[xj31]

its basically throughout the whole jeep.The bus connects the pcm,tcm, airbag module,door modules,abs,cluster overhead module,etc.the wires are purple and white and they are twisted together.they are inside most of the harnesses so I wouldnt just go and start trying to find the problem.A lot of times a module can be shorted internally and that will bring the bus down.Usually I will start by unplugging modules one by one and see if it comes back.Also wiggling harnesses can help you find it if its in the wiring.