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Home >> Infiniti >> 2014 >> Q50 Base, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS P0171 To P0463 (Except Hybrid) >> DTC P0451: EVAP Control System Pressure Sensor >> Diagnosis Procedure

Diagnosis Procedure

  1. CHECK GROUND CONNECTION 
    1. Turn ignition switch OFF.
    2. Check ground connection M111. Refer to Ground Inspection in "CIRCUIT INSPECTION ".

      Is the inspection result normal? 

      YES: GO TO 2.

      NO: Repair or replace ground connection.

  2. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR FOR WATER 
    1. Disconnect EVAP control system pressure sensor harness connector.
    2. Check sensor harness connector for water.

      Water should not exist. 

      Is the inspection result normal? 

      YES: GO TO 3.

      NO: Repair or replace harness connector.

  3. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR POWER SUPPLY CIRCUIT 
    1. Turn ignition switch ON.
    2. Check the voltage between EVAP control system pressure sensor harness connector and ground.
      EVAP control system pressure sensor Ground Voltage (V)
      Connector Terminal
      B84 3 Ground Approx. 5

      Is the inspection result normal? 

      YES: GO TO  8.

      NO: GO TO 4.

  4. CHECK SENSOR POWER SUPPLY CIRCUIT 

    Check harness for short to power and short to ground, between the following terminals.

    ECM Sensor
    Connector Terminal Name Connector Terminal
    F7 46 CKP sensor (POS) F44 1
    F8 64 CMP sensor (PHASE) (bank 2) F62 1
    Battery current sensor E7 4
    M37 103 APP sensor M124(1)
    M126(2)    		 10(1)
    6(2)
    107 EVAP control system pressure sensor B84 3
    Refrigerant pressure sensor E82 3
    (1) With ICC
    (2) Without ICC

    Is the inspection result normal? 

    YES: GO TO 5.

    NO: Repair short to ground or short to power in harness or connectors.

  5. CHECK COMPONENTS 

    Check the following.

  6. CHECK APP SENSOR 

    Refer to "COMPONENT INSPECTION ".

    Is the inspection result normal? 

    YES: GO TO  9.

    NO: GO TO 7.

  7. REPLACE ACCELERATOR PEDAL ASSEMBLY 
    1. Replace accelerator pedal assembly
    2. Go to "SPECIAL REPAIR REQUIREMENT ".

      : INSPECTION END

  8. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR 

    Refer to "COMPONENT INSPECTION ".

    Is the inspection result normal? 

    YES: GO TO 9.

    NO: Replace EVAP control system pressure sensor. Refer to "EXCEPT FOR MEXICO: EXPLODED VIEW ".

  9. CHECK INTERMITTENT INCIDENT 

    Refer to "INTERMITTENT INCIDENT ".

    : INSPECTION END

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