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Engine Failing? 2007 Prius

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by DIYohWhy, Jun 22, 2024.

  1. DIYohWhy

    DIYohWhy Junior Member

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    My Prius has been acting strangely. It started with the engine not staring right away one day after I pushed the button. Instead the check engine light came on and it sounded like it was straining and then the engine started up and the light went off.

    I never changed the oil since I got it, it had been about 6k since then, so I got an oil change. Engine seems to turn on more when idle like at red lights.

    When I turn off the car, sometimes it turns right back on with the check engine light coming on. When I hit the button again it turns off. Next time I turn it on, no check engine light.

    I did check the codes when this happened but my small reader didn't pick up any codes. I may need to try techstream next time it happens in case it can detect more.

    Not really sure if I'm just hitting the button too fast, hard, etc. sometimes or what's up with it. Other times it runs just fine. Seems to do worse in the heat but may be my imagination.

    Possibly unrelated, had my traction light come on and car be a little swervy for first time lately, three times now. One on gravely road, another on a turn, and one on windy roads. Could just be coincidental timing and it works fine?

    Any help would be appreciated!
     
  2. bisco

    bisco cookie crumbler

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    yeah, you need the codes. if you haven't disconnected the 12v, or wiped them with the reader, they will be stored. tech stream or autel200 are recommended.
     
  3. DIYohWhy

    DIYohWhy Junior Member

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    I just checked with Techstream, no codes.
     
  4. bisco

    bisco cookie crumbler

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    unheard of to have trouble lights and no codes on tech stream, i wonder if there's a wiring/ecu issue.
     
  5. DIYohWhy

    DIYohWhy Junior Member

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    I'm not sure. What should I do next? Besides forking over my arms and legs to a mechanic if I can help it.
     
  6. bisco

    bisco cookie crumbler

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    a good question.
    start with a load test of the 12 volt, free at some auto parts stores.
    how is the hybrid battery level when it is running?
    i would make sure that you start it and stop it deliberately each time. foot on the brake, press the power button, don't jab it.
    if you get another light, hook up tech stream.
    trouble shooting electrical problems can be a long arduous process. i also wonder about a combo meter problem, common on gen 2.
     
  7. ChapmanF

    ChapmanF Senior Member

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    Anything else funny about the instrument display, by the way?
     
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  8. DIYohWhy

    DIYohWhy Junior Member

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    I've been making sure to start and stop it properly but it still happens. It has become more frequent. On turning off, dash turns off and then everything comes back on, all the lights, til I hit the start button again and it goes into ready mode. Sometimes the check engine light stays on until I turn it off and on. Once, it stayed on again til I did it again. Have not checked with Techstream again yet. On turning on, sometimes check engine light comes on until engine rumbles to life.

    At lower speeds it feels like engine is more rumbly lately, turning on and off more frequently perhaps or struggling to change gears I'm not sure.

    I checked the voltage of the 12v today when it hadn't been running for a day or so, it ready 12.56V. I checked it because my car died overnight the other day. Well, at least it was unresponsive with no dash lights. Unplugged and replugged in 12v and it turned on again.

    How do I check main battery? My console screen is burnt out on the Prius so I can't do it through there.

    Wish I knew what was going on.
     
  9. DIYohWhy

    DIYohWhy Junior Member

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    Only what I described in my other recent comment. Is there something I should check?
     
  10. ChapmanF

    ChapmanF Senior Member

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    I wonder if anybody else thinks that sounds like a description of combination meter issues.
     
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  11. DIYohWhy

    DIYohWhy Junior Member

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    There was a lot of residue on the connection to the positive terminal of my 12v and it was loose. I cleaned both ends a bit and then tightened it down. Since then my car has started up and shut off normally
     
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  12. dolj

    dolj Senior Member

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    That will do it. Glad you got it all cleaned and snugged up.
     
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