How do you reset a theft deterrent system on a 2007 gmc 1500 pickup?

To reset the theft deterrent system on a 2007 GMC 1500 pickup, first ensure that the vehicle is in the "On" position without starting the engine. Leave the key in this position for about 10 minutes until the security light turns off. Then, turn the key to the "Off" position and back to "On" for another 10 minutes, repeating this process two more times. After the third cycle, the system should be reset, allowing you to start the vehicle.