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Home >> Infiniti >> 2012 >> QX56 AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS U0101 To P0153 >> DTC P0087: FRP Control System >> Diagnosis Procedure
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Diagnosis Procedure

  1. BLEED THE FUEL LINE
    1. Start the engine, and let the engine run at idle at least for 10 minutes.
    2. Perform DTC confirmation procedure of DTC P0087.

    Is 1st trip DTC detected? 

    YES: GO TO 2.

    NO: GO TO  6.

  2. CHECK LOW FUEL PRESSURE

    WITH CONSULT

    1. Start the engine.
    2. Check "L/FUEL PRES SEN V" in "DATA MONITOR" mode of "ECM" using CONSULT.
    Monitor item Condition Value (Approx.)
    L/FUEL PRES SEN V Engine speed: idle 3, 000 - 3, 300 mV
    Engine speed: 3, 000 rpm (no load)

    WITHOUT CONSULT

    1. Start the engine.
    2. Check low fuel pressure sensor signal voltage.
    + - Condition Value (Approx.)
    Low fuel pressure sensor
    Connector Terminal
    F25 2 Ground Engine speed: idle 3.0 - 3.3 V
    Engine speed: 3, 000 rpm (no load)

    Is inspection result normal? 

    YES: GO TO 3.

    NO: Check low fuel pressure system. Refer to "DIAGNOSIS PROCEDURE ".

  3. CHECK LOW PRESSURE FUEL LINE FOR INTERNAL LEAKAGE

    WITH CONSULT

    1. Turn ignition switch OFF.
    2. Turn ignition switch ON.
    3. Select "L/FUEL PRES SEN" in "DATA MONITOR" of "ECM" with CONSULT.
    4. Check the following value 30 minutes after turning the ignition switch ON.

      L/FUEL PRES SEN: More than 0.20 MPa 

    WITHOUT CONSULT

    1. Turn ignition switch OFF.
    2. Connect fuel pressure gauge. Refer to "WORK PROCEDURE ".
    3. Turn ignition switch ON.
    4. Check the following value 30 minutes after turning the ignition switch ON.

      Low fuel pressure: 206 kPa (2.1 bar, 2.2 kgf/cm2, 30 psi) or more 

    Is inspection result normal? 

    YES: GO TO 4.

    NO: Replace low pressure fuel pump. Refer to "EXPLODED VIEW ".

  4. CHECK HIGH PRESSURE FUEL PUMP

    Check high pressure fuel pump. Refer to "COMPONENT INSPECTION (HIGH PRESSURE FUEL PUMP) ".

    Is inspection result normal? 

    YES: GO TO 5.

    NO: Repair or replace the error-detected parts.

  5. CHECK LIFTER

    Check lifter. Refer to "REMOVAL AND INSTALLATION ".

    Does the lifter top surface have scratches and/or dents? 

    YES: Replace the error-detected parts.

    NO: Check intermittent incident. Refer to "INTERMITTENT INCIDENT ".

  6. CHECK LOW PRESSURE FUEL LINE FOR INTERNAL LEAKAGE

    WITH CONSULT

    1. Turn ignition switch OFF.
    2. Turn ignition switch ON.
    3. Select "L/FUEL PRES SEN" in "DATA MONITOR" mode of "ECM" using CONSULT.
    4. Check the following value 30 minutes after turning the ignition switch ON.

      L/FUEL PRES SEN: More than 0.20 MPa 

    WITHOUT CONSULT

    1. Turn ignition switch OFF.
    2. Connect fuel pressure gauge. Refer to "WORK PROCEDURE ".
    3. Turn ignition switch ON.
    4. Check the following value 30 minutes after turning the ignition switch ON.

      Low fuel pressure: 206 kPa (2.1 bar, 2.2 kgf/cm2, 30 psi) or more 

    Is inspection result normal? 

    YES: Check intermittent incident. Refer to "INTERMITTENT INCIDENT ".

    NO: Replace low pressure fuel pump. Refer to "EXPLODED VIEW ".