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).
P0191 is set when the Fuel Pressure Signal is too high or low.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Plausibility Check | 1. Fuel Pressure Sensor Circuit 2. Fuel Pressure Sensor (FPS) |
Enable Conditions |
•
Engine Speed: 512-4000 RPM | |
Threshold Value |
•
Fuel Pressure Value Input: Too high/low | |
Diagnostic Time |
•
5 Seconds | |
Mil On Condition |
•
2 Drive Cycles |
RPM | IDLE | 1,500 | 6,300 | Fault |
Fuel Pressure(psi) | 580 | 1305~1450 | 1958 | 65 |
Fuel pressure(bar) | 40 | 90~100 | 135 | 4.5 |
Fuel Pressure rises with rapid increase in RPM.
Fuel Pressure Signal and Power Supply Voltage of Fuel Pressure Sensor at Idle.
Sample: P0191 setting when the Signal Voltage of Fuel Pressure Sensor is Abnormally Low.
Sample: P0191 setting when the Signal Voltage of Fuel Pressure Sensor is Abnormally High.
