Safe to drive after vehicle enter fail safe mode?

Discussion in 'Prius v Care, Maintenance and Troubleshooting' started by autorun, Dec 25, 2017.

  1. autorun

    autorun New Member

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    Merry Christmas everyone, my question is will I able to drive my v to dealer in fail safe mode (hybrid will not engage), but car can be started and driven so far in gas only mode. Will driving in fail safe mode damage anything further?
     
    #1 autorun, Dec 25, 2017
  2. bisco

    bisco cookie crumbler

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    what is it exactly? not recharging the hybrid battery, or not using the hybrid battery for motivation?
     
    #2 bisco, Dec 25, 2017
  3. autorun

    autorun New Member

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    #3 autorun, Dec 25, 2017
  4. bisco

    bisco cookie crumbler

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    i'm no expert, and can't tell from the other thread if the car is charging or discharging. if it is not using the battery to drive, but only to start the engine, and you have plenty of battery charge, you should be able to make it to the dealer.
     
    #4 bisco, Dec 25, 2017
  5. rjparker

    rjparker Tu Humilde Sirviente

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    If you have an inverter problem it probably would be covered. I had one fail and the car would not run at all. Maybe my inverter fail was different. If you bought it used you probably never took it to the dealer to register it or the previous owner ignored the notification since it was running good then. It's always good to not post twice and if you do, why not include the information rather than have someone dig for it? If it were just five miles away and it drives, then yes i would drive it, realizing that if it failed like mine did you are not too far. Remember the engine starts using the HV battery driving the electric motor through the inverter. So if the HV battery is not getting charged, at some point it can't start. 12vdc power is charged through the inverter and HV battery. At some point, no more 12v control power. So the most reasonable thing might be to tow it in. Often you can negotiate with tow truck drivers when it's not an emergency.
     
    #5 rjparker, Dec 25, 2017
    Last edited: Dec 25, 2017
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  6. fuzzy1

    fuzzy1 Senior Member

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    That isn't how the Prius system works. Unlike the old Civic Hybrid, a Prius doesn't have a gas-only mode, and can't move or even start its gasoline engine without engaging the hybrid system.

    If it can move at all, the hybrid system is at least partially working.
     
    #6 fuzzy1, Dec 25, 2017
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  7. autorun

    autorun New Member

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    Thank you to all the people that have responded to my question. Here is the whole story:
    Since I had the exact same 4 warning lights on my dash board, I posted my problem in other thread.
    Couple nights ago, I was driving my 2012 v (trim 3 and purchased new in Nov 2011), currently just over 110,000 miles.
    I was stopped at a red light, the moment I hit gas,
    4 Dashboard lights come on and staying on:
    • Check Engine
    • Hybrid System
    • Slip Indicator
    • Brake System
    My friend have the cable and software he got from ebay.
    After hooking up,I got 2 codes for the Hybrid system. P0A94 DC/DC converter performance and P324E MG-ECU Power relay intermittent circuit.
    I cleared DTC, only P0A94 came back, I have inverter type B. sub code 553 and 557. According to TSB, IPM needs replacement.
    Picture are details before I clear the DTC.
    So my question is would it be safe for me to drive to dealer about 10 miles away, and should I take highway 70mph or go local at 35mph.
    Will driving it cause any damage to the car. (car will start and drive as I have tried that already) Not really sure how to put the car into N for towing without turning on the car.
     

    Attached Files:

    #7 autorun, Dec 25, 2017
  8. rjparker

    rjparker Tu Humilde Sirviente

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    The car will usually still go into N for easy placement on the tow truck as long as there is some 12vdc left. Regardless the tow truck driver can handle getting the car on his truck. Obviously, if you can drive it then it should go into neutral.
     
    #8 rjparker, Dec 25, 2017
    Last edited: Dec 25, 2017
  9. davecook89t

    davecook89t Senior Member

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    Just to be clear, it should not be towed for longer than a few feet in neutral. To get it to the dealer, it needs to be put on a flat bed or set of dollies. Towing it for a long distance in neutral will damage the transaxle.
     
    #9 davecook89t, Dec 25, 2017
  10. rjparker

    rjparker Tu Humilde Sirviente

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    Again tow drivers know that front wheel drive cars are towed on a bed or with the front end off the road.
     
    #10 rjparker, Dec 25, 2017
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  11. Mendel Leisk

    Mendel Leisk Senior Member

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    The answer to that one's easy.

    I don't really understand "fail safe mode", if the car will run it will run. Obviously you want to be as conservative as possible, just get where you need to go (dealership) as sedately/slowly as possible.

    I would not dismiss codes, it accomplishes nothing, might just confuse the mechanics at dealership. At least give them a heads-up what you've done.
     
    #11 Mendel Leisk, Dec 25, 2017
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  12. autorun

    autorun New Member

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    I did not even know there is a fail safe mode, but the car failed on me less than 2 miles from home at night, so I drove it home, so far I have moved it in and out my garage a few times. It will start in gas mode but will not respond when I push power or eco button, also I am guessing regenerative braking is also failing (but mechanical brake works fine), actually all 4 warning light makes sense if IPM is bad.
    This is where I learned about fail safe mode.
    2012–2014 Model Year Prius V Intelligent Power Module (IPM) Warranty Extension ZF5 | TOYO Headquarters
    This is the basis for my trouble shooting on IPM failure.
    http://www.revbase.com/BBBMotor/TSb/DownloadPdf?id=194501
     
    #12 autorun, Dec 25, 2017
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  13. Esthereb

    Esthereb New Member

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    I have the same problem now. Have you gotten this fixed? What was the problem?
     
    #13 Esthereb, Feb 24, 2021
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