LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Nissan-Datsun >> 2012 >> Sentra SE-R >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS P0603 To P2A03 (Qr25DE) >> DTC P2138: App Sensor >> Diagnosis Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnosis Procedure

  1. CHECK GROUND CONNECTIONS
    1. Turn ignition switch OFF.
    2. Loosen and retighten ground screws on the body.

    Refer to "GROUND INSPECTION ".

    Fig 1: Identifying Body Ground (E9 And E15) And Washer Tank With Fuse And Fusible Link Box
    G08185459Courtesy of NISSAN NORTH AMERICA, INC.

    OK or NG 

    OK: GO TO 2.

    NG: Repair or replace ground connections.

  2. CHECK APP SENSOR 1 POWER SUPPLY CIRCUIT
    1. Disconnect accelerator pedal position (APP) sensor (1) harness connector.
    2. Turn ignition switch ON.
      Fig 2: Identifying Accelerator Pedal Position (APP) Sensor
      G04925502Courtesy of NISSAN NORTH AMERICA, INC.
    3. Check voltage between APP sensor terminal 4 and ground with CONSULT or tester.

    Voltage: Approximately 5 V 

    Fig 3: Checking APP Sensor 1 Power Supply Circuit
    G04925503Courtesy of NISSAN NORTH AMERICA, INC.

    OK or NG 

    OK: GO TO 3.

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

  3. CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-I
    1. Turn ignition switch ON.
    2. Check voltage between APP sensor terminal 5 and ground with CONSULT or tester.

    Voltage: Approximately 5 V 

    Fig 4: Checking APP Sensor 2 Power Supply Circuit-I
    G04925581Courtesy of NISSAN NORTH AMERICA, INC.

    OK or NG 

    OK: GO TO  7.

    NG: GO TO 4.

  4. CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-II
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check harness continuity between APP sensor terminal 5 and ECM terminal 87. Refer to Wiring Diagram .

    Continuity should exist  .

    OK or NG 

    OK: GO TO 5.

    NG: Repair open circuit.

  5. CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-III

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

    ECM terminal Sensor terminal Reference Wiring Diagram
    72 Refrigerant pressure sensor terminal 3 "WIRING DIAGRAM "
    76 Crankshaft position sensor (POS) terminal 1 "WIRING DIAGRAM "
    87 APP sensor terminal 5 "WIRING DIAGRAM "
    91 EVAP control system pressure sensor terminal 3 "WIRING DIAGRAM "

    OK or NG 

    OK: GO TO 6.

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

  6. CHECK COMPONENTS

    Check the following.

    OK or NG 

    OK: GO TO  11.

    NG: Replace malfunctioning component.

  7. CHECK APP SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check harness continuity between the following;

      ECM terminal 84 and APP sensor terminal 2,

      ECM terminal 100 and APP sensor terminal 1.

      Refer to Wiring Diagram .

      Continuity should exist  .

    4. Also check harness for short to ground and short to power.

    OK or NG 

    OK: GO TO 8.

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

  8. CHECK APP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
    1. Check harness continuity between the following;

      ECM terminal 81 and APP sensor terminal 3,

      ECM terminal 82 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 

    OK: GO TO 9.

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

  9. CHECK APP SENSOR

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    OK: GO TO  11.

    NG: GO TO 10.

  10. REPLACE ACCELERATOR PEDAL ASSEMBLY

    Replace accelerator pedal assembly. Refer to , "REMOVAL AND INSTALLATION ".

    INSPECTION END 

  11. CHECK INTERMITTENT INCIDENT

    Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .

    INSPECTION END