What Is P0191 Code On Dodge Cummins? (How to Fix It)

The fuel rail pressure sensor informs the powertrain control module (PCM) of the higher pressures in the fuel rail, allowing the computer to calculate how much fuel the engine requires. The PCM logs the P0191 code when it gets an illogical signal from the fuel rail pressure sensor.

This code’s technical definition is Fuel Rail Pressure Sensor Circuit Range/Performance.

Please keep in mind that this code might be related to:

  • P0171 OBD-II Trouble Code (excessively rich fuel system)
  • P0172 OBD-II Trouble Code (excessively lean fuel system)

What Does P0191 Code Mean On Dodge Cummins?

P0191 is a DTC that stands for “Fuel Rail Pressure Sensor Circuit “A” Range/Performance.” It denotes a possible anomaly in the fuel rail pressure data.

The signal received by the fuel rail pressure sensor does not match the value expected by the PCM due to a mechanical or electrical fault.

A “performance” code, such as P0191, is often associated with one of the ECM/rationality PCM’s checks, indicating that the measured value does not match what the ECM/PCM expects to observe based on other inputs relevant to the values being measured.

By managing the fuel injectors, the power control module (PCM) regulates the quantity of fuel discharged into the combustion chambers. This procedure reduces tailpipe emissions.

The power control module must be concerning what the fuel pressure is to function properly. The power control module (PCM) will record the P0191 fault code if the fuel rail pressure sensor gives inconsistent readings.

Symptoms of Getting the P0191 Code on A Dodge Cummins

Because the code P0191 affects the engine’s fuel delivery, the impacts are usually obvious. The following are possible symptoms of a malfunction with the fuel rail pressure sensor and related circuit:

  • Engine inspection light flashes or triggers.
  • Fuel use has increased.
  • Unusual odor in tailpipe emissions.
  • The engine stalls or hesitates.
  • A rich fuel trim code was recorded by the PCM (P0172 Code: Fuel system too rich).
  • A lean fuel trim code was recorded by the PCM (P0171 Code: Fuel system too lean).
  • Emissions test failure.

A vehicle will seldom fail to display any warning indicators linked with a PO0191 code. You may inspect the PCM by inserting your OBD-II scanning tool into the appropriate port and reviewing the diagnostic fault codes registered by the computer.

The Causing Factors of the Error Code P0191

The P0191 error code can be caused by a variety of mechanical and electrical problems. They are as follows:

  • A fuel pressure sensor that is faulty or malfunctioning.
  • There is a problem with the fuel pressure sensor circuit.
  • Excessive or insufficient fuel pressure.
  • A problem with the PCM, such as software that has to be updated.
  • Fuel pressure sensor connection failure.
  • Fuel pressure regulator failure.

How Serious Is Code P0191 on Dodge Cummins?

The P0191 problem code is regarded as critical since it has been linked to drivability difficulties. Operating a vehicle when this code is present may cause the vehicle to stall or jerk while driving.

There might also be an increase in gasoline use, which could be expensive. This code must be taken carefully and diagnosed and corrected as quickly as feasible.

How to Solve P0191 Error Code on Dodge Cummins?

Only automobile owners with significant abilities and expertise in the DIY auto repair should attempt to remedy a P0191 code. Those lacking confidence or time should take their car to a reputable service station for diagnostic and repair. The steps to solve this problem are:

Step 1- You have to utilize the OBD-II scanner to extract the freeze frame information to measure the vehicle’s state when the power control module sets the problem code P0191 (PCM).

Step 2- Then, you should do a test drive and examine the live data to see if the fuel pressure reading is normal.

Step 3- The next step is to determine whether there is a detector issue or a fuel pressure malfunction using a fuel pressure tester.

Step 4- If the fuel pressure is adequate, your job will be to inspect the connections and wire of the fuel rail pressure sensor using an oscilloscope. The goal is to ensure that the sensor’s circuitry is not harmed.

Step 5- If the actual fuel pressure is adequate and the sensor’s circuitry is unaffected, the sensor is most likely faulty.

Step 6- Determine how to resolve the P0191 error code once you’ve determined what caused it. Use reliable web resources. Make certain that the solution you discover is unique to the make and model of your car.

How Much Does It Cost To Solve The Error Code P0191?

The cost of replacing a fuel rail pressure sensor varies greatly based on the make and model of your car. A fuel rail pressure sensor repair will typically cost between $200 and $340.

The parts alone will cost between $60 and $100, and labor to repair the sensor would cost between $140 and $240.

Of course, hiring a dealership to repair will cost you more than hiring an independent technician. In most circumstances, unless you have extensive vehicle repair skills, you should not try replacement yourself.

Common Mistakes While Solving the P0191 Code

When diagnosing the P0191 fault code, it is usual to ignore other parts that may need to be fixed and instead replace the fuel rail pressure sensor immediately.

Wiring that is poorly attached or bristled, a broken fuel pressure regulator or a malfunctioning fuel pump are all items that are frequently overlooked while diagnosing and repairing a vehicle.

Additional Comments to Consider Regarding the P0191 Code

Almost all of the time, other components are to blame for this error number. Before deciding that the fuel rail pressure sensor is malfunctioning, take your time and evaluate all of the options.

Also, ensure that you have all of the essential diagnostic equipment. An OBD-II scanner and an oscilloscope are required.

When situations call for all the power the engine can muster, a lack of gasoline will restrict its output. Adding more gasoline than the engine can burn wastes fuel and raises levels of pollution in the exhaust fumes, possibly damaging the catalytic converter.

The PCM manages the flow of the fuel injectors to provide the correct quantity of fuel to the engine, preventing both low and rich mixes from hurting engine performance.

The PCM in many current cars relies on the fuel rail pressure sensor to feed it a continual stream of precise data and will log the P0191 code if the sensor sends incorrect information.


A P0191 code’s severity ranges from low to severe. This can happen for a variety of reasons, and a technician will need to determine the exact reason for this code to be issued in your circumstance. It is to your greatest advantage to get your car inspected by an expert if you receive this error number.

I hope our talk today provided you with all of the information you required. When it came to the P0191 code on a Dodge Cummins, it was the end of it.

Stay on top of the code and try to repair it as soon as you can. Consider all of my recommendations and, if necessary, seek expert assistance.

Related Posts:

Similar Posts