FixVault
Home › Infiniti › 2011 › QX56 AWD › Repair and Diagnosis › Engine Performance › System › Engine Control System - DTCS U0101 Through P0153 › DTC P006A, P0101: MAF Sensor › Diagnosis Procedure

Diagnosis Procedure

  1. CHECK INTAKE SYSTEM

    Check the following for connection.

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

      Is the inspection result normal? 

      YES: GO TO 2.

      NO: Reconnect the parts.

  2. 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 SPECIFICATION

      Mass air flow sensor Ground Voltage
      Connector Terminal
      F31 5 Ground Battery voltage

      Is the inspection result normal? 

      YES: GO TO  4.

      NO: GO TO 3.

  3. 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 open circuit, short to ground or short to power in harness or connectors.

  4. 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.
      CONTINUITY SPECIFICATION

      Mass air flow sensor ECM Continuity
      Connector Terminal Connector Terminal
      F31 4 F111 25 Existed
    4. Also check harness for short to ground and short to power.

      Is the inspection result normal? 

      YES: GO TO 5.

      NO: Repair open circuit, short to ground or short to power in harness or connectors.

  5. 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.
      CONTINUITY SPECIFICATION

      Mass air flow sensor ECM Continuity
      Connector Terminal Connector Terminal
      F31 3 F111 22 Existed
    2. Also check harness for short to ground and short to power.

      Is the inspection result normal? 

      YES: GO TO 6.

      NO: Repair open circuit, short to ground or short to power in harness or connectors.

  6. CHECK MANIFOLD ABSOLUTE PRESSURE SENSOR

    Check manifold absolute pressure sensor. Refer to "COMPONENT INSPECTION (MAP SENSOR) ".

    Is the inspection result normal? 

    YES: GO TO 7.

    NO: Replace manifold absolute pressure sensor. Refer to "REMOVAL AND INSTALLATION ".

  7. CHECK INTAKE AIR TEMPERATURE SENSOR

    Check intake air temperature sensor. Refer to "COMPONENT INSPECTION (INTAKE AIR TEMPERATURE SENSOR) ".

    Is the inspection result normal? 

    YES: GO TO 8.

    NO: Replace mass air flow sensor (with intake air temperature sensor). Refer to "REMOVAL AND INSTALLATION ".

  8. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

    Refer to "COMPONENT INSPECTION (EVAP CONTROL SYSTEM PRESSURE SENSOR) ".

    Is the inspection result normal? 

    YES-1 (Only DTC P006A is detected): GO TO 9.

    YES-2 (DTC P006A and P0101 are detected): GO TO  10.

    NO: Replace EVAP control system pressure sensor. Refer to "REMOVAL AND INSTALLATION ".

  9. CHECK MASS AIR FLOW SENSOR

    Refer to "COMPONENT INSPECTION (MAF SENSOR) ".

    Is the inspection result normal? 

    YES: GO TO  11.

    NO: Replace mass air flow sensor.

  10. CHECK MASS AIR FLOW SENSOR

    Check mass air flow sensor. Refer to "COMPONENT INSPECTION (MAF SENSOR) ".

    Is the inspection result normal? 

    YES: GO TO 11.

    NO: Replace mass air flow sensor. Refer to "REMOVAL AND INSTALLATION ".

  11. CHECK INTERMITTENT INCIDENT

    Refer to "INTERMITTENT INCIDENT ".

    INSPECTION END

About FixVault