2004 Infiniti FX45FACTORY OEM SERVICE PROCEDURE

Diagnostic Procedure

  1. Inspection Start 

    Which malfunction (A or B) is duplicated?

    A or B

    1. A: go to  3 .
    2. B: 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

    OK or NG

    1. OK: go to  3 .
    2. NG: Reconnect the parts.

  3. Check Ground Connections 
    1. Turn ignition switch OFF.
    2. Loosen and retighten three ground screws on the body. See Figure .

      Refer to GROUND INSPECTION  .

    OK or NG

    1. OK: go to  4 .
    2. NG: Repair or replace ground connections.
  4. Check MAF Sensor Power Supply Circuit 
    1. Disconnect mass air flow (MAF) sensor harness connector.

      For mass air flow sensor & intake air temperature sensor location, see Figure .

    2. Turn ignition switch ON.
    3. Check voltage between MAF sensor terminals 2, 4 and ground with CONSULT-II or tester.
      Fig 1: Checking Voltage At Mass Air Flow Sensor Terminals 2 & 4 (W/DVOM)
      G00344647Courtesy of NISSAN MOTOR CO., U.S.A.
      MASS AIR FLOW SENSOR VOLTAGE SPECIFICATIONS

      Terminal Voltage
      2 5 Approximately Volts
      4 Battery Voltage

    OK or NG

    1. OK: go to  6 .
    2. NG: go to  5 .

  5. Detect Malfunctioning Part 

    Check the following.

    • Harness connectors E211, M41
    • Harness connectors M82, F102
    • 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
      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 67. Refer to wiring diagram. See Figure .
      1. Continuity should exist  .
    4. Also check harness for short to ground and short to power.

    OK or NG

    1. OK: go to  7 .
    2. 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 51.

      Refer to wiring diagram. See Figure .

      1. 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 

    Refer to COMPONENT INSPECTION  .

    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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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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