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EV mode not engaging and rear battery fan always on

Discussion in 'Gen 4 Prius Care, Maintenance and Troubleshooting' started by PriusFan06, May 11, 2017.

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  1. PriusFan06

    PriusFan06 Member

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    Hello All,

    I know my handle name says PriusFan06. I finally traded it in for a new 2016 Prius Two last year. I'm a very happy Prius owner and that is why I decided to get another.

    Here is my issue.

    Lately I noticed that when I drive around town and on the freeway the rear fan under the passenger seat is blowing high when I'm driving 50-70mph and then in the city it'll blow on low. I've never noticed it until lately because I can really hear the air blow when I power off my radio. Is this a concern? I think the fan is for the traction battery. Please correct me.

    I also noticed that my EV mode will not light up as often as before. My battery could be full and EV light will not power on. My MPGs have gone down from avg 61mpg down to about 55-58mpg. I know...58mpg is better than most cars on the road; but this all started about 2 weeks ago. I would also let go of the gas for gauge to go down and wait for EV light to turn on and it doesn't. Sometimes it does; but like I said lately it's been acting up weird.

    Car has about 9k miles and I'm due to take the car in June for my 6 months oil change. I'll bring this up to Toyota but knowing dealerships they'll just say that's normal. AND ITS NOT. The fan constantly blows now. Does this mean my hybrid battery under the rear seats are getting hot or warm? Or indication that the battery is going bad?

    My 06 Prius had to replace the hybrid battery at 9 years and 10 months. Luckily that was under warranty. But I can't believe this is the hybrid battery now because my car is only 8 months old.
     
    #1 PriusFan06, May 11, 2017
  2. Prodigyplace

    Prodigyplace 2025 Camry XLE FWD

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    Have you checked & cleaned the battery vent? It looks like it may be removable on mine but I have not yet tried.
     
    #2 Prodigyplace, May 11, 2017
  3. PriusFan06

    PriusFan06 Member

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    I have not, but can check it tonight. I have no pets and really no passengers as this car is for work commute only. I drive 100-125 miles daily. My car is cleaner than it was when I drove it home from the lot. LOL Basically what I'm saying is I highly doubt anything got sucked into the vent. Will report back.
     
    #3 PriusFan06, May 11, 2017
  4. kithmo

    kithmo Couch Potato

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    I agree it sounds like a blocked vent, a fan sucking air in will increase in speed as the load on the fan is lower if the vent is blocked (no air to move), same effect as blocking the end of a vacuum cleaner (hoover) hose.
     
    #4 kithmo, May 11, 2017
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  5. PriusFan06

    PriusFan06 Member

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    Ok I will check it when I get home tonight. So just use a Phillips to remove the 1 screw? And this is underneath the rear passenger seat right? Remove the plastic vent and I should see a filter or something?

    And would this affect my lack of EV mode? Thanks for all your responses. Much appreciated.

    Posted via the PriusChat mobile app.
     
    #5 PriusFan06, May 11, 2017
  6. Prodigyplace

    Prodigyplace 2025 Camry XLE FWD

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    yeah.
    There also appears to be some other vent near the center of the rear seat, near the floor. Nobody knows what that is for.
     
    #6 Prodigyplace, May 11, 2017
  7. PriusFan06

    PriusFan06 Member

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    Yea was checking out that rear vent near the center. Not sure what it is either.

    Posted via the PriusChat mobile app.
     
    #7 PriusFan06, May 11, 2017
  8. bisco

    bisco cookie crumbler

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    at 9,000 miles and 8 months, can't you take it in under warranty?
     
    #8 bisco, May 11, 2017
  9. PriusFan06

    PriusFan06 Member

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    Yes I'm taking it in next month for the 6 months tire rotation and oil change but you know how the dealerships work. They will say...oh that's normal for the fan to be blowing to keep the traction battery cool. So then what? Just argue with them? You know what I mean. It's hit or miss with the service advisors at my dealership. I will report back what happens when I do take it in.

    Posted via the PriusChat mobile app.
     
    #9 PriusFan06, May 11, 2017
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  10. bisco

    bisco cookie crumbler

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    agreed. and if you aren't getting any dash lights, they will say they can't do anything. but you want it logged into their system in case it becomes a bigger issue after warranty.
    it's hard to believe there is anything in your fan. how warm has it been outside?
     
