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Throwing code U0100 - running on gas engine only

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by satsuke, Jul 10, 2018.

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  1. satsuke

    satsuke Junior Member

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    Has anyone seen their 2012 Prius (3) throw a code U0100.

    I've searched for it on here and seen everything from a charge controller to a bad accessory battery.

    On mine, the engine wasn't revving up smoothly and now it's running the gas engine almost exclusively .. traction battery fully depleted.

    It hasn't thrown a fault light, but the ECV reads codes U0100 and B15FE. The second one is an XM radio code near as I can tell.

    The accessory battery is reading between 12.1 and 12.3 volts while in accessory mode, I can't find my ODB2 reader.

    Any idea what's going on? The battery seams a little low, but that shouldn't cause weirdness once the DC>DC inverter is engaged and supplying a steady 13.8
     
    #1 satsuke, Jul 10, 2018
  2. tankyuong

    tankyuong Senior Member

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    that battery is toast
     
    #2 tankyuong, Jul 11, 2018
  3. Mendel Leisk

    Mendel Leisk Senior Member

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    Googling that code, it says a loss of communication, with ECM/PCM. Maybe the 12 volt battery is low and causing a communication problem with the Electronic Control Module? Simple first step would be to check the 12 volt battery condition more thoroughly. Cheap/quick would be with a digital voltmeter, with the car off overnight.

    Better would be an electronic load tester. You can pick them up on Amazon, or automotive retailers. Any automotive retailer selling 12 volt batteries is likely to have a pro-level test of that type, be willing to check your 12 volt battery for free.

    I'm using a Solar BA5, but there's a lot of options out there now:

    https://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dautomotive&field-keywords=12+volt+battery+electronic+battery+tester
     
    #3 Mendel Leisk, Jul 11, 2018
    Raytheeagle likes this.
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