SFI SYSTEM, Diagnostic DTC:P0140

DTC Code DTC Name
P0140 Heated Oxygen Sensor Circuit No Activity Detected (Bank 1 Sensor 2)

DESCRIPTION

Refer to DTC P0137.

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DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P0140

Heated Oxygen Sensor Circuit No Activity Detected (Bank 1 Sensor 2)

  • All of the following conditions are met (3 trip detection logic):

    1. 100 seconds have elapsed since heated oxygen sensor (sensor 2) dew point judgment* was completed.

    2. Heated oxygen sensor (sensor 2) output voltage is between 1.25 and 3.5 V.

    3. Conditions (a) and (b) are met continuously for 5 seconds.

    4. Active air-fuel ratio control is performed as follows after condition (c) is met:

      1. Pulse signal is applied to heated oxygen sensor (sensor 2) signal line.

      2. Heated oxygen sensor (sensor 2) voltage is measured after pulse signal is applied.

      3. Heated oxygen sensor (sensor 2) voltage after pulse signal applied is 2.8 V or higher.

      4. When condition (3) is met, steps (1) and (2) are repeated 2 more times.

    6. Average difference in heated oxygen sensor (sensor 1) output voltage when active air-fuel ratio control is performed 3 times is 2.8 V or higher.

  • Open in heated oxygen sensor (sensor 2) circuit

  • Heated oxygen sensor (sensor 2)

Comes on

DTC stored
Tip:

*: Condensation may form in the exhaust pipes after the engine is started and before the exhaust system has warmed up. If condensation exists, the sensor element may be damaged if the heated oxygen sensor (sensor 2) heater is heated excessively. Therefore, the ECM will restrict the output of the heated oxygen sensor (sensor 2) heater until it determines condensation is not forming in the exhaust pipes. Dew point judgment is when the ECM judges that condensation is no longer forming.

WIRING DIAGRAM

Refer to DTC P0130.

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CONFIRMATION DRIVING PATTERN

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

DTC P0140 is detected when the vehicle is driven at an average vehicle speed of approximately 50 km/h (31 mph) in an urban area for approximately 30 minutes.

CAUTION / NOTICE / HINT

Note:

After replacing the ECM, perform idle learning.

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Tip:

  • The internal resistance of the heated oxygen sensor (sensor 2) cannot be measured using a tester.

  • 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. READ VALUE USING GTS (O2S B1S2)

    1. Connect the GTS to the DLC3.

    2. Start the engine.

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / O2S B1S2.

      Powertrain > Engine and ECT > Data List

      Tester Display

      O2S B1S2

    5. Warm up the heated oxygen sensor (sensor 2) at an engine speed of 2500 rpm for approximately 3 minutes.

    6. Read the output voltage of the heated oxygen sensor (sensor 2) during racing the engine.

      Standard voltage

      Fluctuates between less than 0.4 V, and higher than 0.55 V (see the following figure).

      A319417E01

    Result

    Proceed to

    OK

    NG
    NG

    CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR (SENSOR 2) - ECM)Click here

    OK

  2. CHECK WHETHER DTC OUTPUT RECURS (DTC P0140)

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs.

      Powertrain > Engine and ECT > Clear DTCs

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

    6. Start the engine and warm it up.

    7. Turn the GTS on.

    8. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

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

    10. Read the pending DTCs.

      Powertrain > Engine and ECT > Trouble Codes

      Result

      Result

      Proceed to

      DTC P0140 is output

      A

      DTCs are not output

      B
    B

    CHECK FOR INTERMITTENT PROBLEMS

    Click here

    A

  3. REPLACE HEATED OXYGEN SENSOR (SENSOR 2)

    1. Replace the heated oxygen sensor (sensor 2).

      Click hereClick here

    Result

    Proceed to

    NEXT
    NEXT

  4. CHECK WHETHER DTC OUTPUT RECURS (DTC P0140)

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs.

      Powertrain > Engine and ECT > Clear DTCs

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

    6. Start the engine and warm it up.

    7. Turn the GTS on.

    8. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

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

    10. Read the pending DTCs.

      Powertrain > Engine and ECT > Trouble Codes

      Result

      Result

      Proceed to

      DTC P0140 is output

      A

      DTCs are not output

      B
    A

    REPLACE ECM

    Click here

    B

    END

  5. CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR (SENSOR 2) - ECM)

    1. Disconnect the heated oxygen sensor (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

      B18-4 (OX1B) - B31-103 (OX1B)

      Always

      Below 1 Ω

      B18-2 (HT1B) - B31-25 (HT1B)

      Always

      Below 1 Ω

      B18-3 (E1) - B31-135 (E12)

      Always

      Below 1 Ω

      B18-4 (OX1B) or B31-103 (OX1B) - Body ground

      Always

      10 kΩ or higher

      B18-2 (HT1B) or B31-25 (HT1B) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE HEATED OXYGEN SENSOR (SENSOR 2)

    Click hereClick here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR