P0191: Fuel Rail Pressure (FRP) Sensor Circuit Performance

WARNING: This page does not describe the selected car, but rather 30 other vehicles, including the 2004 Mercury Sable, 2004 Mercury Mountaineer, 2004 Mercury Monterey, 2004 Mercury Marauder, and 2004 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.

P0191 - FUEL RAIL PRESSURE (FRP) SENSOR CIRCUIT PERFORMANCE

Description:	The comprehensive component monitor (CCM) checks the FRP for acceptable fuel pressure. The test fails when the fuel pressure falls below or exceeds a minimum/maximum calibrated value for a calibrated period of time.
Possible Causes:	High fuel pressure. Low fuel pressure. Damaged FRP sensor. Excessive resistance in the circuit. Low or no fuel.
Diagnostic Aids:	A FRP PID value during key on, engine running of 138 kPa (20 psi) and 413 kPa (60 psi) for gasoline, or 586 kPa (85 psi) and 725 kPa (105 psi) for natural gas (NG) vehicles is acceptable.
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
Fuel Rail Pressure Temperature (FRPT) Sensor	GO to PINPOINT TEST DD: FUEL RAIL PRESSURE (FRP), FUEL RAIL TEMPERATURE (FRT) AND FUEL RAIL PRESSURE TEMPERATURE (FRPT) SENSORS Step 59.	GO to PINPOINT TEST DD: FUEL RAIL PRESSURE (FRP), FUEL RAIL TEMPERATURE (FRT) AND FUEL RAIL PRESSURE TEMPERATURE (FRPT) SENSORS Step 59.	GO to PINPOINT TEST DD: FUEL RAIL PRESSURE (FRP), FUEL RAIL TEMPERATURE (FRT) AND FUEL RAIL PRESSURE TEMPERATURE (FRPT) SENSORS Step 59.
Fuel Rail Pressure (FRP) Sensor ONLY	GO to PINPOINT TEST DD: FUEL RAIL PRESSURE (FRP), FUEL RAIL TEMPERATURE (FRT) AND FUEL RAIL PRESSURE TEMPERATURE (FRPT) SENSORS Step 12.	GO to PINPOINT TEST DD: FUEL RAIL PRESSURE (FRP), FUEL RAIL TEMPERATURE (FRT) AND FUEL RAIL PRESSURE TEMPERATURE (FRPT) SENSORS Step 12.	GO to PINPOINT TEST DD: FUEL RAIL PRESSURE (FRP), FUEL RAIL TEMPERATURE (FRT) AND FUEL RAIL PRESSURE TEMPERATURE (FRPT) SENSORS Step 12.
Fuel Rail Pressure AND Fuel Rail Temperature (FRT) Sensors	GO to PINPOINT TEST DD: FUEL RAIL PRESSURE (FRP), FUEL RAIL TEMPERATURE (FRT) AND FUEL RAIL PRESSURE TEMPERATURE (FRPT) SENSORS Step 12.	GO to PINPOINT TEST DD: FUEL RAIL PRESSURE (FRP), FUEL RAIL TEMPERATURE (FRT) AND FUEL RAIL PRESSURE TEMPERATURE (FRPT) SENSORS Step 12.	GO to PINPOINT TEST DD: FUEL RAIL PRESSURE (FRP), FUEL RAIL TEMPERATURE (FRT) AND FUEL RAIL PRESSURE TEMPERATURE (FRPT) SENSORS Step 12.