I too had an odd occurrance of "trans failsafe prog" right after I tried to turn cruise on. Immediately I got a quick lull in engine (or brake apply, uncertain as it was momentary), then got DSC Inactive, then brake light on, Service Engine Soon on, and finally the dreaded "trans failsafe prog". Knowing about this in previous work I didn't pull over as I was on a road trip between cities and didn't want to get stuck in 2nd gear only. Trans worked perfectly fine but I suspected I wasn't into "lockup" only costing about 200 rpm in fuel. Took it to local trusted mechanic (not stealer) next day and $135 later and a new brake switch and she's as good as new....at least for 128k. Dealer suggested I replace the Trans ECU BTW. Hope this helps. Never underestimate your gut!!!