SFI SYSTEM, Diagnostic DTC:P0088

DTC Code DTC Name
P0088 Fuel Rail / System Pressure - Too High

DESCRIPTION

Refer to DTC P0087 Click here.

DTC No. DTC Detection Condition Trouble Area
P0088

ECM did not command fuel pump for high pressure to open spill control valve, but fuel pressure increases 3 MPa (30.6 kgf/cm2, 435 psi) from target pressure for more than 10 seconds

(1 trip detection logic)

  • Fuel pump for high pressure (bank 1)

  • Fuel pump for high pressure (bank 2)

  • Fuel pressure sensor

  • Fuel relief valve

  • ECM

MONITOR DESCRIPTION

If the fuel pressure does not decrease even after the ECM commands the high-pressure fuel pump to open the spill control valve, a DTC is output.

If there is minimal difference between the fuel pressure before and after the fuel relief valve operates, a DTC is output.

INSPECTION PROCEDURE

Tech Tips


  • Bank 1 refers to the bank that includes the No. 1 cylinder*.

    *: The No. 1 cylinder is the cylinder which is farthest from the transmission.

  • Bank 2 refers to the bank that does not include the No. 1 cylinder.

  • Read freeze frame data using the intelligent tester. 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 running or stopped, 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 OTHER DTCS OUTPUT (IN ADDITION TO DTC P0088)


    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
      P0088 A
      P0088 and other DTCs B

      Tech Tips

      If any DTCs other than P0088 are output, troubleshoot those DTCs first.


    B

    GO TO DTC CHART Click here

    A

  2. CHECK FUEL LINE (FOR HIGH PRESSURE)


    1. Check the fuel line for blockage.


    NG

    REPAIR OR REPLACE FUEL LINE

    OK

  3. CHECK FUEL PRESSURE SENSOR


    1. Connect the intelligent tester to the DLC3.

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

    3. Record the freeze frame data.

    4. Clear the DTCs.

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

    6. Check that fuel pressure fluctuates when the engine is raced.

      OK
      Fuel pressure fluctuates.

    NG

    REPLACE FUEL PRESSURE SENSOR Click here

    OK

  4. READ VALUE USING INTELLIGENT TESTER (FREEZE FRAME DATA)


    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 freeze frame data.

      Result
      Display Proceed to
      Output while driving A
      Output while idling B

    B

    REPLACE FUEL PUMP (FOR HIGH PRESSURE [BANK 1]) Click here

    A

  5. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CHECK FUEL PUMP FOR HIGH PRESSURE)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine and turn the tester on.

    3. Enter the following menus: Powertrain / Engine / Active Test / Control the Target Fuel Pressure / Data List / Fuel Press.

    4. Check that the fuel pressure fluctuates when the target fuel pressure changes.

      Tech Tips

      The Active Test operation lowers the target fuel pressure by 12.5% or increases the target fuel pressure 25%.

      OK
      Fuel pressure fluctuates.

    NG

    REPLACE FUEL PUMP (FOR HIGH PRESSURE [BANK 1]) Click here

    OK

  6. REPLACE FUEL PUMP (FOR HIGH PRESSURE [BANK 2])


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


    NEXT

  7. CHECK IF DTC OUTPUT REOCCURS (SEE IF DTC P0088 IS OUTPUT AGAIN)


    1. Clear DTCs Click here.

    2. Connect the intelligent tester to the DLC3.

    3. Start the engine and turn the tester on.

    4. Perform the driving test.

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

    6. Read the DTCs.

      Result
      Display (DTC output) Proceed to
      No output A
      P0088 B

    B

    INSPECT FUEL RELIEF VALVE Click here

    A

    END

  8. REPLACE FUEL PUMP (FOR HIGH PRESSURE [BANK 1])


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


    NEXT

  9. CHECK IF DTC OUTPUT REOCCURS (SEE IF DTC P0088 IS OUTPUT AGAIN)


    1. Clear DTCs Click here.

    2. Connect the intelligent tester to the DLC3.

    3. Start the engine and turn the tester on.

    4. Perform the driving test.

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

    6. Read the DTCs.

      Result
      Display (DTC output) Proceed to
      No output A
      P0088 B

    B

    INSPECT FUEL RELIEF VALVE Click here

    A

    END

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

    4. Start the engine.

    5. Check the fuel pressure.

      Result
      Tester Display Result Proceed to
      Fuel Press

      Below 15.3 MPa (156.0 kgf/cm2, 2219 psi)

      		 A

      15.3 MPa (156.0 kgf/cm2, 2219 psi) or more

      		 B

    B

    REPLACE FUEL RELIEF VALVE Click here

    A

    REPLACE ECM Click here