Dtc P0088 Fuel Rail / System Pressure - Too High

DESCRIPTION

MONITOR DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

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

CHECK FREEZE FRAME DATA (FUEL PRESS)

INSPECT ECM (FUEL PRESSURE SENSOR OUTPUT VOLTAGE)

REPLACE FUEL SUPPLY PUMP ASSEMBLY (SUCTION CONTROL VALVE)

BLEED AIR FROM FUEL SYSTEM

PERFORM FUEL SUPPLY PUMP INITIALIZATION

CHECK DTC OUTPUT

REPLACE ECM

REPAIR OR REPLACE HARNESS OR CONNECTOR

INSPECT ECM (FUEL PRESSURE SENSOR OUTPUT VOLTAGE)

REPLACE COMMON RAIL ASSEMBLY

BLEED AIR FROM FUEL SYSTEM

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

DESCRIPTION

HINT:

1. For more information on the fuel supply pump assembly (suction control valve) and common rail system, refer to System Description (Toyota Fortuner RM0000012WW024X.html).
   
2. 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 / Fuel Press.
   
   

   Reference

   Engine Speed	Fuel Press
   Idling	Approximately 28000 to 40000 kPa
   3000 rpm (No engine load)	Approximately 30000 to 60000 kPa

3. Check "Fuel Press", "Target Common Rail Pressure" and "Target Pump SCV Current" in the freeze frame data.
   

MONITOR DESCRIPTION

1. 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

INSPECTION PROCEDURE

NOTICE:

1. After replacing the ECM, the new ECM needs registration (Toyota Fortuner RM0000012XK04BX.html) and initialization (Toyota Fortuner RM000000TIN04NX.html).
   
2. After replacing the fuel supply pump assembly, the ECM needs initialization (Toyota Fortuner RM000000TIN04NX.html).
   

HINT:

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, and other data from the time the malfunction occurred.

1. Connect the intelligent tester to the DLC3.
   

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

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

4. Read Current DTCs.
   
   

   Result

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

   HINT:

   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.

1. Connect the intelligent tester to the DLC3.
   

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

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

4. Record the stored DTCs and freeze frame data.
   
   

   Result

   Result	Proceed to
   Value of Fuel Press is shifting towards 160000 kPa or higher in 3rd and 4th set of freeze frame data	B
   Except above	A

1. Connect the positive (+) probe of an oscilloscope to the fuel pressure sensor input terminal of the ECM connector and the negative (-) probe to the body ground.
   

2. Turn the ignition switch to ON.
   

3. Check for any noise in the waveform when vibration is applied to the wire harness and connectors between the fuel pressure sensor and ECM.
   

   
   
   
   
   
   
   
   

   Standard Voltage:

   Tester Connection	Condition	Specified Condition
   E7-26 (PCR1) - Body ground	Vibration is applied to the wire harness and connectors	No noise in the waveform

   Text in Illustration

   *a	Component with harness connected (ECM)

   
   

   Result

   Result	Proceed to
   MIL comes on or noise present in the waveform	B
   Except above	A

1. Replace the fuel supply pump assembly (Toyota Fortuner RM0000014FO006X.html).
   

   HINT:

   Before replacing the fuel supply pump assembly, 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 fuel supply pump assembly.

1. Bleed the air from the fuel system (Toyota Fortuner RM0000014FK006X_01_0002.html).
   

1. Perform fuel supply pump initialization (Toyota Fortuner RM000000TIN04NX.html).
   

1. Connect the intelligent tester to the DLC3.
   

2. Clear the DTCs (Toyota Fortuner RM0000012WY00RX.html).
   

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.
   

   HINT:

   Perform the following procedure using the tester 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

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

      HINT:

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

1. Replace the ECM (Toyota Fortuner RM0000013Z0004X.html).
   

1. Repair or replace the harness or connector.
   

1. Connect the positive (+) probe of an oscilloscope to the fuel pressure sensor input terminal of the ECM connector and the negative (-) probe to the body ground.
   

2. Turn the ignition switch to ON.
   

3. Check for any noise in the waveform when vibration is applied to the wire harness and connectors between the fuel pressure sensor and ECM.
   

   Standard Voltage:

   Tester Connection	Condition	Specified Condition
   E7-26 (PCR1) - Body ground	Vibration is applied to the wire harness and connectors	No noise in the waveform

   Text in Illustration

   *a	Component with harness connected (ECM)

   
   

   Result

   Result	Proceed to
   MIL comes on or noise present in the waveform	A
   Except above	B

1. Replace the common rail assembly (Toyota Fortuner RM000002SY501VX.html).
   

1. Bleed the air from the fuel system (Toyota Fortuner RM0000014FK006X_01_0002.html).
   

1. Connect the intelligent tester to the DLC3.
   

2. Clear the DTCs (Toyota Fortuner RM0000012WY00RX.html).
   

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.
   

   HINT:

   Perform the following procedure using the tester 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.