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Tire Pressure Indicator Warning Light Problem

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by joe1347, Oct 17, 2009.

  1. joe1347

    joe1347 Active Member

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    My tire pressure warning indicator just lit. However, a quick manual check with a gauge shows that all of my tires are fine. Added a little air to each of the tires, but the indicator is still lit.

    Anything to look for or try before heading over to the dealer?
     
  2. jdenenberg

    jdenenberg EE Professor

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    Check the spare tire pressure.
     
  3. joe1347

    joe1347 Active Member

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    It's 39.5psi. But is there an active sensor that monitors the pressure in the spare (in the GenII)? After removing the assembly used to hold the spare in place - I couldn't see anything obvious that would function as a tire pressure monitor. Although I'm assuming or guessing that there is an RF transmitter with integrated pressure sensor also in the spare?

    Inflated the spare to the recommended pressure - but the tire pressure sensor is still lit.

    A gauge check of all of the tires still shows that they are fine.

    Problem apparently now resolved. The indicator tripped on the first cold day of the year and I suspect that the TPMS was last reset on one of the hotter days of the year combined with a long trip to the dealer (tires were still hot when rotated). Also, I was running close to 40 psi at the time. So, a combination of time (air leaking out) and temperature seemed to be the problem. Hence, the solution apparently was simply to just reset the TPMS using the button under the steering wheel (with the tires properly inflated).
     
  4. alanh

    alanh Active Member

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    For the record, no, the spare in a Gen II does not have a TPMS. It pays to check it from time to time, you'll never know when you'll need it.

    And don't assume it came from the dealer properly inflated. I checked mine shortly after buying the car and it was 25 psi.
     
  5. BAllanJ

    BAllanJ Active Member

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    I don't bother checking the pressure in the spare... but since I have my little 12v pump in the car, I can fix that whenever I may need a spare...which I've only needed once in 35 years of driving so far.
     
  6. deirdre5155

    deirdre5155 Junior Member

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    I have had the same problem - light came on first cold day. Have had the pressure checked and all is OK. The service people tried the reset button and the light would go off for a few minutes and then come back on. They think that the sensor in one of the tires is shot. I'm assuming this would be covered under warranty? I have a 2008 under 36,000 miles. Any info appreciated.
     
  7. Sieglinde

    Sieglinde New Member

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    We went from pretty darn hot to pretty darn cold in a matter of a day or so and mine came on. Geeze. Worried about it until a few people told me that happens. I will still check the pressure since I have not done it in at least a month and I have my own compresser. I wlll look for the little reset button. Bother. :)

    My tires are supposed to be at 34 and 35 psi, if I recollect properly. I guess other tires are at 40psi. My tires needed inflation after I took delivery of the car also. I suspect that dealers don't check the pressure when they receive the car or when they give the car to the customer.

    Other than these weirdnesses is this gauge worth it? I think I will continue using my own gauge to check the pressure.

    A 2008 with 36,000 miles should be well within the normal warrently that comes with the car. I would have it fixed just to keep the car in good condition.
     
  8. jch

    jch Junior Member

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    First I am new to Prius- bought 2008 (non touring) from Hertz
    Afew days ago I had new Bridgestone winter tires mounted by Firestone (Rochester NY) when I left the low tire pressure indicator was on.
    I called the Firestone store and was told the light should go off after it recalibrates after about 20 miles. I was told to come back in if the light still was on.
    A hundred miles later I returned to the store and was told by the store mgr said what the clerk said was not ture and I would have to go to a dealer and have the sensor reset.
    I called a Toyota dealer and was told that they would have to run an $80 diagnostic and the repair could cost up to $300.
    I was going to go back to Firestone and confront the mgr that the mechanic likely cause the issue by damaging one of the sensors (dealer said this was a possibility)
    Since this vehicle is a different brand of cat I figured I better learn more about this sensor before I start pointing fingers. I have found forums very helpful so here I am (clueless) asking for help from you folks. thanks in advance- much appreciated
     
  9. firepa63

    firepa63 Former Prius Owner

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    If the tires are inflated to the proper pressure, try resetting the TPMS. The reset button in under the steering wheel column.
     
  10. Tideland Prius

    Tideland Prius Moderator of the North
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    No need to post twice. My response is in here. If you wish, I can close that other thread and have it continue here.

    http://priuschat.com/forums/gen-ii-...eshooting/73492-sensor-low-tire-pressure.html
     
  11. macmaster05

    macmaster05 Senor Member

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    Hey guys,

    Tonight my TPMS light stayed on after the car was sitting out in the cold (41 degrees) for the first time. I just checked my tire pressures and they were 35 (fronts) and 25 (rears) whereas they were 42/40 psi in the summer. I'm at a loss - is this is cold weather issue or are my tires actually punctured?

    I've had both cases and historically the light would turn off after driving (I'm guessing friction would heat up the tire/air), but it didn't turn off this time. But when there was a nail in my tire the next time, it was at 18 psi. That's why I'm confused...25 psi seems too low for a cold weather false alarm but too high for an actual leak. Any suggestions?
     
  12. Rebound

    Rebound Senior Member

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    I drove a rental car today (non-Prius; they wanted $20/day extra for a Prius). The TPMS sensor lit up for the first few miles. I mentioned it when I dropped off the car, and they told me with today's freezing temperature, the same thing happened on eight other cars today.
     
  13. wick1ert

    wick1ert Senior Member

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    It's possible it's a slow leak. It's also possible that you happened to check it not too long after it started, too. I'd recommend filling the rear tires up to where you want them, then monitor it the next few days to see if there is any change. Given the rule of thumb, that a 10 degree temperature drop is roughly a 1 PSI drop, you needed about a 150 degree temperature change if that were the only factor. I don't think it's even quite that warm where you are.

    It could be the seal, valve stem, etc that's got a slow leak, too.

    I'd fill em up and do a quick check every morning to see where they are at. That'll tell you if you need to get them checked out.