Not My Fault!!!

does it say what the A/B switch under the chassis is for? I would assume that the switch on the console gets it sound from the console so I am not sure what the switch on the engine is for.

バンド切り替えスイッチ車体裏倶側
Band changeover switch on the underside of the car body

Seems to me that you need to select A or B on both the chassis and the controller. What happens if you have A on one and B on the other?

I think you're going to have to experiment a bit and figure it out. For example, the sound table for the Shinkansen column seems to be saying select A for E5 Hayabusa sounds, select B for generic Shinkansen sounds.