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Home >> Infiniti >> 2024 >> Q50 Luxe, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTCS) (1 Of 7) >> Engine (ECM) >> 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 1st trip 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 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
      Bank Connector Terminal Connector Terminal
      1 F99 2 F143 41 Existed
    4. Also check harness for short to ground and short to power.

    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 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
      Bank Connector Terminal Connector Terminal
      1 F99 3 F143 30 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 ECM GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Check the continuity between ECM harness connector and ground.
      + - Continuity
      ECM
      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 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
      Bank Connector Terminal Connector Terminal
      1 F99 1 F143 33 Existed
    2. Also check harness for short to ground and short to power.

    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 10.

    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.

    Is the inspection result normal?

    YES>>

    GO TO 11.

    NO>>

    Replace PCV valve.

  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 : Exploded View .

  12. PERFORM EVAP LEAK CHECK 

    Preform the EVAP leak check.

    >>

    GO TO 13

    .

  13. CHECK THROTTLE POSITION SENSOR 

    Check the following with the freeze frame data of DTC P0101

    ENGINE SPEED Idling speed
    VEHICL 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. Refer to Work Procedure .

    NO>>

    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>>

    Check intermittent Incident. Refer to Inspection .

    NO>>

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

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