The Check Engine light is on because there is a problem with the emissions system. Once you have the problem repaired the light will go off.
You can either bring it in to a Chevy dealer or use a programmer/tuner to reset the check engine light.
You can't, you must use a scanner.
You need to rent / purchase an OBD II code reader to check & reset the check engine light.
disconnect battery cables and touch them together! I have done this and it worked. I have an 05 2500hd
Check heat shield on catalytic converter
you have to have a scan tool to do it most shops will check it for a min shop fee or parts stors will do it for free
Special tools are needed to remove those fittings. The tools are not expensive. Check with your local auto parts store, they will have them available.
It is illegal to disable the check engine light.
The 2015 GMC Sierra 2500HD Crew Cab typically comes with a standard audio system featuring four speakers. However, higher trim levels may offer an upgraded audio system with additional speakers, such as a Bose premium sound system that includes up to seven speakers. Always check the specific trim and options for the exact configuration.
Have vehicle scanned to have stored codes erased
You need to rent / borrow / purchase an OBD II code reader to check the code.
Have vehicle scanned to determine the problem - usually either a defective gas cap or a problem in the emission control system