DTC P0088 Fuel Rail / System Pressure - Too High: Description
The D-4S (Direct Injection 4-stroke Gasoline Engine Superior Version) is a high-pressure fuel system. It consists of the following: 1) a spill control valve, which adjusts the discharge amount of the high-pressure fuel; 2) a pump plunger, which operates with the camshaft and pressurizes the fuel; and 3) a check valve, which mechanically opens and closes the pathway to the fuel delivery pipe.
The high-pressure fuel pump is installed on the cylinder head cover (bank 1). It operates with the rear tip of the exhaust camshaft. As the camshaft rotates, the pump plunger is moved up and down, the fuel is pressurized, the high-pressure fuel pushes open the check valve, and the high-pressure fuel flows to the fuel delivery pipe.
The ECM controls the spill control valve, adjusts the fuel pressure to 4 to 13 MPa (40.8 to 132.6 kgf/cm2 ), and maintains the target fuel pressure by monitoring the signals from the fuel pressure sensor. If the fuel pressure in the fuel delivery pipe increases to 15.3 MPa (156 kgf/cm2 ), the fuel relief valve is mechanically opened and fuel is returned to the fuel tank.
Immediately after the power switch is turned OFF, the ECM opens the fuel relief valve to lower the fuel pressure (high-pressure side). This is done to help prevent fuel leaks as a result of residual pressure.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0088 | ECM did not command the fuel pump for high pressure opens spill valve, but fuel pressure increases 3 MPa (30.6 kgf/cm2
, 435 psi) from the target pressure for more than 10 seconds (1 trip detection logic) |
|
| There is minimal difference between fuel pressure before and after fuel relief valve operates (2 trip detection logic) |