Early 2004 woes, catalyst and brake system light warnings?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Ianmeister, Apr 30, 2023.

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  1. Ianmeister

    Ianmeister Active Member

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    Hello all!
    So I’ve got an early gen2 2004 (build date 12/2003). It has $268K on it. I’ve finally solved the P0420 code with a replacement catalytic converter from Amazon. The stock one was packed with what looks like sand. I’ll stick it on a shelf for later. the good news is that it runs better and the mileage is improving.

    Now my vexation is that the ABS and brake system failure lights keep coming on. The come on together at seemingly random times. Always when in motion and always with no brake input. Like barelling down the freeway at 70. Stay on for a few minutes then back off. I tried the “connect a wire from ODB pin 4 to lower ODB pin 5 to start the diagnostic mode trick and clear the lights to reset the ABS system but it comes right back on. Any ideas?
     
    #1 Ianmeister, Apr 30, 2023
  2. mr_guy_mann

    mr_guy_mann Senior Member

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    You might consider figuring out why the brake control ecu is turning the warning lights on. Search for "flash codes" in the forum. You want to count which light flashes how many times while the jumper is in place.

    Then the two digit code can be matched up with the normal five digit alphanumeric code in the service manual.

    Another option is to read this thread that reviews several scantool apps and OBD devices.
    https://priuschat.com/index.php?posts/3290690

    Posted via the PriusChat mobile app.
     
    #2 mr_guy_mann, Apr 30, 2023
  3. Tombukt2

    Tombukt2 Senior Member

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    Abs pump running a lot??? Theirs a reason why . All that whirring etc . You did not have all that 70K miles ago?
     
    #3 Tombukt2, Apr 30, 2023
  4. ChapmanF

    ChapmanF Senior Member

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    In the march of PriusChat progress, we don't have to do searches for that anymore. There's a wiki page for it:

    Blink (a/k/a Flash) Codes – How to. | PriusChat
     
    #4 ChapmanF, Apr 30, 2023
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