1. Fuel Pressure Regulator
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.
When ECM detects open in the FPR control circuit, ECM sets DTC P0090.
Item
Detecting Condition
Possible Cause
DTC Strategy
Signal check
Poor connection
Short to ground in control circuit
FPR
Enable Conditions
-
Threshold Value
Open
Diagnostic Time
Continuous
MIL ON Condition
2 driving cycle
Fig.1) Normal waveform of FPR at idle.