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tire air pressure sensors on 2008?

Discussion in 'Gen 2 Prius Fuel Economy' started by beckerman, Oct 24, 2008.

  1. beckerman

    beckerman Junior Member

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    My tire "guy" said he cannot pump my tires to 42/40 as the pressure sensors will go off and light up on the dashboard?

    True?

    If so, what do I do?
     
  2. diamondlarry

    diamondlarry EPA MPG #'s killer

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    He's only partially correct. They probably will go off but you can easily reset to the new pressures. As long as you don't exceed 72psi you can set them for any pressure. Don't ask me how I know this.;):D
     
  3. beckerman

    beckerman Junior Member

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    How do you reset new pressure?
     
  4. rigormortis

    rigormortis Active Member

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    i think you hold the button down until the tire light flashes 3 times
     
  5. diamondlarry

    diamondlarry EPA MPG #'s killer

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    On page 155 of the Owner's Manual it talks about how to do this. And yes, you do hold the reset button down until the light flashes 3 times. It also says to wait a few minutes then power down. After powering back on, the light should go out after the diagnostic check of all of the lights.
     
  6. Rokeby

    Rokeby Member

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    From another thread, but it fits:

    Life Alert ® - Why do seniors need Life Alert?

    Beckerman,

    it's not you they're laughing at, it's the numbskull at the tire shop.
     
  7. beckerman

    beckerman Junior Member

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    Thanks to all.
     
  8. paprius4030

    paprius4030 My first Prius

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    I have an 08 and always pump my tires up to 42/40 and actually I err on the higher side and the light never comes on. The only time the light ever came on was once when I picked up a nail and had a slow leak and the pressure dropped too low. I have a pkg.#2 I don't know if the pkg. effects it but i didn't think so.
     
  9. rpg51

    rpg51 Member

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    I have an 08 Prius. My tires are at 62/60. The sensors have done nothing. It was always my understanding that the system is designed to prevent running on insufficient tire pressure, not excessive tire pressure.
     
  10. diamondlarry

    diamondlarry EPA MPG #'s killer

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    The way I understand that they work is that you pump them up to your desired pressure then reset so that when the psi drops by a certain % below your desired level the light will come on. If you set the psi higher without doing a reset, I don't think the light will come on until it goes below the original level. Maybe Galaxee or Hobbit or FireEngineer will chime in soon.
     
  11. alanh

    alanh Active Member

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    Once you calibrate it by pressing the button under the steering wheel, it will set off the light when the pressure declines 25%. So if you set it to 32, the light will come on at 24psi.

    If you want the light to come on sooner, you can temporarily overpressurize the tires, set the sensors, then drop them back to the pressure you want. For example, if you want to run at 42 and the light to come on at 37, you could inflate to 50 and then set the sensors -- 25% less is 37.5. You can then drop the pressure back to 42.
     
  12. rcaine

    rcaine Member

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    I attended my dealerships new owner event last week and asked some questions about tire inflation recommendations. I've been reading PriusChat for several months now so I knew the answers to the questions before I asked. The assistant service manager told me that doing the reset process does NOT change anything. The low tire sensor keeps the same alarm point even if you do the reset process in the manual. Has anyone else heard this or had experience with this? I reset my tire pressure to 38/36 (wife refuses to go to 42/40 so far). My Prius did not complain about the change.