P0191 on Infiniti
Fuel Rail Pressure Sensor Circuit Range/Performance
P0191 on Infiniti vehicles indicates fuel rail pressure sensor circuit range/performance. Au7o has documented this code across 1 Infiniti model — most commonly on QX80. 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 Infiniti by Model
Infiniti QX80(1 issue)
- Fuel Pressure Sensor Under-Torqued Causing Fuel Leak and Fire Risk (Recall 14V683000)2014-2015
Fuel pressure sensors were not sufficiently tightened during production. As the vehicle is driven, vibration and thermal cycling allow the under-torqued sensor to loosen further until fuel escapes past its seal. A fuel leak in the engine bay, next to hot exhaust components and ignition sources, is a vehicle fire risk. NHTSA campaign 14V683000 covers QX80 alongside 2012-2014 Nissan Juke, 2012-2013 M56 and QX56, and 2014-2015 Q70 V8 vehicles. The recall began January 25, 2015 and the remedy is simply re-torquing the sensors.
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View P0191 across all makes →Frequently Asked Questions
What does P0191 mean on Infiniti?▼
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 Infiniti specifically, this code is documented across 1 model.
What causes P0191 on Infiniti vehicles?▼
Common causes on Infiniti: 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 Infiniti?▼
Repair costs vary widely depending on the root cause and specific Infiniti model.
Which Infiniti models have P0191 documented?▼
Au7o has documented P0191 on 1 Infiniti model: QX80.