Cummins ISB4.5 CM2150 Fault Code: 257 PID: SID 17 SPN: 632 FMI: 7 Engine Fuel Shutoff Valve Driver – Mechanical System Not Responding Properly or Out of Adjustment.

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 near the fuel pump.

Conditions for Running the Diagnostics
This diagnostic runs immediately after the keyswitch is turned to the OFF position.

Conditions for Setting the Fault Codes
Engine speed 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. INSITE™ electronic service tool can also be used to clear the fault code.

Shop Talk
Verify the 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.

Upon turning the keyswitch OFF, the ECM turns off the voltage supplied to keep the fuel shutoff valve open. The fuel control continues to fire the injectors for a short period of time as the engine speed drops off. The ECM monitors engine speed using the engine position sensor during this time. If the engine speed does not drop after the keyswitch is turned OFF, the ECM activates this fault. A possible cause of this fault code is extra wires attached to the fuel shutoff valve.