GDI ECM operates fuel pressure control valve with the signal from fuel rail pressure sensor to control optimized RPM and rail pressure. But ECM shows this DTC and enters limp home mode limiting fuel mass and maximum RPM in order to prevent abnormal control of ECM under the bad condition out of target rail pressure range.
Rail pressure monitoring error DTC shows indirectly the status of low pressure fuel and mechanical operating status of high pressure pump and fuel pressure regulator with the signal of rail pressure sensor and fuel pressure regulator.
ECM shows P0087 when the rail pressure is lower than the target rail pressure.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Rationality check | 1. Overflow of fuel return 2. Sticking by low pressure of fuel pressure sensor |
Enable Conditions |
•
2 minutes later after engine start | |
Threshold Value |
•
Difference between actual value and target > 1.5 Mpa | |
Diagnostic Time |
•
3 sec. | |
MIL ON Condition |
•
3 driving cycle |
Fig 1) Normal waveform of FPS at acceleration.
