Electronic Control System Signature, ISX and QSX15 Engines – FAULT CODE 259

Fuel Shutoff Valve


Fault Code: 259
PID: S017
SPN: 632
FMI: 7/7
LAMP: Yellow

The ECM detected that the fuel shutoff valve is stuck open mechanically or leaking.

Engine will have a torque derate.

Fuel Shutoff Valve

Circuit Description

Voltage is supplied to the fuel shutoff valve by the ECM while the engine keyswitch is ON. When the keyswitch is OFF, the voltage to the fuel shutoff valve is turned off by the ECM. The fuel shutoff valve closes and stops fuel from flowing to the fueling and timing actuators.

Component Location

The fuel shutoff valve is located on the fuel delivery housing, below the air inlet horn.

Shop Talk

Upon turning the keyswitch off, the ECM turns off the voltage supplied to keep the fuel shutoff open. The ECM continues to fire the fueling and timing actuators as the engine spins down. The ECM monitors fuel pressure using the fuel pressure sensor during this time. If the fuel pressure does
not drop after the fuel shutoff valve is turned off, the ECM activates this fault.

Refer to Troubleshooting Fault Code t05-259.

Last Modified:  26-Oct-2010