They’re two separate buses, high rate and low rate, for different purposes throughout the engine and components. Not the literal high and low pins of each bus.

They’re two separate buses, high rate and low rate, for different purposes throughout the engine and components. Not the literal high and low pins of each bus. High rate, low rate. Think cylinder timing communication speed versus, say, fuel usage. CAN operates at a fixed speed, and I understand high and low rate buses to be a common design (they’re two CAN standards, high is something like a megabit). My code reader has fetched “CAN HI” before and the code was contextually referring to the high-rate bus, not the physical wire. I’m not a deep Jeep tech, just dangerous electrically and with a spanner, so I may be wrong in how I’m spelling those and I’m following the lead of a trouble code. If you’re nice to a service dealer with a laptop you can get a quite lovely wiring diagram that explains it better.