That is a symptom that I am not familiar with, and I have been with cadillac for a decade or so. I can't see it being a concern with the security system, as it should not keep the vehicle running. Several things need to be present for it to continue running, like power to the ECM for spark and injector pulse, and power to the fuel pump. I would assume it doesn't respond to throttle applications when it runs, just idles. When it is stuck running, try removing the ignition one relay in the underhood fuse block. It is controlled by a run/start power supply, and hard wire ground, but it controls B+(hot all times) power to the injectors, the ECM, and possibly the fuel pump as well. I could suspect that relay for sticking and causing these symptoms. After it has exhibited a failure, swap it with a similar relay in the fuse block and see if it happens again. If it is not the relay sticking, I would still bet on the ignition switch.
Thursday, February 17th, 2011 AT 3:46 AM
