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Toyota Prius Hybrid Battery Fan Always On?

Discussion in 'Gen 2 Prius Technical Discussion' started by Friendlyx, Aug 1, 2016.

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  1. Friendlyx

    Friendlyx Member

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    About 3 months ago i posted a question on these forums that in needed help because i had lost power while driving and some of you guys said that it might have been the battery fan. So i went and checked it out and it was torn apart, i'm guessing since the car was salvaged title, that they had just put it back how it was and tried to glue it back. So i went and bought an used fan from another Prius and put it in myself. It was quiet for a few days and when it got really got (around 80) it turns on and i thought i had done a good job.

    After this the fan would turn on at weird times such as around 7 in the evening it would turn on until i got home from school. However recently about a three weeks ago the fan runs almost nonstop. A little after turning on the car and right before turning it off. To be fair the temperature hasn't gone much lower than 80 degrees. I just want to know if this is normal, for the fan to be on all day? Could the fan be broken? Or could the battery be overheating?

    The car is a Toyota Prius 2006, and the grill is not blocked by anything, I've made sure of this, and i also keep the AC running whenever i am in the car to keep the cabin as cool as possible. The triangle of death has never turned on. I also live in California, which is very hot most of the day. I'd appreciate any help, Thank you!
     
    #1 Friendlyx, Aug 1, 2016
  2. jdcollins5

    jdcollins5 Senior Member

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    The fan is controlled by the battery temperature. It turns on around 97F and turns off around 93F and varies the speed the warmer it gets. So with ambient temps in the 90's you will want the fan to run to help cool the battery.
     
    #2 jdcollins5, Aug 1, 2016
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  3. Friendlyx

    Friendlyx Member

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    So what would cause the fan to be on all day? It's obviously, not 97F everyday. It'll be around 60-80 until noon.
     
    #3 Friendlyx, Aug 1, 2016
  4. CR94

    CR94 Senior Member

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    Keep in mind that the battery temperature will be significantly higher than the outdoor temperature if the car's parked in the sun, or if you've been driving it without air conditioning. It will be higher than the interior temperature if you've been driving with air conditioning.

    It's not clear you have a problem. If it continues to run "all day" when cool weather arrives, then you do.
     
    #4 CR94, Aug 1, 2016
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  5. Augustus88

    Augustus88 Junior Member

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    Using my ScanGauge, I have observed that the battery will very quickly warm up during driving. For example, on a 15 minute drive, the battery may start off at 85 degrees (ambient down here), and by the end of the drive can easily be over 105. Park the car for 30 minutes or an hour, come back out to it, and the battery has continued to warm after the car was shut off an could easily be 115-125 degrees. Unless you manually increase the fan speed, it could take a long time for the battery to cool down under city conditions. Normally, the faster you drive, the faster the fan spins. The idea is that you shouldn't hear it over road noise. I manually control my fan speed with my ScanGauge to keep it around 100 degrees.

    And yes, it is normal for the fan to run all the time. Even when stopped. However, you should not be able to hear the fan from the driver's seat. You should only be able to tell it is running if you put your ear up to the fan intake on the rear seats at the passenger side. Unless you are manually controlling the fan to run faster, of course.

    EDIT : I'd like to clarify... You ARE talking about the hybrid battery fan, the one that is in the rear of the car and its intake is on the rear seats next to the passenger side door, not the fans at the front of the car at the radiator?
     
    #5 Augustus88, Aug 3, 2016
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  6. Friendlyx

    Friendlyx Member

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    The only reason i'm a little paranoid is because it is my first Prius, and i am still young so i may not have the knowledge of cars that most people have. However, now in the mornings it is a lot cooler than when i had posted this post, and the fan still runs at times. What worries me the most is that i'll be driving the car and if i don't put my music on i can clearly hear the fan going in the back from the front seat. The fan sounds kinda like "groggy" sound. I hope as the temperatures start to fall i don't hear the fan anymore, because it's really starting to worry me especially with the "Groggy" sound it makes. Yes i am talking about the hybrid battery fan!!! Thank you for your tips! Also, is there other things that are cheaper than ScanGauge that i could use? Thanks!
     
