P0191 on RAM
Fuel Rail Pressure Sensor Circuit Range/Performance
P0191 on RAM vehicles indicates fuel rail pressure sensor circuit range/performance. Au7o has documented this code across 2 RAM models — most commonly on 1500, 2500. 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. Typical repair costs on RAM range from $800 to $12,000, depending on the specific model and root cause.
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 RAM by Model
RAM 1500(1 issue)
- EcoDiesel Fuel Pump Failure / Stalling2014-2022
The 3.0L EcoDiesel engine can experience fuel pump failures and stalling issues. The high-pressure fuel pump (CP4) is sensitive to fuel contamination and can fail catastrophically, sending metal debris throughout the fuel system. Water in fuel accelerates failure.
RAM 2500(1 issue)
- 6.7L Cummins CP4.2 High-Pressure Fuel Pump Catastrophic Failure2019-2025
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. Multiple class-action lawsuits have been filed against Stellantis/Bosch.
Looking for P0191 on a different make?
View P0191 across all makes →Frequently Asked Questions
What does P0191 mean on RAM?▼
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 RAM specifically, this code is documented across 2 models.
What causes P0191 on RAM vehicles?▼
Common causes on RAM: 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 RAM?▼
Repair costs on RAM range from $800 to $12,000, depending on the specific model and root cause.
Which RAM models have P0191 documented?▼
Au7o has documented P0191 on 2 RAM models: 1500, 2500.