Dtc P0087 Fuel Rail / System Pressure - Too Low

Engine. Lexus Gs430, Gs300. Uzs190 Grs190
3Gr-Fse Engine Control System. Lexus Gs430, Gs300. Uzs190 Grs190

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

VISUAL CHECK

CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0087)

CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST

CHECK MISFIRE COUNT (CYL #1, #2, #3, #4, #5 AND #6)

CHECK FUEL PRESSURE SENSOR

CHECK OPERATION OF FUEL PUMP

CHECK FUEL PRESSURE (LOW PRESSURE)

CHECK FUEL LEAK HIGH PRESSURE FUEL LINE

CHECK RELIEF VALVE

REPLACE FUEL PUMP (HIGH PRESSURE)

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.

Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fse Engine Control System.Sfi System. Dtc P0087 Fuel Rail / System Pressure - Too Low


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)
  1. Fuel pump
  2. High pressure side fuel pump
  3. Fuel pipe (Fuel tank - High pressure side fuel pump)
  4. Fuel pipe (High pressure side fuel pump - Injector)
  5. Fuel injector
  6. Fuel relief valve
  7. Fuel pressure sensor
  8. Fuel pressure regulator
  9. ECM

WIRING DIAGRAM

Refer to DTC P0190 Click here.

INSPECTION PROCEDURE

HINT:
  1. If different DTCs related to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.
  2. Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions 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.
1.VISUAL CHECK

  1. Check around and beneath the car for gasoline leaks, fumes, etc.

    OK:
    No gasoline leaks present.


NG
REPAIR OR REPLACE LEAKING PARTS
OK


2.CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0087)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and turn the tester ON.

  1. Clear DTCs.

  1. Start the engine.

  1. Enter the following menus: Power train / Engine / DTC.

  1. Read the DTCs using the intelligent tester.


Result:
Display (DTC output)
Proceed to
P0087
A
P0087 and other DTCs
B
HINT:
If any other codes besides P0087 are output, perform troubleshooting for those DTCs first.


B
GO TO RELEVANT DTC CHART
A


3.CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST


YES
DTC CAUSED BY RUNNING OUT OF FUEL
NO


4.CHECK MISFIRE COUNT (CYL #1, #2, #3, #4, #5 AND #6)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and turn the tester ON.

  1. Enter the following menus: Power train / Engine / Data List / Cylinder #1 (to 6) Misfire Rate.

  1. Allow the engine to idle.

  1. Read each value of CYL #1 to #6 displayed on the tester.

  1. Check if there is a particular cylinder that the misfire count is concentrated on.


Result:
Misfire Count
Proceed to
No misfire counts, or misfire counts occur randomly in all cylinders
A
Misfire counts occur in particular cylinder
B


B
REPLACE INJECTOR
A


5.CHECK FUEL PRESSURE SENSOR

  1. Connect the intelligent tester to the DLC3.

  1. Start the engine.

  1. Turn the tester ON.

  1. Enter the following menus: Power train / Engine / Data List / Fuel Press.

  1. Check that the fuel pressure fluctuates when the engine condition changes from idling to racing.


Result:
Inspection Result
Proceed to
Fuel pressure does not fluctuate
A
Fuel pressure fluctuates
B
Fuel pressure does not rise
C


A
REPLACE FUEL PRESSURE SENSOR

B
Go to step 8
C


6.CHECK OPERATION OF FUEL PUMP


NG
REPLACE FUEL PUMP
OK


7.CHECK FUEL PRESSURE (LOW PRESSURE)


NG
REPLACE FUEL PRESSURE REGULATOR
OK


8.CHECK FUEL LEAK HIGH PRESSURE FUEL LINE

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and turn the intelligent tester ON.

  1. Enter the following menus: Power train / Engine / Data List / Fuel Press.

  1. Start the engine.

  1. Check that the fuel pressure fluctuations when the engine switch is turned off.


Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fse Engine Control System.Sfi System. Dtc P0087 Fuel Rail / System Pressure - Too Low


Result:
Inspection Result
Proceed to
Fuel pressure is almost constant, or fluctuations are gradual
A
Fuel pressure drops suddenly
B


A
Go to step 10
B


9.CHECK RELIEF VALVE

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and turn the intelligent tester ON.

  1. Enter the following menus: Power train / Engine / Data List / Fuel Press.

  1. Start the engine.

  1. 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


A
REPLACE RELIEF VALVE
B


10.REPLACE FUEL PUMP (HIGH PRESSURE)

NEXT


11.CHECK IF DTC OUTPUT REOCCURS (SEE IF DTC P0087 IS OUTPUT AGAIN)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and turn the tester ON.

  1. Clear DTCs.

  1. Start the engine.

  1. Enter the following menus: Power train / Engine / DTC

  1. Read the DTCs using the intelligent tester.


Result:
Display (DTC output)
Proceed to
P0087
A
No output
B


B
SYSTEM OK
A

REPLACE ECM