Internittant starting problem/security light

[rrev75]

I have a 2002 Yukon XL. What the problem is is that the security light comes on while driving, not all the time but enough. If you shut off the engine and restart it usually is off. Every once in a while it won't start. The engine cranks and cranks but won't start. The fuel pump is working because I can hear it. If you give it about 30 minutes from the first time you try, it will start. It had a remote start on it when I bought it but no key fobs so I bought a new one and put it in. This solved the problem for a while then it started again. I had it checked and it said that the ignition switch needed replaced. So I put that in. I'm a bodyman so the column wiring doesn't spook me. This didn't help for long though. Back to the dealer. They said that it needed a BCM. So they fixed that. They told me that the remote start might have shorted the BCM so I pulled the remote start. Fixed for a while then started again. I tore into the wiring and soldered everything that had been cut for the remote start. That helped for a while then started again. Back to the dealer. They told me that they can't get it to not start. It had a code about losing communication I think with the ECM. Still doing it though and now I'm getting really frustrated. The other night my wife was driving it and it wouldn't start. She pulled the key out and put it back in and it started. She also said that a couple of times it seemed sluggish. Could this all be the battery? It cranks fine and doesn't act like a battery problem to me. Any help? We are getting tired of this. Thanks all. Randy