General Information

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

Component Location





General Description

Fuel rail pressure sensor is mounted to fuel rail and it senses fuel rail pressure.
GDI PCM operates fuel pressure regulator (spill valve) with the signal from fuel rail pressure sensor to control optimized RPM and rail pressure.

DTC Description

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

DTC Detecting Condition





Diagnosic Circuit Diagram





Signal Waveform & Data












Fig.1) Normal waveform of rail pressure sensor at idle.
Fig.2) Normal waveform of rail pressure sensor at acceleration.