AutoCodes – Jeep – P0191 Jeep

P0191 Jeep Code - Fuel Rail Pressure Sensor Circuit Range/Performance

Quick Answer

This Diagnostic Trouble Code (DTC) is mapped to an idle diagnostic and runs only at idle. 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 Jeep indicates Fuel Rail Pressure Sensor Circuit Range/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.

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Code Popularity 321

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Nov 04, 2023

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0191 Jeep Description

This Diagnostic Trouble Code (DTC) is mapped to an idle diagnostic and runs only at idle. The key-on error monitors fuel pressure voltage at key-on after an eight-hour cold soak. The Powertrain Control Module (PCM) varies fuel pressure and monitors the final fueling and engine speed to determine if the rate of change of fueling with respect to the rate of change of pressure is within the normal operation limits of the pressure sensor. The engine must be at operating temperature and must not be in an active aftertreatment regeneration mode in order to run this diagnostic. The idle monitor runs once per drive cycle and the PCM will light the MIL lamp after the diagnostic runs and fails in two consecutive drive cycles. The PCM will turn off the MIL lamp after the diagnostic runs and passes in four consecutive drive cycles. The DTC will be set when at idle, the rate of change in fueling with respect to the rate of change of pressure is below the calibrated fail high threshold or above the calibrated fail low threshold while the monitor was running.

OBDII Code P0191 Jeep - Fuel Rail Pressure Sensor Circuit Range/Performance - AutoCodes.com — P0191 Jeep Code - Fuel Rail Pressure Sensor Circuit Range/Performance

What does this mean?

What are the Possible Causes of the DTC P0191 Jeep?

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 Jeep?

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 Jeep 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 Jeep code?

Need more information on how to fix the P0191 Jeep code? Get Access to Factory Service Manuals

Need Help with the Code?

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0191 Jeep Code

1. What are common symptoms of OBDII code P0191 in a Jeep related to the fuel rail pressure sensor circuit?

- Common symptoms include rough idling, decreased engine performance, engine stalling, and illuminated check engine light.

2. What are possible causes of OBDII code P0191 in a Jeep indicating an issue with the fuel rail pressure sensor circuit?

- Potential causes include a faulty fuel rail pressure sensor, wiring or connector issues, fuel pump problems, or issues with the fuel pressure regulator.

3. How can I diagnose the OBDII code P0191 in a Jeep related to the fuel rail pressure sensor circuit?

- Diagnose the code by checking the fuel pressure using a gauge, inspecting the sensor and its wiring for damage, and scanning for any other related trouble codes.

4. How can I repair OBDII code P0191 in a Jeep due to a fuel rail pressure sensor circuit issue?

- Repair options may include replacing the fuel rail pressure sensor, repairing or replacing damaged wiring, checking and potentially replacing the fuel pump or pressure regulator.

5. Can a dirty fuel filter cause OBDII code P0191 in a Jeep?

- Yes, a clogged or dirty fuel filter can restrict fuel flow, leading to issues with fuel pressure and potentially triggering code P0191 in the Jeep.

6. Is it safe to continue driving a Jeep with OBDII code P0191 related to the fuel rail pressure sensor circuit?

- It is not recommended to drive a vehicle with this code as it can lead to engine performance issues and potential damage if left unresolved.

7. How can I prevent OBDII code P0191 from appearing in my Jeep in the future?

- Regularly maintain your vehicle, including fuel system inspections, using quality fuel, and addressing any issues related to fuel pressure promptly.

8. Can a bad fuel pump cause OBDII code P0191 in a Jeep?

- Yes, a malfunctioning fuel pump can lead to inadequate fuel pressure, triggering the P0191 code in the Jeep's system.

9. How much does it typically cost to repair OBDII code P0191 in a Jeep at a mechanic or dealership?

- Repair costs for this code can vary depending on the specific cause, but it may range from $200 to $500 or more, including parts and labor.

10. Will disconnecting the battery reset OBDII code P0191 in a Jeep's system?

- Disconnecting the battery may temporarily clear the code, but it is not a permanent solution as the underlying issue causing the code will need to be addressed.