| DTC Code | DTC Name |
|---|---|
| P0088 | Fuel Rail / System Pressure - Too High |
DESCRIPTION
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Memory |
|---|---|---|---|---|---|
| P0088 | Fuel Rail / System Pressure - Too High | The fuel pressure of the common rail exceeds 200000 kPa (2039 kgf/cm2, 29000 psi) (1 trip detection logic). |
|
Comes on | DTC stored |
| DTC No. | Data List |
|---|---|
| P0088 |
|
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 / Data List / Common Rail Pressure.
| Engine Speed | Common Rail Pressure |
|---|---|
| Idling | Approximately 28000 to 40000 kPa |
| 3000 rpm (No engine load) | Approximately 30000 to 60000 kPa |
Check "Common Rail Pressure", "Target Common Rail Pressure" and "Target Pump SCV Current" in the freeze frame data.
CONFIRMATION DRIVING PATTERN
| DTC Detection Drive Pattern | After idling for 60 seconds, quickly increase engine speed to 2500 rpm repeatedly for 30 seconds |
MONITOR DESCRIPTION
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 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
CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0088)
Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Enter the following menus: Powertrain / Engine / Trouble Codes.
Read Current DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
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 |
|
CHECK FREEZE FRAME DATA (COMMON RAIL PRESSURE)
Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Enter the following menus: Powertrain / Engine / Trouble Codes.
Record the stored DTCs and freeze frame data.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
GO TO STEP 4 Click here |
| A |
|
INSPECT ECM (FUEL PRESSURE SENSOR OUTPUT VOLTAGE)
| *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.
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 | ||||||
|---|---|---|---|---|---|---|
|
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR Click here |
| A |
|
REPLACE FUEL SUPPLY PUMP ASSEMBLY (SUCTION CONTROL VALVE)
Replace the fuel supply pump assembly.
Tech Tips
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.
| Result | ||
|---|---|---|
|
| NEXT |
|
BLEED AIR FROM FUEL SYSTEM
Bleed the air from the fuel system.
| Result | ||
|---|---|---|
|
| NEXT |
|
PERFORM FUEL SUPPLY PUMP INITIALIZATION
Perform fuel supply pump initialization.
| Result | ||
|---|---|---|
|
| NEXT |
|
CHECK DTC OUTPUT
Connect the GTS to the DLC3.
Clear the DTCs.
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 GTS to determine whether or not the DTC judgment has been carried out.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
| Tester Display |
|---|
| All Readiness |
Input DTC P0088.
Check the DTC judgment result.
| Result | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
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 |
|
REPLACE ECM
Replace the ECM.
| Result | ||
|---|---|---|
|
| NEXT |
|
GO TO STEP 13 Click here |
REPAIR OR REPLACE HARNESS OR CONNECTOR
Repair or replace the harness or connector.
| Result | ||
|---|---|---|
|
| NEXT |
|
INSPECT ECM (FUEL PRESSURE SENSOR OUTPUT VOLTAGE)
| *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.
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 | ||||||
|---|---|---|---|---|---|---|
|
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
GO TO STEP 13 Click here |
| A |
|
REPLACE COMMON RAIL ASSEMBLY
Replace the common rail assembly.
| Result | ||
|---|---|---|
|
| NEXT |
|
BLEED AIR FROM FUEL SYSTEM
Bleed the air from the fuel system.
| Result | ||
|---|---|---|
|
| NEXT |
|
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
Connect the GTS to the DLC3.
Clear the DTCs.
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 GTS to determine whether or not the DTC judgment has been carried out.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
| Tester Display |
|---|
| All Readiness |
Input DTC P0088.
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.
| Result | ||
|---|---|---|
|
| NEXT |
|
END |