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Home >> Infiniti >> 2008 >> FX45 >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System (VK45DE) - DTC P0451 Through P1168 >> DTC P0643 Sensor Power Supply >> Diagnostic Procedure

Diagnostic Procedure

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

      Refer to "GROUND INSPECTION ".

    Fig 1: Identifying Ground Connections
    G05217147Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  2.

    NG: Repair or replace ground connections.

  2. CHECK ACCELERATOR PEDAL POSITION SENSOR 1 POWER SUPPLY CIRCUIT 
    1. Disconnect accelerator pedal position (APP) sensor harness connector.
    2. Turn ignition switch ON.
      Fig 2: Identifying Accelerator Pedal Position Sensor
      G05217605Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between APP sensor terminal 6 and ground with CONSULT-III or tester.

      Voltage: Approximately 5V 

    OK or NG 

    OK: GO TO  5.

    NG: GO TO  3.

    Fig 3: Checking Voltage Between APP Sensor Terminal 6 And Ground
    G04875310Courtesy of NISSAN MOTOR CO., U.S.A.
  3. CHECK SENSOR POWER SUPPLY CIRCUITS 

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

    TERMINALS REFERENCE

    ECM terminal Sensor terminal Reference Wiring Diagram
    90 APP sensor terminal 6 WIRING DIAGRAM 
    48 EVAP control system pressure sensor terminal 3 WIRING DIAGRAM 
    49 Refrigerant pressure sensor terminal 1 WIRING DIAGRAM
    68 PSP sensor terminal 1 WIRING DIAGRAM 

    OK or NG 

    OK: GO TO  4.

    NG: Repair short to ground or short to power in harness or connectors.

  4. CHECK COMPONENTS 

    Check the following.

    OK or NG 

    OK: GO TO  7.

    NG: Replace malfunctioning component.

  5. CHECK APP SENSOR 

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    OK: GO TO  7.

    NG: GO TO  6.

  6. REPLACE ACCELERATOR PEDAL ASSEMBLY 
    1. Replace accelerator pedal assembly.
    2. Perform "ACCELERATOR PEDAL RELEASED POSITION LEARNING ".
    3. Perform "THROTTLE VALVE CLOSED POSITION LEARNING ".
    4. Perform "IDLE AIR VOLUME LEARNING ".

    >> INSPECTION END 

  7. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    >> INSPECTION END