I need code stereo

one thing can be done to reset the code just disconnect the battery wire remove both positive as negative battery wire now remove the audio jack or connector at the back of the audio player now 1st reconnect the audio jack in rear or connector after connecting then place both battery terminal now & see for it's working if you still face the problem please better visit the nearest GM Authorized service center were the problem will be sort out for more quarries do write in & we are happy to help you till then do drive safe & have happy motoring till the next time see you soon..!!