GDI ECM/PCM operates fuel pressure control valve with the signal from fuel rail pressure sensor to control optimized RPM and rail pressure. But ECM/PCM shows this DTC and enters limp home mode limiting fuel mass and maximum RPM in order to prevent abnormal control of ECM/PCM 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/PCM shows P0088 when the rail pressure is higher than the target rail pressure.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Rationality check | 1. Poor return of supplied fuel 2. Sticking by high pressure of fuel pressure sensor |
Enable Conditions |
•
2 minutes later after engine start | |
Threshold Value |
•
Difference between actual value and target < -1.8 Mpa | |
Diagnostic Time |
•
3 sec. | |
MIL ON Condition |
•
3 driving cycle |
Fig 1) Normal waveform of RPS at acceleration.
