GDI ECM operates fuel pressure control valve with the signal from fuel rail pressure sensor to control optimized RPM and rail pressure.
High pressure pump adds high pressure to low pressure fuel from low pressure pump. Controling fuel pressure is done by fuel pressure regulator from 40 to 150 bar. Under the abnormal condition of high pressure fuel system, ECM contols fuel system as low pressure.
P0089 is set when a fuel pressure is too low or high compared with a set point.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Rationality check | 1. FPR(Fuel Pressure Regulator) 2. Low power supply to Fuel Pressure Sensor |
Enable Conditions |
•
Engine Speed: 512-4000 RPM | |
Threshold Value |
•
Fuel Presure: Too high or low | |
Diagnostic Time |
•
6.5 sec. | |
MIL ON Condition |
•
3 driving cycle |
Fig.1) Normal waveform of FPR at idle.
