Cummins ISX CM870 (2003-06) Fault Code: 2357 PID: S146 SPN: 2791 FMI: 7/7 EGR Valve Control Circuit – Mechanical System Not Responding or Out of Adjustment. The exhaust gas recirculation (EGR) valve motor has exceeded the duty cycle limit, indicating a stuck open EGR valve.

NOTE: Prior to running the INSITE? electronic service tool EGR Valve and EGR Valve/Turbocharger Operational Test, the ECM Calibration Software Phase could possibly need to be updated to the latest Software Phase. The ECM Calibration Phase Software can be checked in INSITE? electronic service tool, under ‘Features and Parameters’. Expand the selection for ‘System ID and Dataplate’ and go to ‘Calibration Information’. If the Software Phase is earlier than shown below, recalibrate the ECM using the January 2006 INCAL? CD-ROM, or later. Engines with the Software Phase listed below or later do not require a recalibration.

ISX engines with CM870 (engines built after January 2004) require Software Phase 06050302.

ISX engines with CM870 (engines built before January 2004) require no changes at this time.

This is a warrantable calibration change.

Possible causes:

1)Damaged EGR valve position sensor, mechanical or electrical damage.
2)EGR valve assembly damage requiring a high current to operate the valve, such as a stuck or sticking valve.
The ECM monitors the response of the EGR valve and logs a fault code if the valve fails to respond as commanded. When the ECM stops commanding the valve, the fault code will go inactive; therefore, this fault code tree must be used to troubleshoot active and inactive faults.

This also means the only sufficient way to make certain the repair is complete is to run the INSITE? electronic service tool EGR valve test. Operating the engine is not adequate to verify the correct component was repaired or replaced.

Possible repairs:

1)Repair or replace the engine harness or the EGR valve extension harness.
2)Replace the ECM.
3)Replace the EGR valve assembly.