P0087
2GR-FSE ENGINE CONTROL: SFI SYSTEM: P0087: Fuel Rail / System Pressure - Too Low
P0087 - Fuel Rail / System Pressure - Too Low
DESCRIPTION
The high-pressure fuel system consists of the spill control valve, pump plunger, check valve, relief valve and fuel pressure sensor. The spill control 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 fuel pump for high pressure is installed to the cylinder head cover (bank 1) and is driven by the cam located at the rear end of the exhaust camshaft.
The plunger moves up and down by the camshaft rotations, and produces a 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 control valve to regulate the fuel pressure to the target fuel pressure of 4000 to 13000 kPa (40.8 to 132.6 kgf/cm2, 580 to 1885 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 of 15.3 MPa (156 kgf/cm2, 2219 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.
Text in Illustration
MONITOR DESCRIPTION
If the fuel pressure decreases even after the ECM commands the high-pressure fuel pump to close the spill control valve, a DTC is output.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
CONFIRMATION DRIVING PATTERN
1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG) and turn the Techstream on.
3. Record the Freeze Frame Data.
4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) Reading and Clearing Diagnostic Trouble Codes.
5. Turn the engine switch off and wait for 30 seconds.
6. Turn the engine switch on (IG) and turn the Techstream on.
7. Based on engine rpm, engine load and other freeze frame data stored in the ECM, reproduce the conditions present when the DTC was stored.
8. Enter the following menus: Powertrain / Engine / Trouble Codes.
9. Read the DTC.
HINT
- If a DTC is output, the system is malfunctioning.
- If a DTC is not output, perform the following procedure.
10. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
11. Input the DTC: P0087.
12. Check the DTC judgment result.
HINT
- If the judgment result shown ABNORMAL, the system has a malfunction.
- If the judgment result shows NORMAL, the system is normal.
13. If the test result is INCOMPLETE or UNKNOWN and no DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.
HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.
INSPECTION PROCEDURE
HINT
Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
PROCEDURE
1. CHECK FUEL LEAK (HIGH PRESSURE SIDE)
(a) Check around and beneath the car for gasoline leaks, fumes, etc.
OK:
No gasoline leaks present.
NG -- REPAIR OR REPLACE FUEL LEAK POINT
OK -- Continue to next step.
2. CHECK OTHER DTCs OUTPUT (IN ADDITION TO DTC P0087)
(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:
HINT
If any DTCs other than P0087 are output, troubleshoot those DTCs first.
B -- GO TO DTC CHART SFI System
A -- Continue to next step.
3. CHECK FUEL PRESSURE (LOW PRESSURE SIDE)
(a) Check the fuel pressure Fuel System.
NG -- CHECK FUEL PUMP OPERATION
OK -- Continue to next step.
4. CHECK MISFIRE COUNT
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG) and turn the Techstream ON.
(c) Start the engine.
(d) Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Way / Direct.
(e) Allow the engine to idle.
(f) Monitor all of the misfire count values that are displayed on the Techstream: Powertrain / Engine / Data List / Misfire / Cylinder #1 Misfire count to Cylinder #6 Misfire count.
If no misfire counts occur for any of the cylinders, perform the following procedure:
(1) Move the shift lever to D.
(2) Monitor all of the misfire rate values that are displayed on the Techstream.
Result:
B -- REPLACE FUEL INJECTOR FOR DIRECT INJECTION Removal
A -- Continue to next step.
5. INSPECT FUEL RELIEF VALVE
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG) and turn the Techstream ON.
(c) Start the engine.
(d) Enter the following menus: Powertrain / Engine / Data List / Fuel Press.
(e) Record the Fuel Press value.
(f) Turn the engine switch off.
(g) Wait for 10 seconds.
(h) Turn the engine switch on (IG) and turn the Techstream ON.
(i) Enter the following menus: Powertrain / Engine / Data List / Fuel Press.
(j) Compare the Fuel Press value recorded with the engine running to the Fuel Press value currently shown on the Techstream.
Result:
B -- REPLACE FUEL RELIEF VALVE
A -- Continue to next step.
6. REPLACE FUEL PUMP ASSEMBLY (FOR HIGH PRESSURE)
HINT
Replace the fuel pump assembly for high pressure Fuel System.
NEXT -- Continue to next step.
7. CHECK WHETHER DTC OUTPUT RECURS
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG) and turn the Techstream ON.
(c) Clear the DTCs.
(d) Start the engine.
(e) Perform the driving test.
(f) Enter the following menus: Powertrain / Engine / Trouble Codes.
(g) Read the DTCs.
Result:
B -- END
A -- REPLACE ECM Removal
8. CHECK FUEL PUMP OPERATION
(a) Check the fuel pump operation Fuel System.
NG -- REPLACE FUEL PUMP (LOW PRESSURE SIDE) Removal
OK -- CHECK AND REPLACE FUEL SYSTEM (PRESSURE REGULATOR, PIPE LINE AND FILTER)