The CAN Bus That Drove Us Crazy: A Physical Layer Autopsy (From Field Failures to Final Fix)

CAN bus physical layer testing setup with oscilloscope and multimeter on engineer workbench

Last March, a BMW plant in Leipzig handed us a brand new AGV that worked perfectly on their test bench—then died the moment it crossed onto the factory floor. The thing would freeze mid‑route, stutter, and spit out error frames like a jammed ticket machine. We swapped the BCM, reflashed the VCU with three different firmware versions, and spent two hours arguing whether it […]