Help on unusual symptoms p0a94-555

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Henrysprius, Apr 1, 2026 at 12:47 PM.

  1. Henrysprius

    Henrysprius New Member

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    2005 Prius
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    Hi
    I have a prius 2005 with code p0a94-555
    In indicates that is inverter but the car gets ready mode an it runs on battery ac and everything working in the hybrid part the car moves on batteryin all gears, but ice (internal combustion eng.) Not turning on It had the p1122 also change the part and code clear itself but not change in the other symptoms
    Ice. Stil not running .
    The only code is p0a94-555

    Thanks in advance
    Expeting your expertise can help on this
    Thanks
     

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    #1 Henrysprius, Apr 1, 2026 at 12:47 PM
  2. Tombukt2

    Tombukt2 Senior Member

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    Generally here you replacing the thing on bottom of inverter under gold plate with lots screws . Good luck getting that plate off . Faster to change whole inverter
     
    #2 Tombukt2, Apr 1, 2026 at 10:07 PM
  3. ChapmanF

    ChapmanF Senior Member

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    Nope. That's also called a DC/DC converter, but it's the one that drops voltage to 12 volts for the low-voltage system.

    P0A94 is about the other DC/DC converter, the one that boosts voltage to 500 volts for the motor-generators.

    It's inside the inverter assembly, and replacing the inverter assembly as a whole still is probably the much easier way to go.

    The freeze-frame in the OP shows "Voltage before boosting" as 208 and "Voltage after boosting" as 207, which could be normal if the HV control ECU didn't want any boosting at the time, but would be a little disappointing if the system was trying to boost. In any case, the P0A94 code indicates the car can tell there's a problem there.

    The car may not be completely immobile with the boost converter out of commission, but it won't be happy.
     
    #3 ChapmanF, Apr 1, 2026 at 10:57 PM
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