SFI SYSTEM, Diagnostic DTC:P0087

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

DESCRIPTION

The cylinder fuel injection method high-pressure fuel system consists of the spill control valve, pump plunger and check valve. The spill control valve adjusts the discharge amount of the high-pressure fuel, the pump plunger operated by the camshaft pressurizes fuel, and the check valve mechanically opens and closes the line to the fuel delivery pipe. The fuel pump for high pressure is installed to the cylinder head cover (bank 1 and bank 2) and is driven by the cam located at the rear end of the intake camshaft. When the plunger moves up and down by the camshaft rotations, it pressurizes the fuel. The pressurized fuel then pushes open the check valve, and the fuel flows to the fuel delivery pipe. The ECM controls the spill control valve to adjust the fuel pressure to 4 to 13 MPa (41 to 133 kgf/cm2, 574 to 1857 psi). The ECM receives signals from the fuel pressure sensor, monitors the fuel pressure, and maintains the target fuel pressure. If the fuel pressure of the fuel delivery pipe exceeds 15.3 MPa (156 kgf/cm2, 2185 psi), the fuel relief valve opens and returns the fuel to the fuel tank.

A01GMVGE03
DTC No. DTC Detection Condition Trouble Area
P0087

Even though ECM commands fuel pump for high pressure to open spill control valve, fuel pressure decreases 5 MPa (51.0 kgf/cm2, 725 psi) from target pressure for more than 10 seconds

(1 trip detection logic)

  • Leak of fuel

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

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

  • Fuel injector (for direct injection)

  • Fuel relief valve

  • Fuel pressure sensor

  • Fuel pump for low pressure

  • Fuel pump for high pressure (bank 1)

  • Fuel pump for high pressure (bank 2)

  • Injector driver (No. 1)

  • Injector driver (No. 2)

  • 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.

INSPECTION PROCEDURE

Tech Tips

Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE


  1. CHECK FUEL LEAK


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

      OK
      No gasoline leaks present.

    NG

    REPAIR OR REPLACE FUEL LEAK POINT

    OK

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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG) and turn the tester ON.

    3. Enter the following menus: Powertrain / Engine / DTC.

    4. Read the DTCs.

      Result
      Display (DTC output) Proceed to
      P0087 A
      P0087 and other DTCs B

    B

    GO TO DTC CHART Click here

    A

  3. CHECK FUEL PRESSURE (LOW PRESSURE)


    1. Check the fuel pressure Click here.


    NG

    REPLACE FUEL PUMP ASSEMBLY (FOR LOW PRESSURE) Click here

    OK

  4. CHECK MISFIRE COUNT


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG) and turn the tester ON.

    3. Start the engine.

    4. Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Way / Direct.

    5. Allow the engine to idle.

    6. Monitor all of the misfire rate values that are displayed on the tester: Powertrain / Engine / Data List / Misfire / Cylinder #1 Misfire count to Cylinder #8 Misfire count.

      If no misfire counts occur for any of the cylinders, perform the following procedure:


      1. Move the shift lever to the D position.

      2. Monitor all of the misfire rate values that are displayed on the tester.

        Result
        Misfire Count Proceed to
        No misfire counts, or misfire counts occur randomly in all cylinders A
        Misfire counts occur in particular cylinder B

    B

    REPLACE FUEL INJECTOR (FOR DIRECT INJECTION) Click here

    A

  5. INSPECT FUEL RELIEF VALVE


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG) and turn the tester ON.

    3. Start the engine.

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

    5. Write down the Fuel Press value.

    6. Turn the engine switch off.

    7. Wait for 10 seconds.

    8. Turn the engine switch on (IG) and turn the tester ON.

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

    10. Compare the Fuel Press value with the fuel pressure value after the engine switch was turned on (IG).

      Result
      Inspection Result Proceed to
      Fuel Press value is maintained A
      Fuel Press value drops B

    B

    REPLACE FUEL RELIEF VALVE Click here

    A

  6. CHECK FUEL PRESSURE (HIGH PRESSURE)


    1. Check the fuel pressure Click here.


    NG

    REPLACE FUEL PUMP ASSEMBLY (FOR HIGH PRESSURE OF BANK 1 AND BANK 2) Click here

    OK

  7. INSPECT INJECTOR DRIVER (NO. 1 AND NO. 2)


    1. Connect the intelligent tester to the DLC3.

    2. A01GL5JE01

      Replace the No. 1 and No. 2 injector drivers with new or normally functioning ones.

      Note

      Do not disconnect and reconnect the connectors with the engine switch on (IG), as the injector driver (EDU) may be damaged.

    3. Clear the DTC Click here.

    4. Perform the driving test.

    5. Enter the following menus: Powertrain / Engine / DTC.

    6. Read the DTCs.

      Result
      Display (DTC output) Proceed to
      P0087 A
      No output B

    B

    REPLACE INJECTOR DRIVER Click here

    A

  8. REPLACE FUEL PUMP (FOR HIGH PRESSURE OF BANK 1 AND BANK 2)


    1. Replace the fuel pump (for high pressure of bank 1 and bank 2) Click here.


    NEXT

  9. CHECK IF DTC OUTPUT REOCCURS


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG) and turn the tester ON.

    3. Start the engine.

    4. Perform the driving test.

    5. Enter the following menus: Powertrain / Engine / DTC.

    6. Read DTCs.

      Result
      Display (DTC Output) Proceed to
      P0087 A
      No output B

    B

    END

    A

    REPLACE ECM Click here