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Home >> Infiniti >> 2018 >> QX30 Essential, AWD >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System (DTC/Circuit Diagnosis) (4 Of 4) >> DTC/Circuit Diagnosis >> DTC P2540: Fuel Pressure Sensor >> Fuel Pump Control Module (FPCM) >> Diagnosis Procedure
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Diagnosis Procedure

  1. COMPONENT FUNCTION CHECK 

    SYMBOL With CONSULT

    1. Turn ignition switch OFF.
    2. Start the engine and let it idle.
    3. On CONSULT screen, select "FPCM" >> "DATA MONITOR" >> "FUEL PRESSURE".
    4. Check that the indicated value is between 400 kPa (4 bar, 4.08 kg/cm 2 , 58 psi) and 670 kPa (6.7 bar, 6.834 kg/cm 2 , 97.15 psi).

    Is the inspection result normal?

    YES

    INSPECTION END

    NO

    GO TO 2.

  2. CHECK FUEL PRESSURE SENSOR POWER SUPPLY 
    1. Turn ignition switch OFF.
    2. Disconnect fuel pressure sensor harness connector.
    3. Turn ignition switch ON.
    4. Check the voltage between fuel pressure sensor harness connector terminals.

      Fuel pressure sensor

      Voltage

      (Approx.)

      Connector

      +

      -

      Terminal

      M390

      1

      3

      5 V

    Is the inspection result normal?

    YES

    GO TO 5.

    NO

    GO TO 3.

  3. CHECK FUEL PRESSURE SENSOR POWER SUPPLY AND GROUND CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect FPCM harness connector and fuel pressure sensor harness connector.
    3. Check the continuity between FPCM harness connector and fuel pressure sensor harness connector.
      2WD models

      +

      -

      Continuity

      FPCM

      Fuel pressure sensor

      Connector

      Terminal

      Connector

      Terminal

      M135

      8

      M390

      1

      Existed

      6

      3

      AWD models

      +

      -

      Continuity

      FPCM

      Fuel pressure sensor

      Connector

      Terminal

      Connector

      Terminal

      M136

      3

      M390

      1

      Existed

      5

      3

    4. Also check harness for short to ground.

    Is the inspection result normal?

    YES

    GO TO 4.

    NO

    Repair or replace error-detected parts.

  4. CHECK FPCM POWER SUPPLY AND GROUND CIRCUIT 

    Check FPCM power supply and ground circuit. Refer to Diagnosis Procedure .

    Is the inspection result normal?

    YES

    Replace FPCM. Refer to Removal and Installation .

    NO

    Repair or replace error-detected parts.

  5. CHECK FUEL PRESSURE SENSOR SIGNAL CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect FPCM harness connector and fuel pressure sensor harness connector.
    3. Check the continuity between FPCM harness connector and fuel pressure sensor harness connector.
      2WD models

      +

      -

      Continuity

      FPCM

      Fuel pressure sensor

      Connector

      Terminal

      Connector

      Terminal

      M135

      7

      M390

      2

      Existed

      AWD models

      +

      -

      Continuity

      FPCM

      Fuel pressure sensor

      Connector

      Terminal

      Connector

      Terminal

      M136

      4

      M390

      2

      Existed

    4. Also check harness for short to ground.

    Is the inspection result normal?

    YES

    Replace fuel pressure sensor.

    NO

    Repair or replace error-detected parts.