Discovered the key for my 2016 chevy will unlock the doors to my 2021 chevy. I was told by GM that that is normal, they reuse key codes. What are the odds that I would have a key that works in both of my vehicles and how many other keys will open my vehicle. I can never lock anything of value in my vehicle again, wish I knew that before I bought it. User's recommendation: You can't count on Chevy to give you a secure way to lock your vehicle.