I could not find any information in our manual or online for Silverado or Sierra but I was able to find this information on Cadillacs
2013 Cadillac
SERVICE DRIVER ASSIST SYSTEM If this message displays, take the vehicle to your dealer to repair the system. Adaptive Cruise Control (ACC), Forward Collision Alert (FCA), Active Emergency Braking System, Assistance Systems for Parking or Backing, and/or Lane Departure Warning (LDW) system may not work. Do not use these systems until the vehicle has been repaired.
2014 Cadillac
SERVICE DRIVER ASSIST SYSTEM If this message displays, take the vehicle to your dealer to repair the system. Adaptive Cruise Control (ACC), Forward Collision Alert (FCA), Active Emergency Braking System, Assistance Systems for Parking or Backing, and/or Lane Departure Warning (LDW) system may not work. Do not use these systems until the vehicle has been repaired. The radar is not clean. Keep the radar sensors free of mud, dirt, snow, ice, and slush. Clean the entire front and/or rear of the vehicle.