CM870 and ISX Engines – FAULT CODE 449

High Fuel Pressure


Fault Code: 449
PID: P094
SPN: 94
FMI: 0/16
LAMP: Amber

Fuel Pressure High – Warning. High fuel pressure was detected at the fuel rail in the IFSM.

The engine may produce black smoke and may be derated.

Hydraulic Fuel System Circuit

Circuit Description

The gear pump draws fuel from the fuel tank through the suction side fuel filter. The gear pump develops 1724 to 2620 kPa [250 to 380 psi] of fuel pressure. The fuel flows through the pressure fuel filter and fuel shutoff valve to the fueling and timing actuators and the rail fuel pressure sensor. The 1724 kPa [250 psi] regulator controls the fuel pressure in the fuel rail, which supplies fuel to the actuators.

Component Location

Refer to Section E for a detailed component location view.

Shop Talk

The fuel pressure is monitored by the ECM. If the rail fuel pressure is higher than an acceptable range for engine operating conditions, the fault code is logged.

Refer to Troubleshooting Fault Code t05-449

Last Modified:  01-Sep-2010