2004 Infiniti FX45FACTORY OEM SERVICE PROCEDURE

Diagnostic Procedure

  1. Check Exhaust System 

    Visually check exhaust tubes and muffler for dent.

    OK or NG

    1. OK: go to 2.
    2. NG: Repair or replace.

  2. Check Exhaust Gas Leak 
    1. Start engine and run it at idle.
    2. Listen for an exhaust gas leak before the three way catalyst (manifold). See Figure .

    OK or NG

    1. OK: go to 3.
    2. NG: Repair or replace.

  3. Check Intake Air Leak 

    Listen for an intake air leak after the mass air flow sensor.

    OK or NG

    1. OK: go to 4.
    2. NG: Repair or replace.

  4. Check Ignition Timing 

    Check the following items. Refer to BASIC INSPECTION  .

    For ignition timing specifications, see Figure .

    OK or NG

    1. OK: go to 5.
    2. NG: Follow the BASIC INSPECTION  .

  5. Check Injectors 
    1. Stop engine and then turn ignition switch ON.
    2. Check voltage between ECM terminals 21, 22, 23, 40, 41, 42, 44, 63 and ground with CONSULT-II or tester.

      Refer to wiring diagram for Injectors, WIRING DIAGRAM  .

      1. Battery voltage should exist  .

    OK or NG

    1. OK: go to 6.
    2. NG: Perform DIAGNOSTIC PROCEDURE  .
      Fig 1: Testing Fuel Injector At ECM Connector (W/DVOM)
      G00344941Courtesy of NISSAN MOTOR CO., U.S.A.

  6. CHECK IGNITION SPARK 
    1. Turn ignition switch OFF.
    2. Remove ignition coil assembly from rocker cover.
    3. Remove spark plug from ignition coil assembly.
    4. Connect a known-good spark plug to the ignition coil assembly.
    5. Disconnect all injector harness connectors.
    6. Place end of spark plug against a suitable ground and crank engine.
    7. Check for spark.

    OK or NG

    1. OK: go to 7.
    2. NG: Check ignition coil with power transistor and their circuit. Refer to IGNITION SIGNAL  .
      Fig 2: Locating Ignition Coil
      G00344942Courtesy of NISSAN MOTOR CO., U.S.A.
  7. Check Injector 
    1. Turn ignition switch OFF.
    2. Remove injector assembly.

      Refer to FUEL INJECTOR AND FUEL TUBE .

      Keep fuel hose and all injectors connected to injector gallery.

    3. Disconnect all ignition coil harness connectors.
    4. Reconnect injector harness connectors.
    5. Turn ignition switch ON.

      Make sure fuel does not drip from injector.

    OK or NG

    1. OK (Does not drip.): go to 8.
    2. NG (Drips.): Replace the injector(s) from which fuel is dripping.

  8. Check Intermittent Incident 

    Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT  .

    1. Trouble is fixed. Inspection end 
    2. Trouble is not fixed: Replace three way catalyst assembly.
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

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.