Hello,I will be glad to try and assist you with this,Welcome to Just Answer.
With the messages and lights you have described here that are coming on this is indicating a fault within the braking/abs system.
The brakes will still operate normally however when these lights/messages are displayed you wont have any abs brakes.
What needs to be done from here is the fault codes need checked in the vehicles computer systems to see what codes have set,this will aid and in some cases can even pinpoint the failure.This can be done by most shops and dealers or anyone that has a code reader or scan tool that can communicate with the braking system on this vehicle.
This problem could be anywhere from a faulty sensor to wiring issues or even internal control unit faults,this is why this needs done first to start out locating the fault.
Once the fault has been located and then repaired the code(s) can be cleared out with the code reader/scan tool and the lights/messages will turn off.
I don't know the year of your CTS
so I cannot look to see if there are any related bulletins or common faults for this problem on this vehicle.If you can give me the year I might be able to find more info on this problem.
Let me know if you need anything else,click accept if you feel satisfied with your answer as this is how I get credited for my time,Thanks Pete!