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Home >> Infiniti >> 2008 >> QX56 AWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System - DTCS U1000 To P0308 >> DTC P0102, P0103: MAF Sensor >> Diagnosis Procedure
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Diagnosis Procedure

  1. INSPECTION START

    Which malfunction (P0102 or P0103) is duplicated?

    P0102 or P0103 

    P0102: GO TO 2.

    P0103: GO TO  3.

  2. CHECK INTAKE SYSTEM

    Check the following for connection.

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

    OK or NG 

    OK: GO TO 3.

    NG: Reconnect the parts.

  3. CHECK GROUND CONNECTIONS
    1. Turn ignition switch OFF.
    2. Loosen and retighten three ground screws on the body.

      Refer to "GROUND INSPECTION ".

      Fig 1: Identifying Body Ground Screw
      G05739355Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO 4.

    NG: Repair or replace ground connections.

  4. CHECK MAF SENSOR POWER SUPPLY CIRCUIT
    1. Disconnect mass air flow (MAF) sensor harness connector.
    2. Turn ignition switch ON.
      Fig 2: Identifying Mass Air Flow (MAF) Sensor Harness Connector
      G05739356Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between MAF sensor terminal 2 and ground with CONSULT-III or tester.

      Voltage: Battery voltage 

      Fig 3: Checking Voltage Between MAF Sensor Terminal 2 And Ground
      G05739357Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  6.

    NG: GO TO 5.

  5. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness connectors E2, F32
    • Harness for open or short between IPDM E/R and mass air flow sensor
    • Harness for open or short between mass air flow sensor and ECM

    Repair harness or connectors.

  6. CHECK MAF SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check harness continuity between MAF sensor terminal 3 and ECM terminal 67.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

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

    OK or NG 

    OK: GO TO 7.

    NG: Repair open circuit or short to ground or short to power in harness or connectors.

  7. CHECK MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
    1. Check harness continuity between MAF sensor terminal 4 and ECM terminal 51.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

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

    OK or NG 

    OK: GO TO 8.

    NG: Repair open circuit or short to ground or short to power in harness or connectors.

  8. CHECK MASS AIR FLOW SENSOR

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    OK: GO TO 9.

    NG: Replace mass air flow sensor.

  9. CHECK INTERMITTENT INCIDENT

    Refer to "HOW TO CHECK TERMINAL " and "INTERMITTENT INCIDENT ".

    INSPECTION END 

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