2010 prostar suspension dump fault

[Downthehaul]

2010 prostar with an isx 871. My suspension dump switch flashes constantly when truck is on. It shows a code for a fault in the circuit somewhere. The dump position works every time, but the inflate position is fickle as anything, usually takes 5 minutes of flipping back and forth, it just works randomly. I’ve examined the switch and the circuit board behind it, can’t see a problem.

One thing I don’t know is where the body controller is on this model, anyone know?

Thoughts on how to diagnose?