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 200000 kPa (2039 kgf/cm², 29000 psi) (1 trip detection logic).	Suction control valve Pressure discharge valve (common rail) Open or short in suction control valve circuit Fuel pressure sensor (common rail) 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 (See page ).

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 75000 kPa

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

Click here

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


*a	Suction Control Valve

CAUTION / NOTICE / HINT

Note

After replacing the ECM, the new ECM needs registration (See page ) and initialization Click here.
After replacing the fuel supply pump assembly, the ECM needs initialization (See page ).

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, and other data from the time the malfunction occurred.

PROCEDURE

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

Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON and turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / DTC.

Read Current DTCs.

Result
Result	Proceed to
P0088	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.

GO TO FUEL RAIL PRESSURE SENSOR CIRCUIT Click here

CHECK FREEZE FRAME DATA (COMMON RAIL PRESSURE)

Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON and turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / DTC.

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

REPLACE SUCTION CONTROL VALVE Click here

INSPECT ECM (FUEL PRESSURE SENSOR OUTPUT VOLTAGE)

Text in Illustration

*a
Component with harness connected

(ECM)

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.
Turn the ignition switch to ON.

Text in Illustration
*a	Component with harness connected (ECM)

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
C90-16 (PCR1) - Body ground	Vibration is applied to the wire harness and connectors	No noise in the waveform

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

REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

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
BLEED AIR FROM FUEL SYSTEM
1. Bleed the air from the fuel system Click here.
NEXT
PERFORM FUEL SUPPLY PUMP INITIALIZATION
1. Perform fuel supply pump initialization Click here.
NEXT

CHECK DTC OUTPUT

Connect the intelligent tester to the DLC3.
Clear the DTCs Click here.
Turn the ignition switch off for 30 seconds or more.
Turn the ignition switch to ON and start the engine.
After idling for 60 seconds, increase the engine speed from idling to 2500 rpm repeatedly for 30 seconds.

Confirm that the DTC is not output again.

Tech Tips

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

Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input DTC P0088.

Check the DTC judgment result.

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

END

REPLACE ECM
1. Replace the ECM Click here.
NEXT
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here
REPAIR OR REPLACE HARNESS OR CONNECTOR
1. Repair or replace the harness or connector.
NEXT

INSPECT ECM (FUEL PRESSURE SENSOR OUTPUT VOLTAGE)

Text in Illustration

*a
Component with harness connected

(ECM)

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.
Turn the ignition switch to ON.

Text in Illustration
*a	Component with harness connected (ECM)

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
C90-16 (PCR1) - Body ground	Vibration is applied to the wire harness and connectors	No noise in the waveform

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

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

REPLACE COMMON RAIL ASSEMBLY
1. Replace the common rail Click here.
NEXT
BLEED AIR FROM FUEL SYSTEM
1. Bleed the air from the fuel system Click here.
NEXT
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
1. Connect the intelligent tester 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 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 N/A, race the engine to 2500 rpm repeatedly for 30 seconds and increase the idling time.
NEXT
END