The Haltech CAN bus is how an Elite ECU talks to Haltech's own CAN expansion devices: wideband controllers, display dashes like the IC-7, and input and output expander boxes. The Haltech CAN Bus Selection setting chooses which ECU port broadcasts that bus.
Choosing the port
Pick the port your Haltech devices are physically connected to. If they're plugged into one port and the bus is set to another, the ECU won't see them. That's the most common reason for a wideband or dash that suddenly "stops working" after a wiring change.
On cars that also use a factory network, keep the Haltech bus separate from the vehicle CAN bus, unless you've confirmed they can share. The CAN bus overview explains how the ports are laid out. If your devices still don't show up, get in touch.
