2011 GMC Canyon Regular Cab Owner's Manual - Page 153

Infotainment System RDS Radios TheftLock is designed to discourage theft of your vehicle's radio. The feature works automatically by learning a portion of the Vehicle Identification Number (VIN). If the radio is moved to a different vehicle, it does not operate and LOCKED displays. When the radio and vehicle are turned off, the blinking red light indicates that TheftLock is armed. With TheftLock activated, the radio does not operate if stolen. 7-3 Operation AM-FM Radio