SFI SYSTEM(w/o Canister Pump Module), Diagnostic DTC:P2237, P2238, P2239, P2252, P2253

DTC Code DTC Name
P2237 Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1)
P2238 Oxygen (A/F) Sensor Pumping Current Circuit Low (Bank 1 Sensor 1)
P2239 Oxygen (A/F) Sensor Pumping Current Circuit High (Bank 1 Sensor 1)
P2252 Oxygen (A/F) Sensor Reference Ground Circuit Low (Bank 1 Sensor 1)
P2253 Oxygen (A/F) Sensor Reference Ground Circuit High (Bank 1 Sensor 1)

DESCRIPTION

Refer to DTC P2195.

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Tech Tips


  • Although the DTC titles say oxygen sensor, these DTCs relate to the air fuel ratio sensor.

  • Sensor 1 refers to the sensor mounted in front of the three-way catalytic converter and located near the engine assembly.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P2237 Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1) An open in the circuit between terminals A1A+ and A1A- of the air fuel ratio sensor while the engine is running (2 trip detection logic).

  • Open in air fuel ratio sensor (sensor 1) circuit

  • Air fuel ratio sensor (sensor 1)

  • ECM

 Comes on DTC stored
P2238 Oxygen (A/F) Sensor Pumping Current Circuit Low (Bank 1 Sensor 1)

  • Case 1

    Condition (a) or (b) continues for 5.0 seconds or more (2 trip detection logic):

    (a) Voltage at terminal A1A+ is 0.5 V or less.

    (b) Voltage difference between terminals A1A+ and A1A- is 0.1 V or less.

  • Case 2

    Air fuel ratio sensor admittance: Less than 0.0074 1/Ω (2 trip detection logic).

  • Open or short in air fuel ratio sensor (sensor 1) circuit

  • Air fuel ratio sensor (sensor 1)

  • ECM

 Comes on DTC stored
P2239 Oxygen (A/F) Sensor Pumping Current Circuit High (Bank 1 Sensor 1) The A1A+ voltage is higher than 4.5 V (2 trip detection logic).

  • Open or short in air fuel ratio sensor (sensor 1) circuit

  • Air fuel ratio sensor (sensor 1)

  • ECM

 Comes on DTC stored
P2252 Oxygen (A/F) Sensor Reference Ground Circuit Low (Bank 1 Sensor 1) The A1A- voltage is 0.5 V or less (2 trip detection logic).

  • Open or short in air fuel ratio sensor (sensor 1) circuit

  • Air fuel ratio sensor (sensor 1)

  • ECM

 Comes on DTC stored
P2253 Oxygen (A/F) Sensor Reference Ground Circuit High (Bank 1 Sensor 1) The A1A- voltage is higher than 4.5 V (2 trip detection logic).

  • Open or short in air fuel ratio sensor (sensor 1) circuit

  • Air fuel ratio sensor (sensor 1)

  • ECM

 Comes on DTC stored

MONITOR DESCRIPTION

These DTCs are output when there is an open or short in the air fuel ratio sensor circuit, or if the air fuel ratio sensor output drops. To detect these problems, the voltage of the air fuel ratio sensor is monitored when turning the ignition switch to ON, and the admittance (admittance is an electrical term that indicates the ease of flow of current) is checked while driving. If the voltage of the air fuel ratio sensor is between 0.5 V and 4.5 V, it is considered normal. If the voltage is out of the specified range, or the admittance is less than the standard value, the ECM determines that there is a malfunction in the air fuel ratio sensor. If the same malfunction is detected in next driving cycle, the MIL is illuminated and a DTC is stored.

MONITOR STRATEGY

Required Sensors/Components Air fuel ratio sensor
Frequency of Operation Continuous

CONFIRMATION DRIVING PATTERN


  1. Start the engine and wait for 5 minutes or more.

WIRING DIAGRAM

Refer to DTC P0031.

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CAUTION / NOTICE / HINT

Note

Inspect the fuses for circuits related to this system before performing the following procedure.

Tech Tips


  • Sensor 1 refers to the sensor closest to the engine assembly.

  • Sensor 2 refers to the sensor farthest away from the engine assembly.

  • Read freeze frame data using the GTS. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

  • Refer to "Data List / Active Test" [AFS Voltage B1S1].

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PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)


    1. Disconnect the air fuel ratio sensor connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      B8-1 (HA1A) - B77-23 (HA1A) Always Below 1 Ω
      B8-3 (A1A+) - B77-133 (A1A+) Always Below 1 Ω
      B8-4 (A1A-) - B77-134 (A1A-) Always Below 1 Ω
      B8-1 (HA1A) or B77-23 (HA1A) - Body ground Always 10 kΩ or higher
      B8-3 (A1A+) or B77-133 (A1A+) - Body ground Always 10 kΩ or higher
      B8-4 (A1A-) or B77-134 (A1A-) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor.

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      Tech Tips

      Perform "Inspection After Repair" after replacing the air fuel ratio sensor.

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      Result
      Proceed to
      NEXT

    NEXT

  3. CHECK WHETHER DTC OUTPUT RECURS (DTC P2237, P2238, P2239, P2252 OR P2253)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs.

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      Powertrain > Engine and ECT > Clear DTCs

    5. Turn the ignition switch off and wait for at least 30 seconds.

    6. Turn the ignition switch to ON.

    7. Turn the GTS on.

    8. Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.

    9. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.


      Powertrain > Engine and ECT > Utility
      Tester Display
      All Readiness

    10. Input the DTC: P2237, P2238, P2239, P2252 or P2253.

    11. Check the DTC judgment result.

      Result
      Result Proceed to
      NORMAL (DTC is not output) A
      ABNORMAL (DTC P2237, P2238, P2239, P2252 or P2253 is output) B

    A

    END

    B

    REPLACE ECM Click here