Faulty Fuel Pressure Regulator 1
Fuel Pressure Regulator 1 harness is open or shorted
Fuel Pressure Regulator 1 circuit poor electrical connection
Faulty Fuel Injector
Engine Light ON (or Service Engine Soon Warning Light)
The Engine Control Module (ECM) controls the fuel rail pressure by controlling fuel pressure regulator 1 and fuel pressure regulator 2 simultaneously to achieve the desired fuel rail pressure. The ECM compares the desired fuel pressure that is calculated, and the actual fuel pressure reading from the fuel pressure sensor and monitors these two values to detect faults in the fuel system. The Diagnostic Trouble Code (DTC) will be set when the ECM detects that the fuel pressure regulator that is commanding the pressure is lower than the desired value for greater than 10 s.