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Home >> Infiniti >> 2004 >> I35 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System >> DTC P1456: EVAP Control System >> Diagnostic Procedure
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Diagnostic Procedure

  1. CHECK FUEL FILLER CAP DESIGN 
    1. Turn ignition switch OFF.
    2. Check for genuine NISSAN fuel filler cap design. See Figure

      OK or NG 

    1. OK: GO TO 2.
    2. NG: Replace with genuine NISSAN fuel filler cap.
  2. CHECK FUEL FILLER CAP INSTALLATION 

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

    OK or NG 

    1. OK: GO TO 3.
    2. 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 

    1. OK: GO TO  5 .
    2. NG: GO TO 4.
  4. CHECK FUEL TANK VACUUM RELIEF VALVE 
    1. Wipe clean valve housing.
    2. Check valve opening pressure and vacuum. See Figure and Figure .

      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  )

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

      OK or NG 

    1. OK: GO TO 5.
    2. 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. See Figure and Figure .

    NOTE: Improper installation of the EVAP service port adapter to the EVAP service port may cause leaking.
    1. Models with CONSULT-II: GO TO 6.
    2. 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.
    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.
      Fig 1: Displaying CONSULT-II EVAP SYSTEM CLOSE Screen
      G00787275Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Using EVAP leak detector, locate the EVAP leak. For the leak detector, refer to the instruction manual for more details. See Figure .

      Refer to EVAPORATIVE EMISSION LINE DRAWING  .

      Fig 2: Identifying EVAP Leak Detector
      G00787276Courtesy of NISSAN MOTOR CO., U.S.A.

      OK or NG 

    1. OK: GO TO  8 .
    2. 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.)
    3. Apply 12 volts DC to vacuum cut valve bypass valve. The valve will open. (Continue to apply 12V until the end of test.)
      Fig 3: Checking For EVAP Leak Without CONSULT-II
      G00787277Courtesy of NISSAN MOTOR CO., U.S.A.
    4. 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.
    5. Using EVAP leak detector, locate the EVAP leak. For the leak detector, refer to the instruction manual for more details. See Figure .

      Refer to EVAPORATIVE EMISSION LINE DRAWING  .

      OK or NG 

    1. OK: GO TO 8.
    2. NG: Repair or replace.
  8. CHECK WATER SEPARATOR 
    1. Check visually for insect nests in the water separator air inlet.
    2. Check visually for cracks or flaws in the appearance.
    3. Check visually for cracks or flaws in the hose.
    4. Check that and are not clogged by blowing air into with , and then plugged. See Figure .
    5. In case of NG in items 2 - 4, replace the parts.
      NOTE: Do not disassemble water separator.

      OK or NG 

    1. OK: GO TO 9.
    2. NG: Replace water separator.
  9. CHECK EVAP CANISTER VENT CONTROL VALVE, O-RING AND CIRCUIT 

    Refer to DTC P1448 EVAP CANISTER VENT CONTROL VALVE  .

    OK or NG 

    1. OK: GO TO 10.
    2. NG: Repair or replace EVAP canister vent control valve and O-ring or harness/connector.
  10. CHECK IF EVAP CANISTER SATURATED WITH WATER 
    1. Remove EVAP canister with EVAP canister vent control valve attached.
    2. Does water drain from the EVAP canister? See Figure

      Yes or No 

    1. Yes: GO TO 11.
    2. No (With CONSULT-II): GO TO  13 .
    3. No (Without CONSULT-II): GO TO  14 .
  11. CHECK EVAP CANISTER 

    Weigh the EVAP canister with the EVAP canister vent control valve attached.

    The weight should be less than 1.8 kg (4.0 lb). 

    OK or NG 

    1. OK (With CONSULT-II-): GO TO  13 .
    2. OK (With CONSULT-II): GO TO  14 .
    3. NG: GO TO 12.
  12. DETECT MALFUNCTIONING PART 

    Check the following.

    • EVAP canister for damage
    • EVAP hose between EVAP canister and water separator for clogging or poor connection
    1. : Repair hose or replace EVAP canister.
  13. 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.
    4. Touch Qu on CONSULT-II screen to increase PURG VOL CONT/V opening to 100.0%.
    5. Check vacuum hose for vacuum when revving engine up to 2,000 rpm. See Figure .

