SFI SYSTEM, Diagnostic DTC:P0141

DTC Code DTC Name
P0141 Oxygen Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)

DESCRIPTION

Refer to DTC P0137 Click here.

Tech Tips

The ECM provides a pulse width modulated control circuit to adjust the current through the heater. The No. 2 heated oxygen sensor heater circuit uses a relay on the +B side of the circuit.

DTC No. DTC Detection Condition Trouble Area
P0141 Open or short of No. 2 heated oxygen sensor heater or related circuit (3 trip detection logic).

  • Open or short in No. 2 heated oxygen sensor heater circuit

  • No. 2 heated oxygen sensor

  • No. 1 integration relay

  • ECM

Tech Tips


  • DTC P0141 is detected when the engine idles for approximately 20 minutes.

WIRING DIAGRAM

Refer to DTC P0130 Click here.

CAUTION / NOTICE / HINT

Note


  • Perform idle learning after replacing the ECM Click here.

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

Tech Tips


  • Sensor 1 refers to the sensor closest to the engine assembly.

  • Sensor 2 refers to the sensor farthest away from the engine assembly.

  • 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. INSPECT NO. 2 HEATED OXYGEN SENSOR (HEATER RESISTANCE)


    1. Inspect the No. 2 heated oxygen sensor Click here.


    NG

    REPLACE NO. 2 HEATED OXYGEN SENSOR Click here

    OK

  2. CHECK TERMINAL VOLTAGE (NO. 2 HEATED OXYGEN SENSOR)

    A01VM1DE02
    Text in Illustration
    *a

    Front view of wire harness connector

    (to No. 2 Heated Oxygen Sensor)

    1. Disconnect the No. 2 heated oxygen sensor connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      B83-1 (+B) - Body ground Ignition switch ON 11 to 14 V

    NG

    INSPECT NO. 1 INTEGRATION RELAY (EFI MAIN RELAY) Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (NO. 2 HEATED OXYGEN SENSOR - ECM)


    1. Disconnect the B83 No.2 heated oxygen sensor connector.

    2. Disconnect the B97 ECM connector (for LHD).

    3. Disconnect the B101 ECM connector (for RHD).

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      B83-2 (HT1B) - B97-25 (HT1B) Always Below 1 Ω
      B83-2 (HT1B) or B97-25 (HT1B) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      B83-2 (HT1B) - B101-25 (HT1B) Always Below 1 Ω
      B83-2 (HT1B) or B101-25 (HT1B) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK WHETHER DTC OUTPUT RECURS (DTC P0141)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear DTCs Click here.

    5. Turn the ignition switch off and wait for 30 seconds.

    6. Turn the ignition switch to ON.

    7. Turn the GTS on.

    8. Start the engine.

    9. Allow the engine to idle for 20 minutes or more.

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

    11. Read the pending DTCs.

      Result
      Result Proceed to
      DTC is not output A
      DTC P0141 is output B

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

    B

    REPLACE ECM Click here

  5. INSPECT NO. 1 INTEGRATION RELAY (EFI MAIN RELAY)


    1. Inspect the No. 1 integration relay Click here.


    NG

    REPLACE NO. 1 INTEGRATION RELAY Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (NO. 2 HEATED OXYGEN SENSOR - NO. 1 INTEGRATION RELAY)


    1. Disconnect the B83 No. 2 heated oxygen sensor connector.

    2. Remove the No. 1 integration relay from the engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B83-2 (+B) - 1E-4 Always Below 1 Ω
      B83-2 (+B) or 1E-4 - Body ground Always 10 kΩ or higher

    OK

    CHECK ECM POWER SOURCE CIRCUIT Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR