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Home >> Nissan-Datsun >> 2004 >> Altima SE, Standard >> Repair and Diagnosis >> Engine Performance >> Engine Control System - 3.5L >> DTC P2138: App Sensor >> Diagnostic Procedure
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Diagnostic Procedure

  1. CHECK GROUND CONNECTIONS 
    1. Turn ignition switch OFF.
    2. Loosen and retighten two engine ground screws. Refer to "GROUND INSPECTION ".

    OK or NG

    1. OK : GO TO 2.
    2. NG : Repair or replace ground connections.
      Fig 1: Checking Engine Ground Connections
      G02885998Courtesy of NISSAN MOTOR CO., U.S.A.
  2. CHECK APP SENSOR 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
      G02885999Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between APP sensor terminals 1, 2 and ground with CONSULT-II or tester.
      VOLTAGE CONDITION SPECIFICATION

      APP sensor terminal Voltage (V)
      1 Approximately 2.5
      2 Approximately 5

    OK or NG

    1. OK : GO TO  4.
    2. NG : GO TO 3.
      Fig 3: Checking Voltage Between APP Sensor Terminals 1, 2 And Ground
      G02886000Courtesy 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 GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check harness continuity between APP sensor terminal 4 and ECM terminal 58, APP sensor terminal 5 and ECM terminal 70.

      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 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Check harness continuity between ECM terminal 73 and APP sensor terminal 3, ECM terminal 74 and APP sensor terminal 6.

      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. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    1. : INSPECTION END 
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