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p0c73 Replaced inverter pump still there

Discussion in 'Gen 3 Prius Technical Discussion' started by John in AZ, Jul 25, 2021.

  1. John in AZ

    John in AZ Junior Member

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    Ok so got the traction battery reconditioned by a trusted mechanic. After all done 1 st drive went well. On 2nd test drive triangle of death and check hybrid system. So he checks the code and it is p0c73 inverter coolant pump. He doesn’t go those so I take it home. Today I bought new pump from Toyota and replaced it. Great fun but it is done. Clear codes bleed system confirm coolant is flowing in resivour . But continue to get code p0c73 and will pop triangle of death. Don’t know what to do now?
     
  2. ChapmanF

    ChapmanF Senior Member

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    I can't find a P0C73 in a 2006 repair manual to check what its detection condition is. Perhaps it is a code that was added for 2007; maybe someone can look in the 2007 repair manual (more info) and check?

    In general, if there is some one-line description that pops up with a trouble code on a scan tool, or in a google search, it is about as useful as a fortune cookie. If a code comes up with the words "inverter coolant pump" in its fortune cookie, it doesn't mean to go replace the inverter coolant pump, it means that something has been noticed awry in either the operation or the monitoring of that pump, and you need to look up the "detection condition" in the repair manual to see what exactly was noticed, and then do some troubleshooting to find out why. Taking the fortune cookie too literally and just replacing a part it happens to mention will sometimes leave the problem unsolved.
     
  3. John in AZ

    John in AZ Junior Member

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    This is a 2010 Prius not 2007. It is not an uncommon code with the pump being the primary suspect.
     
  4. ChapmanF

    ChapmanF Senior Member

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    My apologies ... your profile says 2007, and you didn't mention the model year of the car in the original post.

    The code is defined for Gen 3, but the fundamental things still apply; it's up to the human to do the troubleshooting to find out why the detection conditions were met; the trouble code can only tell you that they were met.

    In the 2010 manual, most information for troubleshooting a P0C73 seems to be found in the workup section for P0A01/P0A04. Later model year editions may add a dedicated P0C73 section.

    The control and monitoring circuitry for the inverter water pump looks like a dead ringer for the way the engine water pump is controlled, and the triggers for P0C73 seem directly analogous to those for the engine pump's P261B code, so troubleshooting ideas from that section could be pretty directly borrowed for P0C73.

    iwp.png

    That also means you might find the information in this thread to be of use (of course changing all the connector locations to be those for the inverter pump instead of the engine pump).
     
  5. John in AZ

    John in AZ Junior Member

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    Thanks I have not logged on in a long time and didn’t think about the old car in my profile. I will edit post to include year just figured in the 3rd gen it would be assumed was a 2010-14 but I know people do post in the wrong areas.
    Thanks I will try to figure out some of those things and hopefully get lucky. Just hate that it is working but car doesn’t seem to
     
  6. John in AZ

    John in AZ Junior Member

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    Can’t edit post I guess . Car is 2010 for anyone else reading this