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Outside temperature gauge

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by jbean, Apr 23, 2014.

  1. jbean

    jbean Junior Member

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    I have a 2009 Prius. Last summer I noticed that the outside temperature gauge was not working properly. I asked at the wonderful dealership I go to and no one knew anything.

    Where is it located and how can I properly test to see if it's working? I like the feature when it works.
     
  2. JC91006

    JC91006 Senior Member

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    I believe this feature rarely gives you the right outside temperature. It's just to have in your car, but I can't say it's extremely accurate. You literally would have to drive for 15 minutes with the air blowing onto your car before it can give you a proper outside temperature reading. From a standstill in sunlight or in a shaded area, the temperature reading doesn't seem to be accurate.

    I believe the sensor is in the front of your car in front of the radiator
     
  3. jbean

    jbean Junior Member

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    I like to know the outside temperature. I thought it worked accurately until last summer, when for example, I knew it was 100 degrees outside and it seemed to be stuck on something like 75 degrees. Then it was erratic and now I don't know if it's working correctly.

    Couldn't the sensor be replaceable? It's obviously not critical; just something I like.
     
  4. JC91006

    JC91006 Senior Member

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    You can try calling the dealerships that work on many hybrids. Ex. Santa Monica Toyota, Longo Toyota. There should be someone there that can quote you a price on changing the sensor.

    I tried looking this information up about changing the sensor, can't say I found much.
     
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  5. jdcollins5

    jdcollins5 Senior Member

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    The sensor is in front of the radiator as stated above. The sensor is mounted on a bracket and plugs in to a connector. Very easy to remove, check resistance and/or replace.

    The sensor will pick up the heat from an asphalt parking lot and read high. Once you get moving it will adjust to true ambient temperature. I have found mine to be quiet accurate.

    It will also read off when wet, like after washing or going through a car wash. Once the sensor dries it will read right again.
     
  6. dorunron

    dorunron Senior Member

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    +1 what jdcollins5 said. Cant add or detract from it. Simple plug and play. Go buy a new sensor aka thermistor and plug it in. You can see if you bend down and look through the grill. In the center of the radiator/condensor pointed straight up and down. You will see the wires and plug. IIRC, you can access it if you remove the top splash guard over the radiator. Will need sockets and extensions to get in there.

    Dealer can fix it, but they will probably charge at least one hour or more for labor plus the part.
     
  7. jbean

    jbean Junior Member

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    It used to be accurate. How do you check resistance?
    I'll call a dealership and find out what the cost is. Thank you.
     
  8. jbean

    jbean Junior Member

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    DoRunRon,
    Sockets and extensions? Really?
    Thanks for telling me how to find it. I think the dealership owes me one for the reverse battery snafu!
     
  9. bisco

    bisco cookie crumbler

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    reverse battery snafu!
     
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  10. jdcollins5

    jdcollins5 Senior Member

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    You check resistance with a digital meter set to the ohm scale and compare it to the known resistance values in the Repair Manual. There is a table that gives the resistance value at different degrees F.

    In your case since you know the sensor is not reading correctly, I would just buy a new sensor from the dealer and swap it out.
     
  11. jbean

    jbean Junior Member

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    Sorry, that didn't make sense. It was the reverse beep Prius mechanic snafu!
     
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