P0191 Cummins: What is The Meaning Of The Code and How To Fix it?

Is P0191 Cummins a serious error code for vehicles? Though this error code isn’t terribly serious, still you shouldn’t ignore the P0191 code as it causes drivability issues.

If you operate your vehicle when this code has shown up, it may cause the engine to stall, check engine lights, increase fuel usage, etc. Read along to learn more about common causes and their possible solutions.

P0191 Cummins Errors And Their Solutions

From the P0191 Cummins 2004 to P0191 Cummins 2012, issues with the fuel rail pressure sensor A circuit range caused this error code showing in the vehicle.

This generic error code appears in all OBD-II vehicles that feature fuel injection engines (both diesel and gasoline). The error code shows up almost in all vehicles, for example, Ford, VW, Volvo, GMC, etc.

Here are some common causes and symptoms of the error code with the P0191 Cummins fix.

Defective fuel pressure sensorEngine hesitates or stalls
High/low fuel pressureInspection lights of engine triggers
Vacuum leaksIncreased use of fuel
Damaged FRP sensorEngine cut off
Failed connection of the pressure sensorBad odor in the tailpipe emission

Here, we’ll also discuss all the P0191 dodge Cummins 2011 problems and their solutions elaborately.

Defective Fuel Pressure Sensor

This component is part of the EVAP (evaporative emissions system) and is usually built up inside or on top of the tank. The purpose of the fuel pressure sensor is to read pressure in fuel and look for evaporative leaks, for example, a defective gas cap.

When your vehicle has a defective fuel pressure sensor, you may experience engine stalls or hesitate to accelerate.


Replace the defective fuel pressure sensor. Otherwise, the PCM won’t be able to detect the right pressure and adjust the fuel ratio properly, which will bring obstacles to your vehicle’s performance.

High/Low Fuel Pressure

High fuel pressure indicates that the air to fuel number is higher than the ideal ratio. Generally, a clogged return line or faulty fuel regulator is responsible for this imbalance fuel ratio issue. As an indicator of this issue, you may see your engine’s check light come on.

Also Read: [We Found 9 Causes] P207f Cummins- All About Reductant Quality Performance!

On the other hand, if you have a weak pump, restricted fuel lines, dirty filter, inadequate tank venting, defective electric control, etc., you may notice low fuel pressure in your car.


Consider cleaning the clogged fuel lines or changing the defective fuel pump to get rid of the P0191 Cummins 2010 from your vehicle.

Vacuum Leaks

A broken vacuum hose or tube is responsible for the reason behind the code P0191. The internal engine combustion produces extreme heat that breaks or deteriorates the rubber and plastic tubes that cause vacuum leaks in your vehicle.

Generally, vacuum leaks refer to the process of air going through the engine intake tract according to automotive terms. In the normal state of the vacuum hose, this tract’s air usually uses the throttle to bypass.


Repair or replace the vacuum tube or hose to remove the P0191 error code from your vehicle.

Damaged FRP sensor

The FRP sensor was designed to track the fuel pressure of the fuel rail. The sensor transmits data to the ECU, and the electronic control unit (ECU) uses the signal to adjust the fuel and timing of your vehicle.

Also Read: P0234 Cummins- We Have Found 5 Major Causes+ Quick Fixing Guide!

Engine check lights, engine stalls, and sluggish acceleration are the common symptoms of this issue, so it’s possible to fix this problem with other P0191 code problems. Make sure you check other components, too, before applying the solution.


Replace the damaged fuel rail pressure (FRP) sensor to fix the error code and maintain the engine’s performance.

Failed Connection Of The Pressure Sensor

Sometimes the problem isn’t with the component but with the wiring connections behind the generic error codes in the vehicle. If you have checked all the components of the engine and applied the above possible solution, then you should now check the connections.

Run a thorough inspection on the related wiring connection of the engine and try to figure out if any wiring has corrosion, loose connections, or damaged to torn connections.


If you find any issue with the wiring connection, consider repairing or replacing those wires quickly to enhance your engine performance.

A Helpful Tutorial You May Need!

Frequently Asked Questions (FAQs)

What causes a P0191 code?

The P0191 code is an error code that appears when the fuel pressure has some internal issue. The most common reasons behind this error code is vacuum leaks, high or low fuel pressure, defective parts related to Cummins, etc.

Where is the fuel rail pressure sensor on a 6.7 Cummins?

In the 6.7l Cummins p0191, the fuel rail pressure sensor is constructed near the common rail back. This component is made with an attached strain gauge with a steel diaphragm of a high-grade spring.

How do I fix code P0191?

These error codes appear for numerous reasons, and each code holds a different definition. To fix the P0191 error code, you need to first figure out the faulty area and look for a related solution.


So the P0191 Cummins error code is basically a generic indication code for a bad fuel pressure sensor. Thankfully fixing this error code is pretty easy and quick compared to other related problems of the vehicle.

Though you may find it a bit tricky to diagnose the exact error, it’s worth it. On the other hand, this error code isn’t that serious, but it is better to fix it immediately to improve and enjoy the excellent performance of the engine.

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D Conroy

Meet our senior writer and content manager of Automasterx. He has worked in several mechanical garages and mastered different vehicle diagnoses and parts repair. He never stops until finding out the ultimate solutions for any vehicle fault code. However, ensuring the only solid solutions for each vehicle malfunction is his core part of the duty, alongside analyzing fault codes and signals.

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