P0191 GMC Code - Fuel Rail Pressure Sensor Performance
Quick Answer
The Engine Control Module (ECM) uses the Fuel Rail Pressure (FRP) sensor to constantly adjust the high-pressure fuel pump's feed rate so that the ideal pressure is permanently maintained in the high-pressure section (between the high-pressure fuel pump and the injectors) by means of closed-loop control. Common causes include Low or no fuel, Faulty Fuel Rail Pressure (FRP) Sensor, Fuel Rail Pressure 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 GMC indicates Fuel Rail Pressure Sensor Performance.
- Common causes
- Common causes include Low or no fuel, Faulty Fuel Rail Pressure (FRP) Sensor, Fuel Rail Pressure 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 GMC Description
What are the Possible Causes of the DTC P0191 GMC?
- Low or no fuel
- Faulty Fuel Rail Pressure (FRP) Sensor
- Fuel Rail Pressure harness is open or shorted
- Fuel Rail Pressure circuit poor electrical connection
- Faulty Fuel Pump
How to Fix the DTC P0191 GMC?
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.
Code Tech Notes
2006-2010 GMC Savana
2006-2010 GMC Sierra
2006-2010 GMC Topkick
GMC Factory Service Bulletin OBDII Code P0191
User Submitted Video
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0191 GMC 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.
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Information for Specific GMC Models
- P0191 2014 GMC Sierra — Fuel Rail Pressure Sensor Performance
- P0191 2015 GMC Sierra — Fuel Rail Pressure Sensor Performance
- P0191 2016 GMC Sierra — Fuel Rail Pressure Sensor Performance
- P0191 2017 GMC Sierra — Fuel Rail Pressure Sensor Performance
- P0191 2018 GMC Sierra — Fuel Rail Pressure Sensor Performance
Frequently Asked Questions about P0191 GMC Code
1. What does the P0191 code mean on a GMC vehicle?
P0191 indicates a problem with the fuel rail pressure sensor's performance, typically due to irregular or unexpected readings.
2. What are common symptoms of the P0191 code in a GMC?
Symptoms include engine misfires, rough idling, reduced power, difficulty starting, stalling, and the Check Engine Light turning on.
3. What causes the P0191 code to appear on a GMC?
Common causes include a faulty fuel rail pressure sensor, clogged fuel filter, failing fuel pump, damaged wiring, or issues with the fuel pressure regulator.
4. Can I drive my GMC with a P0191 code?
Driving with a P0191 code is not recommended, as it can lead to further engine damage or leave you stranded if the fuel system fails.
5. How do I diagnose the P0191 code on my GMC?
Diagnosis involves checking the fuel rail pressure sensor, inspecting wiring and connectors, testing the fuel pressure, and verifying the operation of the fuel pump.
6. How do I fix a P0191 code on my GMC?
Repairs may include replacing the fuel rail pressure sensor, cleaning or replacing the fuel filter, repairing damaged wiring, or replacing the fuel pump.
7. How much does it cost to fix the P0191 code on a GMC?
Repair costs vary but typically range from $150 to $500 depending on whether it’s a sensor replacement, fuel pump repair, or other component fixes.
8. Can a bad fuel pump trigger the P0191 code on a GMC?
Yes, a failing fuel pump can cause inconsistent fuel pressures, triggering the P0191 code.
9. Will clearing the P0191 code fix the issue on my GMC?
Clearing the code will remove it temporarily, but if the underlying issue isn’t resolved, the code will likely return.
10. How can I prevent the P0191 code from occurring on my GMC?
Regular maintenance, such as replacing the fuel filter, inspecting wiring, and using high-quality fuel, can help prevent fuel system issues associated with this code.
Discuss the causes and fixes for P0191 GMC OBDII Code
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