CM871 and CM876 Electronic Control Systems, ISX and ISM Engines – FAULT CODE 257 (ISX)

Engine Fuel Shutoff Valve Driver – Mechanical System Not Responding Properly or Out of Adjustment


Overview

CODE REASON EFFECT
Fault Code: 257 (ISX)
PID: S017
SPN: 632
FMI: 7/7
LAMP: Amber
SRT: 

Engine Fuel Shutoff Valve Driver – Mechanical System Not Responding Properly or Out of Adjustment. Fuel shutoff valve is stuck open mechanically or leaking.

Engine will run derated. The engine may run on for a brief period when the keyswitch is turned OFF.

Engine Fuel Shutoff Valve
SMALL | MEDIUM | LARGE

Circuit Description

Voltage is supplied to the fuel shutoff valve by the electronic control module (ECM) while the engine keyswitch is ON. While the keyswitch is turned 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 fuel system.

Component Location

The fuel shutoff valve is located on the fuel system. Use the following procedure for a detailed component location view. Refer to Procedure 100-002 in Section E.

Conditions for Running the Diagnostics

This diagnostic runs immediately after the keyswitch is turned to the OFF position.

Conditions for Setting the Fault Codes

Fuel pressure is greater than a calibratable value after the keyswitch is turned off.

Action Taken When the Fault Code is Active

  • The ECM illuminates the amber CHECK ENGINE light immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code

The ECM will turn off the amber CHECK ENGINE light and the fault code state will become inactive immediately after the diagnostic runs and passes. The fault code can also be cleared using the INSITE™ electronic service tool.

Shop Talk

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe™ Online for applicable fixes to the calibration stored in the ECM. If necessary, calibrate the ECM. Refer to Procedure 019-032 in Section 19. This procedure is found in the corresponding Troubleshooting and Repair Manual for the engine being serviced.

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

Refer to Troubleshooting Fault Code t05-257

Last Modified:  09-Jul-2010