Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
2011 Chevy Express 2500 4.8. I have an intermittent communication issue. Through my diag, most of the time I can communicate with all modules. Sometimes they go down but not as though one is always dead. EBCM always has lost communication codes with TCM/ECM. I have verified it is getting wake up power, 12v and grounds are good. From DLC 60ohm from 6 to 14. Gone through harness and wiggled all connections 60ohm stays true. As i was working on it today pulled EBCM 40amp Module fuse. After re installing now cannot communicate to EBCM and van just cranks. Where should i go from here? I am at a lot. Seems as though all my inputs are correct. Thanks
Do you still have power at the module from that fuse? I have had fuse box troubles in those years usually due to water infiltration. Most of the time modules that have loss of com codes in them are not your problem. That just shows they were still alive at the time of failure and were able to capture code. From what Iv seen must of the time the module that has the problem has no codes due to the fact it was dead. If you can recreate the problem which modules do not communicate at that time?
