SFI SYSTEM, Diagnostic DTC:P0087

DTC Code DTC Name
P0087 Fuel Rail / System Pressure - Too Low

DESCRIPTION

The high-pressure fuel system consists of the spill control valve, pump plunger and fuel pressure sensor. The spill control valve opens and closes the low-pressure fuel line (from the fuel tank), the pump plunger (operated by the camshaft) pressurizes fuel and the fuel pressure sensor located on the fuel delivery pipe monitors fuel pressure.

The fuel pump for high pressure is installed to the cylinder head cover (bank 2) and is driven by the cam located at the intake camshaft.

The plunger moves up and down by the camshaft rotations, and produces a vacuum to suck fuel and pressurizes the fuel. This fuel flows into the fuel delivery pipe. The ECM opens and closes the spill control valve to regulate the fuel pressure to the target fuel pressure. In order to obtain and maintain the target pressure, the ECM monitors the fuel pressure using the fuel pressure sensor and performs the feedback control.

Tech Tips

The spill control valve, pump plunger are built into the fuel pump assembly for high pressure.

DTC No. DTC Detection Condition Trouble Area
P0087

Fuel pressure is lower than the target value for 10 seconds or more.

(1 trip detection logic)

  • Leak of fuel

  • Fuel pipe (Fuel tank - Fuel pump assembly (for high pressure) [bank 1 or bank 2])

  • Fuel pipe (Fuel pump assembly (for high pressure) - Fuel injector assembly [for direct injection])

  • Fuel injector assembly (for direct injection)

  • Fuel pump assembly (for high pressure)

  • Injector driver (EDU)

  • Fuel pump assembly

  • ECM

MONITOR DESCRIPTION

If the fuel pressure decreases even after the ECM commands the high-pressure fuel pump to close the spill control valve, a DTC is output.

CONFIRMATION DRIVING PATTERN


  1. Connect the GTS to the DLC3.

  2. Turn the ignition switch to ON and turn the GTS on.

  3. Record the Freeze Frame Data.

  4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) Click here.

  5. Turn the ignition switch off and wait for at least 30 seconds.

  6. Turn the ignition switch to ON and turn the GTS on.

  7. Based on engine speed, engine load and other freeze frame data stored in the ECM, reproduce the conditions present when the DTC was stored.

  8. Enter the following menus: Powertrain / Engine / Trouble Codes.

  9. Read the DTC.

    Tech Tips


    • If a DTC is output, the system is malfunctioning.

    • If a DTC is not output, perform the following procedure.

  10. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

  11. Input the DTC: P0087.

  12. Check the DTC judgment result.

    GTS Display Description
    NORMAL

    • DTC judgment completed

    • System normal
    ABNORMAL

    • DTC judgment completed

    • System abnormal
    INCOMPLETE

    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions
    N/A

    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU's memory limit

    Tech Tips


    • If the judgment result shown ABNORMAL, the system has a malfunction.

    • If the judgment result shows NORMAL, the system is normal.

  13. If the test result is INCOMPLETE or N/A and no DTC is output, perform a universal trip and check for permanent DTCs Click here.

    Tech Tips


    • If a permanent DTC is output, the system is malfunctioning.

    • If no permanent DTC is output, the system is normal.

CAUTION / NOTICE / HINT

Tech Tips

Read freeze frame data using the GTS. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was moving or stationary, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

PROCEDURE


  1. CHECK FUEL LEAK (HIGH PRESSURE SIDE)


    1. Check around and beneath the car for fuel leaks, fumes, etc.

      OK
      No fuel leaks present.

    NG

    REPAIR OR REPLACE FUEL LEAK POINT

    OK

  2. CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0087)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Enter the following menus: Powertrain / Engine / Trouble Codes.

    4. Read the DTCs.

      Result
      Result Proceed to
      DTC P0087 is output A
      DTC P0087 and other DTCs are output B

      Tech Tips

      If any DTCs other than P0087 are output, troubleshoot those DTCs first.


