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P0053 on 2012 w/ 180k, but no CEL? where do I start..?

Discussion in 'Gen 3 Prius Main Forum' started by sukatoro, Nov 10, 2019.

  1. sukatoro

    sukatoro Junior Member

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    Location:
    Houston Tx
    Vehicle:
    2010 Prius
    Model:
    Two
    hi all, Subject pretty much says it all... My 2012 is showing code P0053, but no CEL is thrown? Car is running pretty much fine, the P0053 first appeared when the weather cooled down finally here in Houston, I wouldn’t have even known about if I hadn’t manually scanned for codes using an elm27 bt adapter but it has persisted regardless of weather/temperature since then. Googling shows a generic decoding of “HO2s heater resistance bank 1 sensor 1, which I understand to be the o2 sensor upstream of the cat... but it was unclear to me as to whether they are referring to the O2 sensor itself or it’s heating element being the culprit...

    A prerequisite search of the fora here at priuschat yields literally not one single hit... which I find particularly ominous. Can anyone shed light upon this, and /or give me some sort of attack plan? This event just happens to coincide with my registration expiring, so I was supposed to be off getting an inspection today. :(
     
  2. kc5dlo

    kc5dlo Active Member

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    2021 Prius
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    XLE
    It was my understanding the heating element is part of the O2 sensor. It was also my understanding that a code needs to be tripped twice before the CEL will be illuminated.
     
  3. BZzap!

    BZzap! Senior Member

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    The hearted O2 sensor is probably on the boarder line and below the threshold for a MIL request. The circuit is pretty simple. A power and ground check might reveal an open in either leg from corrosion or something. You can also shoot the parts canon at it and put a new sensor in.
     
  4. sukatoro

    sukatoro Junior Member

    Joined:
    May 1, 2017
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    Location:
    Houston Tx
    Vehicle:
    2010 Prius
    Model:
    Two
    Hmmm... it has been appearing in my code scans for weeks now, I have cleared codes many times and it reappears immediately, within seconds it seems, yet still no CEL... is this surely going to be the sensor itself then? I actually find the lack of a thrown CEL more disconcerting than the code...