2008 Sierra No Crank/Security Issues

[bprice1974]

I bought my 2008 Sierra Crew Cab 4X4 New in Nov. 07'. About 2 years later (35000 miles) after stopping at a gas station...I went to start my truck and nothing happened. No click, no crank. A gentleman there helped me out trying to jump start...no good. He was kind enough to pull me to a nearby mechanic. While there he checked the battery and all was good. He put his scanner on it and did'nt get anything. He then disconnected my positive and reconnected it, and it started right up. Thinking that this was nothing major because getting it to start up by just disconnecting/reconnecting the battery fixed my issue, it did not appear to warrant wasting my time at the dealer knowing they were'nt going to find anything anyhow since no codes popped up and the issue seemed to have gone away. Fast forward 2 years and now at 63000 miles I HAVE NO TRUCK. All I have now is a $32000.00 MISTAKE. The problem reoccurred after the first incident about 3 months later (now out of factory component warranty) and I tried the Disconnect/Reconnect thing again and everything was fine. The problem became progressively worse as time went by. In the past 4 months I have had my factory battery load tested and it checked out fine, but I bought a new one anyhow to keep on hand. I changed the terminal connections and the battery cables. The security light stays on. I have had the dash go completely dead while driving down the highway, yet the truck is still running. I have had the doors lock and unlock on their own while driving. The A/C on two seperate occassions blew hot air at me with the A/C set to cold. I've had check 4wd, check air bag, check tire monitoring, check just about everything, but yet they go away after driving a while. I took it to the dealer when I finally got it to start one day. After getting it started, the Security Symbol popped up after a couple of minutes so I felt this was the best time for a Service Tech to look at it. He politely plugged in his scanner and cleared what was probably the fault codes I had seen pop up in the DIC. The only code he could'nt clear was Security Not Communicating or something like that. He told me they were backed up and would'nt be able to take it for a couple of days. Well a couple of days go by and I could'nt get my truck started to bring it in. Since I noticed the problem would occur when the weather would change, I figured maybe it has something to do with humidity or lack there of. I put my little portable electric heater on an extension cord and put it facing up blowing under the driver side dash with the Key in the Ignition turned to On and the security light lit. After a few minutes of warming up the security light went away and was able to get the truck started. HMMMM!!!!!. Have been trying the relearn thing. Sometimes it works, sometimes it does'nt. Started a little more troubleshooting. Now what warmed up or dried out that all the sudden made things clear. Long story short, Pulled Theft Detterrent Module one morning when the no crank was happening because the Security Light was on and put it by itself in front of my little heater for a few minutes to "Warm it up". Reinstalled it and the security light disappeared. Truck started, went to the dealer, ordered a new Theft Module. Scheduled to have part installed by Tech. Had the job done, Problem did not go away. WHAT NOW. Dealer wants money up front for "Starting from Scratch" at $80.00/Hr. To look around and check things out. Basically they have no clue what to pin point, are where to look first. If they had something specific in mind I would have been more receptive, but I do not make the kind of money to allow someone to charge me $80.00/Hr. with no light at the end of the tunnel and no final dollar amount in sight for diagnosing something that I see Numerous GM owners have experienced with no definate cause posted by anyone. Little Help would be Big Help at this point.