2009 Infiniti QX56 AWDFACTORY OEM SERVICE PROCEDURE

Diagnosis Procedure

  1. INSPECTION START

    Turn ignition switch to START.

    Is any cylinder ignited? 

    Yes or No 

    YES: GO TO 2.

    No: GO TO  3.

  2. CHECK OVERALL FUNCTION

    With CONSULT-III 

    1. Start engine.
    2. Perform "POWER BALANCE" in "ACTIVE TEST" mode with CONSULT-III.
    3. Make sure that each circuit produces a momentary engine speed drop.

    Without CONSULT-III 

    1. Start engine.
    2. Listen to each fuel injector operating sound.

      Clicking noise should be heard. 

      Fig 1: Checking Fuel Injector Operating Sound
      G06315841Courtesy of NISSAN MOTOR CO., U.S.A.

      OK or NG 

      OK: INSPECTION END 

      NG: GO TO 3.

  3. CHECK FUEL INJECTOR POWER SUPPLY CIRCUIT
    1. Turn ignition switch OFF.
    2. Disconnect fuel injector harness connector.
      Fig 2: Identifying Fuel Injector Harness Connectors
      G06315842Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Turn ignition switch ON.
    4. Check voltage between fuel injector terminal 1 and ground with CONSULT-III or tester.

      Voltage: Battery voltage 

      OK or NG 

      OK: GO TO  5.

      NG: GO TO 4.

      Fig 3: Checking Voltage Between Fuel Injector Terminal 1 And Ground
      G06315843Courtesy of NISSAN MOTOR CO., U.S.A.
  4. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness connectors E2, F32
    • IPDM E/R connector E119
    • 15A fuse
    • Harness for open or short between fuel injector and fuse

      Repair harness or connectors.

  5. CHECK FUEL INJECTOR OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check harness continuity between fuel injector terminal 2 and ECM terminals 21, 22, 23, 40, 41, 42, 44, 63.

      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 6.

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

  6. CHECK FUEL INJECTOR

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    OK: GO TO 7.

    NG: Replace malfunctioning fuel injector.

  7. CHECK INTERMITTENT INCIDENT

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

    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.