Cummins code 3868. Verify one or all DEF header datalink Fault Codes 3868, 4572 and/or 4677 are logged. Reference the OEM service manual for a detailed component location view. All of these codes say it has an abnormal update rate. This diagnostic runs continuously when they keyswitch is in the ON position. The Engine Control Module (ECM) lost communication with the aftertreatment DEF quality sensor via the J1939 data link. Verify published troubleshooting has been completed. Because of the lack of DEF header part availability, new ECM calibration codes are being made available that allows the engine to operate normally without engine torque and vehicle speed limits until a DEF header is available for final repair. Apr 2, 2024 · This Technical Service Bulletin describes the verification and resolution of issue of Fault Codes 3868, 4572 and 4677 Caused by Diesel Exhaust Fluid (DEF) Header Malfunction. Mar 27, 2025 · Reference the OEM service manual for a detailed component location view. This diagnostic runs continuously when the keyswitch is in the ON position. Begin by inspecting the exhaust gas recirculation (EGR) valve and associated sensors for dirt or damage. These codes state basically that it has issues with the Diesel Exhaust Fluid Quality, Temperature, and level. . This fault code is triggered when the ECM loses J1939 communications with the DEF quality sensor. appropriate TRPs. Verify DEF header part is not available for the repair. See TRP2484 or TRP2489 for further details. It has Active Fault Codes 3868, 4677, 4572. Codes 4677, 3868, and 4572 typically relate to sensor malfunctions or emission control faults in the Cummins X-15. communication faults are detected. Here is a case study I have using scan Data and some basic Circuit Checks with a Dvom. ophykote zunk ldyy zpfxe xsstb fiy gmajv ywjkpy xldnm oolmf