2004 Infiniti FX45FACTORY OEM SERVICE PROCEDURE

Overall Function Check

Use this procedure to check the overall function of the heated oxygen sensor 2 circuit. During this check, a 1st trip DTC might not be confirmed.

With GST 

  1. Start engine and warm it up to the normal operating temperature.
  2. Turn ignition switch OFF and wait at least 10 seconds.
  3. Start engine and keep the engine speed between 3,500 and 4,000 RPM for at least 1 minute under no load.
  4. Let engine idle for 1 minute.
  5. Set voltmeter probes between ECM terminal 55 [HO2S2 (B1) signal] or 74 [HO2S2 (B2) signal] and ground. See Figure .
  6. Check the voltage when revving up to 4,000 RPM under no load at least 10 times.

    (Depress and release accelerator pedal as soon as possible.)

    A change of voltage should be more than 0.06V for 1 second during this procedure  .

    If the voltage can be confirmed in step 6, step 7 is not necessary  .

  7. Keep vehicle at idling for 10 minutes, then check the voltage. Or check the voltage when coasting from 80 km/h (50 MPH) in D position with OD OFF.

    A change of voltage should be more than 0.06V for 1 second during this procedure  .

  8. If NG, go to DIAGNOSTIC PROCEDURE  .

Factory Service Tools

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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.