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 Code DTC Detection Condition Trouble Area

P2237

P2240

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

  • Open in Air Fuel ratio (A/F) sensor (for Bank 1, 2 Sensor 1) circuit

  • Air Fuel ratio (A/F) sensor (for Bank 1, 2 Sensor 1)

  • ECM

P2238

P2241

  • Case 1:

Condition (a) or (b) continues for 5.0 seconds or more (1 trip detection logic):

(a) The A1A+/A2A+ voltage is 0.5 V or less.

(b) (A1A+/A2A+) - (A1A-/A2A-) = 0.1 V or less.


  • Case 2:

The A/F sensor admittance is below 0.022 1/Ω (2 trip detection logic).

  • Open or short in A/F sensor (for Bank 1, 2 Sensor 1) circuit

  • A/F sensor (for Bank 1, 2 Sensor 1)

  • ECM

P2239

P2242

 The A1A+/A2A+ voltage is higher than 4.5 V for 5.0 seconds or more (2 trip detection logic).

  • Open or short in A/F sensor (for Bank 1, 2 Sensor 1) circuit

  • A/F sensor (for Bank 1, 2 Sensor 1)

  • ECM

P2252

P2255

 The A1A-/A2A- voltage is 0.5 V or less for 5.0 seconds or more (2 trip detection logic).

  • Open or short in A/F sensor (for Bank 1, 2 Sensor 1) circuit

  • A/F sensor (for Bank 1, 2 Sensor 1)

  • ECM

P2253

P2256

 The A1A-/A2A- voltage is higher than 4.5 V for 5.0 seconds or more (2 trip detection logic).

  • Open or short in A/F sensor (for Bank 1, 2 Sensor 1) circuit

  • A/F sensor (for Bank 1, 2 Sensor 1)

  • ECM

Tech Tips


  • DTCs P2237, P2238, P2239, P2252 and P2253 indicate malfunctions related to the bank 1 A/F sensor circuit.

  • DTCs P2240, P2241, P2242, P2255 and P2256 indicate malfunctions related to the bank 2 A/F 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 stored when there is an open or short in the A/F sensor circuit, or if A/F sensor output drops.

To detect these problems, the voltage of the A/F 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 A/F 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 less than the standard value, the ECM will determine that there is a malfunction in the A/F 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 (A/F) sensor varies its output voltage in proportion to the air-fuel ratio. If the A/F 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 A/F sensor circuit.

WIRING DIAGRAM

Refer to DTC P2195 Click here.

INSPECTION PROCEDURE

Tech Tips

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 (A/F SENSOR - ECM)


    1. Disconnect the Air Fuel ratio (A/F) sensor connector.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      C47-2 (+B) - Body ground Engine switch on (IG) 11 to 14 V
      C48-2 (+B) - Body ground Engine switch on (IG) 11 to 14 V

    3. Turn the engine switch off.

    4. Disconnect the ECM connector.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      C47-1 (HA1A) - C53-22 (HA1A) Always Below 1 Ω
      C47-3 (A1A+) - C53-126 (A1A+) Always Below 1 Ω
      C47-4 (A1A-) - C53-125 (A1A-) Always Below 1 Ω
      C48-1 (HA2A) - C53-20 (HA2A) Always Below 1 Ω
      C48-3 (A2A+) - C53-103 (A2A+) Always Below 1 Ω
      C48-4 (A2A-) - C53-102 (A2A-) Always Below 1 Ω
      C47-1 (HA1A) or C53-22 (HA1A) - Body ground Always 10 kΩ or higher
      C47-3 (A1A+) or C53-126 (A1A+) - Body ground Always 10 kΩ or higher
      C47-4 (A1A-) or C53-125 (A1A-) - Body ground Always 10 kΩ or higher
      C48-1 (HA2A) or C53-20 (HA2A) - Body ground Always 10 kΩ or higher
      C48-3 (A2A+) or C53-103 (A2A+) - Body ground Always 10 kΩ or higher
      C48-4 (A2A-) or C53-102 (A2A-) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      C47-1 (HA1A) - C54-22 (HA1A) Always Below 1 Ω
      C47-3 (A1A+) - C54-126 (A1A+) Always Below 1 Ω
      C47-4 (A1A-) - C54-125 (A1A-) Always Below 1 Ω
      C48-1 (HA2A) - C54-20 (HA2A) Always Below 1 Ω
      C48-3 (A2A+) - C54-103 (A2A+) Always Below 1 Ω
      C48-4 (A2A-) - C54-102 (A2A-) Always Below 1 Ω
      C47-1 (HA1A) or C54-22 (HA1A) - Body ground Always 10 kΩ or higher
      C47-3 (A1A+) or C54-126 (A1A+) - Body ground Always 10 kΩ or higher
      C47-4 (A1A-) or C54-125 (A1A-) - Body ground Always 10 kΩ or higher
      C48-1 (HA2A) or C54-20 (HA2A) - Body ground Always 10 kΩ or higher
      C48-3 (A2A+) or C54-103 (A2A+) - Body ground Always 10 kΩ or higher
      C48-4 (A2A-) or C54-102 (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.


    NEXT

  3. CHECK WHETHER DTC OUTPUT RECURS


    1. Connect the intelligent tester to the DLC3.

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

    3. Clear DTCs Click here.

    4. Start the engine.

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

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

    7. Read pending DTCs.

      Result
      Result Proceed to
      No DTC is output A
      P2237, P2238, P2239, P2240, P2241, P2242, P2252, P2253, P2255 or P2256 is output B

    B

    REPLACE ECM Click here

    A

    END