Jump start: low idle, no pedal response- dies

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Gray Badger, Jul 20, 2017.

  1. Gray Badger

    Gray Badger Junior Member

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    Let 2007 sit for 6- 10 wks. Bad idea. Have successfully jumped it before (per manual and under hood terminal), so was hoping for the best. Lights & normal displays kicked on, engine responded, but idle seemed low & gas pedal unresponsive, probably 1 min before dying. Slight delay when pedal to the gas was normal. No response is different. No chance to try again & thought I'd look here beforehand. Not reading an identical fault description, but gist of maybe 300 emails read later is things get more unpredictable with a poor charge on the hybrid battery. Near 100K miles on initial battery. Been great car. Ideas?
     
    #1 Gray Badger, Jul 20, 2017
  2. bisco

    bisco cookie crumbler

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    welcome!

    what fault codes did you read?
     
    #2 bisco, Jul 20, 2017
  3. Gray Badger

    Gray Badger Junior Member

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    I don't have a plug-in fault code reader. I don't recall anything amiss in the usual dash display, just an unresponsive gas pedal before it died. I guess I'm confirming there's not some Prius/Hybrid mode limiting idle/fuel associated with 12V failure? hybrid battery charging issue? It didn't have this problem on a prior jump. If nobody knows, can try jump again.
     
    #3 Gray Badger, Jul 20, 2017
  4. xliderider

    xliderider Senior Member

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    No battery charger available? How old is the 12v battery? Do you have a multimeter, voltage tester?
     
    #4 xliderider, Jul 21, 2017
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    If the engine speed was unresponsive to the accelerator pedal, that means the engine did not actually start. Instead, the reason that the engine is rotating is because MG1 is spinning it, but the engine actually has not started.

    What is the fuel level in the tank?
    Have you recharged the 12V battery yet?
    Can you measure the voltage across the 12V battery?

    Do not continue to try to jumpstart the car without finding a root cause that can be resolved, as you will just deplete the high voltage traction battery which will put you into a worse situation. You may need to seek professional assistance by towing the vehicle to your local Toyota dealer.
     
    #5 Patrick Wong, Jul 21, 2017
  6. Gray Badger

    Gray Badger Junior Member

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    Fuel in the tank Battery 3 yrs old. Analog VOM measures 4V at the underside hood terminals. My little-used electrical theory says I can restore amperage capacity w/ charging but not voltage. Don't think I'm dropping voltage on the feed from the batt or mismeasuring as read good voltage on the other car batt. Windows now up & in N w/ parking brake on. No red triangle of death (for hybrid batt failure?) Will look or replacement process to decide if I'm undertaking it or towing. Plz advise if I got something wrong and thank you for the help. The forum is great.
     
    #6 Gray Badger, Jul 23, 2017
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Replace the 12V battery first, then see if other issues exist.
     
    #7 Patrick Wong, Jul 23, 2017
  8. Gray Badger

    Gray Badger Junior Member

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    Replaced 12V battery & all right in the world again. Getting older and antiquated electrical chops and even lesser hybrid experience made the task intimidating. Your expertise and confirmation of my deductions was a confidence builder and much appreciated. Thanks to all. Your forum is great.
     
    #8 Gray Badger, Aug 2, 2017
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  9. Mendel Leisk

    Mendel Leisk Senior Member

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    Good to hear!

    That's the thing: there really is no such thing as a "successful jump start". It's purely a stop-gap measure, gets the car running, but a jump start followed by a bit of driving around doesn't revive the battery. A charging session with a quality charger might.

    Also, letting it sit for multiple weeks, regardless of it's health at the outset, is almost the same as leaving the headlights on overnight. Same drain, just slower: the modern car always has some minor background drain. If you need to let the car sit for weeks, regularly, get a smart charger, one you can leave on indefinitely. Hopefully that's possible for you, ie you have garage parking with an outlet for the charger.
     
    #9 Mendel Leisk, Aug 2, 2017
  10. ChapmanF

    ChapmanF Senior Member

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    I don't usually join in with the "12 volt battery root of all problems" school of thought, at least not when it's coming back 12.1 or 11.8 or even 11.0. But measure four volts, yeah, I'm in. :)

    -Chap
     
    #10 ChapmanF, Aug 2, 2017
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  11. Gray Badger

    Gray Badger Junior Member

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    Continuing to start/run normally after 12V replacement. Has been started/run at least every 2- 3 days. Remains greatest car I've ever known given overall reliability. Kinda has all the personality of a rolling refridgerator, but I love it. Thanks again.
     
    #11 Gray Badger, Nov 18, 2020
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  12. wtrail

    wtrail Junior Member

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    Some of us like the personality of our fridge and our Prius...
     
    #12 wtrail, Nov 20, 2020
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