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Home >> Infiniti >> 2004 >> M45 >> Repair and Diagnosis >> Engine Performance >> Engine Control System >> DTC P0101: MAF Sensor >> Diagnostic Procedure
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Diagnostic Procedure

  1. Inspection Start 

    Which malfunction (A or B) is duplicated?

    1. A or B 
    2. A: GO TO  3.
    3. B: GO TO 2.
  2. Check Intake System 

    Check the following for connection.

    • Air duct
    • Vacuum hoses
    • Intake air passage between air duct and intake manifold
    1. OK or NG 
    2. OK: GO TO 3.
    3. NG: Reconnect the parts.
  3. Check Ground Connections 
    1. Turn ignition switch OFF.
    2. Loosen and retighten two ground screws.

      Refer to GROUND INSPECTION .

    1. OK or NG 
    2. OK: GO TO 4.
    3. NG: Repair or replace ground connections.
  4. Check MAF Sensor Power Supply Circuit 
    1. Disconnect mass air flow (MAF) sensor harness connector.
      Fig 1: Locating Mass Air Flow Sensor
      G00795717Courtesy of NISSAN MOTOR CO., U.S.A.
    2. Turn ignition switch ON.
    3. Check voltage between MAF sensor terminals 2, 4 and ground with CONSULT-II or tester.
    1. OK or NG 
    2. OK: GO TO  6.
    3. NG: GO TO 5.
  5. Detect Malfunctioning Part 

    Check the following.

    • Harness connectors M135, F105
    • Harness for open or short between mass air flow sensor and ECM relay
    • Harness for open or short between mass air flow sensor and ECM
    1. : Repair open circuit or short to ground or short to power in 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 109.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

    4. Also check harness for short to ground and short to power.
    1. OK or NG 
    2. OK: GO TO 7.
    3. 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 1 and ECM terminal 91.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

    2. Also check harness for short to ground and short to power.
    1. OK or NG 
    2. OK: GO TO 8.
    3. 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 

    1. OK or NG 
    2. OK: GO TO 9.
    3. NG: Replace mass air flow sensor.
  9. Check Intermittent Incident 

    Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .

    1. : INSPECTION END 
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