Shielding vs. Filtering: When to Use Ferrite Cores, Common-Mode Chokes, and Shielded Cables for CAN Bus
I spent last Thursday morning chasing a ghost. A brand new automated guided vehicle (AGV) was dropping off the network every time its lifting mast activated. The team on site had already wrapped the CAN bus cable in enough copper foil to cover a small roof. They called it “heavy shielding.” It didn’t work. The bus still crashed. They were […]
OBD2 Cable Failure Analysis: Port Environment Teardown with Transfer Impedance Measurements
The failure report landed in our engineering queue as a PDF attachment: 18 months of maintenance logs from a Pacific Coast terminal operator. The pattern was unmistakable—a specific “heavy-duty, shielded” OBD2 extension cable model was failing at 30% between months five and seven of deployment. Intermittent connection loss. CAN bus errors. The maintenance supervisor wanted to know […]
When Your CAN Bus Isn’t Talking: A Field Guide to Splitting Ferrites, Common-Mode Chokes, and Shielded Cables
I spent last Tuesday morning staring at an oscilloscope in a customer’s lab, watching a J1939 backbone that looked more like a heartbeat monitor than a clean digital signal. The glitches were random, the error frames were intermittent, and the engineering manager was ready to swap every node on the network. When you are deep in the weeds of diagnosing intermittent CAN […]
The OEM Engineer’s Checklist: Specifying EMI-Hardened Diagnostic Cables for New Equipment
We were three weeks from the prototype ship date. The client, a major European manufacturer of agricultural equipment, had just reported that our new telematics controller was causing intermittent “ghost” errors on the CANbus during field tests. The diagnostic port, our window into the machine’s soul, was showing us nothing but digital noise. The root cause wasn’t […]
Beyond the Welder: 5 Less-Obvious EMI Sources Killing Your Heavy Equipment Diagnostics
You swap a CAN bus sensor, check the 120Ω terminator, even bypass the suspected wiring harness. The fault—usually something vague like “CAN Bus Off” or “ECU Timing”—clears up for a test drive, only to return as soon as the machine works up a sweat. Everyone blames the welder first. And sure, a guy on night […]
The Welder Kicks On, Your Diagnostic Link Drops Out: Hardening Heavy-Duty OBD2 Systems Against Industrial EMI
The bay is clear. You’re deep into a mandated DPF regeneration trace on a quarter-million-dollar hauler, the data stream inching toward a ghost code that’s cost weeks of downtime. Then—crack-hiss. The adjacent stall’s arc welder fires. Your screen stutters, freezes. “Link Lost.” The cycle aborts. You’ve just burned thirty minutes of labor and triggered a forced regen […]