Problem with vehicle when hitting bumps. on 2004 GMC Yukon XL 1500

When hitting significant bumps at speeds 40-70 my door locks will unlock and lock back, my AC COMPRESSOR will kick off, my cruise will kick off, and various warning lights on my cluster will stay on (traction, abs, brakes). My cruise will go back to working if tap brakes, but warning lights on cluster stay on. If I stop and restart vehicle, everthing go back to working perfectly. I have replace abs sensors on front wheels. I have cleaned grounds on abs and the one below the battery tray. It seems as if my car is sensing it being turned off from some ground short. I also had a mechanic to change the brake light sensor after reading that a bad one can give really wierd results. I did have the vehicle in one GM dealer and they immediatly told me it was my ecbm and the other thing that connects to them. I made the mistake of telling them I might trade, and have no confidence in their evaluation. (I told them everything I have typed here and all the shop rep put on the report for the mechanic was that I was having trouble with cruise.)
Anyway, should would like some more suggestions. (vehicle has 115000 miles and still runs great when it is not messing up.)

Asked by for the 2004 GMC Yukon XL 1500
Have a full SCAN test done for ALL modules, especially the Body Control Module. Slow down on bumpy roads!
I finally found my problem today with the help from internet link.

There is a ground wire thin black with yellow stripe that goes down the passenger side to the back of the engine. I pulled on it a little and my engine stuttered. At this point my engine would only run rough so I went all the way and pulled it loose from the engine (I could not get to where it was connected and took a chance that it was a ground wire as the link suggested. I connected enoungh new wire to the broken end to run the ground to the braided ground on firewall in front of driver. My car started ok and at first my checked engine light stayed on, but after restarting it went away. I took car on really bumpy ride and all crazy symtoms are now gone. I have no idea what that ground wire grounds but it affects many things when not properly grounded. Thanks for the help