SFI SYSTEM, Diagnostic DTC:P2237, P2238, P2239, P2240, P2241, P2242, P2252, P2253, P2255, P2256

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)
P2240 Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 2 Sensor 1)
P2241 Oxygen (A/F) Sensor Pumping Current Circuit Low (Bank 2 Sensor 1)
P2242 Oxygen (A/F) Sensor Pumping Current Circuit High (Bank 2 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)
P2255 Oxygen (A/F) Sensor Reference Ground Circuit Low (Bank 2 Sensor 1)
P2256 Oxygen (A/F) Sensor Reference Ground Circuit High (Bank 2 Sensor 1)

DESCRIPTION

Refer to DTC P2195 Click here.

DTC No. DTC Detection Condition Trouble Area

P2237

P2240

 An open in the circuit between terminals A1A+ (A2A+) and A1A- (A2A-) of the air fuel ratio sensor while the engine is running (2 trip detection logic).

  • Open or short in air fuel ratio sensor (bank 1, 2 sensor 1) circuit

  • Air fuel ratio sensor (bank 1, 2 sensor 1)

  • ECM

P2238

P2241

  • Case 1:

Condition (a) or (b) continues for 5.0 seconds or more

(2 trip detection logic):

(a) Voltage at terminal A1A+ (A2A+) is 0.5 V or less

(b) Voltage difference between terminals A1A+ (A2A+) and A1A- (A2A-) is 0.1 V or less


  • Case 2:

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

  • Open or short in air fuel ratio sensor (bank 1, 2 sensor 1) circuit

  • Air fuel ratio sensor (bank 1, 2 sensor 1)

  • ECM

P2239

P2242

 The A1A+ (A2A+) voltage is higher than 4.5 V (2 trip detection logic).

  • Open or short in air fuel ratio sensor (bank 1, 2 sensor 1) circuit

  • Air fuel ratio sensor (bank 1, 2 sensor 1)

  • ECM

P2252

P2255

 The A1A- (A2A-) voltage is 0.5 V or less (2 trip detection logic).

  • Open or short in air fuel ratio sensor (bank 1, 2 sensor 1) circuit

  • Air fuel ratio sensor (bank 1, 2 sensor 1)

  • ECM

P2253

P2256

 The A1A- (A2A-) voltage is higher than 4.5 V (2 trip detection logic).

  • Open or short in air fuel ratio sensor (bank 1, 2 sensor 1) circuit

  • Air fuel ratio sensor (bank 1, 2 sensor 1)

  • ECM

Tech Tips


  • DTCs P2237, P2238, P2239, P2252 and P2253 indicate malfunctions related to the bank 1 air fuel ratio sensor circuit.

  • DTCs P2240, P2241, P2242, P2255 and P2256 indicate malfunctions related to the bank 2 air fuel ratio sensor circuit.

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 engine switch on (IG), 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

Related DTCs

P2237: Air fuel ratio sensor (bank 1) open circuit between A1A+ and A1A-

P2238: Air fuel ratio sensor (bank 1) short circuit between A1A+ and A1A-

P2238: Air fuel ratio sensor (bank 1) short circuit between A1A+ and GND

P2238: Air fuel ratio sensor (bank 1) low admittance

P2239: Air fuel ratio sensor (bank 1) short circuit between A1A+ and +B

P2240: Air fuel ratio sensor (bank 2) open circuit between A2A+ and A2A-

P2241: Air fuel ratio sensor (bank 2) short circuit between A2A+ and A2A-

P2241: Air fuel ratio sensor (bank 2) short circuit between A2A+ and GND

P2241: Air fuel ratio sensor (bank 2) low admittance

P2242: Air fuel ratio sensor (bank 2) short circuit between A2A+ and +B

P2252: Air fuel ratio sensor (bank 1) short circuit between A1A- and GND

P2253: Air fuel ratio sensor (bank 1) short circuit between A1A- and +B

P2255: Air fuel ratio sensor (bank 2) short circuit between A2A- and GND

P2256: Air fuel ratio sensor (bank 2) short circuit between A2A- and +B
Required Sensors/Components (Main) Air fuel ratio sensor
Required Sensors/Components (Related)

Engine coolant temperature sensor

Crankshaft position sensor
Frequency of Operation Continuous
Duration

10 seconds: P2237 and P2240

10 seconds: P2238 and P2241 (air fuel ratio sensor low admittance)

5 seconds: Others
MIL Operation 2 driving cycles
Sequence of Operation None

TYPICAL ENABLING CONDITIONS

P2237, P2238, P2240 and P2241
Monitor runs whenever the following DTCs are not stored

P0016, P0018 (VVT system bank 1, 2 - misalignment)

P0017, P0019 (Exhaust VVT system bank 1, 2 - misalignment)

P0031, P0032, P0051, P0052, P101D, P103D (Air fuel ratio sensor heater)

P0102, P0103 (Mass air flow meter)

P0112, P0113 (Intake air temperature sensor)

P0115, P0117, P0118 (Engine coolant temperature sensor)

P0120, P0121, P0122, P0123, P0220, P0222, P0223, P2135 (Throttle position sensor)

P0125 (Insufficient coolant temperature for closed loop fuel control)

P0128 (Thermostat)

P0171, P0172, P0174, P0175 (Fuel system)

P0301, P0302, P0303, P0304, P0305, P0306 (Misfire)

