This vehicle equipped a front camera (23171580) to provide lane departure warning, collision warning, auto brake function, but after a front window glass change, all these functions are not available, and after research, we found gm require a 30 minutes re-calibrate window, after that i have to replace a new camera. in gm service instruction document sb-10057012-2409.pdf, it said: if after 30 minutes the original camera will not calibrate, replace the front view camera. gm provide a free replacement to vehicles under the bumper-to-bumper coverage, they knew this problem clearly. these functions are important to the safety of this vehicle, and now it's a threaten for some functions are not available. i want gm recall these cameras of replace it for free to customer needed.