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P0A90 TOYOTA Code - Drive Motor 'A' Performance

Discussion in 'Gen 2 Prius Technical Discussion' started by dfairch69, May 8, 2022.

  1. dfairch69

    dfairch69 Junior Member

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    We have a 2008 Toyota Prius and I rebuilt the battery, P0A80 code, with modules bought from Second Life Battery LLC on ebay and the modules came in great condition 8.0 volts. I bought the Prolong deluxe package from Hybrid Automotive, excellent customer service, great unit. I installed the hybrid battery no red triangle, from P0A80 code, but when I put it in gear, it moves back and forth, I get a red triangle and P0A90 code. I have never had a problem with the trans-axle and did not throw that code until now. Could the hybrid battery have taken the HV Control board out? Does the car need to be reset? Thanks everyone.
     
  2. mr_guy_mann

    mr_guy_mann Senior Member

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    The service manual shows 9 different INF or sub codes for P0A90, with all kinds of possible causes. Some of them mention "the wire harness".

    My first thought would be to "go back to the scene of the crime" - reinspect everything you did to install the HV battery. Particularly the connections at the HV contactors. (Did you clean and tighten all HV connection studs/nuts with an INCH-lb torque wrench?

    Otherwise, to read the INF codes you need access to a high-end scantool (such as Toyota Techstream) or get the Autel Maxi AP200 bluetooth device and app to be able to read (all) codes and data on a Gen2.

    Then you can look up the specific code and diagnostic procedure in the service manual.

    Posted via the PriusChat mobile app.
     
  3. dfairch69

    dfairch69 Junior Member

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    I did clean and tighten the nuts with a torque wrench I will go and reinspect everything. I appreciate the help. Thank you.
     
  4. dolj

    dolj Senior Member

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    It might be worth it to you to just spend the $70 or $80 to replace the Wire Frame Harness No. 2 if there is any sign (no matter how minuscule) of corrosion, patina or damage. Pay close attention to the pins in the orange plug of this harness. Also, inspect the pins of the battery ECU (into which this harness plugs. If any of them are damage beyond restoration, buy a secondhand replacement ECU. These are quite inexpensive.
     
  5. SFO

    SFO Senior Member

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  6. dfairch69

    dfairch69 Junior Member

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    Thanks everyone for your help, great information and knowledge. I will replace the wiring harness on wire frame no. 2 thanks again.
     
  7. Tombukt2

    Tombukt2 Senior Member

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    I know on some of these my neg orange cable back in HV case are very dark blue like the wire is getting HOT . Bothers me . A guy here just did similar to the Lexus hv200 thingy had blue hot wires he crimped up 4 ga I think . He said mileage went up too.
     
  8. SFO

    SFO Senior Member

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    If you can, please post a link to the above mentioned thread.
     
  9. dfairch69

    dfairch69 Junior Member

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    Have not received the wire frame no. 2 harness yet, waiting should be here Friday.