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Home >> Nissan-Datsun >> 2004 >> Altima Base, Automatic >> Repair and Diagnosis >> Engine Performance >> Engine Control System - 2.5L >> 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. Refer to "GROUND INSPECTION ".
      Fig 1: Checking Ground Connections
      G02884891Courtesy of NISSAN MOTOR CO., U.S.A.

    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 2: Disconnecting Accelerator Pedal Position (APP) Sensor Harness Connector
      G02884892Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between APP sensor terminal 2 and ground with CONSULT-II or tester.

      Voltage: Approximately 5V 

    OK or NG

    1. OK : GO TO  4.
    2. NG : GO TO 3.
      Fig 3: Checking Voltage Between APP Sensor Terminal 2 & Ground
      G02884893Courtesy of NISSAN MOTOR CO., U.S.A.
  3. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E21, F34
    • 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 and TCM harness connector.
    3. Check harness continuity between APP sensor terminal 4 and ECM terminal 82, TCM terminal 42. Refer to Wiring Diagram .

      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 E21, F34
    • Harness for open or short between ECM and accelerator pedal position sensor
    • Harness for open or short between TCM 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 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Check harness continuity between ECM terminal 106 and APP sensor terminal 3. Refer to Wiring Diagram .

      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 E21, F34
    • 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 9.
    2. NG : Replace accelerator pedal assembly.
  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 
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