Solved: Finally dug into the issue and found an intermittent open for the wire that controls the SVC solenoid. When working correctly the solenoid should get about 10VDC. When not working it would get zero yet the output at the control card was 10VDC. Checking continuity during the error showed zero also. I replaced the entire run of 3 conductor cable ($40 on amazon) and it works 100% now.

Thanks! I guess I'll be ringing out my wiring harness this weekend!

the auxillary functions are controlled by a separate function control board that deals with the display lights, the selector lights will still show whatever function you select even if you are having a problem out on the mast or attachment. The actual function control is done with a separate function distribution board. Or at least that is the way crown used to do it, i'm sure the design hasn't change a whole lot since then.
The most likely scenario is what brewski suggested, check you mast control cable and any other harness's out on the mast and reach mechanism, i'm sure you will find damaged wires in the reach mechanism or shorted wires in the cable.

Sounds like shorted/ broken wires in the mast cable.