P0191 on Lexus
Fuel Rail Pressure Sensor Circuit Range/Performance
P0191 on Lexus vehicles indicates fuel rail pressure sensor circuit range/performance. Au7o has documented this code across 1 Lexus model — most commonly on GS. 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 Lexus by Model
Lexus GS(1 issue)
- Denso Low-Pressure Fuel Pump Impeller Swells and Stops the Pump (Recalls 20V012 / 20V682 / 26V222)2013-2020
The L10 generation GS uses a Denso in-tank low-pressure fuel pump whose impeller was molded from a resin with too little density. The impeller absorbs fuel, swells, and interferes with the surrounding pump body until the pump stops turning. The failure shows first as a rough-running engine and warning lights, then as a stall - and at highway speed a stall raises crash risk. Recovery is often impossible: the car will not restart. This is the same Denso pump defect that grew into one of the largest Toyota recall campaigns ever, and the GS was pulled in over several expansions: 20V012000 covered 2013-2015 GS 350 and 2018-2019 GS 300, 20V682000 covered 2017 GS 200t / 2017-2020 GS 350 / 2019 GS 300, and a 2026 expansion (26V222000) reached 2015-2022 Lexus vehicles including 2016-2020 GS. It is an L10-only issue; the S160 and S190 cars use different pump hardware.
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View P0191 across all makes →Frequently Asked Questions
What does P0191 mean on Lexus?▼
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 Lexus specifically, this code is documented across 1 model.
What causes P0191 on Lexus vehicles?▼
Common causes on Lexus: 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 Lexus?▼
Repair costs vary widely depending on the root cause and specific Lexus model.
Which Lexus models have P0191 documented?▼
Au7o has documented P0191 on 1 Lexus model: GS.