ECD SYSTEM, Diagnostic DTC:P0088

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

DESCRIPTION

P0088
DTC Detection Drive Pattern DTC Detection Condition Trouble Area
After idling for 60 seconds, quickly increase engine speed to 2500 rpm repeatedly for 30 seconds

The fuel pressure of the common rail exceeds 240000 kPa (2447 kgf/cm2, 34800 psi) (1 trip detection logic).

  • Pre-stroke control valve (fuel supply pump assembly)

  • Pressure discharge valve (common rail assembly)

  • Open or short in pre-stroke control valve circuit

  • Fuel pressure sensor (common rail assembly)

  • ECM
Related Data List
DTC No. Data List
P0088

  • Common Rail Pressure

  • Target Common Rail Pressure

Tech Tips


  • For more information on the fuel supply pump assembly (pre-stroke control valve) and common rail system, refer to System Description Click here.

  • When DTC P0088 is stored, check the internal fuel pressure of the common rail by entering the following menus: Powertrain / Engine and ECT / Data List / Common Rail Pressure.

    Reference
    Engine Speed Common Rail Pressure
    Idling Approximately 30000 to 50000 kPa
    3000 rpm (No engine load) Approximately 80000 to 110000 kPa

  • Check "Common Rail Pressure" and "Target Common Rail Pressure" in the freeze frame data.

MONITOR DESCRIPTION

P0088 (Internal fuel pressure too high):

The ECM stores this DTC if the fuel pressure inside the common rail assembly is higher than 240000 kPa (2447 kgf/cm2, 34800 psi). This DTC indicates that: 1) the pre-stroke control valve may be stuck open, or 2) there may be a short in the pre-stroke control valve circuit.

If this DTC is stored, the ECM enters fail-safe mode and limits the engine power. The ECM continues operating in fail-safe mode until the ignition switch off.

INSPECTION PROCEDURE

Note

After replacing the ECM, the new ECM needs registration Click here and initialization Click here.

Tech Tips

Read freeze frame data using the GTS. 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, and other data from the time the malfunction occurred.

PROCEDURE


  1. CHECK FOR ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0088)


    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 and ECT / Trouble Codes.

    4. Read Current DTCs.

      Result
      Result Proceed to
      DTC P0088 is output A
      DTC P0088 and "P0190, P0192 and/or P0193" are output B

      Tech Tips

      When there is an open circuit in the fuel pressure sensor circuit, the fuel pressure sensor outputs the maximum value. Therefore, P0088 may be stored together with DTCs which indicate common rail fuel pressure sensor circuit malfunctions.


    B

    GO TO FUEL RAIL PRESSURE SENSOR CIRCUIT Click here

    A

  2. CHECK FREEZE FRAME DATA (COMMON RAIL PRESSURE)


    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 and ECT / Trouble Codes.

    4. Record the stored DTCs and freeze frame data.

      Result
      Result Proceed to
      Value of Common Rail Pressure is shifting towards 200000 kPa or higher in 3rd and 4th set of freeze frame data B
      Except above A

    B

    REPLACE FUEL SUPPLY PUMP ASSEMBLY Click here

    A

  3. INSPECT ECM (FUEL PRESSURE SENSOR OUTPUT VOLTAGE)

    Tech Tips

    If the MIL has illuminated before in the past, clear the DTC using the GTS before performing this inspection Click here.


    1. Check it the MIL illuminates up when vibration is applied to the wire harness and connectors between the fuel pressure sensor and ECM.

      B007PIME01
      Text in Illustration
      *1 Engine *2 Common Rail Assembly (Fuel Pressure Sensor)
      *3 Engine Wire *4 Wire to Wire
      *5 ECM - -
      *a Vibration Method (Reference) - -
      Result
      Result Proceed to
      MIL does not come on A
      MIL comes on B

    B

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

    A

  4. PERFORM ACTIVE TEST USING GTS (ACTIVATE THE PRE-STROKE CONTROL VALVE)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the Pre-stroke Control Valve

    5. Perform the Active Test and check that operation sounds can be heard from the pre-stroke control valve.

      Tech Tips


      • Perform this procedure with the engine stopped and check the operation sounds from outside the vehicle.

      • Check in a quiet location with the hood opened, as the operation sound is difficult to hear.

      • In order to distinguish between the operation sounds of other actuators, check by using the GTS to turn the Active Test open and close several times.

      OK
      The operation sound is generated when performing the Active Test, and stops when finished.

    OK

    REPLACE ECM Click here

    NG

  5. REPLACE FUEL SUPPLY PUMP ASSEMBLY


    1. Replace the fuel supply pump assembly Click here.


    NEXT

  6. BLEED AIR FROM FUEL SYSTEM


    1. Bleed the air from the fuel system Click here.


    NEXT

  7. CHECK DTC OUTPUT


    1. Connect the GTS to the DLC3.

    2. Clear the DTCs Click here.

    3. Turn the ignition switch off for 30 seconds or more.

    4. Turn the ignition switch to ON and start the engine.

    5. After idling for 60 seconds, increase the engine speed from idling to 2500 rpm repeatedly for 30 seconds.

    6. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    7. Confirm that the DTC is not output again.

      Tech Tips

      Perform the following procedure using the GTS to determine whether or not the DTC judgment has been carried out.


      1. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

      2. Input DTC P0088.

      3. Check the DTC judgment result.

        Result
        GTS Display Result Proceed to
        Pending DTC P0088 is output A
        All Readiness NORMAL B
        ABNORMAL A

        Tech Tips

        If STATUS is INCOMPLETE or N/A, race the engine to 2500 rpm repeatedly for 30 seconds and increase the idling time.


    B

    END

    A

  8. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  9. REPAIR OR REPLACE HARNESS OR CONNECTOR


    1. Repair or replace the harness or connector.


    NEXT

  10. INSPECT ECM (FUEL PRESSURE SENSOR OUTPUT VOLTAGE)

    Tech Tips

    If the MIL has illuminated before in the past, clear the DTC using the GTS before performing this inspection Click here.


    1. Check it the MIL illuminates up when vibration is applied to the wire harness and connectors between the fuel pressure sensor and ECM.

      B007PIME01
      Text in Illustration
      *1 Engine *2 Common Rail Assembly (Fuel Pressure Sensor)
      *3 Engine Wire *4 Wire to Wire
      *5 ECM - -
      *a Vibration Method (Reference) - -
      Result
      Result Proceed to
      MIL comes on A
      MIL does not come on B

    B

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

    A

  11. REPLACE COMMON RAIL ASSEMBLY


    1. Replace the common rail assembly Click here.


    NEXT

  12. BLEED AIR FROM FUEL SYSTEM


    1. Bleed the air from the fuel system Click here.


    NEXT

  13. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the GTS to the DLC3.

    2. Clear the DTCs Click here.

    3. Turn the ignition switch off for 30 seconds or more.

    4. Turn the ignition switch to ON and start the engine.

    5. After idling for 60 seconds, increase the engine speed from idling to 2500 rpm repeatedly for 30 seconds.

    6. Confirm that the DTC is not output again.

      Tech Tips

      Perform the following procedure using the GTS to determine whether or not the DTC judgment has been carried out.


      1. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

      2. Input DTC P0088.

      3. Check that STATUS is NORMAL. If STATUS is INCOMPLETE or N/A, race the engine to 2500 rpm repeatedly for 30 seconds and increase the idling time.


    NEXT

    END