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Home >> Infiniti >> 2005 >> QX56 AWD >> Repair and Diagnosis >> Engine Performance >> Engine Control System >> DTC P0451: EVAP Control System Pressure Sensor >> Diagnostic Procedure

Diagnostic Procedure

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  1. CHECK GROUND CONNECTIONS 
    1. Turn ignition switch OFF.
    2. Loosen and retighten three ground screws on the body.

      Refer to "GROUND INSPECTION ".

    OK or NG 

    1. OK: GO TO 2.
    2. NG: Repair or replace ground connections.
    Fig 1: Checking Ground Connections
    G02388910Courtesy of NISSAN MOTOR CO., U.S.A.
  2. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR FOR WATER 
    1. Disconnect EVAP control system pressure sensor harness connector.
      Fig 2: Locating EVAP Canister Vent Control Valve & EVAP Control System Pressure Sensor
      G02388911Courtesy of NISSAN MOTOR CO., U.S.A.
    2. Check sensor harness connector for water.
      1. Water should not exist. 

    OK or NG 

    1. OK: GO TO 3.
    2. NG: Repair or replace harness connector.
  3. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR 

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    1. OK: GO TO 4.
    2. NG: Replace EVAP control system pressure sensor.
  4. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    For wiring diagram, refer to "WIRING DIAGRAM ".

    1. : INSPECTION END