What does this code mean?
The wording below belongs to the named make and communication. Match the complete code, reporting module, model year and engine before applying it.
A code identifies a detected condition, not a part that must automatically be replaced.
Manufacturer wording
Source wording can vary by vehicle and suffix. It is shown as written, not as a universal diagnosis.
P0191FUEL RAIL PRESSURE SENSOR CIRCUIT PERFORMANCEManufacturer communications
5Original wording in English
FORD, MERCURY
Reported code forms P0191
DRIVEABILITY-MALFUNCTION INDICATOR LAMP (MIL) WITH P0316 WHEN USING WINTER BLEND REFORMULATED FUELS AT TEMPERATURES ABOVE 50 DEGREES F (10 DEGREES C) DURING WINTER MONTHS-ROUGH OR ROLLING IDLE AFTER HOT SOAK RESTART…
FORD, MERCURY
Reported code forms P0191
SOME VEHICLES EQUIPPED WITH A 3.0L 4V ENGINE MAY EXHIBIT A MALFUNCTION INDICATOR LAMP ILLUMINATION WITH A DIAGNOSTIC TROUBLE CODE P0191 (FUEL RAIL PRESSURE SENSOR CIRCUIT PERFORMANCE) IN MEMORY. *TT
FORD, MERCURY
Reported code forms P0191
SOME VEHICLES MAY EXHIBIT A ROUGH ENGINE IDLE, ENGINE IDLE ROUGHNESS OR IDLE RPM DIP WITH THE AIR CONDITIONER ON, A DIAGNOSTIC TROUBLE CODE P0191 OR 1-2 UPSHIFT. *TT
FORD, MERCURY
Reported code forms P0191
SOME VEHICLES MAY EXHIBIT VARIOUS DIAGNOSTIC TROUBLE CODES (DTCS) P1233, P1235, P1237, P0191) AND / OR DRIVEABILITY / TRANSMISSION SHIFTING CONCERNS DUE TO WIRING THAT HAS BECOME CHAFED ON THE TOP OF THE TRANSMISSION…
FORD
Reported code forms P0191
CONCERNS WITH FLEX FUEL EQUIPPED VEHICLES EXHIBITING AN INTERMITTENT DIFFICULT TO DIAGNOSE MALFUNCTION INDICATOR LAMP ON WITH A DIAGNOSTIC TROUBLE CODE P0191 IN MEMORY. *TT
Check vehicle applicability
2A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.