Fault Codes/Cummins/L028CumminsL028UnclassifiedGeneralWhat This Code MeansEquipment shutdownPossible Causes•Low coolant levelRelated Cummins Fault CodesOFFOVER SPEEDH706RED − FLASHINGH669SERVICE DUEH389H268FAIL-TO-SYNCHRONIZE WARNINGE153E125E089Browse all Cummins fault codes→ASK RUDY ABOUT THIS FAULTGet a diagnosis walkthrough for L028 on your specific Cummins unit — cited to the OEM manual, not a forum guess.TRY IT FREE