Regen wiring/switch

[1930fordcoupe]

Does anyone know how to locate the regen wiring/switch on a 2013 Thor Palazzo 33.3? Last summer I had a problem where a check engine light came on and I ended up taking the RV to a repair shop in Columbus, Ohio. Cost me $400. for them to do a "regen procedure". Cummins told me I could have done this myself if I had known about this regen switch/wiring. They sent me a picture (very poor one) showing the regen switch/wiring to the left of the steering column up under the dash. I have looked and I just can't locate it. Anyone know what I should look for?

[Slickrick racer]

it should look something like this but under your dash.