2005 Cadillac SRX sat a lot for about 8 months. It needed new timing chains. Got to where I had to charge it to start it. Finally, had a garage put new timing chains on it. Got the car back, washed it, moved it, and it would not start after that. Key was stuck but I got that out. Bought a new battery and began trying things on the internet to start it. I tried turning key to Accessories for 10 minutes, 5 seconds back one click, and did this 3 times. It still would not start. I tried a couple of similar things like taking the fuse out. It still won't start and I still get the message "Service Theft System. Any ideas?

Thanks.