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Home >> Infiniti >> 2021 >> Q60 Pure, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTCS) (1 Of 7) >> 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 confirmation procedure (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 
    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

      (Approx.)

      Mass air flow sensor

      Bank

      Connector

      Terminal

      1

      F99

      2

      Ground

      5 V

    Is the inspection result normal?

    YES

    GO TO 6.

    NO

    GO TO 5.

  5. CHECK MASS AIR FLOW SENSOR POWER SUPPLY CIRCUIT 
    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

      Bank

      Connector

      Terminal

      Connector

      Terminal

      1

      F99

      2

      F143

      41

      Existed

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

    Is the inspection result normal?

    YES

    Perform the trouble diagnosis for ECM power supply circuit. Refer to Diagnosis Procedure .

    NO

    Repair or replace error-detected parts.

  6. CHECK MASS AIR FLOW SENSOR GROUND CIRCUIT 
    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

      Bank

      Connector

      Terminal

      Connector

      Terminal

      1

      F99

      3

      F143

      30

      Existed

    4. Also check harness for short to power.

    Is the inspection result normal?

    YES

    GO TO 7.

    NO

    Repair or replace error-detected parts.

  7. CHECK ECM GROUND CIRCUIT 
    1. Check the continuity between ECM harness connector and ground.

      ECM

      --

      Continuity

      Connector

      Terminal

      F143

      3

      Ground

      Existed

      F142

      87

      88

      E152

      199

      201

      204

    2. Also check harness for short to power.

    Is the inspection result normal?

    YES

    GO TO 8.

    NO

    Repair or replace error-detected parts.

  8. CHECK MASS AIR FLOW SENSOR INPUT SIGNAL CIRCUIT 
    1. Check the continuity between mass air flow sensor harness connector and ECM harness connector.

      Mass air flow sensor

      ECM

      Continuity

      Bank

      Connector

      Terminal

      Connector

      Terminal

      1

      F99

      1

      F143

      33

      Existed

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

    Is the inspection result normal?

    YES

    GO TO 9.

    NO

    Repair or replace error-detected parts.

  9. 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 (bank 1) (with intake air temperature sensor). Refer to AIR CLEANER AND AIR DUCT : Exploded View .

  10. CHECK PCV VALVE 

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

    Is the inspection result normal?

    YES

    GO TO 11.

    NO

    Replace PCV valve.

  11. PERFORM IDLE AIR VOLUME LEARNING 

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

    GO TO 12.

  12. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR 

    Refer to Component Inspection .

    Is the inspection result normal?

    YES

    GO TO 13.

    NO

    Replace EVAP control system pressure sensor. Refer to EVAP CANISTER : Exploded View .

  13. PERFORM EVAP LEAK CHECK 

    Perform EVAP leak check. Refer to EVAP CANISTER : .

    GO TO 14.

  14. CHECK MASS AIR FLOW SENSOR (BANK 1) 

    Check mass air flow sensor (bank 1). Refer to Component Inspection .

    Is the inspection result normal?

    YES

    INSPECTION END

    NO

    Replace mass air flow sensor (bank 1). Refer to AIR CLEANER AND AIR DUCT : Exploded View .