Fuel Pressure Regulator

The fuel pressure regulator is a diaphragm-operated relief valve mounted on the fuel rail with fuel pump pressure on one side and manifold pressure on the other side. The fuel pressure regulator maintains the fuel pressure available to the injector at three times barometric pressure adjusted for engine load. It may be serviced separately.

If the pressure is too low, poor performance and a DTC P0171, or DTC P1171 will be the result. If the pressure is too high, a DTC P0172 will be the result. For information on diagnosing fuel pressure conditions, refer to Fuel System Diagnosis in this section.