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Home >> Infiniti >> 2004 >> FX45 >> Repair and Diagnosis >> Engine Performance >> Engine Control System >> DTC P2122 & P2123 App Sensor >> Diagnostic Procedure
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Diagnostic Procedure

  1. Check Ground Connections 
    1. Turn ignition switch OFF.
    2. Loosen and retighten three ground screws on the body. See Figure .

      Refer to GROUND INSPECTION  .

    OK or NG

    1. OK: go to 2.
    2. NG: Repair or replace ground connections.

  2. Check APP Sensor 1 Power Supply Circuit 
    1. Disconnect accelerator pedal position (APP) sensor harness connector.
    2. Turn ignition switch ON.
      Fig 1: Locating Accelerator Pedal Position (APP) Sensor
      G00345446Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between APP sensor terminal 6 and ground with CONSULT-II or tester.
      Fig 2: Testing APP Sensor Circuit (W/DVOM)
      G00345447Courtesy of NISSAN MOTOR CO., U.S.A.
      1. Voltage: Approximately 5V 

    OK or NG

    1. OK: go to  4 .
    2. NG: go to 3.

  3. Detect Malfunctioning Part 

    Check the following.

    • Harness connectors E211, M41
    • Harness for open or short between ECM and accelerator pedal position sensor
      1. Repair open circuit or short to ground or short to power in harness or connectors.

  4. Check APP Sensor 1 Ground Circuit For Open And Short 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check harness continuity between APP sensor terminal 3 and ECM terminal 82.

      Refer to wiring diagram. See Figure .

      1. Continuity should exist  .
    4. Also check harness for short to ground and short to power.

    OK or NG

    1. OK: go to  6 .
    2. NG: go to 5.

  5. Detect Malfunctioning Part 

    Check the following.

    • Harness connectors E211, M41
    • Harness for open or short between ECM and accelerator pedal position sensor
      1. Repair open circuit or short to ground or short to power in harness or connectors.

  6. Check APP Sensor Input Signal Circuit For Open And Short 
    1. Check harness continuity between ECM terminal 106 and APP sensor terminal 5.

      Refer to wiring diagram. See Figure .

      1. Continuity should exist  .
    2. Also check harness for short to ground and short to power.

    OK or NG

    1. OK: go to  8 .
    2. NG: go to 7.

  7. Detect Malfunctioning Part 

    Check the following.

    • Harness connectors E211, M41
    • Harness for open or short between ECM and accelerator pedal position sensor
      1. Repair open circuit or short to ground or short to power in harness or connectors.

  8. Check APP Sensor 

    Refer to COMPONENT INSPECTION  .

    OK or NG

    1. OK: go to  10 .
    2. NG: go to 9.

  9. 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  .
    1. Inspection end 
  10. Check Intermittent Incident 

    Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT  .

    1. Inspection end