ECD SYSTEM, Diagnostic DTC:P0138

DTC Code DTC Name
P0138 O2 Sensor Circuit High Voltage Bank 1 Sensor 2

DESCRIPTION

Refer to DTC P0030.

Click here

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P0138

O2 Sensor Circuit High Voltage Bank 1 Sensor 2

The air fuel ratio sensor (for sensor 2) voltage output is 3.2 V or higher for 0.5 seconds.

(3 trip detection logic)

  • Short in air fuel ratio sensor (for sensor 2) circuit

  • Air fuel ratio sensor (for sensor 2)

  • ECM

Does not come on

DTC stored

WIRING DIAGRAM

Refer to DTC P0030.

Click here

CAUTION / NOTICE / HINT

Note:

  • When replacing the ECM, the ECM needs registration and initialization.

    Click here

  • After replacing the air fuel ratio sensor, the ECM needs initialization.

    Click here

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

Tip:

Read freeze frame data using the GTS. 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. READ OUTPUT DTC (DTC P0138)

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

      Powertrain > Engine and ECT > Trouble Codes

    5. Read the DTCs.

      Result

      Result

      Proceed to

      DTC P0138 is output

      A

      DTC P0138 and other DTCs are output

      B
    B

    GO TO DTC CHART

    Click here

    A

  2. CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR (FOR SENSOR 2) - ECM)

    1. Disconnect the air fuel ratio sensor (for sensor 2) 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

      B133-1 (AF2+) - B112-130 (AF2+)

      Always

      Below 1 Ω

      B133-2 (AF2-) - B112-133 (AF2-)

      Always

      Below 1 Ω

      B133-3 (HAF2) - B112-17 (HAF2)

      Always

      Below 1 Ω

      B133-5 (TR2) - B112-131 (TR2)

      Always

      Below 1 Ω

      B133-6 (RE2) - B112-134 (RE2)

      Always

      Below 1 Ω

      B133-1 (AF2+) or B112-130 (AF2+) - Body ground

      Always

      10 kΩ or higher

      B133-2 (AF2-) or B112-133 (AF2-) - Body ground

      Always

      10 kΩ or higher

      B133-3 (HAF2) or B112-17 (HAF2) - Body ground

      Always

      10 kΩ or higher

      B133-5 (TR2) or B112-131 (TR2) - Body ground

      Always

      10 kΩ or higher

      B133-6 (RE2) or B112-134 (RE2) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTORClick here

    OK

  3. CHECK AIR FUEL RATIO SENSOR (FOR SENSOR 2)

    1. Check the air fuel ratio sensor for tightness and damages.

      OK

      No damage.

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE AIR FUEL RATIO SENSOR (FOR SENSOR 2)Click here

    OK

  4. REPLACE AIR FUEL RATIO SENSOR (FOR SENSOR 2)

    1. Replace the air fuel ratio sensor (for sensor 2).

      Click here

    2. Perform the O2 sensor learning value reset.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick here

  5. REPAIR OR REPLACE AIR FUEL RATIO SENSOR (FOR SENSOR 2)

    1. Repair or replace the air fuel ratio sensor (for sensor 2).

      1. Apply compressed air to remove soot stuck to the air fuel ratio sensor. If soot cannot be removed, replace the air fuel ratio sensor.

        Tip:

        When the air fuel ratio sensor is replaced, perform initialization.

        Click here

    Result

    Proceed to

    NEXT
    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick here

  6. REPAIR OR REPLACE HARNESS OR CONNECTOR

    1. Repair or replace the harness or connector.

    Result

    Proceed to

    NEXT
    NEXT

  7. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

    1. Connect the GTS to the DLC3.

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

    3. Clear the DTCs.

      Powertrain > Engine and ECT > Clear DTCs

    4. Turn the ignition switch off and wait for 60 seconds or more [A].

    5. Perform road test [B].

    6. Repeat [A] and [B] for the number of trips detected.

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

      Powertrain > Engine and ECT > Trouble Codes

    8. Confirm that the DTC is not output again.

    Result

    Proceed to

    NEXT
    NEXT

    END