I got a Cts and there is no DIC in it because the previous owners took it out for the aftermarket stereo. Any suggestions ?

 

You could go to dealer with the VIN he should be able to tell what was in it originally. you will need to take Aftermarket one loose to see what installer did. If you are lucky jumper harness was installed and original wiring is not hacked up. so OEM radio would plug in and be programmed. If wiring is cut up you will need to undo what was done and correct any issued related to the A/M install.