ECD SYSTEM, Diagnostic DTC:P0138

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

DESCRIPTION

Tech Tips

Refer to DTC P0030 Click here.

DTC No. DTC Detection Condition Trouble Area
P0138

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

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.

Tech Tips

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 tester on.

    4. Enter the following menus: 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
      B113-1 (AF2+) - B91-130 (AF2+) Always Below 1 Ω
      B113-2 (AF2-) - B91-133 (AF2-) Always Below 1 Ω
      B113-3 (HAF2) - B91-17 (HAF2) Always Below 1 Ω
      B113-5 (TR2) - B91-131 (TR2) Always Below 1 Ω
      B113-6 (RE2) - B91-134 (RE2) Always Below 1 Ω
      B113-1 (AF2+) or B91-130 (AF2+) - Body ground Always 10 kΩ or higher
      B113-2 (AF2-) or B91-133 (AF2-) - Body ground Always 10 kΩ or higher
      B113-3 (HAF2) or B91-17 (HAF2) - Body ground Always 10 kΩ or higher
      B113-5 (TR2) or B91-131 (TR2) - Body ground Always 10 kΩ or higher
      B113-6 (RE2) or B91-134 (RE2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click 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.

    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.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  5. REPAIR OR REPLACE HARNESS OR CONNECTOR


    1. Repair or replace the harness or connector.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  6. 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.

      Tech Tips

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


    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 Click here.

    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.

    8. Confirm that the DTC is not output again.


    NEXT

    END