General Information

Engine Control
P0091 Fuel Pressure Regulator 1 Control Circuit Low - General Information

Component Location





General Description

The Low Pressure Pump (LPP) supplies 65 psi(4.5 bar) of fuel pressure to the High Pressure Pump (HPP).
Using the internally located Fuel Pressure Regulator Valve (FPR), the HPP will boost the fuel pressure from 580 psi(40 bar) at idle to a maximum of 1958 psi(135 bar).
The Fuel Pressure Sensor (FPS) confirms the fuel pressure and returns the signal to the Powertrain Control Module (PCM).
Fuel pressure during limp-home mode is 65 psi(4.5 bar).

DTC Description

P0091 is set when the Fuel Pressure Regulator Valve (FPR) circuit shorts to ground.

DTC Detecting Condition





Specification





Diagnostic Circuit Diagram





Signal Waveform & Data




- Normal idle state.




- When FPR circuit shorts to ground.