P0a72-515 engine error code help

Discussion in 'Gen 2 Prius Technical Discussion' started by Spencer MaeCroft, Oct 6, 2025 at 6:58 PM.

  1. Spencer MaeCroft

    Spencer MaeCroft New Member

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    I have a 2008 Prius that has an intermittent warning light on the dash with error code P0a72-515. I downloaded the diagnostic papers for this error but just wondered if anyone else has encountered this error and found a solution.

    I’ve also read that the inverter is a low issue part and often times not the actual issue so I wanted to test out other potential problem sources before replacing the inverter.
     
  2. Tombukt2

    Tombukt2 Senior Member

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    This is where there's a phase problem on the output generator motor or something like that right I wouldn't inverter itself could finar phasing . Would think that would happen actually at the motor generator ?
     
  3. ChapmanF

    ChapmanF Senior Member

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    I hope when you downloaded "the diagnostic papers" you mean you got the section for that code from the Toyota repair manual. This link might work (though when I open it the spaces look funky on the last couple pages—still readable though).

    The code reports a problem with the current sensor reading for the V phase connection of MG1.

    The current sensors (two of them, a main and a sub) are located inside the inverter housing. In gen 3 there's an "MG ECU" right inside that housing too, but in your gen 2 there isn't: the sensors are inside the inverter housing, but they are wired to the HV control ECU under the dash. You can see how the troubleshooting instructions tell you to check that wiring and those connections first, and if you find the problem there, you just fix it.

    You can see that inverter replacement (huh, I guess they didn't sell the sensors separately?) is only the last step, only if you didn't already find the problem with the wiring or connections.