You turned the key to OFF and it was as if you didn't? I suggest getting it checked out. There're probably stored DTCs that'll point to the problem.

 

Yeah. There is no check engine light or trouble codes showing?

 

Sounds like an ignition problem. There should be codes, but it won't be a check engine light, the codes will most likely be stored in the body control module. I have come across a few vehicles that have done this, but for some reason I can't remember exactly what fixed it. I would take it to a dealer to get it fixed.

As for the key fob it is common for the terminals for the battery contacts to break. The solder breaks off of the circuit board and the contacts come off.

 

The theft icon being on is probably because it's running with the key out of the ignition. The ignition switch or the electrical center under the hood could be the problem. I know you killed it by pulling the relay, but is there still battery power on?

Chevyguy, do you work at a dealership?

 

Yep, I work at a Chevy dealership. Why do you ask?

 

Helps to know who's in the crew with me.