LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Infiniti >> 2021 >> Q50 Signature Edition, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTCS) (5 Of 6) >> Engine (ECM) >> P2270 O2 Sensor >> Confirmation Procedure >> VR30DDTT engine
April 5, 2026: LEMON Manuals is launched! Read the announcement.

VR30DDTT engine

  1. PRECONDITIONING 

    If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.

    1. Turn ignition switch OFF and wait at least 10 seconds.
    2. Turn ignition switch ON.
    3. Turn ignition switch OFF and wait at least 10 seconds.

    GO TO 2.

  2. PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION A 
    1. Start engine and warm it up to the normal operating temperature.
    2. Turn ignition switch OFF and wait at least 10 seconds.
    3. Turn ignition switch ON.
    4. Turn ignition switch OFF and wait at least 10 seconds.
    5. Start engine and keep the engine speed between 3, 500 and 4, 000 RPM for at least 1 minute under no load.
    6. Let engine idle for 2 minutes.
    7. Check 1st trip DTC.

    Is 1st trip DTC detected?

    YES

    Refer to DTC Diagnosis Procedure .

    NO

    With CONSULT: GO TO 3.

    NO

    Without CONSULT: GO TO 5.

  3. PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION B 
    NOTE: For better results, perform "DTC WORK SUPPORT" at a temperature of 0 to 30 deg. C (32 to 86 deg. F).
    1. Select "DATA MONITOR" mode with CONSULT.
    2. Start engine and warm it up to the normal operating temperature.
    3. Turn ignition switch OFF and wait at least 10 seconds.
    4. Turn ignition switch ON.
    5. Turn ignition switch OFF and wait at least 10 seconds.
    6. Start engine and keep the engine speed between 3, 500 and 4, 000 RPM for at least 1 minute under no load.
    7. Let engine idle for 1 minute.
    8. Make sure that "COOLAN TEMP/S" indicates more than 70 deg. C (158 deg. F).

      If not, warm up engine and go to next step when "COOLAN TEMP/S" indication reaches 70 deg. C (158 deg. F).

    9. Open engine hood.
    10. Select "HO2S2 (B1) P1146" (for DTC P2270) of "HO2S2" in "DTC WORK SUPPORT" mode with CONSULT.
    11. Start engine and follow the instruction of CONSULT display.
      NOTE: It will take at most 10 minutes until "COMPLETED" is displayed.
    12. Touch "SELF-DIAG RESULTS".

    Which is displayed on CONSULT screen?

    OK

    INSPECTION END

    NG

    Refer to DTC Diagnosis Procedure .

    CON NOT BE DIAGNOSED

    GO TO 4.

  4. PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION B AGAIN 
    1. Turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle).
    2. Perform DTC confirmation procedure again.

    GO TO 3.

  5. PERFORM COMPONENT FUNCTION CHECK FOR MALFUNCTION-1 
    NOTE: Use component function check to check the overall function of the heated oxygen sensor 2 circuit. During this check, a 1st trip DTC might not be confirmed.

    SYMBOL Without CONSULT

    1. Start engine and warm it up to the normal operating temperature.
    2. Turn ignition switch OFF and wait at least 10 seconds.
    3. Start engine and keep the engine speed between 3, 500 and 4, 000 RPM for at least 1 minute under no load.
    4. Let engine idle for 1 minute.
    5. Check the voltage between ECM harness connector terminals under the following condition.

      ECM

      Condition

      Voltage

      Connector

      +

      -

      Terminal

      Terminal

      F143

      49

      81

      Revving up to 4, 000 RPM under no load at least 10 times

      The voltage should be below 0.18 V at least once during this procedure.

    Is the inspection result normal?

    YES

    To check malfunction symptom before repair: Refer to Inspection .

    YES

    Confirmation after repair: INSPECTION END

    NO

    GO TO 6.

  6. PERFORM COMPONENT FUNCTION CHECK FOR MALFUNCTION-2 

    Check the voltage between ECM harness connector terminals under the following condition.

    ECM

    Condition

    Voltage

    Connector

    +

    -

    Terminal

    Terminal

    F143

    49

    81

    Keeping engine at idle for 10 minutes

    The voltage should be below 0.18 V at least once during this procedure.

    Is the inspection result normal?

    YES

    To check malfunction symptom before repair: Refer to Inspection .

    YES

    Confirmation after repair: INSPECTION END

    NO

    GO TO 7.

  7. PERFORM COMPONENT FUNCTION CHECK FOR MALFUNCTION-3 

    Check the voltage between ECM harness connector terminals under the following condition.

    ECM

    Condition

    Voltage

    Connector

    +

    -

    Terminal

    Terminal

    F143

    49

    81

    Coasting from 80 km/h (50 MPH) in D position

    The voltage should be below 0.18 V at least once during this procedure.

    Is the inspection result normal?

    YES

    To check malfunction symptom before repair: Refer to Inspection .

    YES

    Confirmation after repair: INSPECTION END

    NO

    Refer to DTC Diagnosis Procedure .

scientia non olet · About LEMON Manuals