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P2237 Code still there

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by AndT, Aug 9, 2024.

  1. AndT

    AndT Junior Member

    Joined:
    Apr 12, 2023
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    Location:
    Rochester, NY
    Vehicle:
    2009 Prius
    Model:
    Two
    Can't get rid of this P2237 code on my 2009, I have read through many of the threads here.

    The code comes back pretty much immediately after resetting, not like most other codes.

    I have changed both O2 sensors, replaced with Denso. I changed the ECM, hoping that would solve it. Put in a used ECM from eBay, so I suppose it could have been faulty.

    Is it time to start chasing wires? Any suggestions on fuses or relays to check? I appreciate any input.
     
    #1 AndT, Aug 9, 2024
  2. mr_guy_mann

    mr_guy_mann Senior Member

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    Location:
    NJ-USA
    Vehicle:
    2006 Prius
    Model:
    Four
    Where did you get the Denso sensors? I have seen cheap aftermarket (or counterfeit) Air Fuel Sensors cause this code.

    However it is unlikely that two sensors or two ECMs have the same fault.

    So yes, I would look at wiring. P2237 indicates an open in the Air Fuel "sense" circuit (AF+ & AF-).

    af%20wiring.jpeg

    Posted via the PriusChat mobile app.
     
    #2 mr_guy_mann, Aug 11, 2024
  3. AndT

    AndT Junior Member

    Joined:
    Apr 12, 2023
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    Location:
    Rochester, NY
    Vehicle:
    2009 Prius
    Model:
    Two
    Thanks for the reply. The Denso sensors came from eBay. So I suppose they could be counterfeit, not sure if there's a good way to know? I will work look closely and test wiring, hopefully I can isolate the issue.
     
    #3 AndT, Aug 12, 2024
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