    #10 bisco, May 11, 2017
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  11. PriusFan06

    PriusFan06 Member

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    It's around high 70s to low 80s in my area. I'm driving around 70mph.

    No dash lights.

    But I will report it so it can be documented.

    Posted via the PriusChat mobile app.
     
    #11 PriusFan06, May 11, 2017
  12. Data Daedalus

    Data Daedalus Senior Member

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    Have you tried using the Airconditioning on minimal settings when driving? Actually, do you use your AC at all? Just curious.

    The best cooling solution for the Prius HV battery is the AC included with the vehicle.

    IMHO, the Prius AC plays an important role in keeping the operational temperatures of the HV battery down in warm / hot weather - and I do believe long term, will also prolong its life.

    I'm curious as to how your HV cooling fan would behave if your AC was on while you're driving along at 70mph.

    Summers can get pretty hot in London, UK - and that's why I always use my AC unfailingly - albeit at minimum life support settings (17c on 2nd to the lowest fan speed on a hot day).

    If I don't, I can hear my rear HV cooling fan on high by the time I drive uphill to my home, on the last leg of my journey. If I use AC for the trip, I might hear the fan running on its lowest setting (as in barely audible - and yes, I do have exceptionally sensitive hearing, so I often pick up sounds that are inaudible to others around me).


    iPhone ?
     
    #12 Data Daedalus, May 11, 2017
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  13. PriusFan06

    PriusFan06 Member

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    Yes, I have tried using the AC on low and on eco mode and while driving 65 to 70mph; the HV battery fan continues to blow on high. I can hear it even with music on. I too have exceptionally sensitive hearing. My son can never sneak out of our house. Haha

    As I slow down to speeds of 10 to 15mph I can hear the HV battery fan blow slower. Once I reach a stop the fan is blowing very low. This doesn't seem normal.

    I'll see what Toyota will say when I take it in. The loud fan is anoyying and just worrys me that something is over heating or wrong.

    Posted via the PriusChat mobile app.
     
    #13 PriusFan06, May 11, 2017
  14. bisco

    bisco cookie crumbler

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    could it just be a noisy/defective fan, and you've only noticed it because it's running more, as it should, at higher speeds and warmer weather?
     
    #14 bisco, May 11, 2017
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  15. alanclarkeau

    alanclarkeau Senior Member

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    The "EV" lamp is inconsistent - it might give a better idea using the ENERGY MONITOR
    upload_2017-5-12_8-53-32.png
     
    #15 alanclarkeau, May 11, 2017
  16. PriusFan06

    PriusFan06 Member

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    From what I see and hear I highly doubt it is a faulty or defective HV fan. I'm very sensitive to hearing and would have noticed it for the 7-8 months of ownership. I just recently started hearing the fan. Today as I drove home the fan was on again. Blowing hard when I was driving 60-70mph and then the fan blew softer as I slowed down to 20-30mph. The temperature today was in the 80-82. Not cold and not hot. just perfect driving weather.

    I really feel something is wrong w/ the Hybrid system or HV battery. Just got a feeling.
     
    #16 PriusFan06, May 12, 2017
  17. Harters

    Harters Active Member

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    I notice you are in Power Mode, have you tried normal mode to see if you get the same behaviour?
     
    #17 Harters, May 12, 2017
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  18. Prodigyplace

    Prodigyplace 2025 Camry XLE FWD

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    Be sure to verify tire pressure after the rotation. My dealer wrote 32 for all wheels :eek: while actually raising them to a more reasonable 39.
     
    #18 Prodigyplace, May 12, 2017
  19. PriusFan06

    PriusFan06 Member

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    I just happened to drive in power mode when I took the picture. Most of the tone I drive in normal mode and same result. Fan blows. Same for eco mode.

    Posted via the PriusChat mobile app.
     
    #19 PriusFan06, May 12, 2017
  20. PriusFan06

    PriusFan06 Member

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    I fill my tires myself at Costco. I always double check and fill when tires are cold to warm.

    Posted via the PriusChat mobile app.
     
    #20 PriusFan06, May 12, 2017
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