When Engine Repowers Go Wrong: The Business Case for J1939 Calibration Audits Before Fleet Retrofits
The first thing I noticed on the J1939 log was the arbitration ID 0x0CF00400 appearing twice — once from the replacement ECM, and once from a PTO controller that had no legitimate reason to occupy Source Address 0. The CAN bus had been silently at war with itself for eleven days. The fleet hadn’t found it because the engine started clean every time. That arbitration […]