SFI SYSTEM(w/ EGR System), Diagnostic DTC:P2237,P2238,P2239,P2240,P2241,P2242,P2252,P2253,P2255 and 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.

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DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

Memory

P2237

Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1)

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

  • Open in air fuel ratio sensor (for Bank 1, 2 Sensor 1) circuit

  • Air fuel ratio sensor (for Bank 1, 2 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) AF+ voltage is 0.5 V or less.

(b) (AF+) - (AF-) is 0.1 V or less.

  • Case 2:

Air fuel ratio sensor admittance is below 0.022 1/Ω (2 trip detection logic).

  • Open or short in air fuel ratio sensor (for Bank 1, 2 Sensor 1) circuit

  • Air fuel ratio sensor (for Bank 1, 2 Sensor 1)

  • ECM

Comes on

DTC stored

P2239

Oxygen (A/F) Sensor Pumping Current Circuit High (Bank 1 Sensor 1)

AF+ voltage is higher than 4.5 V for 5.0 seconds or more (2 trip detection logic).

  • Open or short in air fuel ratio sensor (for Bank 1, 2 Sensor 1) circuit

  • Air fuel ratio sensor (for Bank 1, 2 Sensor 1)

  • ECM

Comes on

DTC stored

P2240

Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 2 Sensor 1)

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

  • Open in air fuel ratio sensor (for Bank 1, 2 Sensor 1) circuit

  • Air fuel ratio sensor (for Bank 1, 2 Sensor 1)

  • ECM

Comes on

DTC stored

P2241

Oxygen (A/F) Sensor Pumping Current Circuit Low (Bank 2 Sensor 1)

  • Case 1:

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

(a) AF+ voltage is 0.5 V or less.

(b) (AF+) - (AF-) is 0.1 V or less.

  • Case 2:

Air fuel ratio sensor admittance is below 0.022 1/Ω (2 trip detection logic).

  • Open or short in air fuel ratio sensor (for Bank 1, 2 Sensor 1) circuit

  • Air fuel ratio sensor (for Bank 1, 2 Sensor 1)

  • ECM

Comes on

DTC stored

P2242

Oxygen (A/F) Sensor Pumping Current Circuit High (Bank 2 Sensor 1)

AF+ voltage is higher than 4.5 V for 5.0 seconds or more (2 trip detection logic).

  • Open or short in air fuel ratio sensor (for Bank 1, 2 Sensor 1) circuit

  • Air fuel ratio sensor (for Bank 1, 2 Sensor 1)

  • ECM

Comes on

DTC stored

P2252

Oxygen (A/F) Sensor Reference Ground Circuit Low (Bank 1 Sensor 1)

AF- voltage is 0.5 V or less for 5.0 seconds or more (2 trip detection logic).

  • Open or short in air fuel ratio sensor (for Bank 1, 2 Sensor 1) circuit

  • Air fuel ratio sensor (for Bank 1, 2 Sensor 1)

  • ECM

Comes on

DTC stored

P2253

Oxygen (A/F) Sensor Reference Ground Circuit High (Bank 1 Sensor 1)

AF- voltage is higher than 4.5 V for 5.0 seconds or more (2 trip detection logic).

  • Open or short in air fuel ratio sensor (for Bank 1, 2 Sensor 1) circuit

  • Air fuel ratio sensor (for Bank 1, 2 Sensor 1)

  • ECM

Comes on

DTC stored

P2255

Oxygen (A/F) Sensor Reference Ground Circuit Low (Bank 2 Sensor 1)

AF- voltage is 0.5 V or less for 5.0 seconds or more (2 trip detection logic).

  • Open or short in air fuel ratio sensor (for Bank 1, 2 Sensor 1) circuit

  • Air fuel ratio sensor (for Bank 1, 2 Sensor 1)

  • ECM

Comes on

DTC stored

P2256

Oxygen (A/F) Sensor Reference Ground Circuit High (Bank 2 Sensor 1)

AF- voltage is higher than 4.5 V for 5.0 seconds or more (2 trip detection logic).

  • Open or short in air fuel ratio sensor (for Bank 1, 2 Sensor 1) circuit

  • Air fuel ratio sensor (for Bank 1, 2 Sensor 1)

  • ECM

Comes on

DTC stored

Tip:
  • 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.

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

  • Bank 2 refers to the bank that includes the No. 2 cylinder.

MONITOR DESCRIPTION

These DTCs are output when there is an open or short in the air fuel ratio sensor circuit, or if 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 0.6 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 (Main)

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 P2195.

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CAUTION / NOTICE / HINT

Tip:
  • Refer to "Data List / Active Test" [AFS Voltage B1S1 and AFS Voltage B2S1] (See page ).

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  • Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition 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.

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

      C20-1 (HA1A) - C31-17 (HA1A)

      Always

      Below 1 Ω

      C20-3 (A1A+) - C30-1 (A1A+)

      Always

      Below 1 Ω

      C20-4 (A1A-) - C30-2 (A1A-)

      Always

      Below 1 Ω

      C19-1 (HA2A) - C31-19 (HA2A)

      Always

      Below 1 Ω

      C19-3 (A2A+) - C30-7 (A2A+)

      Always

      Below 1 Ω

      C19-4 (A2A-) - C30-8 (A2A-)

      Always

      Below 1 Ω

      C20-1 (HA1A) or C31-17 (HA1A) - Body ground

      Always

      10 kΩ or higher

      C20-3 (A1A+) or C30-1 (A1A+) - Body ground

      Always

      10 kΩ or higher

      C20-4 (A1A-) or C30-2 (A1A-) - Body ground

      Always

      10 kΩ or higher

      C19-1 (HA2A) or C31-19 (HA2A) - Body ground

      Always

      10 kΩ or higher

      C19-3 (A2A+) or C30-7 (A2A+) - Body ground

      Always

      10 kΩ or higher

      C19-4 (A2A-) or C30-8 (A2A-) - Body ground

      Always

      10 kΩ or higher

      Result

      Result

      OK

      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK
  2. REPLACE AIR FUEL RATIO SENSOR

    1. Replace the air fuel ratio sensor.

      Click here

      Result

      Result

      NEXT

    NEXT
  3. CHECK WHETHER DTC OUTPUT RECURS

    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

    4. Clear the DTCs.

      Click here

      Powertrain > Engine and ECT > Clear DTCs

    5. Start the engine.

    6. Allow the engine to idle for 5 minutes or more.

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

    8. Read the pending DTCs.

      Powertrain > Engine and ECT > Trouble Codes

      Result

      Result

      Proceed to

      No DTC is output

      A

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

      B

    A

    END

    B

    REPLACE ECM