P0191 Fuel Rail Pressure Sensor Circuit Range/Performance
What does P0191 mean?
P0191 — Fuel Rail Pressure Sensor Circuit Range/Performance. This is an OBD-II diagnostic trouble code a scanner retrieves when your vehicle's computer detects fuel rail pressure sensor circuit range/performance. The level of risk depends on how the vehicle is currently running and how long you've been driving with the light on.
Common causes of P0191
- Faulty fuel rail pressure sensor
- Limited-range circuit or connector issue
- Intermittent wiring damage
- Actual fuel pressure out of expected range
How to fix P0191
- Compare sensor pressure to a mechanical gauge
- Blend the rail to see if the value tracks real changes
- Test the sensor's voltage reference and signal output
- Inspect wiring and the connector for damage
- Replace the sensor if the value does not track actual pressure