P0191: How to Diagnose & Fix — Fuel Rail Pressure Sensor Circuit Range/Performance
21 vehicles · 13 makes · $150-$18,000 repair
How to diagnose and fix P0191: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
RAM 2500 · 2019–2025
The 2019+ RAM 2500 with the 6.7L Cummins diesel uses a Bosch CP4.2 high-pressure fuel injection pump that is prone to catastrophic self-destruction. The CP4.2 relies on diesel fuel for internal lubrication, and any contamination, water intrusion, or low fuel levels cause the pump to disintegrate, sending metal shavings throughout the entire fuel system. This contaminates fuel injectors ($500+ each x6), fuel rails, fuel lines, and the fuel tank, requiring a complete fuel system replacement costing $8,000-12,000+. The previous-generation CP3 pump was far more reliable. A class-action lawsuit (Sharp, et al. v. FCA US LLC, et al.) has been filed against FCA and Cummins.
Common Symptoms
- Engine no-start or sudden loss of power
- Metallic debris in fuel filter
- Loud knocking or grinding from fuel pump area
- Check engine light with fuel pressure codes (P0087, P0088, P228D)
- Excessive cranking before starting
- Fuel filter clogging frequently
- White or black smoke from exhaust
How to Fix
2019-2020 trucks are covered by NHTSA safety recall 21V-880 (FCA recall Y78): dealers replace the high-pressure fuel pump, update the PCM software and inspect/replace other fuel system components free of charge, so check your VIN first. If the CP4.2 has failed, the ENTIRE fuel system must be replaced or thoroughly cleaned: fuel pump, all 6 injectors (Bosch 0445120413), fuel rails, high-pressure fuel lines, fuel tank (or professionally cleaned), and fuel filter. Total cost: $8,000-12,000+ at dealer. Prevention: Install a FASS or AirDog lift pump system ($800-1,200) that provides additional fuel filtration and water separation before the CP4.2. Some owners proactively replace the CP4.2 with a CP3 conversion kit ($3,000-4,500) from S&S Diesel Motorsport or Fleece Performance for permanent reliability.
Sources for this issue (3)
Ford F-250 Super Duty · 2011–2016
The 2011-2016 6.7L Power Stroke uses a Bosch CP4.2 high-pressure fuel pump, which is lubricated by the diesel fuel passing through it. When the pump wears internally, it sheds metal particles. The pump feeds fuel to the injectors at very high pressure, so those particles can be carried into the injectors, fuel rails, high-pressure lines and the return side of the system. A diesel parts seller describes some early CP4 failures as sudden ("grenade") failures that send debris through the whole fuel system, and says flushing and cleaning will not restore it. Owners have sued Ford over the pump. The lawsuits claim the CP4 design is fragile and incompatible with U.S. diesel fuel, which they describe as low in lubricity, and that Ford knew this and did not disclose it. Ford disputes that the pump is defective. It says the pump was adequately designed and tested, and that failures can come from causes such as contaminated fuel. In Droesser v. Ford (E.D. Mich., No. 2:19-cv-12365), the court certified classes in California, Louisiana, Ohio, Pennsylvania and South Carolina on September 30, 2026. The classes cover owners of 2011-and-later 6.7L trucks who paid out of pocket for a CP4 repair. That ruling does not find Ford liable, and there is no settlement, payment amount or claim process yet. Once metal has spread, the repair usually means replacing the pump, injectors, rails and lines. One diesel shop reports that dealer bills for this job routinely run $8,000 to $12,000.
