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Home >> Lexus >> 2008 >> IS F >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - SFI System Diagnostics (1 Of 4) >> DTC P0087 Fuel Rail / System Pressure - Too Low >> Description

DTC P0087 Fuel Rail / System Pressure - Too Low: Description

The direct injection high-pressure fuel system has a 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 the 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 lobe located at the rear end of each intake camshaft When the plunger moves up and down due to camshaft rotation, 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

Fig 1: Fuel Rail/System Pressure Flow Diagram (Too Low)
G05751462Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
DTC DETECTION CONDITION CHART

DTC No. DTC Detection Condition Trouble Area
P0087 Even though ECM commands fuel pump for high pressure to open spill control valve, fuel pressure decreases 5 MPa (51 0 kgf/cm2 , 725 psi) from target pressure for more than 10 seconds (1 trip detection logic)
  • Leak of fuel
  • Fuel pipe (Fuel tank - Fuel pump for high pressure [bank 1 or bank 2])
  • Fuel pipe (Fuel pump for high pressure - Fuel injector [for direct injection])
  • Fuel injector (for direct injection)
  • Fuel relief valve
  • Fuel pump for high pressure (bank 1)
  • Fuel pump for high pressure (bank 2)
  • Injector driver (No 1)
  • Injector driver (No 2)
  • ECM