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2006 Prius Won't start - Ignition & Acc works fine

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by bulldog, Sep 27, 2020.

  1. bulldog

    bulldog Member

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    Over the last few months the 2006 Prius won't start, it acts as if the brake pedal is not pushed. It first turns on ACC & then Ignition if you push the Start button.

    Keyfob and 12V battery seems fine. Also the brake pedal seems very firm. If you push on the brake pedal pretty hard and after a few tries it does seem to sense it and start.

    My question is if I should reface the brake light switch or the brake pedal position sensor?
    It seems like it is not sensing the brake pedal is pushed, not sure if it uses the position sensor to determine if it is pushed hard enough. Or is there perhaps another issues with the brake system.

    Once you get it to start it seems to be fine for quite a while.
     
  2. JC91006

    JC91006 Senior Member

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    Have you worked on the brakes recently? The stiff pedal feel is the problem, if the brake light switch can't be depressed, the car won't start.
     
  3. bulldog

    bulldog Member

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    Haven't worked on the brakes for quite some time. I ordered a new Stop Light switch and will probably replace that and see. The brakes seem to get harder if you press the pedal, like on old vacuum boost if you don't run the engine.

    Not sure I'm I'm dealing with a catch 22, can't start if the brakes aren't depressed and brakes need ignition to be in READY state to start the brake booster.
     
  4. SFO

    SFO Senior Member

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    Happen to have any OBD2 codes (DTCs) that you could share with us?
     
  5. TMR-JWAP

    TMR-JWAP Senior Member

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    The switch located on the brake bracket needs very little movement to change states. Whether the car is ready or not or the accumulator/pump running should have no impact on the switch functioning. Just press the power button 2 times with your foot off the brake to put the car in ig-on mode. Then press the pedal and see if the lights work.
     
  6. bulldog

    bulldog Member

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    No OBD codes.

    With the little required, made me wonder about the switches, but not sure if it is the stop light switch or brake position sensor.
     
  7. SFO

    SFO Senior Member

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    No OBD2 codes are being stored, or are able to be retrieved?

    Which OBD2 scanner are you using?
     
  8. bulldog

    bulldog Member

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    Sorry, was a bit busy. There were no OBDII codes. I noticed the brake lights will flicker at times with light pressure, and tested it a bit. I replaced the Stock Light switch or Brake light switch - which is a huge PITA.

    The brake lights seem to work fine now, and have not noticed the issue with starting again. Will keep an eye on it, to see if that is the cause.
     
    bisco likes this.
  9. bisco

    bisco cookie crumbler

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    congrats!(y)