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Home >> Infiniti >> 2012 >> QX56 AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS P1550 To P2A03 >> DTC P2138: App Sensor >> Diagnosis Procedure
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Diagnosis Procedure

  1. CHECK ACCELERATOR PEDAL POSITION SENSOR 1 POWER SUPPLY CIRCUIT
    1. Disconnect accelerator pedal position (APP) sensor harness connector.
    2. Turn ignition switch ON.
    3. Check the voltage between APP sensor harness connector and ground.
    APP sensor Ground Voltage (V)
    Connector terminal
    E110 (Without ICC) 2 Ground Approx. 5
    E67 (With ICC) 12

    Is the inspection result normal? 

    YES: GO TO  3.

    NO: GO TO 2.

  2. DETECT MALFUNCTIONING PART

    Check the following.

    • Loose or poor connection for each connector and harness
    • Harness for open or short between ECM and APP sensor

    : Repair open circuit, 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 the voltage between APP sensor harness connector and ground.
    APP sensor Ground Voltage (V)
    Connector terminal
    E110 (Without ICC) 1 Ground Approx. 5
    E67 (With ICC) 9

    Is the inspection result normal? 

    YES: GO TO  8.

    NO: GO TO 4.

  4. CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-II
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check the continuity between APP sensor harness connector and ECM harness connector.
    APP sensor ECM Continuity
    Connector Terminal Connector terminal
    E110 (Without ICC) 1 E80 131 Existed
    E67 (With ICC) 9

    Is the inspection result normal? 

    YES: GO TO  6.

    NO: GO TO 5.

  5. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness for open or short between ECM and accelerator pedal position sensor
    • Loose or poor connection for each connector and harness

    : Repair open circuit.

  6. CHECK SENSOR POWER SUPPLY CIRCUIT

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

    ECM Sensor
    Connector Terminal Name Connector terminal
    F110 76 Crankshaft position sensor F74 1
    77 Camshaft position sensor (bank 1) F84 1
    E80 133 Battery current sensor E63 2
    Refrigerant pressure sensor E77 1
    EVAP control system pressure sensor C17 3
    131 APP sensor (Without ICC) E110 1
    APP sensor (with ICC) E67 9

    Is the inspection result normal? 

    YES: GO TO 7.

    NO: Repair short to ground or short to power in harness or connectors.

  7. CHECK COMPONENTS

    Check the following.

    Is the inspection result normal? 

    YES: GO TO  14.

    NO: Replace malfunctioning component.

  8. CHECK APP SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check the continuity between APP sensor harness connector and ECM harness connector.
      APP sensor ECM Continuity
      Connector Terminal Connector terminal
      E110 (Without ICC) 4 E80 140 Existed
      5 129
      E67 (With ICC) 11 E80 140 Existed
      8 129
    4. Also check harness for short to ground and short to power.

    Is the inspection result normal? 

    YES: GO TO  10.

    NO: GO TO 9.

  9. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness for open or short between ECM and accelerator pedal position sensor
    • Loose or poor connection for each connector and harness

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

  10. CHECK APP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
    1. Check the continuity between APP sensor harness connector and ECM harness connector.
      APP sensor ECM Continuity
      Connector Terminal Connector terminal
      E110 (Without ICC) 3 E80 136 Existed
      6 126
      E67 (With ICC) 10 E80 136 Existed
      7 126
    2. Also check harness for short to ground and short to power.

    Is the inspection result normal? 

    YES: GO TO  12.

    NO: GO TO 11.

  11. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness for open or short between ECM and accelerator pedal position sensor
    • Loose or poor connection for each connector and harness

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

  12. CHECK APP SENSOR

    Refer to "COMPONENT INSPECTION (ACCELERATOR PEDAL POSITION SENSOR) ".

    Is the inspection result normal? 

    YES: GO TO  14.

    NO: GO TO 13.

  13. REPLACE ACCELERATOR PEDAL ASSEMBLY

    Replace accelerator pedal assembly. Refer to "MODELS WITHOUT DISTANCE CONTROL ASSIST SYSTEM: REMOVAL AND INSTALLATION " (Without distance control assist system) or "MODELS WITH DISTANCE CONTROL ASSIST SYSTEM: REMOVAL AND INSTALLATION " (With distance control assist system).

    : INSPECTION END

  14. CHECK INTERMITTENT INCIDENT

    Refer to "INTERMITTENT INCIDENT ".

    : INSPECTION END

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