P0191: Fuel Rail Pressure Sensor Circuit Range/Performance
Can you still drive? Drive with caution. If the engine is stalling or running very rough, it is best to have the vehicle towed to avoid being stranded.
What Does P0191 Mean?
Code P0191 indicates that the fuel rail pressure sensor is sending a signal that is outside the expected range or not responding correctly to changes in fuel pressure. This sensor is critical for direct injection engines to maintain precise fuel delivery at extremely high pressures. Incorrect readings can cause poor fuel metering and driveability issues.
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An OBD-II scanner lets you read and clear diagnostic trouble codes from your vehicle's computer. Most scanners work with any car made after 1996.
Browse OBD-II Scanners on AmazonCommon Causes
- Faulty fuel rail pressure sensor
- Weak or failing high-pressure fuel pump
- Clogged fuel filter
- Wiring or connector issue at the sensor
- Low fuel system pressure from a failing low-pressure pump
Symptoms
- Check engine light on
- Hard starting or extended cranking
- Rough idle
- Hesitation or stumbling under load
- Possible engine stalling
Diagnostic Steps
- 1Read fuel rail pressure PID with scan tool and compare to specification
- 2Check sensor wiring and connector for damage or corrosion
- 3Test sensor reference voltage (typically 5V) and ground
- 4Monitor fuel pressure at various RPMs and loads
- 5Check for fuel leaks at the rail or injector connections
- 6Test high-pressure fuel pump output
Recommended Parts & Tools
fuel rail pressure sensor
fuel pressure gauge
scan tool with live data
Estimated Repair Cost
| Type | Estimated Cost |
|---|---|
| Total Repair Cost Range | $100 - $800 |
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Chat with AI About P0191Commonly Affected Vehicles
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Frequently Asked Questions
What does the fuel rail pressure sensor do?
The fuel rail pressure sensor monitors the fuel pressure at the injector rail and sends this data to the ECM so it can precisely control fuel injection timing and duration, especially in direct injection engines.
Can a bad fuel pump cause P0191?
Yes, if the fuel pump cannot maintain adequate pressure, the fuel rail pressure sensor will report out-of-range readings, triggering P0191.
Community Fix Reports
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