New owner of a 2007 Trailblazer SS. Issues with the car not starting frequently and dashboard lights up. Symptoms: Car will start and run after sitting for hours, however if engine cut off, the car may or may not start for at least 20-30 minutes with no fault codes, then the car will start and run as usual. There was an occasion while in a food drive through the car cut off and wouldnt start. I got online and read that you should remove the fuses for the tcm, bcm, and i think the starter for 5 minutes and the car started. Once started the car will drive on the highway with no issues unless the car is shut off. This car is tuned and the dealership is saying the seller changed the password and locked the TCM so no one can get into it, they want to replace the TCM and think its the tune causing the issues, however I am unsure whether replacing the TCM will fix this non start issue...Any advice would be greatly appreciated...Thanks in advance.... I have read this forum and heard (Ignition switch, BCM, TCM) however no one has mentioned no fault code like my car is not throwing fault codes so the dealership is stumped....Note: air bags removed, aftermarket radio installed, and tuned so maybe some of those mods have screwed something up...any help or suggestions appreciated...