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Home >> Nissan-Datsun >> 2004 >> Pathfinder LE, RWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System >> DTC P1446: EVAP Canister Vent Control Valve >> Diagnostic Procedure

Diagnostic Procedure

  1. CHECK RUBBER TUBE 
    1. Turn ignition switch "OFF".
    2. Disconnect rubber tube connected to EVAP canister vent control valve.
    3. Check the rubber tube for clogging.
      Fig 1: Checking Rubber Tube
      G00781084Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 2.
    2. NG: Clean rubber tube using an air blower.
  2. 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 A  and C  are not clogged by blowing air into B  with A  , and then C  plugged.
      Fig 2: Checking Water Separator
      G00781085Courtesy of NISSAN MOTOR CO., U.S.A.
    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 3.
    2. NG: Clean or replace water separator.
  3. CHECK EVAP CANISTER VENT CONTROL VALVE-I 
    1. Remove EVAP canister vent control valve from EVAP canister.
    2. Check portion B  of EVAP canister vent control valve for being rusted.
      Fig 3: Checking Portion B Of EVAP Canister Vent Control Valve
      G00781086Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 4.
    2. NG: Replace EVAP canister vent control valve.
  4. CHECK EVAP CANISTER VENT CONTROL VALVE-II 

    With CONSULT-II

    1. Turn ignition switch ON.
    2. Perform "VENT CONTROL/V" in "ACTIVE TEST" mode.
    3. Check air passage continuity and operation delay time.
      Fig 4: Checking Air Passage Continuity And Operation Delay Time Using CONSULT II (With CONSULT-II)
      G00781087Courtesy of NISSAN MOTOR CO., U.S.A.

    Without CONSULT-II

    Check air passage continuity and operation delay time under the following conditions.

    Fig 5: Checking Air Passage Continuity And Operation Delay Time Using CONSULT II (Without CONSULT-II)
    G00781088Courtesy of NISSAN MOTOR CO., U.S.A.

    Make sure new O-ring is installed properly. 

    OK or NG 

    1. OK: GO TO  6 .
    2. NG: GO TO 5.
  5. CHECK EVAP CANISTER VENT CONTROL VALVE-III 
    1. Clean the air passage (Portion A  to B  ) of EVAP canister vent control valve using an air blower.
    2. Perform the procedure 4 again.

    OK or NG 

    1. OK: GO TO 6.
    2. NG: Replace EVAP canister vent control valve.
  6. CHECK IF EVAP CANISTER SATURATED WITH WATER 
    1. e EVAP canister with EVAP canister vent control valve attached.
    2. Check if water will drain from the EVAP canister.
      Fig 6: Removing EVAP Canister With EVAP Canister Vent Control Valve Attached
      G00781089Courtesy of NISSAN MOTOR CO., U.S.A.

    Yes or No 

    1. Yes: GO TO 7.
    2. No: GO TO  9 .
  7. 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: GO TO  9 .
    2. NG: GO TO 8.
  8. 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.
  9. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR HOSE 

    disconnection or improper connection of hose connected to EVAP control system pressure sensor.

    OK or NG 

    1. OK: GO TO 10.
    2. NG: Repair it.
  10. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR 
    1. Disconnect EVAP control system pressure sensor harness connector.
      Fig 7: Disconnecting EVAP Control System Pressure Sensor Harness Connector
      G00781090Courtesy of NISSAN MOTOR CO., U.S.A.
    2. Check connectors for water.

      Water should not exist. 

    OK or NG 

    1. OK: GO TO 11.
    2. NG: Replace EVAP control system pressure sensor.
  11. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR 
    1. Remove EVAP control system pressure sensor with its harness connector connected.
      • Never apply force to the air hole protector of the sensor if equipped. 
        Fig 8: Identifying Air Hole Protector
        G00781091Courtesy of NISSAN MOTOR CO., U.S.A.
    2. Remove EVAP control system pressure sensor from EVAP canister.

      Do not reuse the O-ring, replace it with a new one. 

    3. Install a vacuum pump to EVAP control system pressure sensor.
    4. Turn ignition switch "ON" and check output voltage between ECM terminal 32 and ground under the following conditions.
      Fig 9: Installing Vacuum Pump To EVAP Control System Pressure Sensor
      G00781092Courtesy of NISSAN MOTOR CO., U.S.A.
      CAUTION:
      • Always calibrate the vacuum pump gauge when using it.
      • Do not apply below -93.3 kPa (-700 mmHg, -27.56 inHg) or pressure over 101.3 kPa (760 mmHg, 29.92 inHg).
      • 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 12.
    2. NG: Replace EVAP control system pressure sensor.
  12. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT  " .

    1. INSPECTION END