SFI SYSTEM, Diagnostic DTC:P2237, P2238, P2239, P2252, P2253

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

DESCRIPTION

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.

  • Refer to DTC P0031 Click here

DTC No. DTC Detection Condition Trouble Area
P2237

Open in the circuit between terminals A1A+ and A1A- of the air fuel ratio sensor while engine is running

(2 trip detection logic)

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

  • Air fuel ratio sensor (bank 1 sensor 1)

  • ECM
P2238

Any of the following conditions are met

(2 trip detection logic)


  • Air fuel ratio sensor output drops while engine is running.


  • Voltage at terminal A1A+ is 0.5 V or less.


  • Voltage difference between terminals A1A+ and A1A- is 0.1 V or less.

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

  • Air fuel ratio sensor (bank 1 sensor 1)

  • ECM
P2239

A1A+ voltage is more than 4.5 V

(2 trip detection logic)

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

  • Air fuel ratio sensor (bank 1 sensor 1)

  • ECM
P2252

A1A- voltage is 0.5 V or less

(2 trip detection logic)

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

  • Air fuel ratio sensor (bank 1 sensor 1)

  • ECM
P2253

A1A- voltage is more than 4.5 V

(2 trip detection logic)

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

  • Air fuel ratio sensor (bank 1 sensor 1)

  • ECM

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 0.6 V and 4.5 V, it is considered normal. If the voltage is outside of the specified range, or the admittance is below the standard value, the ECM will determine that there is a malfunction in the air fuel ratio sensor. If the same malfunction is detected in the next driving cycle, the MIL is illuminated and a DTC is stored.

The air fuel ratio sensor varies its output voltage in proportion to the air-fuel ratio. If the air fuel ratio sensor impedance (alternating current resistance) or output voltage deviates greatly from the standard range, the ECM determines that there is an open or short in the air fuel ratio sensor circuit.

MONITOR STRATEGY

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

CONFIRMATION DRIVING PATTERN


  1. Connect the intelligent tester to the DLC3.

  2. Turn the ignition switch to ON and turn the tester on.

  3. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation)

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

  5. Turn the ignition switch to ON and turn the tester on.

  6. Start the engine and wait 5 minutes.

  7. Enter the following menus: Powertrain / Engine and ECT / DTC.

  8. Read the pending DTCs.

    Tech Tips


    • If a pending DTC is output, the system is malfunctioning.

    • If a pending DTC is not output, perform the following procedure.

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

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

  11. Check the DTC judgment result.

    Tester Display Description
    NORMAL

    • DTC judgment completed

    • System normal
    ABNORMAL

    • DTC judgment completed

    • System abnormal
    INCOMPLETE

    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions
    N/A

    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    Tech Tips


    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

    • If the judgment result shows INCOMPLETE or N/A, perform the Confirmation Driving Pattern and the DTC judgment result again.

WIRING DIAGRAM

Refer to DTC P0031 Click here.

CAUTION / NOTICE / HINT

Note

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

Tech Tips


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

  • Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when malfunctions are detected. 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.

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

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

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
      for LHD
      Tester Connection Condition Specified Condition
      B39-1 (HA1A) - B22-23 (HA1A) Always Below 1 Ω
      B39-3 (A1A+) - B22-133 (A1A+) Always Below 1 Ω
      B39-4 (A1A-) - B22-134 (A1A-) Always Below 1 Ω
      B39-1 (HA1A) or B22-23 (HA1A) - Body ground Always 10 kΩ or higher
      B39-3 (A1A+) or B22-133 (A1A+) - Body ground Always 10 kΩ or higher
      B39-4 (A1A-) or B22-134 (A1A-) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      B39-1 (HA1A) - B23-23 (HA1A) Always Below 1 Ω
      B39-3 (A1A+) - B23-133 (A1A+) Always Below 1 Ω
      B39-4 (A1A-) - B23-134 (A1A-) Always Below 1 Ω
      B39-1 (HA1A) or B23-23 (HA1A) - Body ground Always 10 kΩ or higher
      B39-3 (A1A+) or B23-133 (A1A+) - Body ground Always 10 kΩ or higher
      B39-4 (A1A-) or B23-134 (A1A-) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor Click here.

      Tech Tips

      Perform "Inspection After Repairs" after replacing the air fuel ratio sensor Click here.


    NEXT

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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Clear the DTCs Click here.

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

    6. Turn the ignition switch to ON.

    7. Turn the tester 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.

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

    11. Check the DTC judgment.

      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