ECD SYSTEM (w/o DPF), 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 200000 kPa (2039 kgf/cm2, 29000 psi) (1 trip detection logic).


  • Suction control valve

  • Pressure discharge valve (common rail assembly)

  • Open or short in suction 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

  • Target Pump SCV Current

Tech Tips


  • For more information on the fuel supply pump assembly (suction 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 40000 kPa
    3000 rpm (No engine load) Approximately 45000 to 90000 kPa
  • Check "Common Rail Pressure", "Target Common Rail Pressure" and "Target Pump SCV Current" 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 is higher than 200000 kPa (2039 kgf/cm2, 29000 psi). This DTC indicates that: 1) the suction control valve may be stuck open, or 2) there may be a short in the suction 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 is turned off.

WIRING DIAGRAM

A003CXHE47

INSPECTION PROCEDURE

Note


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

  • After replacing the fuel supply pump assembly, the ECM needs 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
      P0088 is output A
      P0088 and "P0190, P0192 and/or P0193" 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
    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 160000 kPa or higher in 3rd and 4th set of freeze frame data B
      Except above A

    B
    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.

      A003DWYE04
      Text in Illustration
      *1 Engine *2 Engine Wire
      *3 Common Rail Assembly (Fuel Pressure Sensor) 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
    A
  4. REPLACE SUCTION CONTROL VALVE


    1. Replace the suction control valve Click here.

      Tech Tips

      Before replacing the suction control valve, check that the wire harness between the suction control valve and ECM is not shorted to ground.

      When there is a malfunction in the wire harness, Target Pump SCV Current is outside the range of 923 to 1123 mA when idling, and outside the range of 1013 to 1212 mA when the engine is running at 2500 rpm without load.

      If there are no problems with the engine condition during idling, it is not necessary to perform the above wire harness inspection.

      When the wire harness between the suction control valve and ECM is not shorted to ground, it can be assumed that DTC P0088 was stored due to a malfunction in the operation of the suction control valve. Therefore, it is necessary to replace the suction control valve.


    NEXT
  5. BLEED AIR FROM FUEL SYSTEM


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


    NEXT
  6. PERFORM FUEL SUPPLY PUMP ASSEMBLY INITIALIZATION


    1. Perform fuel supply pump assembly initialization 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. 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 UNKNOWN, race the engine to 2500 rpm repeatedly for 30 seconds and increase the idling time.


    B
    A
  8. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT
  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.

      A003DWYE04
      Text in Illustration
      *1 Engine *2 Engine Wire
      *3 Common Rail Assembly (Fuel Pressure Sensor) 4 Wire to Wire
      *5 ECM - -
      *a Vibration Method (Reference) - -
      Result
      Result Proceed to
      MIL does not come on A
      MIL comes on B

    A
    B
  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 UNKNOWN, race the engine to 2500 rpm repeatedly for 30 seconds and increase the idling time.


    NEXT