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Home >> Infiniti >> 2021 >> QX80 Premium Select, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTCS) (1 Of 5) >> Engine (ECM) >> DTC P0101: MAF Sensor >> DTC Diagnosis Procedure

DTC Diagnosis Procedure

  1. CHECK DTC PRIORITY 

    If DTC P0101 is displayed with other DTC, first perform the trouble diagnosis for other DTC.

    Is applicable DTC detected?

    YES

    Perform diagnosis of applicable. Refer to DTC Index .

    NO

    GO TO 2.

  2. CHECK HARNESS CONNECTOR 
    1. Disconnect mass air flow sensor harness connector and ECM harness connector.
    2. Connect mass air flow sensor harness connector and ECM harness connector.
    3. Perform DTC confirmation procedure. Refer to Confirmation Procedure .

    Is DTC detected?

    YES

    GO TO 3.

    NO

    INSPECTION END

  3. CHECK INTAKE SYSTEM 

    Check the following items to see the installation condition and the connection condition of the joint.

    • Air duct
    • Vacuum hoses
    • Intake air passage between air duct and intake manifold

    Is the inspection result normal?

    YES

    GO TO 4.

    NO

    Reconnect or replace error-detected parts.

  4. CHECK MASS AIR FLOW SENSOR POWER SUPPLY CIRCUIT 
    1. Disconnect mass air flow sensor harness connector.
    2. Turn ignition switch ON.
    3. Check the voltage between mass air flow sensor harness connector and ground.

      +

      -

      Voltage

      Mass air flow sensor

      Connector

      Terminal

      F31

      5

      Ground

      Battery voltage

    Is the inspection result normal?

    YES

    GO TO 6.

    NO

    GO TO 5.

  5. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness for open or short between mass air flow sensor and ECM
    • Harness for open or short between mass air flow sensor and IPDM E/R
    • Loose or poor connection for each connector and harness

    Repair or replace error-detected parts.

  6. CHECK MASS AIR FLOW SENSOR GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check the continuity between mass air flow sensor harness connector and ECM harness connector.

      Mass air flow sensor

      ECM

      Continuity

      Connector

      Terminal

      Connector

      Terminal

      F31

      4

      F91

      42

      Existed

    4. Also check harness for short to ground and short to power.

    Is the inspection result normal?

    YES

    GO TO 7.

    NO

    Repair or replace error-detected parts.

  7. CHECK MASS AIR FLOW SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Check the continuity between mass air flow sensor harness connector and ECM harness connector.

      Mass air flow sensor

      ECM

      Continuity

      Connector

      Terminal

      Connector

      Terminal

      F31

      3

      F91

      37

      Existed

    2. Also check harness for short to ground and short to power.

    Is the inspection result normal?

    YES

    GO TO 8.

    NO

    Repair or replace error-detected parts.

  8. CHECK INTAKE AIR TEMPERATURE SENSOR 

    Check intake air temperature sensor. Refer to Component Inspection .

    Is the inspection result normal?

    YES

    GO TO 9.

    NO

    Replace mass air flow sensor (with intake air temperature sensor). Refer to AIR CLEANER AND AIR DUCT : Removal & Installation .

  9. CHECK PCV VALVE 

    Check the PCV valve. Refer to POSITIVE CRANKCASE VENTILATION : Periodic Maintenance Operation .

    Is the inspection result normal?

    YES

    GO TO 10.

    NO

    Replace PCV valve.

  10. PERFORM IDLE AIR VOLUME LEARNING 

    Perform the idle air volume learning. Refer to Work Procedure .

    GO TO 11.

  11. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR 

    Refer to Component Inspection .

    Is the inspection result normal?

    YES

    GO TO 12.

    NO

    Replace EVAP control system pressure sensor. Refer to EVAP CANISTER : Removal & Installation .

  12. PERFORM EVAP LEAK CHECK 

    Perform EVAP leak check. Refer to EVAP CANISTER : Periodic Maintenance Operation .

    GO TO 13.

  13. CHECK MASS AIR FLOW SENSOR 

    Check mass air flow sensor. Refer to Component Inspection .

    Is the inspection result normal?

    YES

    Check intermittent incident. Refer to Inspection .

    NO

    Replace mass air flow sensor. Refer to AIR CLEANER AND AIR DUCT : Exploded View .