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Problem with my 2003, is there no Gen 1 forum here?

Discussion in 'Generation 1 Prius Discussion' started by James Henry, Feb 22, 2019.

  1. James Henry

    James Henry New Member

    Joined:
    Feb 22, 2019
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    Location:
    Missouri
    Vehicle:
    2003 Prius
    Model:
    ----USA----
    Not sure where to post this but I'm at my wits end with my 2003 Prius.

    Long story short a few months ago the car, while being driven daily, quit starting. I ran codes (forgotten now) and got some that indicated a bad 12v battery.

    Recently I finally got around to replacing the 12v battery and now it attempts to start, but wont fire up. I ran codes again and got some indicating throttle body issues. I replaced the throttle body but it is doing the same thing.

    I'm not getting any codes now, but this may be because I can't get it to start to read them. I've tried recharging the new battery AND jumping the car. Nothing works.

    Any ideas?
     
    #1 James Henry, Feb 22, 2019
  2. ericbecky

    ericbecky Hybrid Battery Hero

    Joined:
    Mar 12, 2004
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    Location:
    Madison, Wisconsin
    Vehicle:
    2005 Prius
    Model:
    Two
    How longldod it sit with a bad 12v. A day or two? Longer?

    What is the voltage of the hybrid battery? Maybe it is too low to spin the gas engine fast enough?

    Are you using Toyota Techstream as a diagnostic tools? Of you are, then post some screenshots of the hybrid battery info. State of Charge, battery block voltage, Delta SOC.
     
    #2 ericbecky, Feb 22, 2019
  3. James Henry

    James Henry New Member

    Joined:
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    Location:
    Missouri
    Vehicle:
    2003 Prius
    Model:
    ----USA----
    No, it sat for a few months with a bad 12v. I just didn't have time to mess with it.

    I didn't know the voltage of the hybrid battery had anything to do with the gas engine starting. Does the gas motor not have it's own starter?

    I am using a standard automotive diagnostic tool.

    Thanks!
     
    #3 James Henry, Feb 24, 2019
  4. Prodigyplace

    Prodigyplace Senior Member

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    Location:
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    Vehicle:
    2017 Prius
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    The hybrid battery provides the power for MG1 to start the engine.
    MG1 is also used to charge the hybrid battery when the engine is running.
     
    #4 Prodigyplace, Feb 24, 2019
  5. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Location:
    Pennsylvania
    Vehicle:
    2018 Prius c
    Model:
    Two
    There is no traditional starter in any Prius. The 12v battery is there to boot the computers and actuate the relays for the high-voltage battery and operate the lighting and cabin convenience features. It isn't involved in cranking the engine.

    Starting the engine is always done by the high voltage pack as described above. If that HV pack has discharged, the car won't start and that battery would have to be bench-charged before trying again. Not a simple procedure.

    A standard diagnostic tool won't be of much use. There are a lot of extra systems with their own codes and a standard tool won't know to ask about them. Some can be field-programmed to gain these extra functions but most can't. The gold standard for this is a hacked copy of Toyota Techstream software (ebay) running on an old windows laptop.
     
    #5 Leadfoot J. McCoalroller, Feb 24, 2019
    Brian in Tucson likes this.
  6. James Henry

    James Henry New Member

    Joined:
    Feb 22, 2019
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    Location:
    Missouri
    Vehicle:
    2003 Prius
    Model:
    ----USA----
    Sorry just coming back to this conversation, no real updates though.

    So with the cost of even a rebuilt hybrid battery well over 1,000 and me having only spent 1500 on the car itself I am considering salvaging this one and looking at purchasing a newer Prius.

    I could spend the time learning how to replace cells and bench charge but to be honest, I just don't have the time to spend.

    Thank you all for your input, i appreciate it!
     
    #6 James Henry, Mar 18, 2019
    Prodigyplace likes this.
  7. ericbecky

    ericbecky Hybrid Battery Hero

    Joined:
    Mar 12, 2004
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    Location:
    Madison, Wisconsin
    Vehicle:
    2005 Prius
    Model:
    Two
    Thanks for circling back.
    Sometimes you have to cut your losses.
    Good luck.
     
    #7 ericbecky, Mar 18, 2019
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