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P1509 – Infiniti DTC

Infiniti DTC P1509 – IAC System RPM High

DTC P1509 meaning on Infiniti

DTC P1509 on an Infiniti indicates an issue with the Idle Air Control (IAC) System RPM being too high. The Engine Control Module (ECM) detects that the engine idle speed is higher than expected.

Infiniti DTC P1509 symptoms

  • High idle speed
  • Engine stalling at idle
  • Possible rough idle
  • Check Engine Light illuminated

Infiniti DTC P1509 causes

  • Dirty or faulty Idle Air Control (IAC) valve
  • Vacuum leaks
  • Throttle body issues
  • Wiring or connector problems in the IAC circuit

Infiniti DTC P1509 seriousness

The seriousness of DTC P1509 on an Infiniti depends on the underlying cause. If left unresolved, it can lead to poor engine performance, reduced fuel efficiency, and potential stalling issues.

How to diagnose DTC P1509 on Infiniti

  1. Use a scan tool to retrieve the DTC and freeze frame data
  2. Inspect the IAC valve for dirt or carbon buildup
  3. Check for vacuum leaks in the intake system
  4. Inspect the throttle body for any issues
  5. Test the IAC valve and related wiring for proper operation

How to fix DTC P1509 on Infiniti

  1. Clean or replace the IAC valve if dirty or faulty
  2. Repair any vacuum leaks in the intake system
  3. Clean the throttle body if necessary
  4. Repair or replace any damaged wiring or connectors in the IAC circuit
  5. Perform an idle relearn procedure after repairs

How to erase DTC P1509 on Infiniti

  1. Use a scan tool to clear the DTC and reset the ECM
  2. Ensure the underlying issue has been resolved before clearing the code
  3. Perform a road test to verify the repair and ensure the DTC does not return

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← All Infiniti Diagnostic Trouble Codes

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