Fault-Code Library · Fuel delivery
P0191: Fuel rail pressure sensor range / performance
The rail-pressure signal is implausible or does not follow commanded pressure correctly.
Common symptoms
- •Long cranking
- •Hesitation
- •Reduced-power mode
- •Stalling
Likely causes
- •Rail-pressure sensor fault
- •Wiring or connector problem
- •Supply restriction
- •Pump or pressure-regulator fault
First checks
- •Compare pressure key-on and during cranking
- •Inspect sensor wiring
- •Verify low-pressure supply before condemning high-pressure parts
Important
Never loosen high-pressure fuel lines on a running common-rail engine.
A fault code identifies a detected condition, not a failed part. Confirm manufacturer-specific subcodes and live data.
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