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Hybrid Transaxle Temperature Monitoring

Discussion in 'Prime Main Forum (2017-2022)' started by mkarolian, May 25, 2019.

  1. mkarolian

    mkarolian Junior Member

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    If theoretically, I were to tow a small motorcycle trailer behind my Prime, I'd like to keep an eye on the transaxle fluid temp. Good idea?

    I have the Torque App for android, yet I can't seem to be able to configure it to read out the transaxle fluid temperature. Any suggestions here?
     
  2. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Is there even a trans oil temp sensor in these? The fluid never bears the driving load like in a traditional trans with torque converter, so I'd think there's little need.

    There are other temp sensors in the transmission, and they are there for parts that are soaked in the ATF bath, so perhaps just as valuable for your purposes. I'd think you could read MG2 temp and see all you need there.
     
    Raytheeagle likes this.
  3. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    Starting at 7:40 and going to 9:15 We see both external oil lines and external coolant lines, adding a Temp sensor for oil or coolant or both would be easy, a 'radiator' for the WS ATF oil would be easy. (previous Prius all had internal channels, so it would be harder)
    If the Gen 3 Prius does not have sensors for what you want, here are examples.

    www.amazon.com/Bosch-SP0F000049-Style-Electrical-Temperature/dp/B00UZ9H59A (ATF or water)

    www.amazon.com/Hayden-Automotive-676-Rapid-Cool-Transmission/dp/B000C39CL8

    I would be temped to add the transmission cooler and skip the gauges.
     
    #3 JimboPalmer, May 25, 2019
    Last edited: May 25, 2019
  4. Trollbait

    Trollbait It's a D&D thing

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    The fluid used is ATF though, so it doesn't stand up to heat as well as a fluid used in manual transmissions.

    The gen3 Prius doesn't have a tow rating even in countries in which people do tow with small cars. The gen4 has better cooling for the fluid, so Toyota gives it a tow rating for those markets, still lower than comparable cars though.

    The Xgauge function of the Scangauge II allows the programing of gauges beyond the standard ones. A transmission temperature display is one possible, and the Prius appears to have such a sensor. So that might be an option.
     
  5. lextoy

    lextoy Active Member

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    its only a motorcycle on small trailer ?? just make sure the tires on the car and on the trailer are all well inflated, lube the trailer bearings, and go...
     
  6. mr88cet

    mr88cet Senior Member

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    I’d think we’d be more concerned about the inverter-coolant temperature. (Well, meaning the inverter temperature.)
     
  7. mr88cet

    mr88cet Senior Member

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    Yeah, I too am inclined to think that it’s probably not a huge concern, perhaps unless you plan to climb mountains with it. Admittedly though, I don’t have a lot of data to back up.

    However, I’m pretty sure I recall my brother’s family pulled a small trailer with their 2005 (Gen.-2) Prius.
     
    #7 mr88cet, May 26, 2019
    Last edited: May 26, 2019
  8. mkarolian

    mkarolian Junior Member

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    Hmmm great point re: inverter temp. I wonder if it’s possible to monitor that using the torque app
     
  9. jb in NE

    jb in NE Senior Member

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    Hybrid Assistant monitors this. It shows on the app display and also is reported with the companion Hybrid Reporter app. Here is an example of the report:


    upload_2019-5-26_9-41-8.png
     
  10. Dmitriy Sokol

    Dmitriy Sokol Active Member

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    Maybe I am missing something, but I am looking for normal operating range temperatures for the transaxle (either MG1 or MG2). I have been using OBD fusion to monitor temps and my motor generator (MG1 or MG2) gets up to 205F (driving for hours at 70). I am trying to figure out what’s normal. Thank you in advance.


    iPhone ?
     
  11. Sonic_TH

    Sonic_TH Active Member

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    My 2012 Prius C Motor Generator 2 temperature got to 116° C on a hilly trip today while taking my brother to a construction site work.