In an example embodiment, a power switching circuit of an automobile audio bus (A2B) chip is provided in a bi-directional, multi-node two-wire conductor system that includes a plurality of A2B chips interconnected on a twisted wire pair bus (A2B bus), with at least one A2B chip functioning as a master and the remaining A2B chips functioning as slaves. The power switching circuit of the A2B chip powers up a next downstream A2B chip in the A2B bus sequentially according to a power switching procedure, and the power switching circuit is configured to detect faults in the A2B bus before, during, and after the power switching procedure. Each A2B chip enables power to the next downstream A2B chip without risk of damage to any components in the system due to line faults on the downstream A2B bus, or collapse of the power supply at the local A2B chip.