Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Infiniti >> 2024 >> QX80 Premium Select, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTCS) (1 Of 4) >> 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 or 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 or 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 or Component Inspection . Is the inspection result normal?

    YES>>

    GO TO 9

    .

    NO>>

    Replace mass air flow sensor (with intake air temperature sensor) or AIR CLEANER AND AIR DUCT : Removal and Installation .

  9. CHECK PCV VALVE 

    Check the PCV valve or POSITIVE CRANKCASE VENTILATION : Periodic Maintenance . Is the inspection result normal?

    YES>>

    GO TO 10.

    NO>>

    Replace PCV valve.

  10. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR 

    Refer to Component Inspection . Is the inspection result normal?

    YES>>

    GO TO 11

    .

    NO>>

    Replace EVAP control system pressure sensor or EVAP CANISTER : Removal and Installation .

  11. PERFORM EVAP LEAK CHECK 

    Perform EVAP leak check or EVAP CANISTER : Periodic Maintenance .

    >>

    GO TO 12

    .

  12. CHECK THROTTLE POSITION SENSOR 

    Check the following with the freeze frame data of DTC P0101:

    ENGINE SPEED Idling speed
    VEHICLE SPEED 0 KM/H
    S-FUEL TRM-B1 not 125%

    Is the freeze frame data under the above condition?

    YES>>

    Perform idle air volume learning or Work Procedure .

    NO>>

    GO TO 13.

  13. CHECK MASS AIR FLOW SENSOR 

    Check mass air flow sensor or Component Inspection . Is the inspection result normal?

    YES>>

    Check intermittent incident or Inspection .

    NO>>

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