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Home >> Infiniti >> 2021 >> QX80 Premium Select, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTCS) (3 Of 5) >> Engine (ECM) >> DTC P0507: ISC System >> DTC Diagnosis Procedure
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DTC Diagnosis Procedure

  1. CHECK PCV HOSE CONNECTION 

    Confirm that PCV hose is connected correctly.

    Is the inspection result normal?

    YES

    GO TO 2.

    NO

    Repair or replace malfunctioning part.

  2. CHECK INTAKE AIR LEAKAGE 
    1. Start engine and let it idle.
    2. Listen for an intake air leakage after the mass air flow sensor.

    Is intake air leakage detected?

    YES

    Discover air leakage location and repair.

    NO

    GO TO 3.

  3. REPLACE ECM 
    1. Stop engine.
    2. Replace ECM.
    3. Perform additional service when replacing ECM. Refer to Work Procedure .

    INSPECTION END