Just thought I'd close out my post of Mar 2012. I had the Blazer towed to the Dealer. I wasn't going to spend too much so I asked for an estimate. They found the problem quite quickly. Body computer was missing power. Wire had an open from the engine compartment fuse block to the Body computer. They couldn't find the actual break but hey installed a new wire. Everything works now. Too bad they don't have an idiot light for that computer. 4 hours labor.

 

i just went threw this problem. I replaced the ignition lock cylinder for the key. I disconnected positive and negative cables from battery and held them together for 5 minutes. connected the battery back up, did the drive cycle and wella the security was off has not come back since.