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Home >> Lexus >> 2007 >> LS 460 >> Repair and Diagnosis >> External Pages >> Different car >> Section 236 (Engine Control System) >> DTC P0456: EVAP Control System >> Diagnostic Procedure
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Diagnostic Procedure

WARNING: This page is about a different car, the 2005 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK FUEL FILLER CAP DESIGN 
    1. Turn ignition switch OFF.
    2. Check for genuine NISSAN fuel filler cap design.

    OK or NG

    • OK: GO TO 2.
    • NG: Replace with genuine NISSAN fuel filler cap.
      Fig 1: Identifying Fuel Filler Cap
      G02474184Courtesy of NISSAN MOTOR CO., U.S.A.
  2. CHECK FUEL FILLER CAP INSTALLATION 

    Check that the cap is tightened properly by rotating the cap clockwise.

    OK or NG

    • OK: GO TO 3.
    • NG:
      1. Open fuel filler cap, then clean cap and fuel filler neck threads using air blower.
      2. Retighten until ratcheting sound is heard.
  3. CHECK FUEL FILLER CAP FUNCTION 

    Check for air releasing sound while opening the fuel filler cap.

    OK or NG

    • OK: GO TO  5.
    • NG: GO TO 4.
  4. CHECK FUEL TANK VACUUM RELIEF VALVE 

    Refer to "FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FULLER CAP) ".

    OK or NG

    • OK: GO TO 5.
    • NG: Replace fuel filler cap with a genuine one.
  5. INSTALL THE PRESSURE PUMP 

    To locate the EVAP leak, install EVAP service port adapter and pressure pump to EVAP service port securely.

    NOTE: Improper installation of the EVAP service port adapter to the EVAP service port may cause leaking.
    Fig 2: Locating EVAP Service Port
    G02474185Courtesy of NISSAN MOTOR CO., U.S.A.
    Fig 3: Installing Pressure Pump
    G02474186Courtesy of NISSAN MOTOR CO., U.S.A.
    • Models with CONSULT-II: GO TO 6.
    • Models without CONSULT-II: GO TO  7.
  6. CHECK FOR EVAP LEAK 

    With CONSULT-II 

    1. Turn ignition switch ON.
    2. Select "EVAP SYSTEM CLOSE" of "WORK SUPPORT" mode with CONSULT-II.
      Fig 4: CONSULT-II EVAP System Close Display
      G02474187Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Touch "START" and apply pressure into the EVAP line until the pressure indicator reaches the middle of the bar graph.
      NOTE:
      • Never use compressed air or a high pressure pump.
      • Do not exceed 4.12 kPa (0.042 kg/cm2 , 0.6 psi) of pressure in the system.
    4. Using EVAP leak detector, locate the EVAP leak. For the leak detector, refer to leak detector instruction manual for more details.
      Fig 5: Identifying Leak Detector
      G02474188Courtesy of NISSAN MOTOR CO., U.S.A.

      Refer to "EVAPORATIVE EMISSION LINE DRAWING ".

    OK or NG

    • OK: GO TO  8.
    • NG: Repair or replace.
  7. CHECK FOR EVAP LEAK 

    Without CONSULT-II 

    1. Turn ignition switch OFF.
    2. Apply 12 volts DC to EVAP canister vent control valve. The valve will close. (Continue to apply 12 volts until the end of test.)
      Fig 6: Locating EVAP Canister Vent Control Valve
      G02474189Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Pressurize the EVAP line using pressure pump with 1.3 to 2.7 kPa (10 to 20 mmHg, 0.39 to 0.79 inHg), then remove pump and EVAP service port adapter.
      NOTE:
      • Never use compressed air or a high pressure pump.
      • Do not exceed 4.12 kPa (0.042 kg/cm2 , 0.6 psi) of pressure in the system.
    4. Using EVAP leak detector, locate the EVAP leak. For the leak detector, refer to leak detector instruction manual for more details. Refer to "EVAPORATIVE EMISSION LINE DRAWING ".
      Fig 7: Identifying Leak Detector
      G02474190Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    • OK: GO TO 8.
    • NG: Repair or replace.
  8. CHECK EVAP CANISTER VENT CONTROL VALVE 

    Check the following.

