P0191 Code - Fuel Rail Pressure Sensor Circuit Range/Performance
Quick Answer
The FRP sensor is a diaphragm strain gauge device. Common causes include Low or no fuel, Faulty Rail Pressure (FRP) Sensor, FRP harness is open or shorted. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P0191 indicates Fuel Rail Pressure Sensor Circuit Range/Performance.
- Common causes
- Common causes include Low or no fuel, Faulty Rail Pressure (FRP) Sensor, FRP harness is open or shorted.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P0191 Description
The FRP sensor is located on the fuel rail, and provides a feedback signal to indicate the fuel rail pressure to the Powertrain Control Module (PCM). The PCM uses the FRP signal to command the correct injector timing and pulse width for correct fuel delivery at all speed and load conditions. The FRP sensor, along with the fuel volume regulator (part of the fuel injection pump), form a closed loop fuel pressure control system. An electrically faulted FRP sensor results in the deactivation of the fuel injection pump. Fuel pressure to injectors is then provided only by the FP module. When the fuel injection pump is de-energized and the injectors are active, the fuel rail pressure is approximately 70 kPa (10 psi) lower than FP module pressure due to the pressure drop across the fuel injection pump. Thus, if the FP module pressure is 448 kPa (65 psi), then the fuel rail pressure would be approximately 379 kPa (55 psi) if the injectors are active.
What are the Possible Causes of the DTC P0191?
- Low or no fuel
- Faulty Rail Pressure (FRP) Sensor
- FRP harness is open or shorted
- FRP circuit poor electrical connection
- Faulty Fuel Pump
How to Fix the DTC P0191?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0191 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
Need more information about the P0191 code?
Need more information on how to fix the P0191 code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P0191 code diagnosed by a professional: Find a repair shop in your area
Information for Specific Makes
- P0191 Buick — Fuel Rail Pressure Sensor Performance
- P0191 Cadillac — Fuel Rail Pressure Sensor Performance
- P0191 Chevrolet — Fuel Rail Pressure Sensor Performance
- P0191 Chrysler — Fuel Rail Pressure Sensor Circuit Range/Performance
- P0191 Dodge — Fuel Rail Pressure Sensor Circuit Range/Performance
- P0191 Ford — Fuel Rail Pressure Sensor Circuit Range/Performance
- P0191 GMC — Fuel Rail Pressure Sensor Performance
- P0191 Honda — Fuel Rail Pressure Sensor Circuit/Range Performance Problem
- P0191 Isuzu — Fuel Rail Pressure Sensor Performance
- P0191 Jaguar — Fuel Rail Pressure Sensor Circuit Range/Performance
- P0191 Jeep — Fuel Rail Pressure Sensor Circuit Range/Performance
- P0191 Lexus — Fuel Rail Pressure Sensor Circuit Range / Performance
- P0191 Lincoln — Fuel Rail Pressure Sensor Circuit Range/Performance
- P0191 Mazda — Fuel Rail Pressure Sensor Signal Circuit Fault
- P0191 Mercedes-Benz — Fuel Rail Pressure Sensor Circuit Range/Performance
- P0191 Mercury — Fuel Rail Pressure Sensor Circuit Range/Performance
- P0191 RAM — Fuel Rail Pressure Sensor Circuit Range/Performance
- P0191 Toyota — Fuel Rail Pressure Sensor Circuit Range / Performance
- P0191 Volkswagen — Fuel Rail Pressure Sensor
Frequently Asked Questions about P0191 Code
1. What are the common symptoms of OBDII code P0191?
- Common symptoms include rough idling, reduced engine performance, stalling, and illuminated Check Engine Light.
2. What can cause the OBDII code P0191 to trigger?
- The code is typically triggered by issues with the fuel rail pressure sensor circuit, such as sensor malfunction, wiring problems, or fuel pressure regulator issues.
3. How can I diagnose the cause of OBDII code P0191?
- Diagnosing the code involves checking the fuel rail pressure sensor for proper operation, inspecting the sensor wiring for damage, and testing the fuel pressure regulator.
4. What are the repair options for OBDII code P0191?
- Repair options include replacing the fuel rail pressure sensor, repairing or replacing damaged wiring, and addressing any issues with the fuel pressure regulator.
5. Can driving with OBDII code P0191 cause further damage to the vehicle?
- Continuing to drive with the code may lead to poor engine performance, reduced fuel efficiency, and potential damage to engine components over time.
6. How much does it typically cost to repair OBDII code P0191?
- The cost of repairs for this code can vary depending on the underlying issue, but it may range from $100 to $300 for parts and labor.
7. Is it safe to continue driving with the Check Engine Light on due to OBDII code P0191?
- While the vehicle may still be operable, it is recommended to address the issue promptly to prevent further damage and ensure optimal engine performance.
8. Can a DIY enthusiast fix OBDII code P0191 at home?
- Depending on the individual's skill level and access to tools, some DIY enthusiasts may be able to diagnose and repair the issue themselves. However, professional help is often recommended for accurate diagnosis and proper repair.
9. How often does OBDII code P0191 occur in vehicles?
- OBDII code P0191 related to the fuel rail pressure sensor circuit range/performance is a relatively common code that can occur in both older and newer vehicles.
10. Are there any preventative maintenance tips to avoid OBDII code P0191?
- Regularly servicing the fuel system, including fuel filter replacement and fuel pressure checks, can help prevent issues that may lead to OBDII code P0191.
Discuss the causes and fixes for P0191 OBDII Code
-
code p0191 on toyota i tried to change pressure sensor but miss continue help me.
-
06 f350 code po191 changed rail pressure sensor worked for 30 miles and went back to bogging down after half throttle
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
