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Home >> Infiniti >> 2021 >> QX80 Premium Select, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTCS) (1 Of 5) >> Engine (ECM) >> DTC P0018: Intake Valve Timing Control >> DTC Diagnosis Procedure

DTC Diagnosis Procedure

  1. CHECK OIL PRESSURE WARNING LAMP 
    1. Start engine.
    2. Check that oil pressure warning lamp is not illuminated.
      G04073790Courtesy of NISSAN NORTH AMERICA, INC.

    Is oil pressure warning lamp illuminated?

    YES

    Refer to ENGINE OIL : Inspection .

    NO

    GO TO 2.

  2. CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE 

    Refer to Component Inspection .

    Is the inspection result normal?

    YES

    GO TO 3.

    NO

    Replace malfunctioning intake valve timing control solenoid valve. Refer to TIMING CHAIN : Exploded View .

  3. CHECK CRANKSHAFT POSITION SENSOR 

    Refer to Component Inspection .

    Is the inspection result normal?

    YES

    GO TO 4.

    NO

    Replace crankshaft position sensor. Refer to CYLINDER BLOCK : Exploded View .

  4. CHECK CAMSHAFT POSITION SENSOR 

    Refer to Component Inspection .

    Is the inspection result normal?

    YES

    GO TO 5.

    NO

    Replace malfunctioning camshaft position sensor. Refer to CYLINDER BLOCK : Exploded View .

  5. CHECK CAMSHAFT (INTAKE) 

    Check the following.

    • Accumulation of debris on the signal plate of camshaft front end
      GNSJMBIA0962Z-962Courtesy of NISSAN NORTH AMERICA, INC.
    • Chipping signal plate of camshaft front end

    Is the inspection result normal?

    YES

    GO TO 6.

    NO

    Remove debris and clean the signal plate of camshaft front end or replace camshaft. Refer to TIMING CHAIN : Exploded View . or Refer to CAMSHAFT : Removal & Installation .

  6. CHECK TIMING CHAIN INSTALLATION 

    Check service records for any recent repairs that may cause timing chain misalignment.

    Are there any service records that may cause timing chain misalignment?

    YES

    Check timing chain installation. Refer to CAMSHAFT : Removal & Installation .

    NO

    GO TO 7.

  7. CHECK LUBRICATION CIRCUIT 

    Perform "Inspection of Camshaft Sprocket (INT) Oil Groove". Refer to CAMSHAFT : Inspection .

    Is the inspection result normal?

    YES

    GO TO 8.

    NO

    Clean lubrication line.

  8. CHECK INTERMITTENT INCIDENT 

    Refer to Inspection .

    INSPECTION END