    OK or NG

    • OK: GO TO 9.
    • NG: Repair or replace EVAP canister vent control valve and O-ring.
  9. CHECK IF EVAP CANISTER SATURATED WITH WATER 
    1. Remove EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor attached.
    2. Does water drain from the EVAP canister?
      Fig 8: Checking EVAP Canister Saturated With Water
      G02474191Courtesy of NISSAN MOTOR CO., U.S.A.

    Yes or No

    • Yes: GO TO 10.
    • No (With CONSULT-II): GO TO  12.
    • No (Without CONSULT-II): GO TO  13.
  10. CHECK EVAP CANISTER 

    Weigh the EVAP canister with the EVAP canister vent control valve and EVAP control system pressure sensor attached.

    The weight should be less than 2.1 kg (4.6 lb). 

    OK or NG

    • OK (With CONSULT-II): GO TO  12.
    • OK (Without CONSULT-II): GO TO  13.
    • NG: GO TO 11.
  11. DETECT MALFUNCTIONING PART 

    Check the following.

    • EVAP canister for damage
    • EVAP hose between EVAP canister and vehicle frame for clogging or poor connection
    • : Repair hose or replace EVAP canister.
  12. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION 

    With CONSULT-II 

    1. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port.
    2. Start engine.
    3. Perform "PURG VOL CONT/V" in "ACTIVE TEST" mode.
      Fig 9: CONSULT-II Active Test Display
      G02474192Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Touch "Qu" on CONSULT-II screen to increase "PURG VOL CONT/V" opening to 100%.
    5. Check vacuum hose for vacuum when revving engine up to 2, 000 RPM.

    OK or NG

    • OK: GO TO  15.
    • NG: GO TO  14.
  13. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION 

    Without CONSULT-II 

    1. Start engine and warm it up to normal operating temperature.
    2. Stop engine.
    3. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port.
    4. Start engine and let it idle for at least 80 seconds.
    5. Check vacuum hose for vacuum when revving engine up to 2, 000 RPM.
      • Vacuum should exist. 

    OK or NG

    • OK: GO TO  16.
    • NG: GO TO 14.
  14. CHECK VACUUM HOSE 

    Check vacuum hoses for clogging or disconnection. Refer to "VACUUM HOSE DRAWING ".

    OK or NG

    • OK: GO TO 15.
    • NG: Repair or reconnect the hose.
  15. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE 

    Refer to "COMPONENT INSPECTION ".

    OK or NG

    • OK: GO TO 16.
    • NG: Replace EVAP canister purge volume control solenoid valve.
  16. CHECK FUEL TANK TEMPERATURE SENSOR 

    Refer to "COMPONENT INSPECTION ".

    OK or NG

    • OK: GO TO 17.
    • NG: Replace fuel level sensor unit.
  17. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR 

    Refer to "COMPONENT INSPECTION ".

    OK or NG

    • OK: GO TO 18.
    • NG: Replace EVAP control system pressure sensor.
  18. CHECK EVAP PURGE LINE 

    Check EVAP purge line (pipe, rubber tube, fuel tank and EVAP canister) for cracks or improper connection.

    Refer to "EVAPORATIVE EMISSION LINE DRAWING ".

    OK or NG

    • OK: GO TO 19.
    • NG: Repair or reconnect the hose.
  19. CLEAN EVAP PURGE LINE 

    Clean EVAP purge line (pipe and rubber tube) using air blower.

    • : GO TO 20.
  20. CHECK EVAP/ORVR LINE 

    Check EVAP/ORVR line between EVAP canister and fuel tank for clogging, kink, looseness and improper connection. For location, refer to "ON BOARD REFUELING VAPOR RECOVERY (ORVR) ".

    OK or NG

    • OK: GO TO 21.
    • NG: Repair or replace hoses and tubes.
  21. CHECK RECIRCULATION LINE 

    Check recirculation line between filler neck tube and fuel tank for clogging, kink, cracks, looseness and improper connection.

    OK or NG

    • OK: GO TO 22.
    • NG: Repair or replace hose, tube or filler neck tube.
  22. CHECK REFUELING EVAP VAPOR CUT VALVE 

    Refer to "COMPONENT INSPECTION ".

    OK or NG

    • OK: GO TO 23.
    • NG: Replace refueling EVAP vapor cut valve with fuel tank.
  23. CHECK FUEL LEVEL SENSOR 

    Refer to "FUEL LEVEL SENSOR UNIT CHECK ".

    OK or NG

    • OK: GO TO 24.
    • NG: Replace fuel level sensor unit.
  24. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    • : INSPECTION END 
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