LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Nissan-Datsun >> 2008 >> Quest Base >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System - DTCS P0444 Through P1168 >> DTC P0643 Sensor Power Supply >> Diagnostic Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

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 Screws On Body
      G04905675Courtesy 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 (APP) 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 5V 

    OK or NG 

    OK: GO TO  6.

    NG: GO TO 3.

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

    CONNECTOR TERMINAL CONTINUITY SPECIFICATION

    ECM terminal Sensor terminal
    90  APP sensor terminal 7
    48  EVAP control system pressure sensor terminal 3
    49 Refrigerant pressure sensor terminal 1
    68  PSP sensor terminal 3

    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 

scientia non olet · About LEMON Manuals