Lexus IS250 IS220d GSE20 ALE20 4GR-FSE ENGINE CONTROL SYSTEM
CHECK FUEL LEAKAGE (HIGH PRESSURE SIDE)
CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0087)
CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST
CHECK MISFIRE COUNT (CYL #10, #20, #30, #40, #50 AND #60)
CHECK FUEL PRESSURE (LOW PRESSURE SIDE)
CHECK FUEL LEAKAGE (HIGH PRESSURE FUEL LINE)
REPLACE FUEL PUMP (HIGH PRESSURE SIDE)
CHECK IF DTC OUTPUT REOCCURS (SEE IF DTC P0087 IS OUTPUT AGAIN)
DTC P0087 Fuel Rail / System Pressure - Too Low
DESCRIPTION
The high-pressure fuel system consists of the spill valve, pump plunger, check valve, relief valve and fuel pressure sensor. The spill valve opens and closes the low-pressure fuel line (from the fuel tank), the pump plunger operated by the camshaft pressurizes fuel, the check valve mechanically opens and closes the high pressure fuel line (to the fuel delivery pipe), the relief valve prevents fuel pressure from becoming extremely high, and the fuel pressure sensor located on the fuel delivery pipe monitors fuel pressure.
The high-pressure side fuel pump is installed to the cylinder head cover (bank 1) and is driven by the cam located at the rear end of the exhaust camshaft.
Let the plunger moves up and down by the camshaft rotations, it produces vacuum to suck fuel and pressurizes the fuel. This fuel then pushes the check valve open and flows into the fuel delivery pipe. The ECM opens and closes the spill valve to regulate the fuel pressure to the target fuel pressure 4 to 13 MPa (40.8 to 132.6 kgf/cm2, 580 to 1,885 psi). In order to obtain and maintain the target pressure, the ECM monitors the fuel pressure using the fuel pressure sensor and performs the feedback control.
If the internal fuel pressure of the fuel delivery pipe exceeds the standard pressure 15 MPa (153 kgf/cm2, 2,175 psi), the fuel relief valve installed on gateway of the fuel delivery pipe discharges the fuel pressure and then returns the fuel back to the fuel tank.
| DTC No. | DTC Detection Condition | Trouble Area |
| P0087 | Despite ECM commanded that the high pressure fuel pump opens the spill valve, fuel pressure decreases 5 MPa (51.0 kgf/cm2, 725 psi) for more than 10 seconds (1 trip detection logic) | Fuel pump High pressure side fuel pump Fuel pipe (Fuel tank - High pressure side fuel pump) Fuel pipe (High pressure side fuel pump - Injector) Fuel injector Fuel relief valve Fuel pressure sensor Fuel pressure regulator ECM |
WIRING DIAGRAM
Refer to DTC P0190 .
INSPECTION PROCEDURE
- HINT:
| 1.CHECK FUEL LEAKAGE (HIGH PRESSURE SIDE) |
Check around and beneath the car for gasoline leaks, fumes, etc.
- OK:
- No gasoline leaks present.
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| C | |
| 6.CHECK OPERATION OF FUEL PUMP |
Check the fuel pump operation.
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| B | |
| 9.CHECK RELIEF VALVE |
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG) and turn the intelligent tester ON.
Enter the following menus: Power train / Engine / Data List / Fuel Press.
Start the engine.
Check that the fuel pressure fluctuations when the fuel hose is pressed with your fingers.
- Result:
Inspection Result Proceed to Pressing the hose raises the fuel pressure slightly A Fuel pressure does not fluctuate B
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| B | |
| 10.REPLACE FUEL PUMP (HIGH PRESSURE SIDE) |
| NEXT | |
| 11.CHECK IF DTC OUTPUT REOCCURS (SEE IF DTC P0087 IS OUTPUT AGAIN) |
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG) and turn the tester ON.
Clear DTCs.
Start the engine.
Enter the following menus: Power train / Engine / DTC.
Read the DTCs using the intelligent tester.
- Result:
Display (DTC output) Proceed to P0087 A No output B
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| A | ||
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