hers is a 2009 Prius, non-SKS

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    Vehicle:
    2005 Prius
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    N/A
    Today I noticed that my 2005 Prius doesn't get rolling down the steeper hills.

    I take my soon to school everyday and I know which hills my Prius loves to roll down. My route is uphill in which the battery drops to 2 bars. The SOC doesn't increase until about mile 6.

    I noticed my SOC was going back and forth between 3 and 4 bars uphill. It's never done that before. On the way back down the hills, the car actually decelerated. It's never done that before either. I usually lightly ride the brake to get additional regeneration. The parking brake *seems* to be fine.

    On the hills where it's not steep enough (downhill) I use the cruise control. Today it no longer works. Coincidence? Symptom or sign of something bigger?

    My tires are nitrogen Nokian WGR2. They're fine. We just got back from a 2,200 mile trip through the desert SW. No issues of any kinds during the trip. My wife did report that she heard clicking noises yesterday when starting up the car, and that the noises went away when she put it into reverse.

    We did going through 800 miles of strong wind with tons of blowing dust and sand. I have fine sand in the engine compartment. I did the battery check and I show 14v. What else should I do? WHat else can I check?
     
  2. usbseawolf2000

    usbseawolf2000 HSD PhD

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    Were you in B gear by any chance?
     
    1 person likes this.
  3. don_chuwish

    don_chuwish Well Seasoned Member

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    If the battery check showed 14V then you checked it after 2 presses of the power button at which point the traction battery is providing that power, not the 12V battery. To get a true unloaded, unassisted reading press the power button only once with your foot off the brake and no lights, A/C, etc.

    - D
     
  4. PeterPrius

    PeterPrius Hers is a 2009 Prius, non-SKS

    Joined:
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    Location:
    Lakewood, Colorado
    Vehicle:
    2005 Prius
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    N/A
    SOLVED Re: Decelerates downhill

    You're very smart. I probably accidentally knocked it into B when messing with the wiper controls.

    To confirm I went up and down one of my hills and sure enough, it was B that was causing the problem.

    False alarm then. I like having a car that is smarter than me :eek: (boy do I look dumb at times, eh?) and I like that this forum has smart contributors.
     
  5. usbseawolf2000

    usbseawolf2000 HSD PhD

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    Re: SOLVED Re: Decelerates downhill

    Now that you now know about the B gear feature, you can use it for your benefit. :) It saves you the hassle of braking constantly to adjust speed. However, B gear wastes energy -- in your case, 2-3 HV battery bars less.
     
  6. PeterPrius

    PeterPrius Hers is a 2009 Prius, non-SKS

    Joined:
    Jan 5, 2010
    48
    12
    0
    Location:
    Lakewood, Colorado
    Vehicle:
    2005 Prius
    Model:
    N/A
    Yep, now I know. I'll try that on Vail Pass for sure. It's a got a few sustained steep sections.

    UPDATE:
    The B is perfect for snow-covered roads, for braking naturally. I don't ever slow down in the snow so I just drive as usual and then when I need to brake I just tap it into B and don't stress about it - except I do stress about others poor driving habits.