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2007 Prius suddenly won't start.

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Dustin Lowe, Jul 30, 2023.

  1. Dustin Lowe

    Dustin Lowe New Member

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    They just moved from Cali and put a brand new battery in before the move so the battery is maybe a few months old at most. I could certainly pull it and take it in for testing though.
    As far as clicks, I am hearing clicks in both the front and the rear of the car so it seams like it's readying to start but then nothing.
     
  2. Dustin Lowe

    Dustin Lowe New Member

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    I am certainly concerned about the lack of brake lights. I tend to think that there is still a problem there that is keeping it from running. I checked codes with a standard OBDII reader but nothing shows. I know this is not the best option but it's all I have at the moment.
     
  3. bisco

    bisco cookie crumbler

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    the brake switch is an interlock. you can't make the car ready without it being closed
     
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  4. Dustin Lowe

    Dustin Lowe New Member

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    OK, makes sense. I just checked the old switch with a meter and it seems to work just fine. Power flows through it when the button is released and ceases when pushed in. Is there possibly a bad relay somewhere that I can check or replace. I have looked at all of the fuses I can find labeled anything that might relate to brakes but they all seem fine.
     
  5. ColoradoCrow

    ColoradoCrow Active Member

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    [​IMG]
    i found this... stilll searching under brake light schematic
     
  6. ColoradoCrow

    ColoradoCrow Active Member

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    @ChapmanF hopefully will come along soon. He probably has them in his files
     
  7. Tombukt2

    Tombukt2 Senior Member

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    You getting power at the rear sockets or the connections that run up to the LED they're kind of tricky to access It is common for these LEDs to get funky their connections get weird moisture whatever I have one that's intermittent all the time It's the right side too If I get out and smack it lightly wouldn't open hand boom it comes right back on and works for months I have not had my tail lights apart yet but I've taken a few apart at the junkyard to get new pieces with nicer chrome that go under the lenses
     
  8. ChapmanF

    ChapmanF Senior Member

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    The stop light switch is wired to a bunch of different places. There's a "stop light control relay" too (not really a relay, more an electronic gizmo, but that's what they call it) on the way to the lights in back, but I wouldn't worry about that right away as far as starting the car.

    I would look at the "hybrid vehicle immobiliser" section, or the "hybrid system, shift control system" section, in the wiring diagram.

    Toyota Service Information and Where To Find It | PriusChat

    They show the side of the stop light switch that's supposed to be open when you're not pressing the pedal wired to the STP terminal on the power management control ECU. This seems to be how the ECU decides if you are pressing the pedal and should go to READY instead of ACC or IG-ON. That circuit just runs from the switch to the ECU, doesn't involve the stop light relay.

    The switch has another side that is supposed to be closed when the pedal is not pressed, and opens when the pedal is pressed, kind of the opposite of what the first side does. That's also wired to the power management control ECU, terminal ST1- (the trailing - probably indicating a signal with the opposite sense of STP). I think that one is just used for canceling cruise control, but testing both sides wouldn't be much more work than testing one.
     
  9. Dustin Lowe

    Dustin Lowe New Member

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    FIXED!!! Turns our it WAS a bad fuse. I had visually inspected them and couldn't see anything wrong so I started swapping them out just to be sure and BOB'S YOUR UNCLE! It started and drove as it's supposed to!

    Thank you all for your assistance, patience and guidance! I have never had a car that depended on the brakes just to start so this was new to me! Learn something new every day!
     
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  10. ColoradoCrow

    ColoradoCrow Active Member

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    excellent. now keep a spare fuse handy and see if you can find out WHY the fuse popped.
     
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  11. Dustin Lowe

    Dustin Lowe New Member

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    Ordered a whole bunch of them! Thanks!
     
  12. Tombukt2

    Tombukt2 Senior Member

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    Most of the time it's generally something pretty simple. I'm chasing a similar problem in an '08 that I just got the other day for like 700 bucks I got it to start in their driveway and drove it home. Then it stopped starting all of a sudden and it's probably going to be something relatively simple like a fuse or what have you I haven't even had time to really look.
     
  13. ChapmanF

    ChapmanF Senior Member

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    Well, it's not so much that it depends on the brakes to start, as that it's built to make sure your foot is on the brake before it starts. In my lifetime they've made a lot of cars that way to cut down on accidents.

    One car I had with a manual had the switch on the clutch pedal instead.