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Electric mode not engaging sometimes...

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by hellochicken, Jul 28, 2018.

  1. hellochicken

    hellochicken Junior Member

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    when I drive my gen3 Prius around town, someitmes I would notice that the Electric motor doesnt seem to engage when I feel like it should. Example: driving around town at under 35mph, while practicing the good fuel efficiency techniques. Sometimes it works, someitmes it doesn't, sometimes the electric mode light goes on when I'm finally stopped, and someitmes it doesn't go on at all, despite having at least half on my hybrid battery level. i'm also averaging around 30mpgs in city driving, and I think it's due to the electric engine not engaging.
    When I drive Freeways, all seems to work fine, and I average anywhere between 45-50mpg, depending on hills and whatnot.

    I fear this will be a costly issue....

    any ideas?
     
    #1 hellochicken, Jul 28, 2018
  2. bisco

    bisco cookie crumbler

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    could be your hybrid battery going south. how many miles on her?
     
    #2 bisco, Jul 28, 2018
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  3. hellochicken

    hellochicken Junior Member

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    91k miles. I imagine that's pretty low for the hybrid battery to go bad already...

    But IF it is the hybrid battery going bad already, aren't hybrid battery replacements pretty costly?
     
    #3 hellochicken, Jul 28, 2018
  4. bisco

    bisco cookie crumbler

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    around 3k, but you have 10/150 warranty.
     
    #4 bisco, Jul 28, 2018
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  5. hellochicken

    hellochicken Junior Member

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    OH! I didn't know about the battery warranty - that's good to know! I actually bought this car used, although it only had 15k miles on it when I purchased it...
     
    #5 hellochicken, Jul 28, 2018
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  6. 4est

    4est Active Member

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    Ev won't engage is the battery or inverter is too hot, too cold, or some other reasons.
    Usually in the summer

    So it's normal, I think
     
    #6 4est, Jul 29, 2018
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  7. Grit

    Grit Senior Member

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    If you parked it under sun for couple of hours during triple digit heat and drive without AC on, EV may not engage as hv battery is beyond hot to even charge and discharge so ice stays on.
     
    #7 Grit, Jul 29, 2018
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  8. FuelMiser

    FuelMiser Senior Member

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    Can you select the Energy Monitor on the big display (I think you press the "Car" button) and watch whether the electric motor powers the wheels? This may not be what is actually happening, but this is what the computer is thinking what should be happening.
     
    #8 FuelMiser, Jul 29, 2018
  9. Elektroingenieur

    Elektroingenieur Senior Member

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    As @4est and @grid kindly mentioned, it may just be the warm summer weather. The temperature of the hybrid battery and the demand for energy for air conditioning can both affect how much the engine runs.

    If the hybrid control system detects a malfunction, it stores a diagnostic trouble code (DTC) and almost always turns on the master warning light (red triangle). I’d suggest confirming that the master warning and malfunction indicator (check engine) lights both come on briefly during the lamp test when you start the car and then turn off and stay off. If the warning lights are working as expected, just keep on cluckin’.

    If you or a friend has a Toyota Techstream diagnostic system or third-party equivalent, you could check for stored DTCs. With only the behavior you’ve described, however, I wouldn’t consider it worth paying a diagnostic fee to have a dealer or independent shop do this for you.
     
    #9 Elektroingenieur, Jul 29, 2018
  10. hellochicken

    hellochicken Junior Member

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    Thanks for the responses yall!
    Yes, the master warning and check engine light both come on briefly at startup. So based on what yall are saying, and what I'm noticing, I guess I'll stop worrying about it for now.
     
    #10 hellochicken, Jul 29, 2018
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  11. Grit

    Grit Senior Member

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    Allmost forgot, the first couple of minutes after startup when ICE goes off as you drive, ICE will come back on and will stay on a bit as you begin to accelerate so engine can reach operating temp. Mine takes about 15 minute of highway driving for engine temp to be at 200-ish degrees- normal engine temp.
     
    #11 Grit, Jul 29, 2018
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