2004 Infiniti Q45FACTORY OEM SERVICE PROCEDURE

With GST

  1. Start engine and warm it up to normal operating temperature.
  2. Turn ignition switch OFF and wait at least 10 seconds.
  3. Disconnect mass air flow sensor harness connector. Then restart and let it idle for at least 5 seconds at idle speed.
  4. Stop engine and reconnect mass air flow sensor harness connector.
  5. Select "MODE 3" with GST. Make sure DTC P0102 is detected.
  6. Select "MODE 4" with GST and erase the DTC P0102.
  7. Start engine again and let it idle for at least 10 minutes.
  8. Select "MODE 7" with GST. The 1st trip DTC P0171 or P0174 should be detected at this stage, if a malfunction exists. If so, go to Diagnostic Procedure  .
  9. If it is difficult to start engine at step 7, the fuel injection system has a malfunction.
  10. Crank engine while depressing accelerator pedal. If engine starts, go to Diagnostic Procedure  . If engine does not start, check exhaust and intake air leak visually.
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.

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