      Vacuum should exist. 

      OK or NG 

    1. OK: GO TO  16 .
    2. NG: GO TO  15 .
  14. 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 

    1. OK: GO TO  17 .
    2. NG: GO TO 15.
  15. CHECK VACUUM HOSE 

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

    OK or NG 

    1. OK (With CONSULT-II): GO TO 16.
    2. OK (Without CONSULT-II): GO TO  17 .
    3. NG: Repair or reconnect the hose.
  16. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE 

    Without CONSULT-II 

    1. Start engine.
    2. Perform PURG VOL CONT/V in ACTIVE TEST mode with CONSULT-II. Check that engine speed varies according to the valve opening. See Figure .

      OK or NG 

    1. OK: GO TO  18 .
    2. NG: GO TO 17.
  17. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALUE 

    With CONSULT-II 

    Check air passage continuity of EVAP canister purge volume control solenoid valve under the following conditions. See Figure and Figure .

    Without CONSULT-II 

    Check air passage continuity of EVAP canister purge volume control solenoid valve under the following conditions. See Figure and Figure .

    OK or NG 

    1. OK: GO TO 18.
    2. NG: Replace EVAP canister purge volume control solenoid valve.
  18. CHECK FUEL TANK TEMPERATURE SENSOR 
    1. Remove fuel level sensor unit.
    2. Check resistance between fuel level sensor unit and fuel pump terminals 4 and 5 by heating with hot water or heat gun as shown in Figure .

      OK or NG 

    1. OK: GO TO 19.
    2. NG: Replace fuel level sensor unit.
  19. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR 
    1. Remove EVAP control system pressure sensor with its harness connector connected. See Figure .
      CAUTION: Never apply force to the air hole protector of the sensor if equipped.
    2. Remove hose from EVAP control system pressure sensor.
    3. Turn ignition switch ON.
    4. Use pump to apply vacuum and pressure to EVAP control system pressure sensor as shown in Figure .
      CAUTION:
      • Always calibrate the vacuum pump gauge when using it.
      • Do not apply below -20 kPa (-150 mmHg, -5.91 inHg) or over 20 kPa (150 mmHg, 5.91 inHg) of pressure.
    5. Check input voltage between ECM terminal 60 and ground. See Figure and Figure .
      CAUTION: Discard and EVAP control system pressure sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.

      OK or NG 

    1. OK: GO TO 20
    2. NG: Replace EVAP control system pressure sensor.
  20. 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 SYSTEM  .

    OK or NG 

    1. OK: GO TO 21.
    2. NG: Repair or reconnect the hose.
  21. CLEAN EVAP PURGE LINE 

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

    1. OK: GO TO 22
  22. CHECK REFUELING EVAP VAPOR LINE 

    Check refueling EVAP vapor line between EVAP canister and fuel tank for clogging, kink, looseness and improper connection. For location, refer to EVAPORATIVE EMISSION LINE DRAWING  .

    OK or NG 

    1. OK: GO TO 23
    2. NG: Repair or replace hoses and tubes.
  23. CHECK SIGNAL LINE AND RECIRCULATION LINE 

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

    OK or NG 

    1. OK: GO TO 24
    2. NG: Repair or replace hoses, tubes or filler neck tube.
  24. CHECK REFUELING CONTROL VALVE 
    1. Remove fuel filler cap.
    2. Check air continuity between hose ends A and B. Blow air into hose end B. Air should flow freely into the fuel tank.
    3. Blow air into hose end A and check that there is no leakage.
    4. Apply pressure to both hose ends A and B [20 kPa (150 mmHg, 5.91 inHg)] using a pressure pump and a suitable 3-way connector. Check that there is no leakage. See Figure .

      OK or NG 

    1. OK: GO TO 25
    2. NG: Repair or refueling control valve with fuel tank.
  25. CHECK FUEL LEVEL SENSOR 

    Refer to FUEL LEVEL SENSOR UNIT CHECK

    OK or NG 

    1. OK: GO TO 26
    2. NG: Replace fuel level sensor unit.
  26. CHECK INTERMITTENT INCIDENT 

    Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT  .

    1. INSPECTION END