Fault Codes/Rehlko/CAN COMM FAULT SDRehlkoCAN COMM FAULT SDUnclassifiedGeneralWhat This Code MeansEngine CAN communications faultPossible Causes•Faulty wiring to ECM•Loss of power to ECMSuggested Actions1Check wiring to ECM2Check power to ECMRelated Rehlko Fault CodesCHECK EXER NOT SCHCHKNGMETERCAN COMM FAULT ARCMBATTERYCHARGERFAULTCOMMON FAULT SHUTDWNBATTERYCHARGER FAULTCOMMON WARNGBATTERY VOLTAGE LOW AVCONCHECKINGBATTERY VOLTAGE HIGH AVCURRENT A HIGH WARNINGBrowse all Rehlko fault codes→ASK RUDY ABOUT THIS FAULTGet a diagnosis walkthrough for CAN COMM FAULT SD on your specific Rehlko unit — cited to the OEM manual, not a forum guess.Your question about CAN COMM FAULT SDGET THE ANSWERFree account required — we'll bring your question with you.