I have a 2016 c7 and is having issue on theft device needing service on dashboard. I cant restart the car and it evenbtually drained the battery. Whatr is the procedure to service tore, air bag and anti theft showing on dash

 

Welcome to the forums. Only three things can cause this that you need to figure out. Service manual would help, Cars battery needs to be in good condition and charged. The fob must have a good battery and condition and operating correctly, you can try using your second fob to see if that helps if you have one. Or there is a malfunction in the system. Charge or change batteries, get in the car and lock the doors, turn on the ignition with push button or the key if possible. If you can't get good results it might need professional help at a shop.