I have a 2009 CTS-V. My key fob has a key inside of it. Yours should too. Your drivers side door has a lock for a key doesn’t it? Where do you think the key is? This is for the emergency key hidden inside the fob. There is a little tab on your key fob that opens the fob and you will find the key inside. It’s an odd looking key but it opens the drivers door. There is also a USB-like slot inside the center console where your key fob can be inserted. There is a ‘crystal’ (GM’s description not mine) in the key that matches with this insertion slot to allow the car to be started in the event that the ‘proximity fob’ is not detected due to a depleted battery or whatever. I know with the 2009 CTS models, it was reported that the CTS has problems with the electronic keys. With one of my two fobs I routinely get the message “electronic key not detected” but I can start the car. When I turn the car off it says “electronic key not detected – restart allowed”. It’s a proximity key fob as everyone knows, and it appears that the car isn’t detecting this fob. The other one of the two fobs works fine. The dealership checked the battery in the troublesome fob. Their suggestion now is to bring the car in with both fobs. My guess is that they will replace one (or both) of them.