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P2237 troubleshooting.

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by CloudJumper, Jul 29, 2023.

  1. CloudJumper

    CloudJumper Junior Member

    Joined:
    Oct 16, 2022
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    Location:
    Minnesota
    Vehicle:
    2010 Prius
    Model:
    I
    Howdy Y'all, I recently had my catalytic converter replaced due to it getting clogged and tripping a P0420 code. Prior to replacement, I had no other codes. After replacement, I now see a P2237.

    P2237 - Powertrain
    2) O2 Sensor Positive Current Control/Open Bank 1 Sensor 1

    This code is seen as a pending fault in Torque Pro. I will attach a screenshot of some readings from Torque Pro. In the first screenshot, the top two diagrams are "O2 Sensor[1,2] Voltage" while the bottom diagrams are "O2 Sensor [1,2] Wide Range Voltage." I'm assuming one or both sensors need replacement, however after looking more into this issue I've seen many reports of a new sensor(s) not resolving the issue, so I was wondering if anyone else had some additional insight. Thank you in advance.

    Some additional information that may be relevant:
    Year: 2010
    Miles: 215K
    EGR: Replaced at 110K, cleaned again at 200K.
    New Cat: Aftermarket (Recommended by my local Toyota dealership)
    A visual inspection of both sensors do not show any damage to the sensor exteriors or wires (an inspection of the inside of the sensor has not been performed as I do not have the tools to remove the sensor myself).
     

    Attached Files:

    #1 CloudJumper, Jul 29, 2023
    Last edited: Jul 29, 2023
  2. Mr. F

    Mr. F Active Member

    Joined:
    Sep 21, 2020
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    Location:
    Washington
    Vehicle:
    2010 Prius
    Model:
    IV
    P2237 is telling you that there's a break in the air fuel ratio sensor's output circuit, which matches what Torque Pro is telling you (no voltage detected in Bank 1 Sensor 1).

    There is a loss of continuity or malfunction in either of these 3 locations:
    1. wiring harness between A/F sensor and ECM
    2. A/F sensor
    3. ECM

    upload_2023-7-29_17-5-50.png
    Remove the connectors from both the A/F sensor (D24) and the ECM (D28) and check for continuity between the following terminals:
    1. D24-3 (A1A+) - D28-103 (A1A+)
    2. D24-4 (A1A-) - D28-126 (A1A-)
    If both of them check out, replace the A/F sensor, make two trips, and see if the problem went away.
    If that didn't help either, you replace the ECM and call it a day.

    At no point is the actual O2 sensor (Bank 1 Sensor 2) implicated in this.
     

    Attached Files:

    #2 Mr. F, Jul 29, 2023
    Last edited: Jul 30, 2023
    CloudJumper likes this.
  3. CloudJumper

    CloudJumper Junior Member

    Joined:
    Oct 16, 2022
    26
    7
    0
    Location:
    Minnesota
    Vehicle:
    2010 Prius
    Model:
    I
    After inspecting the wiring harness and ECM, which both proved to be in perfect operation, I purchased a cheap multimeter to test the output of the sensor itself, the sensor has indeed gone bad and will be replaced tonight. Thank you for your input.
     
    #3 CloudJumper, Aug 13, 2023
    Mr. F likes this.
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