General Information

Engine Control
P0191 Fuel Rail Pressure Sensor Circuit Range/Performance - General Information

Component Location





General Description

Rail pressure sensor, which is mounted on the fuel rail, measures fuel rail pressure.
GDI(Gasoline Direct Injection) ECM calculates controlled variable with the signal from fuel rail pressure sensor to control optimized RPM and rail pressure. ECM sends it to IDB(Injector Drive Box). IDB operates fuel pressure valve according to controlled variable from ECM.

DTC Description

ECM shows P0191 when the average value from fuel rail pressure sensor is out of range of threshold value. This code is for abnormal sensor.

DTC Detecting Condition





Diagnosic Circuit Diagram





Signal Waveform & Data




Fig.1) Normal waveform of FPS at acceleration.