Common Symptoms
- Loss of power during acceleration
- Engine hesitation and stumbling under load
- Hard start, or cranks but will not start
- Fuel rail pressure too low codes (P0087, P0191)
- Check engine light with fuel system pressure codes
- Metal particles found in the fuel filter
- Engine shutting off while driving
How to Fix
Check first: if the truck is hard to start, cranks but won't start, loses power, or sets a fuel rail pressure code, have the fuel filters checked for metal. A diesel shop advises cutting open the return filter and inspecting the media. Metal in the filter means the pump is failing or has failed. If metal is confirmed, Ford sells a complete Motorcraft fuel system contamination repair kit. The part number depends on the truck: - 2011-2014 trucks (build dates 2/22/2010 to 3/17/2014): EC3Z-9B246-C. It includes a CP4 pump, 8 injectors, both fuel rails, and the high-pressure and return lines. - 2015-2016 F-250/F-350 pickups: FC3Z-9B246-F. It includes the CP4 pump, injectors, both rails, fuel lines, and the fuel pressure regulator and sensor. It does not fit cab-chassis trucks. Confirm the right kit for your VIN with a Ford dealer. Online sellers list the kits at roughly $3,400 to $5,300, plus a refundable core charge and labor. One diesel shop reports that dealer bills for the full job routinely run $8,000 to $12,000. Coverage: you may be a member of the certified class in Droesser v. Ford if you bought your truck in California, Louisiana, Ohio, Pennsylvania or South Carolina, paid out of pocket for a CP4 repair, did not sign a dealer arbitration agreement, and have not already been reimbursed by Ford. No settlement or claim process exists yet, so keep all repair invoices. Risk reduction is up to the owner, and none of these are Ford repairs. Some owners add a diesel lubricity additive. Others fit an aftermarket "disaster prevention" kit, which is a return-line filter and bypass meant to contain debris. It does not stop the pump from failing. A third option is replacing the CP4 with a different pump, such as a Stanadyne DCR-style conversion.
Sources for this issue (9)
- Ford Super Duty Fuel Pumps Are Defective, Claims New Class Action Lawsuit - Ford Authorityarticle
- Ford Power Stroke Lawsuit Filed Over Defective Fuel Pumps - Ford Authorityarticle
- 6.7 Powerstroke 2011-2014 CP4 Fuel Pump Failure / DEF Contamination Kit - Motorcraft EC3Z9B246Carticle
- Ford Diesel CP4 Fuel Pump Class Action: Five Classes Certifiedlegal
- Ford class action alleges certain diesel trucks contain defective fuel injection pumpsnews
- What Is a CP4 Disaster Prevention Kit for a 6.7L Power Stroke?repair-shop
- Ford Powerstroke 6.7L Catastrophic CP4 Failure Kit (2011-2014)parts-listing
- Ford Motorcraft Fuel System Contamination Repair Kit, 2015-16 F-250 & F-350 6.7L Power Stroke Pickupparts-listing
- OEM 11-14 Ford 6.7L Powerstroke Diesel Fuel Contamination Repair Kit - EC3Z9B246Cparts-listing
MINI Cooper S · 2007–2012
The N14 engine's high-pressure fuel pump fails prematurely, causing long cranking, rough running, and stalling. The internal cam follower wears down, reducing fuel pressure to the direct injection system.
Common Symptoms
- Long crank time
- Rough idle
- Stalling
- Loss of power under acceleration
- Fuel pressure fault codes
How to Fix
Replace HPFP and inspect cam follower for wear. Updated HPFP has revised internals. Check fuel pressure with scan tool - should be 50+ bar at idle, 100+ bar under load.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Vitesco MINI N14 high-pressure fuel pump 13517588879OEMVitesco 5640001100 / MINI 13517588879
VIN-confirmed N14 high-pressure pump failure after low-side supply and rail controls are proven good Fitment/availability: The inspected direct U.S. Confirm VIN and c
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (2)
Volkswagen Jetta · 2006–2008
GMC Sierra 2500HD · 2011–2016
Find P0191 by make
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P0191 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0191 mean?
P0191 stands for "Fuel Rail Pressure Sensor Circuit Range/Performance." This code sets when the fuel rail pressure sensor's signal is out of its expected range or doesn't match what the computer expects for current conditions. On direct-injection and many modern engines, this sensor reports fuel pressure in the rail so the computer can precisely control fueling and the fuel pump. When the reading is implausible — too steady, erratic, or inconsistent with commanded pressure — this code is set, sometimes with hard starting, hesitation, or reduced power. It generally points to the sensor or its wiring, though an actual fuel-pressure problem can also trigger it.
What are the most common causes of P0191?
The most common causes of P0191 are: Faulty fuel rail pressure sensor, Corroded, loose, or damaged sensor connector, Open, shorted, or high-resistance sensor wiring, Actual fuel pressure out of range (weak pump or regulator), Restricted fuel filter or supply line, Loss of reference voltage or ground from the ECM/PCM, Faulty fuel pressure regulator or control valve. The specific cause varies by vehicle.
How much does it cost to fix P0191?
Repair costs for P0191 range from $150 to $18,000, depending on the vehicle and root cause.
Which vehicles are affected by P0191?
Au7o has documented P0191 across 21 vehicle models from 13 manufacturers: Acura, Alfa Romeo, Audi, BMW, Chevrolet, Ford, GMC, Genesis, Infiniti, Lexus, MINI, RAM, Volkswagen.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.