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Battery fan odd behavior

Discussion in 'Gen 3 Prius Technical Discussion' started by rtb, Jul 31, 2021.

  1. rtb

    rtb Junior Member

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    Location:
    Monrovia, California
    Vehicle:
    2013 Prius
    Model:
    Persona
    My Gen 3 Prius has only 39,000 miles. On rare occasion, every few months usually, the fan vent on the right rear seat comes on shortly after I start the car and start driving. This usually occurs within an hour or two after having driven it maybe only a couple miles as is typical for this car. It loses power, barely goes. If I pull over it continues to run and it draws lots of air creating a good suction. It will run for as long as I have it stopped but have not tested it for more that 5 to 7 minutes. I'm in Southern California so it is usually warm. If I shut it off then immediately restart it, the fan no longer runs and the car operates just fine. Have asked several Toyota service managers and they have no answers. No warnings showing on the dash. This car has generally been no problem. One time this occurred twice in one week but it has not happened for several months until yesterday.
     
    #1 rtb, Jul 31, 2021
  2. bisco

    bisco cookie crumbler

    Joined:
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    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    the heat is causing the car to go into battery protection mode. clean the fan, intake grille and inside the battery case.
    pray for cooler weather
     
    #2 bisco, Jul 31, 2021
  3. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
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    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    Agree. Normally the fan can run at a lower speed that most do not hear. Usually the blower blades have excessive buildup.
     
    #3 rjparker, Jul 31, 2021
  4. wheezyglider

    wheezyglider Active Member

    Joined:
    Mar 12, 2011
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    Location:
    SF Bay Area
    Vehicle:
    2010 Prius
    Model:
    Five
    The fact that its so intermittent, happens only on a warm start, and goes away immediately upon a restart is *odd*.

    Although it isn't rainy these days in SoCal, maybe check for water incursion in the hatch just to rule it out. People have had that issue, not sure if anyone has had it affect their HV battery. (Been through the car wash shortly before any of these episodes?)

    I'd buy a cheap ($20-ish) OBD adapter* and use something like the Dr. Prius app to keep an eye on the hybrid battery temperatures (it has three sensors). And whenever the problem occurs badly enough to cause the car to go into limp mode (suprised there's no "check hybrid system" message with that), there might very well still be codes ("DTCs") that can be read by OBD. If you get readable codes then a mechanic will have something to work with...

    *(FYI on OBD adapters -- if you use an iPhone then most of the cheaper bluetooth ones won't be compatible. They make WiFi ones or ones that are wired via OTG cable that would work.)
     
    #4 wheezyglider, Jul 31, 2021
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