    #6 Friendlyx, Aug 19, 2016
  7. Mendel Leisk

    Mendel Leisk Senior Member

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    When I had Scan Gauge II hooked up, driving on cool evenings, outside air around 12~15C, with the car fully warmed up, I was seeing battery temps around 35C. The battery warms up, regardless of ambient temperatures.

    Step one: I would clean the fan.
     
    #7 Mendel Leisk, Aug 19, 2016
  8. Friendlyx

    Friendlyx Member

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    Hey! So as i stated in my first post i did the following: "So i went and checked it out and it was torn apart, i'm guessing since the car was salvaged title, that they had just put it back how it was and tried to glue it back. So i went and bought an used fan from another Prius and put it in myself." when i did put in the new one i made sure it was clean and dusted what dust was on it.
     
    #8 Friendlyx, Aug 19, 2016
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  9. Mendel Leisk

    Mendel Leisk Senior Member

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    Sorry, missed that. :oops:
     
    #9 Mendel Leisk, Aug 19, 2016
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  10. Augustus88

    Augustus88 Junior Member

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    If your hybrid battery fan sounds groggy, that is a sign of a bad fan motor or bearings. Grindy, rattly is never a good sound from a fan. All you should hear is a slight whirr of airflow when you put your ear next to it. Another possibility is that the fan is running at full speed. A good condition fan at full speed sounds like a computer with loud fans at worst, not groggy or rattly.

    Does your fan sound similar to the one in this video?

    If so, get another fan to test.
     
    #10 Augustus88, Aug 19, 2016
  11. Philliplewis590

    Philliplewis590 New Member

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    Did replacing the hv battery fan solve the issue?
     
    #11 Philliplewis590, Mar 10, 2018
  12. Friendlyx

    Friendlyx Member

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    What fixed my issue was changing the fan again, it was broken and that what was causing my battery to overheat.
     
    #12 Friendlyx, Mar 10, 2018
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  13. Philliplewis590

    Philliplewis590 New Member

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    #13 Philliplewis590, Mar 10, 2018
  14. Philliplewis590

    Philliplewis590 New Member

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    While this was happening did you get any warning lights? How's everything with the car since then? How the hv battery holding up?
     
    #14 Philliplewis590, Mar 10, 2018
  15. Blulyf

    Blulyf New Member

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    My fan broke. P0A80 code came up. Replaced fan with one from pick and pull. Don't ever here fan running so I'm going to replace it again before moving on. P0A80 code is super annoying any software I can purchase to read ecu?
     
    #15 Blulyf, Oct 20, 2018
  16. Mendel Leisk

    Mendel Leisk Senior Member

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    A ScanGauge can monitor fan speed, at with regular 3rd gen Prius, not sure about c. It's not one of the pre-programmed "gauges", I had to enter it in, it's an "XGauge". FWIW, I would see fan speed anywhere between 0 and 4 (there's 5 or 6 speeds?), but never heard the fan. Don't assume it's not running if you're not hearing it.

    There's very likely some phone apps that can monitor fan speed too?
     
    #16 Mendel Leisk, Oct 20, 2018
  17. zeron1982

    zeron1982 Junior Member

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    Did you fix it , if so how ?
    I have the same problem here with a salvage prius the fan wasn't working at all so I replaced it now the new fan stays on I get the red triangle and code that says fan high voltage the fun is running none stop as soon as I start the car even if the car and Hv battery is cold the fan is running at level 6 or 7 there is no difference is when I control it with tech stream the computer shows 0 to 6 but even on zero it spins at high speed .

    Posted via the PriusChat mobile app.
     
    #17 zeron1982, Jan 23, 2019
  18. Friendlyx

    Friendlyx Member

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    Hey! Yeah I fixed it by swapping the fan and after that it wouldn't turn on a lot or make a lot of noise.
     
    #18 Friendlyx, Jan 23, 2019
  19. zeron1982

    zeron1982 Junior Member

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    #19 zeron1982, Jan 23, 2019
  20. magnumrtawd

    magnumrtawd Member

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    #20 magnumrtawd, Oct 28, 2020
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