P0191 on Acura
Fuel Rail Pressure Sensor Circuit Range/Performance
P0191 on Acura vehicles indicates fuel rail pressure sensor circuit range/performance. Au7o has documented this code across 1 Acura model — most commonly on ILX. 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.
Common Causes of P0191
- •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
P0191 on Acura by Model
Acura ILX(1 issue)
- In-Tank Low-Pressure Fuel Pump Impeller Failure Causing Engine Stall2013-2022
The Denso-supplied in-tank fuel pump module fitted across virtually the entire ILX production run uses an impeller that was molded with insufficient density and inadequately dried. The impeller absorbs fuel, swells, and interferes with the pump body. The pump then fails to deliver pressure - typically presenting first as a long crank or a hard start, then progressing to an engine stall that can happen at road speed with no warning and no restart. The ILX coverage was expanded twice: an initial 2019-2020 campaign (21V215, itself an expansion of ) was later broadened to cover 2013-2023 ILX under 23V858, so this spans every powertrain the car was sold with - 2.0 automatic, 2.4 manual, hybrid, and 2.4 DCT alike.
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View P0191 across all makes →Frequently Asked Questions
What does P0191 mean on Acura?▼
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 Acura specifically, this code is documented across 1 model.
What causes P0191 on Acura vehicles?▼
Common causes on Acura: 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. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0191 on a Acura?▼
Repair costs vary widely depending on the root cause and specific Acura model.
Which Acura models have P0191 documented?▼
Au7o has documented P0191 on 1 Acura model: ILX.