    B

    GO TO DTC CHART Click here

    A

  3. CHECK IF VEHICLE HAS RUN OUT OF FUEL IN PAST


    1. Has the vehicle run out of fuel in the past?


    NO

    DTC CAUSED BY RUNNING OUT OF FUEL

    YES

  4. READ VALUE USING GTS (FUEL PRESS)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Start the engine.

    4. Enter the following menus: Powertrain / Engine / Data List / Fuel Press.

    5. Read Fuel Press when racing the engine.

      Result
      Result Proceed to
      Fuel Press value varies. A
      Fuel Press value does not increase. B
      Fuel Press value does not vary. C

    B

    CHECK FUEL LEAK (HIGH PRESSURE SIDE) Click here

    C

    REPLACE FUEL PRESSURE SENSOR Click here

    A

  5. PERFORM ACTIVE TEST USING GTS (CONTROL THE FUEL PUMP / SPEED)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Start the engine.

    4. Enter the following menus: Powertrain / Engine / Active Test / Control the Fuel Pump / Speed.

    5. When performing the Active Test, check for an operating sound from the fuel pump.


    NG

    CHECK FUEL PUMP OPERATION Click here

    OK

  6. CHECK FUEL PRESSURE (LOW PRESSURE SIDE)


    1. Check the fuel pressure (low pressure side) Click here.


    NG

    REPLACE FUEL PRESSURE REGULATOR Click here

    OK

  7. CHECK FUEL LEAK (HIGH PRESSURE SIDE)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Enter the following menus: Powertrain / Engine / Data List / Fuel Press.

    4. Check changes in the fuel pressure when the engine is stopped.

      Tech Tips

      Turn the ignition switch to ON immediately after turning the ignition switch off.

      A004K9PE11
      *1 Ignition Switch
      *2 OFF
      *3 Engine Speed
      *4 Fuel Pressure
      Result
      Result Proceed to
      The fuel pressure drops immediately after turning the ignition switch off. A
      The fuel pressure is nearly maintained, or with moderate variations. B

    B

    REPLACE INJECTOR DRIVER (EDU) Click here

    A

  8. INSPECT FUEL PUMP ASSEMBLY (FOR HIGH PRESSURE)


    1. Inspect the fuel pump assembly (for high pressure) Click here.


    NG

    REPLACE FUEL PUMP ASSEMBLY (FOR HIGH PRESSURE) Click here

    OK

  9. REPLACE INJECTOR DRIVER (EDU)


    1. Replace the fuel injector driver (EDU) Click here.


    NEXT

  10. PERFORM CONFIRMATION DRIVING PATTERN


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs Click here.

    5. Turn the ignition switch off and wait for at least 30 seconds.

    6. Turn the ignition switch to ON and turn the GTS on.

    7. Start the engine and warm it up.

    8. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    9. Enter the following menus: Powertrain / Engine / Trouble Codes.

    10. Read the DTC.

      Result
      Result Proceed to
      DTC P0087 is output A
      DTC is not output B

    B

    END

    A

  11. REPLACE FUEL PUMP ASSEMBLY (FOR HIGH PRESSURE)


    1. Replace the fuel pump assembly (high pressure side) Click here.

      Tech Tips

      If the fuel pump assembly (for high pressure) has been replaced in step 8, then proceed to step 13 without replacing the fuel pump assembly (for high pressure).


    NEXT

  12. PERFORM CONFIRMATION DRIVING PATTERN


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs Click here.

    5. Turn the ignition switch off and wait for at least 30 seconds.

    6. Turn the ignition switch to ON and turn the GTS on.

    7. Start the engine and warm it up.

    8. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    9. Enter the following menus: Powertrain / Engine / Trouble Codes.

    10. Read the DTC.

      Result
      Result Proceed to
      DTC P0087 is output A
      DTC is not output B

    B

    END

    A

  13. CHECK FUEL LEAK (HIGH PRESSURE SIDE)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Enter the following menus: Powertrain / Engine / Data List / Fuel Press.

    4. Check changes in the fuel pressure when the engine is stopped.

      Tech Tips

      Turn the ignition switch to ON immediately after turning the ignition switch off.

      A004K9PE11
      *1 Ignition Switch
      *2 OFF
      *3 Engine Speed
      *4 Fuel Pressure
      Result
      Result Proceed to
      The fuel pressure drops immediately after turning the ignition off. A
      The fuel pressure is nearly maintained, or with moderate variations. B

    A

    REPLACE ECM Click here

    B

    REPLACE FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION) Click here