2010 Prius Base Difficulty Starting

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by stab244, Nov 15, 2025 at 10:24 PM.

  1. stab244

    stab244 Junior Member

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    2010 Prius
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    Hi all,

    Got a strange issue with my 2010 prius. I press on brake and power on but while my dash turns on, my after market stereo and the engine do not start. I release brake and press power button to power off. Press on brake to start back up and it'll start up normally. Sometimes I might need to repeat. I did notice tonight that if I had lights on before starting, it wouldn't start up at all until I turned off lights. I did have one start up where 30 seconds after I powered it on, the stereo display lit up then I could start the engine without powering off first. This started happening about a month ago after I went on vacation for about 9 days. When it is started properly, I don't see any check engine lights. I checked the 12V battery and it was around 12.4V. My best guess now is my aftermarket stereo was sipping power causing some issue. The aftermarket stereo is one of those chinese Android Auto/CarPlay devices.
     
    #1 stab244, Nov 15, 2025 at 10:24 PM
  2. Brian1954

    Brian1954 Senior Member

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    The problem is probably the 12v battery. How old is the battery? How much do you drive the car during the week?
     
    #2 Brian1954, Nov 16, 2025 at 8:37 AM
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  3. BiomedO1

    BiomedO1 Senior Member

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    Where did you check the battery? At the battery terminals or the jump point, under the hood? You may have loose or dirty terminal connections.
     
    #3 BiomedO1, Nov 16, 2025 at 9:29 AM
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  4. ASRDogman

    ASRDogman Senior Member

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    12.4 volts is low for a Prius. How old is the battery? If it's 6 or more years, it's likely
    time for a new one. You could try charging it for 6-8 hours at 5 amps or less.



     
    #4 ASRDogman, Nov 16, 2025 at 12:50 PM
  5. bisco

    bisco cookie crumbler

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    do the brake lights come on when you press the brake pedal?
     
    #5 bisco, Nov 16, 2025 at 1:04 PM
  6. bisco

    bisco cookie crumbler

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    sometimes people hit the power button too fast before the brake switch is fully depressed, going into acc mode
     
    #6 bisco, Nov 16, 2025 at 1:05 PM
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