Stub Lengths That Kill: Calculating Reflection Timing and Signal Integrity on a J1939 Backbone
The transmission ECU dropped offline for exactly 417 milliseconds — I still keep the Vector log file ohio_truck3_ghost_node_004.asc as a reminder. Six identical refuse trucks. Same J1939 backbone layout they’d been running since 2015. Yet these six would randomly shed nodes. Sometimes the transmission ECU vanished for 417 milliseconds. Sometimes the body controller threw a timeout, then recovered. No […]