P1187 Code: Meaning, Causes, and Symptoms | OBD2 Codes
P1187 – Fuel Pressure Monitoring – Regulator Valve Stick
P1187 Possible Symptoms
Engine Light ON (or Service Engine Soon Warning Light)
P1187 Possible Causes
Faulty Fuel Pressure Regulator (FPR),Faulty Rail Pressure Sensor (RPS),Engine Control Module (ECM)
Fuel pressure monitoring is used to detect the troubles and the fuel leakage in high pressure system. The Engine Control Module (ECM) determines the rail pressure value as a function of the engine??? operating conditions and controls the fuel pressure regulator to ensure that the rail pressure reaches the required value. Fuel pressure in the fuel line including the pumps and injector are continuously monitored during engine running. If the rail pressure is excessive, the fuel pressure regulator opens and a portion of the fuel is returned from the rail to the fuel tank via a collector line. If the rail pressure is too low, the fuel pressure regulator closes. The fuel pressure regulator closes. the fuel pressure regulator is installed in the tail end of high pressure accumulator. In case of the insufficient fuel supply in the fuel line, the engine symptoms will occur a shut down and a starting impossible. If the fuel pressure monitoring in engine fuel pressure line generates threshold value, the ECM judged this as a fault and the P1187 code is set.