P0335 (Crankshaft position sensor)

P0451, P0452, P0453 (EVAP system)

P0500 (Vehicle speed sensor)

P0505 (Idle speed control)

P219A, P219B (Air-fuel ratio imbalance)
P2239, P2242, P2252, P2253, P2255 and P2256
Monitor runs whenever the following DTCs are not stored None
P2237 and P2240: Air Fuel Ratio Sensor Open Circuit Between A1A+ and A1A-/A2A+ and A2A-
Estimated sensor temperature 450 to 550°C (842 to 1022°F)
Engine Running
Battery voltage 11 V or higher
Engine switch On (IG)
Time after engine switch is off to on (IG) 5 seconds or more
P2238 and P2241: Low Admittance
Estimated sensor temperature 700 to 800°C (1292 to 1472°F)
Engine coolant temperature 5°C (41°F) or higher (varies with engine coolant temperature at engine start)
Fuel cut Not executed
Others
Battery voltage 11 V or higher
Engine switch On (IG)
Time after engine switch is off to on (IG) 5 seconds or more

TYPICAL MALFUNCTION THRESHOLDS

P2237 and P2240: Open Circuit Between A1A+ and A1A-/A2A+ and A2A-
Air fuel ratio sensor admittance Less than 0.002 1/Ω
P2238 and P2241: Low Admittance
Air fuel ratio sensor admittance Less than 0.0074 1/Ω
P2238 and P2241: Short Circuit Between A1A+ and GND/A2A+ and GND
A1A+/A2A+ terminal voltage 0.5 V or less
P2238 and P2241: Short Circuit Between A1A+ and A1A-/A2A+ and A2A-
Difference between A1A+ and A1A-/A2A+ and A2A- terminal voltage 0.1 V or less
P2239 and P2242: Short Circuit Between A1A+ and +B/A2A+ and +B
A1A+/A2A+ terminal voltage Higher than 4.5 V
P2252 and P2255: Short Circuit Between A1A- and GND/A2A- and GND
A1A-/A2A- terminal voltage 0.5 V or less
P2253 and P2256: Short Circuit Between A1A- and +B/A2A- and +B
A1A-/A2A- terminal voltage Higher than 4.5 V

CONFIRMATION DRIVING PATTERN


  1. Connect the Techstream to the DLC3.

  2. Turn the engine switch on (IG) and turn the Techstream on.

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

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

  5. Turn the engine switch on (IG) and turn the Techstream on.

  6. Start the engine and wait 5 minutes.

  7. Enter the following menus: Powertrain / Engine / Trouble Codes.

  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 / Utility / All Readiness.

  10. Input the DTC: P2237, P2238, P2239, P2240, P2241, P2242, P2252, P2253, P2255 or P2256.

  11. Check the DTC judgment result.

    Techstream 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, idle the engine for 5 minutes and check the DTC judgment result again.

  12. If no pending DTC is output, perform a universal trip and check for permanent DTCs Click here.

    Tech Tips


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

    • If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

Refer to DTC P2195 Click here.

INSPECTION PROCEDURE

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 and AFS Voltage B2S1] Click here.

  • Read freeze frame data using the Techstream. 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.

  • Bank 1 refers to the bank that includes the No. 1 cylinder*.

    *: The No. 1 cylinder is the cylinder which is farthest from the transaxle.

  • Bank 2 refers to the bank that does not include the No. 1 cylinder.

  • 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
      Tester Connection Condition Specified Condition
      E19-1 (HA1A) - E26-26 (HA1A) Always Below 1 Ω
      E19-3 (A1A+) - E26-100 (A1A+) Always Below 1 Ω
      E19-4 (A1A-) - E26-132 (A1A-) Always Below 1 Ω
      E48-1 (HA2A) - E26-20 (HA2A) Always Below 1 Ω
      E48-3 (A2A+) - E26-99 (A2A+) Always Below 1 Ω
      E48-4 (A2A-) - E26-131 (A2A-) Always Below 1 Ω
      E19-1 (HA1A) or E26-26 (HA1A) - Body ground Always 10 kΩ or higher
      E19-3 (A1A+) or E26-100 (A1A+) - Body ground Always 10 kΩ or higher
      E19-4 (A1A-) or E26-132 (A1A-) - Body ground Always 10 kΩ or higher
      E48-1 (HA2A) or E26-20 (HA2A) - Body ground Always 10 kΩ or higher
      E48-3 (A2A+) or E26-99 (A2A+) - Body ground Always 10 kΩ or higher
      E48-4 (A2A-) or E26-131 (A2A-) - 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 Repair" after replacing the air fuel ratio sensor Click here.


    NEXT

  3. CHECK WHETHER DTC OUTPUT RECURS


    1. Connect the Techstream to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the Techstream on.

    4. Clear the DTCs Click here.

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

    6. Turn the engine switch on (IG) and turn the Techstream on.

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

    8. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

    9. Input the DTC: P2237, P2238, P2239, P2240, P2241, P2242, P2252, P2253, P2255 or P2256.

    10. Check the DTC judgment result.

      Result
      Result Proceed to
      NORMAL (DTC is not output) A

      ABNORMAL

      (DTC P2237, P2238, P2239, P2240, P2241, P2242, P2252, P2253, P2255 or P2256 is output)

      		 B

    B

    REPLACE ECM Click here

    A

    END