Ok, so update...it is an intermittent problem that has corrected itself on occasion. It was currently acting up, IE. No brake lights, not shifting out of park and I could not get the engineering test mode to work(it said service brake and stopped the engineering test mode ). I disconnected the battery and shorted the two leads to reset the whole cars computer system. After connecting them back to the battery, everything works as it should....so i am stumped at this point. Is the computer sensing an issue and hen shutting down the affected brake system(a built in fail safe). Or is it something else? Anybody on this thread work on these and have some advice or info?

 

Anybody have schematics for this SUV?????

 

So update, it was the main power wire from the SJB that had a break in it. A new wire was installed and spliced into the system between the SJB and the brake pedal switch.