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Home >> Infiniti >> 2004 >> I35 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System >> DTC P0102, P0103: MAF Sensor >> Diagnostic Procedure
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Diagnostic Procedure

  1. INSPECTION START 

    Which malfunction (P0102 or P0103) is duplicated?

    P0102 or P0103 

    1. P0103: GO TO  3 .
    2. P0102: GO TO 2.
  2. CHECK INTAKE SYSTEM 

    Check the following for connection.

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

    OK or NG 

    1. OK: GO TO 3.
    2. NG: Reconnect the parts.
  3. RETIGHTEN GROUND SCREWS 
    1. Turn ignition switch OFF.
    2. Loosen and retighten engine ground screws. See Figure .
    1. : GO TO 4.
  4. CHECK MAF SENSOR POWER SUPPLY CIRCUIT 
    1. Disconnect mass air flow (MAF) sensor harness connector.
      Fig 1: Identifying Mass Air Flow Sensor
      G00786544Courtesy 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.
    Fig 2: Checking Voltage Between MAF Sensor Terminals & Ground
    G00786545Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO  6 .
    2. NG: GO TO 5.
  5. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E15, F18
    • Harness for open or short between ECM relay and mass air flow sensor
    • Harness for open or short between mass air flow sensor and ECM
    1. : 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 80. Refer to Wiring Diagram.

      Continuity should exist. 

    4. Also check harness for short to power.

    OK or NG 

    1. OK: GO TO 7.
    2. NG: Repair open circuit 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 62. Refer to Wiring Diagram.

      Continuity should exist. 

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

    OK or NG 

    1. OK: GO TO 8.
    2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
  8. CHECK MASS AIR FLOW SENSOR 
    1. Reconnect harness connectors disconnected.
    2. Start engine and warm it up to normal operating temperature.
    3. Check voltage between ECM terminal 62 (Mass air flow sensor signal) and ground.
      Fig 3: Checking Voltage Between ECM Terminal And Ground
      G00786546Courtesy of NISSAN MOTOR CO., U.S.A.
    4. If the voltage is out of specification, disconnect MAF sensor harness connector and connect it again. Then repeat above check.

    OK or NG 

    1. OK: GO TO 9.
    2. NG: Replace mass air flow sensor.
  9. CHECK INTERMITTENT INCIDENT 

    Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT  .

    1. : INSPECTION END 
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