P0088

1UR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0088: Fuel Rail / System Pressure - Too High

DTC P0088 - Fuel Rail / System Pressure - Too High

DESCRIPTION

The cylinder fuel injection method high-pressure fuel system consists of the spill control valve, pump plunger and check valve. The spill control valve adjusts the discharge amount of the high-pressure fuel, the pump plunger operated by the camshaft pressurizes fuel, the check valve mechanically opens and closes the line to the fuel delivery pipe. The fuel pump for high pressure is installed to the cylinder head cover (bank 1 and bank 2) and is driven by the cam located at the rear end of the intake camshaft. When the plunger moves up and down by the camshaft rotations, it pressurizes the fuel. The pressurized fuel then pushes open the check valve, and the fuel flows to the fuel delivery pipe. The ECM controls the spill control valve to adjust the fuel pressure to 4 to 13 MPa (41 to 133 kgf/cm2). The ECM receives signals from the fuel pressure sensor, monitors the fuel pressure, and maintains the target fuel pressure. If the fuel pressure of the fuel delivery pipe exceeds 15.3 MPa (156 kgf/cm2), the fuel relief valve opens and returns the fuel to the fuel tank.














MONITOR DESCRIPTION

If the fuel pressure does not decrease even after the ECM commands the high-pressure fuel pump to open the spill control valve, a DTC is output.
If there is minimal difference between the fuel pressure before and after the fuel relief valve operates, a DTC is output.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





INSPECTION PROCEDURE
HINT: Read freeze frame data using the Techstream. 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, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

1. CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0088)
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG) and turn the Techstream ON.
(c) Enter the following menus: Powertrain / Engine / Trouble Codes.
(d) Read the DTCs.
Result:






B -- GO TO DTC CHART SFI System
A -- Continue to next step.

2. READ VALUE USING TECHSTREAM (FREEZE FRAME DATA)
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG) and turn the Techstream ON.
(c) Enter the following menus: Powertrain / Engine / Trouble Codes.
(d) Read the freeze frame data.
Result:






B -- REPLACE FUEL PUMP (FOR HIGH PRESSURE [BANK 2])
A -- Continue to next step.

3. PERFORM ACTIVE TEST USING TECHSTREAM (CHECK FUEL PUMP FOR HIGH PRESSURE [BANK1])
(a) Connect the Techstream to the DLC3.
(b) Start the engine and turn the Techstream ON.
(c) Enter the following menus: Powertrain / Engine / Active Test / Control the Target Fuel Press / All Data / Fuel Press.
(d) Check that the fuel pressure fluctuates when the target fuel pressure changes.
HINT: The Active Test operation lowers the target fuel pressure by 12.5% or increase the target fuel pressure 25%.

OK:
Fuel pressure fluctuates.
NG -- REPLACE FUEL PUMP (FOR HIGH PRESSURE [BANK 2])
OK -- Continue to next step.

4. REPLACE FUEL PUMP (FOR HIGH PRESSURE [BANK 1])
(a) Replace the fuel pump (for high pressure) Removal.
NEXT -- Continue to next step.

5. CHECK IF DTC OUTPUT REOCCURS (SEE IF DTC P0088 IS OUTPUT AGAIN)
(a) Clear DTCs DTC Check / Clear.
(b) Connect the Techstream to the DLC3.
(c) Start the engine and turn the Techstream ON.
(d) Enter the following menus: Powertrain / Engine / Trouble Codes.
(e) Read the DTCs.
Result:






B -- END
A -- REPLACE ECM
6. REPLACE FUEL PUMP (FOR HIGH PRESSURE [BANK 2])
(a) Replace the fuel pump (for high pressure) Removal.
NEXT -- Continue to next step.

7. CHECK IF DTC OUTPUT REOCCURS (SEE IF DTC P0088 IS OUTPUT AGAIN)
(a) Clear DTCs DTC Check / Clear.
(b) Connect the Techstream to the DLC3.
(c) Start the engine and turn the Techstream ON.
(d) Enter the following menus: Powertrain / Engine / Trouble Codes.
(e) Read the DTCs.
Result:






B -- END
A -- REPLACE ECM