LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Infiniti >> 2014 >> Q50 Base, RWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS P0171 To P0463 (Except Hybrid) >> DTC P0456: EVAP Control System >> Component Inspection
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Component Inspection

  1. CHECK FUEL TANK VACUUM RELIEF VALVE 
    1. Turn ignition switch OFF.
    2. Remove fuel filler cap.
    3. Wipe clean valve housing.
      Fig 1: Identifying Pressure And Vacuum Valves, Spring Gasket And Plate
      G09160136Courtesy of NISSAN NORTH AMERICA, INC.
    4. Check valve opening pressure and vacuum.

      Pressure: 15.3 - 20.0 kPa (0.156 - 0.204 kg/cm 2  , 2.22 - 2.90 psi) 

      Vacuum: -6.0 to -3.3 kPa (-0.061 to -0.034 kg/cm 2  , -0.87 to -0.48 psi) 

      Is the inspection result normal? 

      YES: INSPECTION END

      NO: GO TO 2.

      Fig 2: Checking Valve Opening Pressure And Vacuum
      G09160137Courtesy of NISSAN NORTH AMERICA, INC.
  2. REPLACE FUEL FILLER CAP 

    Replace fuel filler cap.

    CAUTION: Use only a genuine fuel filler cap as a replacement. If an incorrect fuel filler cap is used, the MIL may illuminate.

    : INSPECTION END