When One Module Unplugged Fixes Everything: Diagnosing Double-Termination and Switched Terminators on J1939

I’ve watched a forty-ton articulated dump truck sit dead in a yard for six days because no one thought to unplug a GPS tracker. You chase intermittent J1939 communication errors for two days, replace a controller, re-pin a connector, and still the network collapses every few hours. Then somebody unplugs one module — maybe that GPS tracker, […]