Used 2nd key still same problem has occurred twice within a week apart, always while sitting at traffic light, "service Theft system" light comes on, then traction control light stays on!
Key will not release from ignition, gauges don't register, on 2004 Cadillac SRX
Engine Control Module. Had same problem, also trunk would not open.
Have you replaced the car battery? I had the same problem..display went black. I didn't turn off the car until I got into the garage and the key wouldn't release from the ignition. Found out later it was caused by a bad cell in the battery.