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Home >> Nissan-Datsun >> 2009 >> Quest Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS P0447 To P1168 >> DTC P0643 Sensor Power Supply >> Diagnosis Procedure

Diagnosis 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 Body Ground Connections
    G05931755Courtesy 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-I
    1. Disconnect accelerator pedal position (APP) sensor harness connector.
    2. Turn ignition switch ON.
      Fig 2: Identifying Accelerator Pedal Position Sensor Harness Connector
      G04905676Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between APP sensor terminal 7 and ground with CONSULT-III or tester.

    Voltage: Approximately 5 V 

    Fig 3: Checking Voltage Between APP Sensor Terminal 7 And Ground
    G04905677Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  6.

    NG: GO TO 3.

  3. CHECK ACCELERATOR PEDAL POSITION SENSOR 1 POWER SUPPLY CIRCUIT-II
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check harness continuity between APP sensor terminal 7 and ECM terminal 90. Refer to WIRING DIAGRAM .

    Continuity should exist. 

    OK or NG 

    OK: GO TO 4.

    NG: Repair open circuit.

  4. CHECK SENSOR POWER SUPPLY CIRCUITS

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

    TERMINALS REFERENCE CHART

    ECM terminal Sensor terminal Reference Wiring Diagram
    90 APP sensor terminal 7 WIRING DIAGRAM 
    48 EVAP control system pressure sensor terminal 3 WIRING DIAGRAM 
    49 Refrigerant pressure sensor terminal 1 WIRING DIAGRAM
    68 PSP sensor terminal 3 WIRING DIAGRAM 

    OK or NG 

    OK: GO TO 5.

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

  5. CHECK COMPONENTS

    Check the following.

    OK or NG 

    OK: GO TO  8.

    NG: Replace malfunctioning component.

  6. CHECK APP SENSOR

    Refer to , "COMPONENT INSPECTION ".

    OK or NG 

    OK: GO TO  8.

    NG: GO TO 7.

  7. 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 

  8. CHECK INTERMITTENT INCIDENT

    Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .

    INSPECTION END 

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