2010 GMC Sierra 1500 Crew Cab Owner's Manual - Page 157

Sun Visors Pull the sun visor down to block glare. Swing the sun visor to the side to cover the side window. The passenger's side sun visor may have a vanity mirror. To arm the theft-deterrent system: 1. Open the door. 2. Lock the door with the Remote Keyless Entry (RKE) transmitter. The security light should come on and flash. If the delayed locking feature is active, the alarm will not be activated until all doors are closed and the security light goes off. 3. Close all doors. The security light will stop flashing and go off after approximately 30 seconds. The content theft deterrent alarm is not armed until the security light goes off. If a locked driver door is opened without using the RKE transmitter, a ten second pre-alarm will occur. The horn will chirp and the lights will flash. If the key is not placed in the ignition and turned to START or the door is not unlocked by pressing the unlock button on the RKE transmitter during the ten second pre-alarm, the alarm will go off. Your vehicle's headlamps will flash and the horn will sound for about 30 seconds, then will turn off to save the battery power. Theft-Deterrent Systems Vehicle theft is big business, especially in some cities. This vehicle has theft-deterrent features, however, they do not make it impossible to steal. Content Theft-Deterrent Your vehicle may have a content theft-deterrent alarm system. This is the security light. 3-19