P0191 on Chevrolet: How to Diagnose & Fix
Fuel Rail Pressure Sensor Circuit Range/Performance
2 Chevrolet models · 2 documented issues · 1 critical · $600-$1,400 repair
P0191 on Chevrolet by model: symptoms, diagnosis and fix
GM opened customer satisfaction/field action N232432960 covering replacement of the fuel rail pressure sensor on affected 2024 vehicles because the sensor's output can shift out of specification over time. On the direct-injected 1.2L turbo the ECM trims high-pressure fuel delivery directly from this sensor, so a drifting signal shows up as a hard or extended crank, a rough or surging idle, a stumble under load, and a check engine light for fuel rail pressure performance. Because the symptom set overlaps the far more serious rod-knock complaints, it is worth ruling in or out first: a pressure-sensor fault produces a stumble and a stored fuel code, not a mechanical bang. Early 1.2L builds have also drawn complaints about injectors that clog or stick, which produces a similar rough idle and a misfire code on a single cylinder.
Common Symptoms
- Long or hard crank before starting
- Rough or surging idle
- Stumble or hesitation under acceleration
- Check engine light for fuel rail pressure performance
- Single-cylinder misfire after the car sits
How to Fix
Have the dealer check the VIN against field action N232432960 - if it applies, the fuel rail pressure sensor is replaced free of charge. Otherwise the sensor is a straightforward warranty or roughly $200-$400 repair. If the fault is a sticking or clogged injector instead, GM's intake and injector decarbonizing procedures (bulletins 16-NA-383 and 04-06-04-051H) are the first step before condemning an injector; a single-cylinder misfire that survives cleaning means injector replacement, roughly $350-$600 for one on this engine. Running TOP TIER detergent gasoline is GM's own documented preventive measure for this engine family.
Sources for this issue (2)
Every direct-injected 3.6L V6 in the Traverse runs a cam-driven high-pressure fuel pump mounted in the valley that steps rail pressure up past 2,000 PSI. The pump's internal plunger seal and check valve wear, and the follower/cam lobe interface can wear as well, so rail pressure falls below the commanded value. Owners see progressively longer crank times, then a hot-restart no-start, then a hard stumble and reduced power under load. A failing pump can also dilute the engine oil with fuel, which accelerates every other wear item on an engine already known for timing chain and phaser trouble. Traverse Forum carries multi-page HPFP replacement threads across the LLT, LFX and LFY.
Common Symptoms
- Extended crank before start
- Crank but no start when hot
- Check engine light with low fuel rail pressure
- Loss of power under acceleration
- Fuel smell in engine oil
- Rough running and misfire under load
How to Fix
Do not replace the pump on the code alone. First verify low-side supply pressure from the in-tank module (roughly 50-70 PSI); a weak lift pump produces the same low-rail codes and will destroy a new high-pressure pump. With supply confirmed, replace the high-pressure fuel pump, its seal and the pump-to-rail line, and inspect the camshaft lobe and pump follower for wear before assembly. Change the engine oil and filter afterward if the oil smells of fuel. Because the pump sits under the intake in the engine valley, plan on significant labor. No recall or special coverage exists for this failure — it is a wear item and is billed as one.
Sources for this issue (4)
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 on a Chevrolet?
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. On Chevrolet it is documented across 2 models: Trax, Traverse.
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 on a Chevrolet?
Published repair estimates on Chevrolet range from $600 to $1,400 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0191 on a different make?
View P0191 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.